MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Bioprocess and Biosystems Engineering' source. Thu, 18 Mar 2010 16:53:04 +0100 http://www.medworm.com/index.php?rid=3362829&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20224919%26dopt%3DAbstract Authors: Vig A, Igloi A, Adanyi N, Gyemant G, Csutoras C, Kiss A An amperometric detector and an enzymatic reaction were combined for the measurement of L: -ascorbic acid. The enzyme cell (containing immobilized ascorbate oxidase) was connected to a flow injection analyzer (FIA) system with a glassy carbon electrode as an amperometric detector. During optimization and measurements two sample injectors were used, one before and one after the enzyme cell, thus eliminating the background interferences. Subtraction of the signal area given in the presence of enzyme from the one given in the absence of enzyme was applied for measuring analyte concentrations and calibration at 400 mV. Analysis capacity of system is 25 samples/hour. The relative standard deviation (RSD) was below 5% (5 times ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3362829 Fri, 12 Mar 2010 00:00:00 +0100 3362829 http://www.medworm.com/index.php?rid=3362828&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20224920%26dopt%3DAbstract Authors: López E, Deive FJ, Longo MA, Sanromán MA The aim of the present study was to investigate the feasibility of several food-processing wastes as support substrate for lipolytic enzymes production by the fungus Rhizopus oryzae under solid-state conditions. Different experiments were conducted to select the variables that allow obtaining high levels of lipolytic enzyme activity. In particular, the use of inert and non-inert solid materials and lipidic and surfactant compounds was evaluated. It was observed that the addition of Triton X-100 together with barley bran involved lipolytic production values tenfold higher than the cultures exclusively grown on an inert support. In addition, from preliminary thermoinactivation kinetics studies, it was concluded that the strategy... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3362828 Fri, 12 Mar 2010 00:00:00 +0100 3362828 http://www.medworm.com/index.php?rid=3355097&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20217142%26dopt%3DAbstract This study is a beneficial attempt to improve the efficiency of biocathode MFCs and provide a good candidate of bioremediation process for Cr (VI)-contaminated sites. PMID: 20217142 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3355097 Wed, 10 Mar 2010 00:00:00 +0100 3355097 http://www.medworm.com/index.php?rid=3340192&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20204663%26dopt%3DAbstract Authors: Bartek T, Rudolf C, Kerßen U, Klein B, Blombach B, Lang S, Eikmanns BJ, Oldiges M The pyruvate dehydrogenase complex was deleted to increase precursor availability in Corynebacterium glutamicum strains overproducing L: -valine. The resulting auxotrophy is treated by adding acetate in addition glucose for growth, resulting in the puzzling fact of gluconeogenic growth with strongly reduced glucose uptake in the presence of acetate in the medium. This result was proven by intracellular metabolite analysis and labelling experiments. To increase productivity, the SugR protein involved in negative regulation of the phosphotransferase system, was inactivated, resulting in enhanced consumption of glucose. However, the surplus in substrate uptake was not converted to L: -valine; i... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3340192 Fri, 05 Mar 2010 00:00:00 +0100 3340192 http://www.medworm.com/index.php?rid=3340193&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20204662%26dopt%3DAbstract Authors: Li J, Jiang M, Chen KQ, Ye Q, Shang LA, Wei P, Ying HJ, Chang HN The effects of redox potential used as a control parameter on the process of succinic acid production in batch cultures of Actinobacillus succinogenes NJ113 have been investigated. In batch fermentation, cell growth and metabolite distribution were changed with redox potential levels in the range of -100 to -450 mV. From the results, the ORP level of -350 mV was preferable, which resulted in high succinic acid yield (1.28 mol mol(-1)), high succinic acid productivity (1.18 g L(-1) h(-1)) and high mole ratio of succinic acid to acetic acid (2.02). The mechanism of redox potential regulation was discussed by metabolic flux analysis and the ratio of NADH/NAD(+). We expected that redox potential can be used as a valu... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3340193 Thu, 04 Mar 2010 00:00:00 +0100 3340193 http://www.medworm.com/index.php?rid=3322769&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20191365%26dopt%3DAbstract Authors: Michels MH, van der Goot AJ, Norsker NH, Wijffels RH The effect of shear stress on the viability of Chaetoceros muelleri was studied using a combination of a rheometer and dedicated shearing devices. Different levels of shear stress were applied by varying the shear rates and the medium viscosities. It was possible to quantify the effect of shear stress over a wide range, whilst preserving laminar flow conditions through the use of a thickening agent. The threshold value at which the viability of algae was negatively influenced was between 1 and 1.3 Pa. Beyond the threshold value the viability decreased suddenly to values between 52 and 66%. The effect of shear stress was almost time independent compared to normal microalgae cultivation times. The main shear stress effect was ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3322769 Sat, 27 Feb 2010 00:00:00 +0100 3322769 http://www.medworm.com/index.php?rid=3285971&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20165886%26dopt%3DAbstract The objective of this study was to detect and identify the products of enzymatic hydrolysis of chitosan (dimers to hexamers) using a crude extract of chitosanolytic enzymes produced by the fungus Metarhizium anisopliae. These fungus was able to produce, during 48 h cultivation in a medium containing chitosan, chitooligosaccharides ranging from dimers, trimers, tetramers and pentamers at concentrations 0.2, 0.19, 0.06, 0.04 mg/mL, respectively, and the enzymatic activity was 2.5 U/L. Using the crude enzyme extract for chitosan hydrolysis, we detected the presence of dimers to hexamers at hydrolysis times of 10, 20, 30, 40, 50 and 60 min of enzymatic reaction, but the yields were higher at 10 min (54%). The hexamers was obtained only with 30 min of reaction with concentration of 0.004 mg/mL.... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3285971 Thu, 18 Feb 2010 00:00:00 +0100 3285971 http://www.medworm.com/index.php?rid=3270043&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20148266%26dopt%3DAbstract Authors: Rodríguez FA, Martínez-Toledo MV, González-López J, Hontoria E, Poyatos JM Pure oxygen to supply the aerobic condition was used in the performance of a bench-scale submerged membrane bioreactor (MBR). The pilot plant was located in the wastewater treatment plant of the city of Granada (Spain) and the experimental work was divided into two stages (Unsteady state and steady state conditions). Operation parameters (MLSS, MLVSS and dissolved oxygen concentration) and physical characteristics (temperature, conductivity, pH, COD and BOD(5)) were daily monitored. The results showed the capacity of the MBR systems to remove organic material under a hydraulic retention time of 18.46 h and sludge retention time of 18.6 days. Therefore, Viscosity of the sludge and alp... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3270043 Thu, 11 Feb 2010 00:00:00 +0100 3270043 http://www.medworm.com/index.php?rid=3270042&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20148267%26dopt%3DAbstract In this study, Saccharomyces cerevisiae expressing a flavonoid glucosyltransferase from Dianthus caryophyllus was used as a whole-cell biocatalyst. The yeast system's performance was characterized using the flavanone naringenin as a model substrate for the production of naringenin glycosides. It was found that final naringenin glycoside yields increased in a dose-dependent manner with increasing initial naringenin substrate concentrations. However, naringenin concentrations >0.5 mM did not give further enhancements in glycoside yield. In addition, a method for controlling overall selectivity was discovered where the glucose content in the culture medium could be altered to control the selectivity, making either naringenin-7-O-glucoside (N7O) or naringenin-4'-O-glucoside (N4O) the major ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3270042 Thu, 11 Feb 2010 00:00:00 +0100 3270042 http://www.medworm.com/index.php?rid=3270041&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20148268%26dopt%3DAbstract Authors: Pandey PK, Ndegwa PM, Alldredge JR, Pitts M, Soupir ML The effects of granules-inocula on the start-up of anaerobic reactors treating dairy manure were studied in a batch-fed reactor. The effects of start-up period and ratio of granules to feed were analyzed. Results indicated that the effects of start-up period could be described by Langmuir model, while the Extended Freundlich model could be used to model the effects of ratio of granules to feed on cumulative biogas production. In addition, transmission electron microscopes (TEM) and scanning electron microscope analysis were conducted to elucidate the distribution of microbial population and micro-colonies in granules and manure. From the TEM micrographs analyses, the ratios the Syntrophobacter and methanogens in granule an... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3270041 Thu, 11 Feb 2010 00:00:00 +0100 3270041 http://www.medworm.com/index.php?rid=3244972&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20131068%26dopt%3DAbstract Authors: Benhalla A, Houssou M, Charif M This paper deals with the linearization of the full activated sludge model No 1 (ASM1) in the scope of interaction analysis. For consistency, the linearization procedure is developed and validated within the BSM1 simulation benchmark framework. It is based on reaction rate approximation by linear combinations of states. The linear rate models are identified and incorporated in the mass balance equations, yielding a linear locally equivalent to the ASM1 model. Linear models for anoxic and aerated compartments are proposed. It is observed that the presented models track very closely the nonlinear ASM1 responses to various influent data. The key feature of this linearization strategy is that the gotten linear version of the ASM1 model is linear tim... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3244972 Thu, 04 Feb 2010 00:00:00 +0100 3244972 http://www.medworm.com/index.php?rid=3172676&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20066440%26dopt%3DAbstract Authors: Storms ZJ, Arsenault E, Sauvageau D, Cooper DG Existing models for bacteriophage adsorption are modified with the addition of a new term, adsorption efficiency, and applied to a T4-Escherichia coli system. The adsorption efficiency is the fraction of phage that adsorbs irreversibly to the host. Adsorption kinetics were modeled using the adsorption rate constant (k) and the adsorption efficiency (epsilon). Experimental data demonstrated that the adsorption rate constant depends strongly on the condition of the host while the adsorption efficiency is a property of the bacteriophage population. The adsorption efficiency exhibited a marked dependence on the concentration of L: -tryptophan. The system was used to study the effect of adsorption kinetics on bacteriophage amplificatio... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3172676 Tue, 12 Jan 2010 00:00:00 +0100 3172676 http://www.medworm.com/index.php?rid=3120660&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20033429%26dopt%3DAbstract Authors: Guo JL, Mu XQ, Xu Y The enantioselective reduction of methyl benzoylformate to (R)-methyl mandelate, an important pharmaceutical intermediate and a versatile resolving agent, was investigated in this study. After minimizing the reaction-specific constraints (constraints dependent on the nature of the substrate and product) by preliminary selection of the reaction parameters, an effective whole cell biocatalyst (Saccharomyces cerevisiae AS2.1392) was obtained by simple screening procedures. Under further optimized conditions, a product concentration of 103 mmol L(-1) could be attained within 5 h with a yield of 85.8% and an enantiometric excess of 95.4%, indicating S. cerevisiae AS2.1392 an efficient biocatalyst for the asymmetric synthesis of (R)-methyl mandelate. Furthermore,... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3120660 Wed, 23 Dec 2009 00:00:00 +0100 3120660 http://www.medworm.com/index.php?rid=3115539&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20024663%26dopt%3DAbstract Authors: Hermansyah H, Wijanarko A, Kubo M, Shibasaki-Kitakawa N, Yonemoto T A rigorous kinetic model describing the stepwise triglyceride hydrolysis at the oil-water interface, based on the Ping Pong Bi Bi mechanism using suspended lipase having positional specificity, was constructed. The preference of the enzyme to cleave to the ester bonds at the edge and the center of the glycerol backbone of the substrates (tri-, di- or monoglyceride) was incorporated in the model. This model was applied to the experimental results for triolein hydrolysis using suspended Porcine pancreatic lipase (an sn-1,3 specific lipase) and Candida rugosa lipase (a non-specific lipase) in a biphasic oil-water system under various operating conditions. In order to discuss the model's advantages, other models t... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3115539 Sat, 19 Dec 2009 00:00:00 +0100 3115539 http://www.medworm.com/index.php?rid=3057473&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19957193%26dopt%3DAbstract In this study, we present data suggesting that flow stratification is closely related to the aeration rate and the arrangement of aerators. A full-scale oxidation ditch, with a total volume of 6,500 m(3) and a membrane-diffused aerated zone of 60 x 7 x 5 m (length-width-depth), was selected for water velocity measurements. Two profiles of the oxidation ditch were studied in detail: the first one was at the end of the aerated zone and the second one at the end of the anoxic zone. The results of this work demonstrate that the horizontal water velocity at the end of the aerated zone displayed significant stratification, with maximum velocity near the water surface (0.5-0.7 m/s) and almost zero velocity at a depth of 2.5 m. At the end of the anoxic zone, water velocity was uniform and equal to... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3057473 Thu, 03 Dec 2009 00:00:00 +0100 3057473 http://www.medworm.com/index.php?rid=3049334&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19949814%26dopt%3DAbstract Authors: Tišma M, Sudar M, Vasić-Rački D, Zelić B Trametes versicolor is a white-rot fungus known as a producer of extracellular enzymes such as laccase, manganese-peroxidase, and lignin-peroxidase. The production of these enzymes requires detailed knowledge of the growth characteristics and physiology of the fungus. Submerged cultivations of T. versicolor on glucose, fructose, and sucrose as sole carbon sources were performed in shake flasks. Sucrose hydrolysis catalyzed by the whole cells of T. versicolor was considered as one-step enzymatic reaction described with Michaelis-Menten kinetics. Kinetic parameters of invertase-catalyzed sucrose hydrolysis were estimated (K (m) = 7.99 g dm(-3) and V (m) = 0.304 h(-1)). Monod model was used for description of kineti... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3049334 Tue, 01 Dec 2009 00:00:00 +0100 3049334 http://www.medworm.com/index.php?rid=3042010&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19946709%26dopt%3DAbstract Authors: Zhang YW, Prabhu P, Lee JK Recombinant Escherichia coli whole cells harboring Bacillus licheniformis L: -arabinose isomerase (BLAI) were immobilized with alginate. The operational conditions for immobilization were optimized with response surface methodology. Optimal alginate concentration, Ca(2+) concentration, and cell mass loading were 1.8% (w/v), 0.1 M, and 44.5 g L(-1), respectively. The interactions between Ca(2+) concentration, alginate concentration, and initial cell mass were significant. After immobilization of BLAI, cross-linking with 0.1% glutaraldehyde significantly reduced cell leakage. The half-life of immobilized whole cells was 150 days, which was 50-fold longer than that of free cells. In seven repeated batches for L: -ribulose production, the productivity wa... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3042010 Sat, 28 Nov 2009 00:00:00 +0100 3042010 http://www.medworm.com/index.php?rid=3009354&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19921275%26dopt%3DAbstract Authors: Mazumdar S, Sachdeva S, Chauhan VS, Yazdani SS The C-terminal, 19-kDa domain of Plasmodium falciparum merozoite surface protein-1 (PfMSP-1(19)) is among the leading vaccine candidate for malaria due to its essential role in erythrocyte invasion by the parasite. We designed a synthetic gene for optimal expression of recombinant PfMSP-1(19) in Escherichia coli and developed a scalable process to obtain high-quality PfMSP-1(19). The synthetic gene construct yielded a fourfold higher expression level of PfMSP-1(19) in comparison to the native gene construct. Optimization of cultivation conditions in the bioreactor indicated important role of yeast extract and substrate feeding strategy for obtaining enhanced expression of soluble and correctly folded PfMSP-1(19). It was observed t... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3009354 Wed, 18 Nov 2009 00:00:00 +0100 3009354 http://www.medworm.com/index.php?rid=3009353&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19921276%26dopt%3DAbstract Authors: Andersson C, Petrova E, Berglund K, Rova U During dual-phase fermentations using Escherichia coli engineered for succinic acid production, the productivity and viable cell concentration decrease as the concentration of succinic acid increases. The effects of succinic acid on the fermentation kinetics, yield, and cell viability were investigated by resuspending cells in fresh media after selected fermentation times. The cellular succinic acid productivity could be restored, but cell viability continuously decreased throughout the fermentations by up to 80% and subsequently the volumetric productivity was reduced. Omitting complex nutrients in the resuspension media had no significant effect on cellular succinate productivity and yield, although the viable cell concentration and... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3009353 Tue, 17 Nov 2009 00:00:00 +0100 3009353 http://www.medworm.com/index.php?rid=3003688&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19916029%26dopt%3DAbstract Authors: Zhu Y, Ni J, Huang W Based on the response surface methodology, an effective microbial system for diosgenin production from enzymatic pretreated Dioscorea zingiberensis tubers with Trichoderma reesei was studied. The fermentation medium was optimized with central composite design (3(5)) depended on Plackett-Burmann design which identified significant impacts of peptone, K(2)HPO(4) and Tween 80 on diosgenin yield. The effects of different fermentation conditions on diosgenin production were also studied. Four parameters, i.e. incubation period, temperature, initial pH and substrate concentration were optimized using 4(5) central composite design. The highest diosgenin yield of 90.57% was achieved with 2.67% (w/v) of peptone, 0.29% (w/v) of K(2)HPO(4), 0.73% (w/v) of Tween 80 an... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3003688 Sun, 15 Nov 2009 00:00:00 +0100 3003688 http://www.medworm.com/index.php?rid=3003692&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19915871%26dopt%3DAbstract Authors: Yeom SH, Daugulis AJ, Nielsen DR One of the key roles of an organic solvent has emerged to be the enhancement of oxygen transfer in two-phase partitioning bioscrubbers (TPPBs). In order to determine an optimum organic fraction for a given VOCs loading, the oxygen demand of the total cell mass must be estimated, which depends upon the magnitude of the cellular maintenance coefficient. We have estimated the dynamics of the maintenance coefficient for benzene degradation by Achromobacter xylosoxidans Y234 in a TPPB and found that the maintenance coefficient generally decreased as cells accumulated in the TPPB but converged to a specific value of 1.750 x 10(-2) h(-1) at biological steady state. Due to its important influence on all of the essential design parameters of the TPPB sy... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3003692 Sat, 14 Nov 2009 00:00:00 +0100 3003692 http://www.medworm.com/index.php?rid=3003691&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19915872%26dopt%3DAbstract Authors: Ahmad Z, Mat Don M, Mortan SH, Mat Noor RA Recently, the increased demand of fructooligosaccharides (FOS) as a functional food has alarmed researchers to screen and identify new strains capable of producing fructosyltransferase (FTase). FTase is the enzyme that converts the substrate (sucrose) to glucose and fructose. The characterization of complex sugar such as table sugar, brown sugar, molasses, etc. will be carried out and the sugar that contained the highest sucrose concentration will be selected as a substrate. Eight species of macro-fungi will be screened for its ability to produce FTase and only one strain with the highest FTase activity will be selected for further studies. In this work, neural networks (NN) have been chosen to model the process based on their excelle... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=3003691 Sat, 14 Nov 2009 00:00:00 +0100 3003691 http://www.medworm.com/index.php?rid=2985588&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19902261%26dopt%3DAbstract Authors: Calabrò V, Ricca E, De Paola MG, Curcio S, Iorio G In this paper, the reaction of enzymatic trans-esterification of glycerides with ethanol in a reaction medium containing hexane at a temperature of 37 degrees C has been studied. The enzyme was Lipase from Mucor miehei, immobilized on ionic exchange resin, aimed at achieving high catalytic specific surface and recovering, regenerating and reusing the biocatalyst. A kinetic analysis has been carried out to identify the reaction path; the rate equation and kinetic parameters have been also calculated. The kinetic model has been validated by comparison between predicted and experimental results. Mass transport resistances estimation was undertaken in order to verify that the kinetics found was intrinsic. Model potentialities... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2985588 Tue, 10 Nov 2009 00:00:00 +0100 2985588 http://www.medworm.com/index.php?rid=2968790&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19888605%26dopt%3DAbstract Authors: Vu KD, Tyagi RD, Valéro JR, Surampalli RY Bacillus thuringiensis var. kurstaki biopesticide was produced in batch and fed-batch fermentation modes using starch industry wastewater as sole substrate. Fed-batch fermentation with two intermittent feeds (at 10 and 20 h) during the fermentation of 72 h gave the maximum delta-endotoxin concentration (1,672.6 mg/L) and entomotoxicity (Tx) (18.5 x 10(6) SBU/mL) in fermented broth which were significantly higher than maximum delta-endotoxin concentration (511.0 mg/L) and Tx (15.8 x 10(6) SBU/mL) obtained in batch process. However, fed-batch fermentation with three intermittent feeds (at 10, 20 and 34 h) of the fermentation resulted in the formation of asporogenous variant (Spo-) from 36 h to the end of fermentation (72 h) which re... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2968790 Wed, 04 Nov 2009 00:00:00 +0100 2968790 http://www.medworm.com/index.php?rid=2968789&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19888606%26dopt%3DAbstract Authors: Chanfreau S, Mena M, Porras-Domínguez JR, Ramírez-Gilly M, Gimeno M, Roquero P, Tecante A, Bárzana E The syntheses of poly-L: -lactide (PLLA) and poly-L: -lactide-co-glycolide (PLLGA) is reported in the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate [HMIM][PF(6)] mediated by the enzyme lipase B from Candida antarctica (Novozyme 435). The highest PLLA yield (63%) was attained at 90 degrees C with a molecular weight (M ( n )) of 37.8 x 10(3) g/mol determined by size exclusion chromatography. This procedure produced relatively high crystalline polymers (up to 85% PLLA) as determined by DSC. In experiments at 90 degrees C product synthesis also occurred without biocatalyst, however, PLLA synthesis in [HMIM][PF(6)] at 65 degrees C followed only the enzy... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2968789 Wed, 04 Nov 2009 00:00:00 +0100 2968789 http://www.medworm.com/index.php?rid=2955134&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19882175%26dopt%3DAbstract Authors: Liu Z, Zhang D, Hua Z, Li J, Du G, Chen J Low-energy ion implantation was employed to breed laccase producing strain Paecilomyces sp. WSH-L07 and a mutant S152 that exhibited an activity of more than three times over the wild strain was obtained. The optimum substrate of both the wild and mutant laccases was 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate), and followed by guaiacol with optimal pH at 3.4 and 5.0, respectively, while the mutant laccase exhibited a broader active pH range. The mutant laccase had a higher optimal catalytic temperature (60-65 degrees C) than the wild one (55 degrees C), and the wild laccase deactivated rapidly when temperature increased above 55 degrees C. Furthermore, the mutant laccase was more stable under neutral and alkaline conditions. A t... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2955134 Sat, 31 Oct 2009 00:00:00 +0100 2955134 http://www.medworm.com/index.php?rid=2948583&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19876651%26dopt%3DAbstract Authors: Ganesh R, Rajinikanth R, Thanikal JV, Ramanujam RA, Torrijos M The treatment of winery wastewater in three upflow anaerobic fixed-bed reactors (S9, S30 and S40) with low density floating supports of varying size and specific surface area was investigated. A maximum OLR of 42 g/l day with 80 +/- 0.5% removal efficiency was attained in S9, which had supports with the highest specific surface area. It was found that the efficiency of the reactors increased with decrease in size and increase in specific surface area of the support media. Total biomass accumulation in the reactors was also found to vary as a function of specific surface area and size of the support medium. The Stover-Kincannon kinetic model predicted satisfactorily the performance of the reactors. The maximum remov... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2948583 Fri, 30 Oct 2009 00:00:00 +0100 2948583 http://www.medworm.com/index.php?rid=2935717&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19859743%26dopt%3DAbstract Authors: Liu Y, Yuan R, Chai Y, Hong C, Guan S A novel amperometric immunosensor based on chitosan-gold nanoparticles (Chit-GNPs) composite film and thionine (Thi) was prepared for the determination of alpha-1-fetoprotein (AFP). The immunosensor was prepared by electro-depositing a Chit-GNPs composite matrix on the surface of the glass carbon electrode, then Thi was immobilized onto the Chit-GNPs film using glutaraldehyde as a cross-linker. Furthermore, the GNPs were chemisorbed onto Thi film for immobilization of alpha-1-fetoprotein antibody. The procedure of the immunosensor was characterized by means of cyclic voltammograms. The performance and influencing factors of the resulting immunosensor were studied in details. Under optimal conditions, the immunosensor was highly sensitive t... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2935717 Tue, 27 Oct 2009 00:00:00 +0100 2935717 http://www.medworm.com/index.php?rid=2935716&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19859744%26dopt%3DAbstract Authors: Babaeipour V, Pesaran Haji Abbas M, Sahebnazar Z, Alizadeh R Development of inexpensive and simple culture media is always favorable for recombinant protein over-expression in E. coli. The effects of medium composition on the production of recombinant human granulocyte-colony stimulating factor (rh-GCSF) were investigated in batch culture of E. coli BL21 (DE3) [pET23a-hgcsf]. First, the optimum medium for production of rh-GCSF was determined; and, then it was shown that mixture of amino acid addition at induction time, which was determined on the basis of amino acids frequency in the recombinant protein, increases recombinant protein expression level significantly. Furthermore, the effect of glucose concentration on productivity of rh-GCSF was investigated; 20 g/l of glucose w... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2935716 Tue, 27 Oct 2009 00:00:00 +0100 2935716 http://www.medworm.com/index.php?rid=2924636&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19851786%26dopt%3DAbstract Authors: Lee SM, Jin LH, Kim JH, Han SO, Na HB, Hyeon T, Koo YM, Kim J, Lee JH beta-Glucosidase (betaG) can relieve the product inhibition of cellobiose in the cellulosic ethanol production by converting cellobiose into glucose. For the potential recycled uses, betaG was immobilized and stabilized in the form of enzyme coating on polymer nanofibers. The betaG coating (EC-betaG) was fabricated by crosslinking additional betaG molecules onto covalently attached betaG molecules (CA-betaG) via glutaraldehyde treatment. The initial activity of EC-betaG was 36 times higher than that of CA-betaG. After 20 days of incubation under shaking, CA-betaG and EC-betaG retained 33 and 91% of each initial activity, respectively. Magnetic nanofibers were also used for easy recovery and recycled uses of ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2924636 Fri, 23 Oct 2009 00:00:00 +0100 2924636 http://www.medworm.com/index.php?rid=2920633&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19847461%26dopt%3DAbstract Authors: Rodríguez-Meza MA, Chávez-Gómez B, Poggi-Varaldo HM, Ríos-Leal E, Barrera-Cortés J This paper reports the effect of the operation and design characteristics of rotating drum bioreactors (RDBs) aerated by natural convection and applied to the treatment of a soil highly polluted with weathered total petroleum hydrocarbons (TPH) (55,000 +/- 2,600 mg/kg). The parameters studied were length to diameter ratio (L/D), rotating speed (N) and lifter type. The highest TPH removal (59.6 +/- 0.7%) was obtained with the RDB of the lowest L/D ratio (1.5). Removals diminished by 27, 36 and 56%, with a ratio increment of 2.1, 3.1 and 5.1, respectively. Increment of the N, at an optimal value and lifter change from straight to helicoidal showed an improvement on the TPH... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2920633 Wed, 21 Oct 2009 23:00:00 +0100 2920633 http://www.medworm.com/index.php?rid=2912917&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19838737%26dopt%3DAbstract Authors: Hirota Y, Hakoda M, Wakizaka Y The separation characteristics of a wire-wire type dielectrophoretic (DEP) filter were evaluated using animal cells. The separation of cells with different activities was examined using a DEP filter. The specific growth rate of the cells in retention liquid was larger than that in permeation liquid. From the culture results of the separated cells, it becomes clear that the specific growth rate of the cells of the retention liquid was higher than that of the cells of the permeation liquid. Furthermore, as a result of separating cells two kinds of cell suspensions using the DEP filter, the difference between the retention ratios of the two groups of obtained cells was about 20% at maximum. PMID: 19838737 [PubMed - as supplied by publisher] (Sou... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2912917 Fri, 16 Oct 2009 23:00:00 +0100 2912917 http://www.medworm.com/index.php?rid=2902249&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19830458%26dopt%3DAbstract Authors: Paroul N, Biasi A, Rovani AC, Prigol C, Dallago R, Treichel H, Cansian RL, Oliveira JV, de Oliveira D This work investigated the influence of temperature, enzyme concentration, substrates molar ratio, in the absence and presence of organic solvent, at two molar ratios of the substrates on the enzymatic production of linalil esters using the immobilized lipase Novozym 435 as catalyst, different acids and linalool and Ho-Sho essential oil as substrates. The best reaction conversion was obtained at the highest temperature (70 degrees C), for both solvent free (3.81%) and with solvent addition (2.25%), for a solvent to substrates molar ratio of 2:1, enzyme concentration of 5 wt% and acid to alcohol molar ratio of 1:1. The reaction kinetics revealed that Ho-Sho essential oil afford... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2902249 Wed, 14 Oct 2009 23:00:00 +0100 2902249 http://www.medworm.com/index.php?rid=2872617&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19809834%26dopt%3DAbstract Authors: Zhang WX, Tang YJ, Zhong JJ Liquid static cultivation of Ganoderma lucidum was previously found to be very efficient for improving the production of its valuable antitumor compound ganoderic acid (GA) (Fang and Zhong in Biotechnol Prog 18:51-54, 2002). In this work, effects of oxygen concentration within the range of 21-100% (v/v) in the gaseous phase on the mycelia growth, GA production, and gene transcription of key enzymes for GA biosynthesis in liquid static cultures of G. lucidum were investigated. A high cell density of 29.8 +/- 1.7 g/l DW and total GA production of 1427.2 +/- 74.2 mg/l were obtained under an optimal gaseous O(2) level of 80%. The expression of 3-hydroxy-3-methyl-glutaryl-CoA reductase, squalene synthase and lanosterol synthase genes of GA biosynthetic p... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2872617 Tue, 06 Oct 2009 23:00:00 +0100 2872617 http://www.medworm.com/index.php?rid=2824914&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19768471%26dopt%3DAbstract Authors: Zhu HY, Xu H, Dai XY, Zhang Y, Ying HJ, Ouyang PK A new yeast, isolated from natural osmophilic sources, produces D: -arabitol as the main metabolic product from glucose. According to 18S rRNA analysis, the NH-9 strain belongs to the genus Kodamaea. The optimal culture conditions for inducing production of D: -arabitol were 37 degrees C, neutral pH, 220 rpm shaking, and 5% inoculum. The yeast produced 81.2 +/- 0.67 g L(-1) D: -arabitol from 200 g L(-1) D: -glucose in 72 h with a yield of 0.406 g g(-1) glucose and volumetric productivity [Formula: see text] of 1.128 g L(-1) h(-1). Semi-continuous repeated-batch fermentation was performed in shaker-flasks to enhance the process of D: -arabitol production by Kodamaea ohmeri NH-9 from D: -glucose. Under repeated-batch culture cond... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2824914 Fri, 18 Sep 2009 23:00:00 +0100 2824914 http://www.medworm.com/index.php?rid=2768151&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19727832%26dopt%3DAbstract Authors: Nucci ER, Cruz AJ, Giordano RC The complexity of biological processes often makes impractical the development of detailed, structured phenomenological models of the cultivation of microorganisms in bioreactors. In this context, data pre-treatment techniques are useful for bioprocess control and fault detection. Among them, principal component analysis (PCA) plays an important role. This work presents a case study of the application of this technique during real experiments, where the enzyme penicillin G acylase (PGA) was produced by Bacillus megaterium ATCC 14945. PGA hydrolyzes penicillin G to yield 6-aminopenicilanic acid (6-APA) and phenyl acetic acid. 6-APA is used to produce semi-synthetic beta-lactam antibiotics. A static PCA algorithm was implemented for on-line detecti... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2768151 Tue, 01 Sep 2009 23:00:00 +0100 2768151 http://www.medworm.com/index.php?rid=2768150&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19727833%26dopt%3DAbstract Authors: Zhao CH, Zhang T, Chi ZM, Chi Z, Li J, Wang XH The intracellular protein in the highly thermosensitive and permeable mutant can be easily released when they are incubated both in the low-osmolarity water and at the non-permissive temperature (usually 37 degrees C). After the mutant was grown in the yacon extract for 45 h, the crude protein content in the highly thermosensitive and permeable mutant Z114 was 59.1% and over 61% of the total protein could be released from the cells treated at 37 degrees C. The mutant cells grown in the yacon extract still contained high level of essential amino acids and other nutrients. This means that the yacon extract could be used as the medium for growth of the highly thermosensitive and permeable mutant which contained high content of crude ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2768150 Mon, 31 Aug 2009 23:00:00 +0100 2768150 http://www.medworm.com/index.php?rid=2768149&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19727834%26dopt%3DAbstract Authors: Yamamoto E, Yamaguchi S, Sasaki N, Kim HB, Kitamori T, Nagamune T Protein refolding using a simple dilution method in a microchannel often led to the formation of protein aggregates, which bound to the microchannel wall, resulting in low refolding yields. To inhibit aggregation and improve refolding yields, an artificial chaperone-assisted (ACA) refolding, which employed detergents and beta-cyclodextrin was used. Model proteins, hen egg white lysozyme and yeast alpha-glucosidase, were successfully refolded in a microchannel. The microscopic observation showed that the ACA method suppressed protein aggregation and facilitated the refolding of lysozyme, whereas significant aggregation was observed when a simple dilution method was employed. The ACA method increased the lysozyme ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2768149 Sat, 29 Aug 2009 23:00:00 +0100 2768149 http://www.medworm.com/index.php?rid=2768148&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19727835%26dopt%3DAbstract Authors: Kim JM, Park JJ, Lee HJ, Kim WS, Muramatsu H, Chang SM A novel glucose sensor was constructed, and its analytical potential examined. A chip-type three-electrode system for use in a flow-type electrochemical glucose sensor was fabricated using a UV lithography technique on a glass slide. An Ag/AgCl reference electrode was made by electroplating silver onto a Pt electrode and dipping in a saturated KCl solution for 30 min. In addition, a glucose-sensing electrode was fabricated using a two-photon adsorbed photopolymerization technique with a photo-reactive resin containing a glucose oxidase enzyme, ferrocene mediator, non-ionic surfactant, and carbon nanotubes. The cyclic voltammetry of the potassium ferrocyanide in the Pt sensor system showed a stable electrode condition. The ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2768148 Fri, 28 Aug 2009 23:00:00 +0100 2768148 http://www.medworm.com/index.php?rid=2768147&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19727836%26dopt%3DAbstract Authors: Paciello L, Romano F, de Alteriis E, Parascandola P, Romano V A cultural system, aimed at the production of glucoamylase with cells of a non-conventional yeast transformed for the enzyme expression, Kluyveromyces lactis JA6-GAA was realised. Glucoamylase production was accomplished in a reactor operating in fed batch mode to avoid limitations with respect to oxygen transfer, and achieve high cell density. A mathematical model able to describe batch and fed batch operations was developed. The theoretical and experimental approach permitted to catch sight of possible physiological changes in the producer strain and set up a suitable fed-batch run to achieve a higher cell density. PMID: 19727836 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineerin... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2768147 Fri, 28 Aug 2009 23:00:00 +0100 2768147 http://www.medworm.com/index.php?rid=2745906&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19714365%26dopt%3DAbstract Authors: Jeon YJ, Park MB, Kim IH L: -Ribose has recently received attention as the starting material for nucleoside drugs. As it is not found in nature, it is being produced by enzymatic or epimerization reaction. We investigated an epimerization reaction by molybdenium oxide and examined the effects of temperature, solvent, and molybdenum oxide amount on epimerization. L: -Ribose has a yield of 22% under the conditions of 100 kg/m(3) L: -arabinose, 20% methanol, 5 kg/m(3) MoO(3), and 90 degrees C. In addition, simulated moving bed (SMB) that was equipped with three NH(2)-HPLC columns was used to separate L: -arabinose and L: -ribose resulting from L: -arabinose epimerization. A 3-zone SMB process was developed to eliminate the high pressure problem in the conventional 4-zone SMB. Asp... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2745906 Thu, 27 Aug 2009 23:00:00 +0100 2745906 http://www.medworm.com/index.php?rid=2745905&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19714366%26dopt%3DAbstract Authors: Lee JH, Chung SW, Lee HJ, Jang KS, Lee SG, Kim BG Five recombinant Escherichia coli extracts harboring overexpressed galactokinase, galactose-1-phosphate uridyltransferase, UDP-glucose pyrophophorylase, UMP kinase, and acetate kinase (AK) were utilized for the production of UDP-galactose (UDP-Gal). We analyzed the parameters which limit the yield of UDP-Gal in the reaction, and the reaction was optimized by increasing the concentration of AK. AK was used for the ATP regeneration as well as the conversion of UDP to UTP. The activities of four overexpressed enzymes were identically fixed, and then we increased the activity of AK to 20 times higher than others. The extracts catalyzed the production of UDP-Gal from UMP (10 mM), galactose (12 mM), ATP (1 mM), and acetyl phosphate (... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2745905 Thu, 27 Aug 2009 23:00:00 +0100 2745905 http://www.medworm.com/index.php?rid=2737208&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19707795%26dopt%3DAbstract Authors: Kim J, Kim S, Ohashi T, Muramatsu H, Chang SM, Kim WS To construct a novel simultaneous SPR and QCM sensing system, an AT-cut quartz crystal is fabricated by sputtering 250 nm of ITO on one side of the quartz plate over a 5-nm thick underlay of titanium, while a 50-nm thick layer of gold is sputter-deposited on the other side to induce a total light reflection of an incident laser beam on the thin gold layer. The signals of the sensing system are detected using a Handy-SPR and QCA922 when dropping 200 muL of Milli-Q water into the sensing cell. A decrease in the SPR reflected light intensity is clearly identified. In the same experiment, the changes in the resonant frequency and resistance are about 2 kHz and 200 Omega, respectively. Furthermore, the oscillation stabilities of... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2737208 Tue, 25 Aug 2009 23:00:00 +0100 2737208 http://www.medworm.com/index.php?rid=2730672&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19701776%26dopt%3DAbstract Authors: Song JY, Kwon EY, Kim BS The leaf extract of Diopyros kaki was used as a reducing agent in the ecofriendly extracellular synthesis of platinum nanoparticles from an aqueous H(2)PtCl(6).6H(2)O solution. A greater than 90% conversion of platinum ions to nanoparticles was achieved with a reaction temperature of 95 degrees C and a leaf broth concentration of >10%. A variety of methods was used to characterize the platinum nanoparticles synthesized: inductively coupled plasma spectrometry, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). The average particle size ranged from 2 to 12 nm depending on the reaction temperature and concentrations of the leaf broth and PtCl(6) ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2730672 Sat, 22 Aug 2009 23:00:00 +0100 2730672 http://www.medworm.com/index.php?rid=2730671&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19701777%26dopt%3DAbstract Authors: Oh IS, Lee JC, Lee MS, Chung JH, Kim DM Botulinum neurotoxin serotype B (BoNT/B)-specific Fab was expressed in a cell-free protein synthesis system derived from an E. coli extract. The cell-free synthesized antibody fragment was found to be effective in neutralizing the toxicity of BoNT/B in animal studies. Expression of functional Fab required an appropriately controlled and stably maintained redox potential. Under an optimized redox condition, the cell extract, whose disulfide reducing activity had been exhausted, could generate bio-functional Fab molecules. Use of a cell extract enriched with molecular chaperones (GroEL/ES) and disulfide bond isomerases were effective in obtaining larger quantities of functional Fab. Under the optimized reaction conditions, approximately 30... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2730671 Sat, 22 Aug 2009 23:00:00 +0100 2730671 http://www.medworm.com/index.php?rid=2730670&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19701778%26dopt%3DAbstract Authors: Kim YJ, Kim YS, Niazi JH, Gu MB An electrochemical aptasensor was developed for the detection of tetracycline using ssDNA aptamer that selectively binds to tetracycline as recognition element. The aptamer was highly selective for tetracycline which distinguishes minor structural changes on other tetracycline derivatives. The biotinylated ssDNA aptamer was immobilized on a streptavidin-modified screen-printed gold electrode, and the binding of tetracycline to aptamer was analyzed by cyclic voltammetry and square wave voltammetry. Our results showed that the minimum detection limit of this sensor was 10 nM to micromolar range. The aptasensor showed high selectivity for tetracycline over the other structurally related tetracycline derivatives (oxytetracycline and doxycycline) in ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2730670 Sat, 22 Aug 2009 23:00:00 +0100 2730670 http://www.medworm.com/index.php?rid=2730669&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19701779%26dopt%3DAbstract Authors: Sung JH, Shuler ML After administration, drugs go through a complex, dynamic process of absorption, distribution, metabolism and excretion. The resulting time-dependent concentration, termed pharmacokinetics (PK), is critical to the pharmacological response from patients. An in vitro system that can test the dynamics of drug effects in a more systematic way would save time and costs in drug development. Integration of microfabrication and cell culture techniques has resulted in 'cells-on-a-chip' technology, which is showing promise for high-throughput drug screening in physiologically relevant manner. In this review, we summarize current research efforts which ultimately lead to in vitro systems for testing drug's effect in PK-based manner. In particular, we highlight the cont... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2730669 Sat, 22 Aug 2009 23:00:00 +0100 2730669 http://www.medworm.com/index.php?rid=2730668&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19701780%26dopt%3DAbstract We describe a new device with parallel optical measurement of dissolved oxygen (DO) and pH in up to nine shake flasks applicable in any conventional shaking incubator. Measurement ranges are 0-500% of air saturation for oxygen and 5.5-8.5 for pH. It was used to characterize growth profiles of different L: -lysine producing strains of Corynebacterium glutamicum, of Saccharomyces cerevisiae and of Escherichia coli. Cultures in unbaffled flasks were highly reproducible. Oxygen limitation was indicated online which is particularly important when cultivating fast growing cells as E. coli. C. glutamicum strains showed distinct characteristic patterns of DO and pH indicating biological events. During the cultivation of S. cerevisiae on glucose, fructose and galactose, oxygen uptake rate was deter... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2730668 Sat, 22 Aug 2009 23:00:00 +0100 2730668 http://www.medworm.com/index.php?rid=2721009&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19690894%26dopt%3DAbstract Authors: Debik E, Manav N The purpose of this work was to determine optimum sequence retention times for nutrient removal with low-cost using very short aeration time in an SBR treating domestic wastewater. During the study, four different CYCLEs were evaluated, with the highest removal efficiencies recorded for the CYCLE with fill, anaerobic, aerobic1, anoxic, aerobic2, settle, and decant sequences operated at retention times of 0.5, 2, 2, 1, 0.75, 1, and 0.5 h, respectively. For this CYCLE, the removal efficiencies of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), ammonia nitrogen (NH(3)-N), total phosphorus (TP), and ortho-phosphate (PO(4)-P) were found, on average, to be 91, 78, 85, 87, and 83%, respectively. The optimum sequence retention time was determined via the ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2721009 Tue, 18 Aug 2009 23:00:00 +0100 2721009 http://www.medworm.com/index.php?rid=2704001&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19680693%26dopt%3DAbstract Authors: Ha SH, Hiep NM, Lee SH, Koo YM Lipase-catalyzed esterification of glucose with fatty acids in ionic liquids (ILs) mixture was investigated by using supersaturated glucose solution. The effect of ILs mixture ratio, substrate ratio, lipase content, and temperature on the activity and stability of lipase was also studied. The highest yield of sugar ester was obtained in a mixture of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([Bmim][TfO]) and 1-methyl-3-octylimidazolium bis[(trifluoromethyl)-sulfonyl]amide ([Omim][Tf(2)N]) with a volume ratio of 9:1, while Novozym 435 (Candida antarctica type B lipase immobilized on acrylic resin) showed the optimal stability and activity in a mixture of [Bmim][TfO] and [Omim][Tf(2)N] with a 1:1 volume ratio. Reuse of lipase and ILs wa... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2704001 Wed, 12 Aug 2009 23:00:00 +0100 2704001 http://www.medworm.com/index.php?rid=2704000&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19680694%26dopt%3DAbstract Authors: Li W, Li Z, Ye Q In the present study, permeated yeast cells were used as the catalyst to synthesize glutathione. When waste cells of brewer's yeast were incubated with the three precursor amino acids and glucose for 36 h, 899 mg/L of glutathione were produced. To release the feedback inhibition of gamma-glutamylcysteine synthetase caused by glutathione, two-stage reaction was adopted. In the first stage, glycine was omitted from the reaction mixture and only gamma-glutamylcysteine was formed. Glycine was then added in the second stage, and 1,569 mg/L of glutathione were produced. The conditions of the two-stage reaction were optimized using Plackett-Burman design and response surface methodology. Under the optimized condition, commercially available baker's yeast produced 3,4... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2704000 Wed, 12 Aug 2009 23:00:00 +0100 2704000 http://www.medworm.com/index.php?rid=2703999&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19680695%26dopt%3DAbstract Authors: Bizukojc M, Dietz D, Sun J, Zeng AP Clostridium butyricum can convert glycerol into 1,3-propanediol, thereby generating unfortunately a high amount of acetate, formate and butyrate as inhibiting by-products. We have proposed a novel mixed culture comprising C. butyricum and a methane bacterium, Methanosarcina mazei, to relieve the inhibition and to utilise the by-products for energy production. In order to examine the efficiency of such a mixed culture, metabolic modelling of the culture system was performed in this work. The metabolic networks for the organisms were reconstructed from genomic and physiological data. Several scenarios were analysed to examine the preference of M. mazei in scavenging acetate and formate under conditions of different substrate availability, incl... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2703999 Wed, 12 Aug 2009 23:00:00 +0100 2703999 http://www.medworm.com/index.php?rid=2682614&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19662437%26dopt%3DAbstract Authors: Kang CD, Han SJ, Choi SP, Sim SJ A fed-batch culture process followed by subsequent photoautotrophic induction was established for the high density culture of astaxanthin-rich Haematococcus pluvialis using a CO(2)-fed flat type photobioreactor under unsynchronized illumination. Fed-batch culture was performed with an exponential feeding strategy of the growth-limiting nutrients, nitrate and phosphate, concurrently with the stepwise supplementation of light depending on the cell concentration. During the growth phase, a biomass of 1.47 g/L was obtained at a biomass productivity of 0.33 g/L/day. Photoautotrophic induction of the well-grown vegetative cells was performed consecutively by increasing the light intensity to 400 mumol photon/m(2)/s, while keeping the other conditions... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2682614 Thu, 06 Aug 2009 23:00:00 +0100 2682614 http://www.medworm.com/index.php?rid=2682615&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19657679%26dopt%3DAbstract Authors: Liu H Genome-wide transcriptional regulatory networks (TRNs) specify the interactions between transcription factors (TFs) and their target genes. Many methods have been proposed to reconstruct regulatory networks from gene expression datasets and/or genome sequences, but most of them can only infer qualitative regulation relationships. Thus, developing a quantitative model that can estimate the kinetic parameters of transcriptional regulatory functions is an urgent and important task. In this paper I propose REMBE, a regulatory model based on binding energy, to quantify transcriptional regulatory networks. My model combines multiple kinetic quantities, including binding strength, TF-DNA's binding energy, transcription productivity with respect to each binding state, and hidden... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2682615 Wed, 05 Aug 2009 23:00:00 +0100 2682615 http://www.medworm.com/index.php?rid=2668991&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19649657%26dopt%3DAbstract In this study, nanofiltration with NF200 membrane was employed to remove KCl from ion-exchanged solutions containing potassium clavulanate. The pore radius of NF200 membrane was estimated to be around 0.39 nm. The effects of operating pressure on separation performance were investigated in a range of 100-400 psig. The influences of cross-flow velocity (0.14-0.70 cm/s), temperature (4-25 degrees C), and feed composition were also investigated. In all experiments, clavulanate rejection showed high levels from 0.91 to 0.99, while chloride rejection ranged from 0.06 to 0.54. In a case at an operating pressure of 50 psig and 25 degrees C, as much as 94% of clavulanate was retained while 94% of chloride was removed, indicating that NF200 membrane was a suitable choice for selectively removing KC... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2668991 Sat, 01 Aug 2009 23:00:00 +0100 2668991 http://www.medworm.com/index.php?rid=2668990&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19649658%26dopt%3DAbstract Authors: Shao X, Lynd L, Bakker A, Laroche R, Wyman C The absence of a systematic scale-up approach for biological conversion of cellulosic biomass to commodity products is a significant bottleneck to realizing the potential benefits offered by such conversion. Motivated by this, we undertook to develop a scale-up approach for conversion of waste paper sludge to ethanol. Physical properties of the system were measured and correlations were developed for their dependence upon cellulose conversion. Just-suspension of solid particles was identified as the scale up criterion based on experiments at lab scale. The impeller speed for just solids suspension at large scale was predicted using computational fluid dynamics simulations. The scale-up strategy was validated by analyzing mixing requ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2668990 Sat, 01 Aug 2009 23:00:00 +0100 2668990 http://www.medworm.com/index.php?rid=2668989&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19649659%26dopt%3DAbstract Authors: Yu R, Dong S, Zhu Y, Jin H, Gao M, Duan Z, Zheng Z, Shi Z, Li Z Efficient porcine interferon-alpha (pIFN-alpha) expression in high density recombinant Pichia pastoris cultivation was achieved in a 5 l bench-scaled bioreactor. The results indicated that a high and stable oxygen uptake rate (OUR) during induction phase was closely related with pIFN-alpha production efficiency. The multi-variables clustering and analysis results showed that the achievement of a high and stable OUR relied on a higher glycerol consumption rate during fed-batch culture phase and a moderate methanol level (around 10 g/l) during induction phase. In the high and stable OUR environments (200-300 mmol/l/h), the highest pIFN-alpha antiviral activity could reach a level of 6.7 x 10(6) IU/ml, which was more... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2668989 Sat, 01 Aug 2009 23:00:00 +0100 2668989 http://www.medworm.com/index.php?rid=2661058&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19644709%26dopt%3DAbstract Authors: Lee PC, Lee SY, Chang HN Succinic acid-producing Anaerobiospirillum succiniciproducens was anaerobically grown in a glycerol-fed continuous bioreactor in order to investigate the physiological responses of the cell to different pH values (5.9, 6.2, or 6.5) and various dilution rates, D. In these experiments, A. succiniciproducens showed a pH-dependent glycerol consumption behavior. When pH was maintained at 5.9 or 6.5, glycerol started to accumulate even at a very low D of 0.027 h(-1). Succinic acid yield was not significantly affected by the pH of the culture or the Ds. However, more acetic acid formation was observed when the growth rate of A. succiniciproducens was fast on glycerol at pH 6.2 (at D >/= 0.15 h(-1)). The highest obtainable succinic acid/acetic acid ratio wa... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2661058 Thu, 30 Jul 2009 23:00:00 +0100 2661058 http://www.medworm.com/index.php?rid=2654447&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19639343%26dopt%3DAbstract In this study, we examined the formation of MSAMs on gold nanoparticles (AuNPs) and the immobilization of hexa-arginine-tagged esterase (Arg(6)-esterase) on the surfaces of the resulting particles. The functionalization of AuNPs with MSAMs was achieved by introducing a mixture of tethering and shielding ligands into an AuNP solution. The formation of self-assembled monolayers (SAMs) on the AuNP surface was characterized by UV/visible spectroscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. Arg(6)-esterase was immobilized in a highly specific manner onto AuNPs treated with mixed SAMs (MSAM-AuNPs) by providing a shielding ligand which reduce the non-specific adsorption of enzymes caused by hydrophobic interaction compared to AuNPs treated with single-compo... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2654447 Tue, 28 Jul 2009 23:00:00 +0100 2654447 http://www.medworm.com/index.php?rid=2654448&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19636592%26dopt%3DAbstract In this study, we present in vitro cytotoxicity of iron oxide (Fe(3)O(4)) and manganese oxide (MnO) using live/dead cell assay, lactate dehydrogenase assay, and reactive oxygen species detection with variation of the concentration of nanoparticles (5-500 mug/ml), incubation time (18-96 h), and different human cell lines (lung adenocarcinoma, breast cancer cells, and glioblastoma cells). The surface of nanoparticles is modified with polyethyleneglycol-derivatized phospholipid to enhance the biocompatibility, water-solubility, and stability under an aqueous media. While the cytotoxic effect was negligible for 18 h incubation even at highest concentration of 500 mug/ml, MnO nanoparticle represented higher level of toxicity than those of Fe(3)O(4) and the commercial medical contrast reagent, F... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2654448 Mon, 27 Jul 2009 23:00:00 +0100 2654448 http://www.medworm.com/index.php?rid=2611768&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19603187%26dopt%3DAbstract Authors: Ul-Haq N, Park JK An enantio-selective D: -Phe imprinted P(AA-co-AN) membrane was prepared using the wet-phase inversion method. The membrane not only selectively adsorbed phenylalanine but also rejected it with a rejection selectivity of 0.82-0.64 and 0.91-0.63 during the filtration of 100 and 10 ppm (g m(-3)) racemate solutions, respectively. The fluxes of D: -Phe and L: -Phe during filtration of 10 ppm racemate solution were 0.0077-0.0229 and 0.0064-0.0208 mg m(-2) s(-1), respectively, and the fluxes of D: -Phe and L: -Phe during filtration of 100 ppm racemate solution were 0.1287-0.2522 and 0.1174-0.2458 mg m(-2) s(-1), respectively. The adsorption selectivity was higher at low concentration. The adsorption selectivities varied from 1.11 to 1.65 and from 1.64 to 2.78 durin... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2611768 Tue, 14 Jul 2009 23:00:00 +0100 2611768 http://www.medworm.com/index.php?rid=2603170&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19597742%26dopt%3DAbstract Authors: Min WK, Cho YJ, Park JB, Bae YH, Kim EJ, Park K, Park YC, Seo JH Fumonisin B(1) (FMB(1)) is a food-born mycotoxin produced by Fusarium moniliforme. Monoclonal antibody against FMB(1) (anti-FMB(1) mAb) was produced in the hybridoma DV9, which was established from a BALB/c mouse immunized with bovine serum albumin conjugated FMB(1) (FMB(1)-BSA). A competitive direct enzyme-linked immunosorbent assay (ELISA) showed that anti-FMB(1) mAb has about 10 ppb of minimum FMB(1) detection concentration and 220 ppb of 50% inhibition concentration (IC(50)). Much lower cross-reactivity of anti-FMB(1) mAb on ochratoxin A, aflatoxin B(1) and deoxynivalenol provided that anti-FMB(1) mAb was specific for FMB(1). The gene coding single chain variable fragment against FMB(1) (anti-FMB(1) scFv) was... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2603170 Sat, 11 Jul 2009 23:00:00 +0100 2603170 http://www.medworm.com/index.php?rid=2592418&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19590901%26dopt%3DAbstract Authors: Omasa T, Furuichi K, Iemura T, Katakura Y, Kishimoto M, Suga KI Generally, mammalian cells utilize glucose and glutamine as primary energy sources. To investigate the effect of energy sources on metabolic fluxes and antibody production, glucose- or glutamine-limited serum-free continuous culture of hybridoma 3A21 cells, which produce anti-ribonuclease A antibody, was carried out. The cell volume and dry cell weight were evaluated under various steady-state conditions. The specific consumption and production rates were evaluated on the basis of dry cell weight. On the basis of these results, the fluxes of the metabolic pathway were calculated. It was found that increasing the specific growth rate causes the specific ATP and antibody production rates to decrease. The fluxes betw... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2592418 Thu, 09 Jul 2009 23:00:00 +0100 2592418 http://www.medworm.com/index.php?rid=2580949&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19578877%26dopt%3DAbstract Authors: Yao B, Ni C, Xiong C, Zhu C, Huang B Sodium alginate was hydrophobically modified by coupling of polybutyl methacrylate onto the alginate. The polybutyl methacrylate was previously prepared through polymerization of butyl methacrylate in the presence of 2-amino-ethanethiol as a chain transfer agent. The structure of the product was characterized by Fourier-transformed infrared spectrometry, nuclear magnetic resonance ((1)HNMR) and thermogravimetry. The result of fluorescence analysis showed that the hydrophobicity of the modified alginate was obviously increased. The modified alginate conjugate was used for immobilization of bovine serum albumin in the presence of calcium chloride. In addition, the release behavior of the drug-loaded alginate in deionized water and Tris-HCl bu... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2580949 Fri, 03 Jul 2009 23:00:00 +0100 2580949 http://www.medworm.com/index.php?rid=2573576&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19572152%26dopt%3DAbstract In this study, OBPs originating from rat and pig were cloned into a mammalian expression vector, pcDNA3, and expressed in HEK-293 cells, and their specificity for odorants and olfactory receptors was examined. Results suggest that OBPs have a high affinity for the olfactory receptors when both the OBP and receptor originate from the same species. The rat OBPs were bound not only to the rat olfactory receptor I7 but also to the odorant specific to I7. The solubility of the odorant was increased by both OBP2 and OBP3, which originate from rat, but with different efficiencies. These results demonstrate that OBPs specifically interact with odorants as well as olfactory receptors, and these interactions can influence the sensitivity of olfactory receptor-based biosensors. PMID: 19572152 [Pu... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2573576 Wed, 01 Jul 2009 23:00:00 +0100 2573576 http://www.medworm.com/index.php?rid=2573575&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19572153%26dopt%3DAbstract This study demonstrates that ANNs and regression models are robust tools for predicting iron precipitation in the integrated process and can thus be used in the management of such systems. PMID: 19572153 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2573575 Wed, 01 Jul 2009 23:00:00 +0100 2573575 http://www.medworm.com/index.php?rid=2563007&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19565273%26dopt%3DAbstract Authors: Lee SY PMID: 19565273 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2563007 Mon, 29 Jun 2009 23:00:00 +0100 2563007 http://www.medworm.com/index.php?rid=2550474&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19557439%26dopt%3DAbstract Authors: Bayramoglu G, Yilmaz M, Yakup Arica M Cross-linked magnetic chitosan beads were prepared by phase-inversion technique in the presence of epichlorohydrin under alkaline condition, and used for covalent immobilization of laccase. The activity of the immobilized laccase on the magnetic chitosan was about 260 U (g/dry beads) with an enzyme loading of about 16.33 +/- 0.39 mg [(g/dry beads) mg/g]. Kinetic parameters, V (max) and K (m) values were determined as 21.7 U/mg protein and 9.4 muM for free enzyme, and 15.6 U/mg protein and 19.7 muM for the immobilized laccase, respectively. The operational and thermal stabilities of the immobilized laccase were improved compared to free counterpart. The immobilized laccase was operated in a batch reactor for the decolorization of reactive d... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2550474 Thu, 25 Jun 2009 23:00:00 +0100 2550474 http://www.medworm.com/index.php?rid=2525878&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19548006%26dopt%3DAbstract Authors: Guo X, Zou X, Sun M PMID: 19548006 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525878 Mon, 22 Jun 2009 23:00:00 +0100 2525878 http://www.medworm.com/index.php?rid=2525877&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19548007%26dopt%3DAbstract Authors: Gómez X, Cuetos MJ, Tartakovsky B, Martínez-Núñez MF, Morán A Organic matter contained in food waste was degraded by anaerobic digestion under mesophilic and thermophilic conditions at two hydraulic retention times. Evolution of the digestion process was followed by thermogravimetry analysis, fluorescence spectroscopy and (1)H nuclear magnetic resonance. All analytical methods suggested that longer retention times might be required for food waste stabilization under mesophilic conditions as compared to thermophilic stabilization. All the analytical methods showed that the stabilization process consisted of two steps, where complex organic molecules were formed during initial stabilization and then digested providing sufficient hydraulic retention time.... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525877 Mon, 22 Jun 2009 23:00:00 +0100 2525877 http://www.medworm.com/index.php?rid=2525876&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19548008%26dopt%3DAbstract Authors: Guiavarch E, Pons A, Christophe G, Creuly C, Dussap CG Continuous cultures of Fibrobacter succinogenes S85 were performed on a standardized fully synthetic culture medium with glucose as carbon source at a dilution rate (D = 0.02 h(-1)) in a 5-L bioreactor. The culture was stabilized during 20 days and demonstrated the ability of Fibrobacter succinogenes to grow in this synthetic medium. CO(2) partial pressure and redox potential probes were used to check the anaerobic state of the culture. The biomass yield was calculated 0.206 g (g glucose)(-1) and the production yield of succinate, the major end-product, was 0.63 mol (mol glucose)(-1). The consistency of the experimental data was checked by proton and mass (C, N) balances. The results were satisfactory (90-110% recovery) le... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525876 Mon, 22 Jun 2009 23:00:00 +0100 2525876 http://www.medworm.com/index.php?rid=2525875&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19548009%26dopt%3DAbstract In this study, various additives including organic acids, alcohols, vegetable oils, surfactants and polymers were added in the cultural medium to investigate their stimulatory effects on Grifola umbellate mycelia growth and exopolysaccharide (EPS) production. It was found that the commonly used stimulatory additives, effective in other mushrooms' cultures, exhibited negative results in Grifola umbellata submerged culture. In contrast, the polymer additive, polyethylene glycol (PEG), displayed an effective stimulatory effect on both biomass and EPS productions. With the addition of PEG8 (molecular weight: 8,000 Da), the mycelial biomass production at day 12 was increased from 4.69 to 6.30 g/L, accounting for a 34% increase. Meanwhile, the EPS production was enhanced from 0.478 to 0.767 g/L,... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525875 Mon, 22 Jun 2009 23:00:00 +0100 2525875 http://www.medworm.com/index.php?rid=2525879&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19543751%26dopt%3DAbstract Authors: Geng J, Yuan J A macrokinetic model employing cybernetic methodology is proposed to describe mycelium growth and penicillin production. Based on the primordial and complete metabolic network of Penicillium chrysogenum found in the literature, the modeling procedure is guided by metabolic flux analysis and cybernetic modeling framework. The abstracted cybernetic model describes the transients of the consumption rates of the substrates, the assimilation rates of intermediates, the biomass growth rate, as well as the penicillin formation rate. Combined with the bioreactor model, these reaction rates are linked with the most important state variables, i.e., mycelium, substrate and product concentrations. Simplex method is used to estimate the sensitive parameters of the model. Fin... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525879 Thu, 18 Jun 2009 23:00:00 +0100 2525879 http://www.medworm.com/index.php?rid=2525881&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19533174%26dopt%3DAbstract Authors: Thongchul N, Navankasattusas S, Yang ST Cassava pulp was hydrolyzed with acids or enzymes. A high glucose concentration (>100 g/L) was obtained from the hydrolysis with 1 N HCl at 121 degrees C, 15 min or with cellulase and amylases. While a high glucose yield (>0.85 g/g dry pulp) was obtained from the hydrolysis with HCl, enzymatic hydrolysis yielded only 0.4 g glucose/g dry pulp. These hydrolysates were used as the carbon source in fermentation by Rhizopus oryzae NRRL395. R. oryzae could not grow in media containing the hydrolysates treated with 1.5 N H(2)SO(4) or 2 N H(3)PO(4), but no significant growth inhibition was found with the hydrolysates from HCl (1 N) and enzyme treatments. Higher ethanol yield and productivity were observed from fermentation with the hydroly... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525881 Tue, 16 Jun 2009 23:00:00 +0100 2525881 http://www.medworm.com/index.php?rid=2525880&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19533175%26dopt%3DAbstract Authors: Lee JW, Lee SY Using two-dimensional gel electrophoresis (2-DE) and mass spectrometry, the proteome of a metabolically engineered succinic acid-overproducing bacterium, Mannheimia succiniciproducens LPK7, was examined and compared with that of its wild type strain, MBEL55E, to elucidate the physiological and metabolic changes responsible for succinic acid overproduction and cell growth. Comparative proteomic studies clearly showed that the expression levels of enzymes involved in the ATP formation and consumption (AtpD, Ppa, SerS, ProS, Pnp, PotD, MalK, RbsB, and TbpA), pyruvate metabolism (AceF and Lpd), glycolysis (GapA, Pgk, Fba, and TpiA), and amino acid biosynthesis (Asd, DapA, DapD, Gdh, ArgD, and ArgG) varied significantly in the LPK7 strain compared with those in the M... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525880 Tue, 16 Jun 2009 23:00:00 +0100 2525880 http://www.medworm.com/index.php?rid=2525883&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19513757%26dopt%3DAbstract Authors: Lin CW, Chen LH, I YP, Lai CY To remediate benzene, toluene, ethylbenzene and xylene (BTEX) -contaminated groundwater, a biotreatment process including biostimulation and bioaugmentation was simulated using oxygen-releasing reactive barriers (ORRB) and water with added BTEX in a lab-scale system. The results showed that the capability for BTEX removal decreases in the order of benzene, toluene, p-xylene, ethylbenzene for both added-nitrogen and no-added-nitrogen under BTEX concentrations at 30 mg l(-1). The removal efficiencies in ORRB systems were higher in the nitrogen-added condition for biostimulation compared with the no-nitrogen-added condition; moreover, an increased pattern for removal was observed during the bioaugmentation process. The oxygen content was found to be ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525883 Tue, 09 Jun 2009 23:00:00 +0100 2525883 http://www.medworm.com/index.php?rid=2525882&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19513758%26dopt%3DAbstract Authors: Westerberg K, Degerman M, Nilsson B Preparative chromatographic columns that run at high loads are highly sensitive to batch-to-batch disturbances of the process parameters, placing high demands on the strategy used for pooling of the product fractions. A new approach to pooling control is presented in a proof-of-concept study. A model-based sensitivity analysis was performed identifying the critical process parameters to product purity and optimal cut points. From this, the robust fixed cut points were found and pooling control strategies for variations in the critical parameters were designed. Direct measurements and indirect measurements based on the UV detector signal were used as control signals. The method is demonstrated for two case studies of preparative protein chrom... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525882 Tue, 09 Jun 2009 23:00:00 +0100 2525882 http://www.medworm.com/index.php?rid=2525884&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19506911%26dopt%3DAbstract In this study, mainly biological treatment of prawn waste for chitin production was investigated. Lactic acid and protease fermentations were applied to extract chitin from prawn waste in the presence of various glucose concentrations. The results obtained were also compared with those of chemical method which was consisted of first mineral removal and then protein removal sequence. Different strategies were applied using lactic acid producing bacterium, Lactococcus lactis, and a protease producer, marine bacterium Teredinobacter turnirae. Both bacteria were first cultivated individually and then cofermented. In their individual cultivation, L. lactis removed the inorganic materials efficiently, while T. turnirae performed better in deproteinization process. Cofermentation of both bacteria... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525884 Mon, 08 Jun 2009 23:00:00 +0100 2525884 http://www.medworm.com/index.php?rid=2525885&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19504270%26dopt%3DAbstract Authors: Xu MW, Mu XQ, Xu Y An extractive biocatalytic method of aqueous two-phase system was employed for stereoinversing (R)-1-phenyl-1,2-ethanediol into (S)-1-phenyl-1,2-ethanediol by Candida parapsilosis CCTCC M203011. It was observed that substrate and product inhibitions in microbial stereoinversion through one-pot oxidation and reduction were removed efficiently by extractive biocatalysis in aqueous two-phase system with PEG 4000/phosphate potassium system, and that the substrate concentration was enhanced from 15 to 30 g/L with product optical purity of 99.02% e.e. and yield of 90% after 60 h. Simultaneously, it was observed that change in cell morphology impedes the further enhancement of substrate concentration in this system but can be reversibly changed after stereoinversio... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525885 Sat, 06 Jun 2009 23:00:00 +0100 2525885 http://www.medworm.com/index.php?rid=2525886&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19495799%26dopt%3DAbstract Authors: Omidinia E, Shahbaz Mohamadi H, Dinarvand R, Taherkhani HA This work presents a comprehensive study between the polymer/salt aqueous two-phase systems (ATPS) and chromatography process for downstream processing of recombinant Bacillus badius phenylalanine dehydrogenase (PheDH). First, the partitioning behavior of recombinant PheDH in polyethylene glycol (PEG)/K(2)HPO(4) ATPS was examined. For comparative purpose, a classical chromatographic protocol was performed as well. Investigation of chromatography and ATPS procedures revealed that the ATPS comprising of 9% (w/w) PEG-6000, 16% (w/w) K(2)HPO(4) and 16% (w/w) KCl with pH of 8.0, volume ratio (V ( R )) of 0.25, temperature of 25 degrees C and 40% (w/w) cell lysate ensured the most favorable approach for PheDH downstream proc... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525886 Wed, 03 Jun 2009 23:00:00 +0100 2525886 http://www.medworm.com/index.php?rid=2525887&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19475425%26dopt%3DAbstract Authors: Wolfson A, Atyya A, Dlugy C, Tavor D Glycerol triacetate was successfully used as a green solvent and as the acyl donor in the transesterification of isoamyl alcohol to produce isoamyl acetate using free and immobilized Candida antarctica lipase B. Immobilized lipase was more catalytically active than free lipase and could be easily separated from the reaction mixture by filtration. In addition, it was found that increasing either the reaction temperature or the enzyme to substrate ratio increased the conversion of isoamyl alcohol. Using triacetin as the solvent also enabled the separation of product by simple extraction with petroleum ether and catalyst recycling. PMID: 19475425 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525887 Wed, 27 May 2009 23:00:00 +0100 2525887 http://www.medworm.com/index.php?rid=2525888&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19471972%26dopt%3DAbstract Authors: Domínguez A, Deive FJ, Pastrana L, Rúa ML, Longo MA, Sanroman MA Several studies in laboratory-scale bioreactors are undertaken in order to verify the beneficial effect of thermal spring water in the culture medium of Thermus thermophilus HB27. Two bioreactor configurations, stirred tank and airlift, are investigated to determine the most suitable one to develop a continuous process. Water mineral composition affects the lipolytic enzyme secretion and growth of T. thermophilus HB27 in both bioreactor configurations. Furthermore, the lipolytic activity is strongly enhanced when stirred tank bioreactor is used. Moreover, operation in a stirred tank at an agitation rate of 650 rpm leads to the highest total lipolytic activity (intra- and extracellular enzyme) around 280... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525888 Tue, 26 May 2009 23:00:00 +0100 2525888 http://www.medworm.com/index.php?rid=2525890&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19466460%26dopt%3DAbstract Authors: Chen M, Kim JH, Yang M, Wang Y, Kishida N, Kawamura K, Sudo R Incomplete denitrification and ammonia accumulation were found to cause proliferation of filamentous microorganisms in sequencing batch reactors (SBRs) for swine wastewater treatment. Foaming was observed in response to the accumulation of 115.2 and 12.2 mg/L of nitrate and ammonia, respectively. The mixed liquor suspended solids (MLSS) level in SBRs was decreased to 2,000 mg/L and the suspended solids in the effluent reached 200 mg/L when foaming appeared. However, the use of swine waste as an external carbon source for enhanced biological nitrogen removal was found to effectively control the foaming caused by filamentous microorganisms. Therefore, an optimum strategy for the addition of swine waste was designed us... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525890 Sat, 23 May 2009 23:00:00 +0100 2525890 http://www.medworm.com/index.php?rid=2525889&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19466461%26dopt%3DAbstract This study will be helpful to the future commercial development of the new bacteria-based antiviral ribonuclease fermentation process. PMID: 19466461 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525889 Fri, 22 May 2009 23:00:00 +0100 2525889 http://www.medworm.com/index.php?rid=2525892&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19449037%26dopt%3DAbstract Authors: Peng Z, Fang J, Li J, Liu L, Du G, Chen J, Wang X, Ning J, Cai L The effect of both dissolved oxygen (DO) and pH on L: -isoleucine production by batch culture of Brevibacterium lactofermentum was investigated. A two-stage agitation speed control strategy was developed, and the isoleucine production reached 23.3 g L(-1) in a relative short time (52 h), increased by 11.6% compared to the results obtained in the single agitation speed control process. In order to make sure whether the combination of DO and pH control can boost the production by a mutual effect, different control modes were conducted, based on the data obtained from the two-stage agitation speed control strategy and the analysis of kinetics parameters at different pH values. The results showed that the mode of com... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525892 Fri, 15 May 2009 23:00:00 +0100 2525892 http://www.medworm.com/index.php?rid=2525895&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19430984%26dopt%3DAbstract Authors: Richetti A, Leite SG, Antunes OA, Lerin LA, Dallago RM, Emmerich D, Di Luccio M, Vladimir Oliveira J, Treichel H, de Oliveira D This work reports the optimization of 2-ethylhexyl palmitate production by esterification reaction in a solvent-free system using a commercial lipase as catalyst. For this, a sequential strategy was performed applying three experimental designs. An empirical model was built so as to assess the effects of process variables on the reaction conversion. Afterward, the operating conditions that optimized 2-ethylhexyl palmitate production were determined to be acid to alcohol molar ratio of 1:5.5, 70 degrees C, 150 rpm and 10.5 wt% of enzyme, leading to a reaction conversion as high as 93%. From this point, a kinetic study was carried out evaluating the inf... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525895 Mon, 11 May 2009 23:00:00 +0100 2525895 http://www.medworm.com/index.php?rid=2525894&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19434429%26dopt%3DAbstract Authors: Sun L, Wang C, Ma C, Shi L To probe the effects of renewal regime on the production of polysaccharides, Porphyridium cruentum was cultured semi-continuously in flat plate photobioreactor. Uniform design was used to optimize renewal conditions. Quadratic mathematic models related to productivity, total recovery yield of biomass and polysaccharides were set up to clarify the influence of individual factors and their interactions. According to the mathematic models, the optimal semi-continuous condition for total yield of polysaccharide was NaNO(3) 3.5 g/L, renewal rate 27%, renewal period 2.91 days. The optimal condition for polysaccharide output rate was NaNO(3) 0.5 g/L, renewal rate 5%, renewal period 7 days. With the optimal renewal regime, the maximal total recovery yields o... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525894 Mon, 11 May 2009 23:00:00 +0100 2525894 http://www.medworm.com/index.php?rid=2525896&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19430818%26dopt%3DAbstract Authors: Guo X, Zou X, Sun M Effects of phytohormones including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and 1-naphthalentacetic acid (NAA) on mycelial growth of medicinal mushroom Phellinus linteus were investigated. Under the optimal IAA, IBA and NAA concentration of 1.0, 1.5 and 5.0 mg/l, the maximal mycelial diameter reached 8.6 +/- 0.4, 7.3 +/- 2.6 and 9.0 +/- 1.0 mm, respectively. The mycelial biomass and exopolysaccharide (EPS) production with addition of 5.0 mg/l NAA in a shake flask were 6.24 +/- 0.18 g/l at 168 h and 0.86 +/-0.01 g/l at 192 h, which were enhanced by 15.98 and 56.36% compared to the control, respectively. However, the molecular weight and infrared spectrum of EPS were coincident with the control. Results indicated that NAA at the proper concentr... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525896 Fri, 08 May 2009 23:00:00 +0100 2525896 http://www.medworm.com/index.php?rid=2525897&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19421781%26dopt%3DAbstract Authors: Ghorbani Shahna F, Golbabaei F, Hamedi J, Mahjub H, Darabi HR, Shahtaheri SJ An adapted bioactive foamed emulsion bioreactor for the treatment of benzene vapor has been developed. In this reactor, bed clogging was resolved by bioactive foam as a substitute of packing bed for interfacial contact of liquid to gaseous phase. The pollutant solubility has been increased using biocompatible organic phase in liquid phase and this reactor can be applied for higher inlet benzene concentration. Experimental results showed a benzene elimination capacity (EC) of 220 g m(-3) h(-1) with removal efficiency (RE) of 85% for benzene inlet concentration of 1-1.2 g m(-3) at 15 s gas residence time in bioreactor. Assessment of benzene concentration in liquid phase showed that a significant amount ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525897 Wed, 06 May 2009 23:00:00 +0100 2525897 http://www.medworm.com/index.php?rid=2525898&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19418073%26dopt%3DAbstract Authors: Diamantis V, Aivasidis A A two-stage lab-scale UASB reactor, incorporating a selector-type UASB prior to the main reactor was operated at 37 degrees C with an easily biodegradable food wastewater having a COD of 3,000 mg/L. Varying the hydraulic retention time from 25 to 5 h, the removal of COD by the two-stage process was higher than 95%. Effluent soluble COD was consistently below 75 mg/L and the methane production rate close to theoretical values. The selector UASB removed the majority of the organic load (70-90%) at high organic loading rate, i.e. between 6 and 30 g/(Ld) and the granular sludge developed was characterized by dense microbial colonies, high volatile suspended solids' content and high substrate degradation efficiency. Design of a two-stage process, incorporat... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525898 Tue, 05 May 2009 23:00:00 +0100 2525898 http://www.medworm.com/index.php?rid=2525899&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19415340%26dopt%3DAbstract In this study, the effect of glucose on the activity of branched-chain alpha-keto acid dehydrogenase (BCKDH), which catalyzed the rate-limiting as well as the first irreversible reaction oxidative decarboxylation for branched-chain amino acids degradation, and isovaleryispiramycin biosynthesis was investigated. In the initial glucose concentration experiment, when the residual glucose concentration in the medium declined to 2-4 g/L, the BCKDH activity rose rapidly, and glucose deprivation and the summit of BCKDH activity appeared nearly at the same time. After a delay of about 6 h, the maximal isovalerylspiramycin content was observed. However, the shortage of glucose at the later production phase resulted in the marked decrease in BCKDH activity and isovaleryispiramycin content. In the fe... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525899 Mon, 04 May 2009 23:00:00 +0100 2525899 http://www.medworm.com/index.php?rid=2525900&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19408017%26dopt%3DAbstract Authors: Findrik Z, Presečki AV, Vasić-Rački D A commercial enzyme Dextrozyme was tested as catalyst for maltose hydrolysis at two different temperatures: 40 and 65 degrees C at pH 5.5. Its operational stability was studied in different reactor types: batch, repetitive batch, fed-batch and continuously operated enzyme membrane reactor. Dextrozyme was more active at 65 degrees C, but operational stability decay was observed during the prolonged use in the reactor at this temperature. The reactor efficiencies were compared according to the volumetric productivity, biocatalyst productivity and enzyme consumption. The best reactor type according to the volumetric productivity for maltose hydrolysis is batch and the best reactor type according to the biocatalyst productivi... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525900 Thu, 30 Apr 2009 23:00:00 +0100 2525900 http://www.medworm.com/index.php?rid=2525902&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19404681%26dopt%3DAbstract Authors: Wang SS, Hung YT, Lin YC Here, we examined the change of glutathione (GSH) under different conditions and determined the appropriate kinetic schemes to describe its change of concentration. GSH was continuously oxidized into glutathione disulfide (GSSG) as incubation period increased at the temperatures ranging from 10 to 50 degrees C while certain oxidation by-products were also observed at the later stage of reaction at higher temperatures (70-90 degrees C). The addition of 0.3 mM GSSG in 3 mM GSH solution delayed the onset of GSH oxidation without significantly changing the rate of GSH oxidation. Our results also revealed that GSH oxidation could be facilitated upon the addition of copper (II) ion whereas GSH oxidation was found to be decelerated when EDTA was present. In k... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525902 Wed, 29 Apr 2009 23:00:00 +0100 2525902 http://www.medworm.com/index.php?rid=2525901&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19404682%26dopt%3DAbstract Authors: Tawfik A, El-Gohary F, Temmink H The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor and a moving bed biofilm reactor (MBBR) at a temperature of (22-35 degrees C) was evaluated. The entire treatment system was operated at different hydraulic retention times (HRT's) of 13.3, 10 and 5.0 h. An overall reduction of 80-86% for COD(total); 51-73% for COD(colloidal) and 20-55% for COD(soluble) was found at a total HRT of 5-10 h, respectively. By prolonging the HRT to 13.3 h, the removal efficiencies of COD(total), COD(colloidal) and COD(soluble) increased up to 92, 89 and 80%, respectively. However, the removal efficiency of COD(suspended) in the combined system remained unaffected when increasing the total HRT ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525901 Wed, 29 Apr 2009 23:00:00 +0100 2525901 http://www.medworm.com/index.php?rid=2525906&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19396466%26dopt%3DAbstract Authors: Höpfner T, Bluma A, Rudolph G, Lindner P, Scheper T To observe and control cultivation processes, optical sensors are used increasingly. Important variables for controlling such processes are cell count, cell size distribution and the morphology of cells. Among turbidity measurement methods, imaging procedures are applied for determining these process values. A disadvantage of most previously developed imaging procedures is that they are only available offline, which requires sampling. On the other hand, available imaging inline probes can only deliver a limited number of process values so far. This contribution gives an overview of optical procedures for the inline determination of cell count, cell size distribution and other variables. In particular, by in situ microsco... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525906 Fri, 24 Apr 2009 23:00:00 +0100 2525906 http://www.medworm.com/index.php?rid=2525904&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19396467%26dopt%3DAbstract Authors: Tang YJ, Xu XL, Zhong JJ This work optimized the novel biotransformation process of 4'-demethylepipodophyllotoxin (DMEP) into 4'-demethylepipodophyllic acid (DMEPA) by Bacillus fusiformis CICC 20463. Firstly, the biotransformation process was significantly affected by medium composition. 5 g/L of yeast extract and 10 g/L of peptone were optimal for DMEPA production (i.e., 2.81 +/- 0.21 mg/L), while not beneficial for the cell growth of B. fusiformis. This indicated that the biosynthesis of DMEPA was not corresponded well to the cell growth of B. fusiformis. 40 g/L of sucrose was optimal for DMEPA production (i.e., 2.94 +/- 0.17 mg/L), and 3 g/L of NaCl was the best for DMEPA production (i.e., 4.10 +/- 0.18 mg/L). Secondly, the production of DMEPA was significantly enhanced by ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525904 Fri, 24 Apr 2009 23:00:00 +0100 2525904 http://www.medworm.com/index.php?rid=2525908&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19381690%26dopt%3DAbstract In this study, the increased oxidative stress in A. tumefaciens culture by the supplementation of Ca(2+) is hypothesized to stimulate the increase of specific CoQ(10) content in order to protect the membrane against lipid peroxidation. Our results improve the understanding of Ca(2+) effect on CoQ(10) biosynthesis in A. tumefaciens and should contribute to better industrial production of CoQ(10) by biological processes. PMID: 19381690 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525908 Mon, 20 Apr 2009 23:00:00 +0100 2525908 http://www.medworm.com/index.php?rid=2525910&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19350276%26dopt%3DAbstract Authors: Yakup Arica M, Soydogan H, Bayramoglu G Poly(2-hydroxyethyl methacrylate/ethylenglycol dimethacrylate) beads were grafted with poly(glycidylmethacrylate) via surface initiated atom transfer radical polymerization. Epoxy groups of the grafted polymer were modified in to sulfone groups. Sulfonated beads were characterized by swelling studies, FT-IR, SEM and elemental analysis, and were used for reversible immobilization of lipase. Under given experimental conditions, the beads had an adsorption capacity of 44.7 mg protein/g beads. The adsorbed lipase on beads retained up to 67.4% of its initial activity. The immobilized lipase exhibited improved thermal and storage stabilities over those of the free enzyme. The immobilized lipase could desorb 1.0 M NaCl solution at pH 8.0, and t... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2525910 Mon, 06 Apr 2009 23:00:00 +0100 2525910 http://www.medworm.com/index.php?rid=2300794&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19330358%26dopt%3DAbstract Authors: Zhang BG, Zhou SG, Zhao HZ, Shi CH, Kong LC, Sun JJ, Yang Y, Ni JR Sulfide and vanadium (V) are pollutants commonly found in wastewaters. A novel approach has been investigated using microbial fuel cell (MFC) technologies by employing sulfide and V(V) as electron donor and acceptor, respectively. This results in oxidizing sulfide and deoxidizing V(V) simultaneously. A series of operating parameters as initial concentration, conductivity, pH, external resistance were carefully examined. The results showed that these factors greatly affected the performance of the MFCs. The average removal rates of about 82.2 and 26.1% were achieved within 72 h operation for sulfide and V(V), respectively, which were accompanied by the maximum power density of about 614.1 mW m(-2) under all test... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2300794 Sat, 28 Mar 2009 04:00:00 +0100 2300794 http://www.medworm.com/index.php?rid=2300796&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19326149%26dopt%3DAbstract Authors: Sarkar S, Roy D, Mukherjee J After initial small-scale experiments, a 25.0 l rotating disk bioreactor (RDBR) was investigated for the cultivation of a biofilm-forming salt-tolerant Streptomyces sp. MS1/7, producing an antimicrobial compound. Peak activity attainment rate, PAAR (ratio of the peak antimicrobial activity, PAMA and the time taken to attain PAMA) was determined. Of the three pH values examined (8.0, 9.0 and 10.0) maximum PAAR (1.82 mm/h) was attained at pH 9.0. Three aeration rates (9.0, 6.0 and 3.0 l/min) were considered at three levels (25, 50 and 75%) of disk submergence. At the highest aeration rate and 50% submergence level, PAMA (41 mm), PAAR (1.86 mm/h) and biofilm density (BD, 0.91 g/ml) attained their highest values. At any given aeration rate, PAMA was al... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2300796 Fri, 27 Mar 2009 04:00:00 +0100 2300796 http://www.medworm.com/index.php?rid=2300797&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19308458%26dopt%3DAbstract Authors: Ko J, Su WJ, Chien IL, Chang DM, Chou SH, Zhan RY The rice straw, an agricultural waste from Asians' main provision, was collected as feedstock to convert cellulose into ethanol through the enzymatic hydrolysis and followed by the fermentation process. When the two process steps are performed sequentially, it is referred to as separate hydrolysis and fermentation (SHF). The steps can also be performed simultaneously, i.e., simultaneous saccharification and fermentation (SSF). In this research, the kinetic model parameters of the cellulose saccharification process step using the rice straw as feedstock is obtained from real experimental data of cellulase hydrolysis. Furthermore, this model can be combined with a fermentation model at high glucose and ethanol concentrations to f... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2300797 Tue, 24 Mar 2009 04:00:00 +0100 2300797 http://www.medworm.com/index.php?rid=2275167&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19288138%26dopt%3DAbstract Authors: Gandhimathi R, Seghal Kiran G, Hema TA, Selvin J, Rajeetha Raviji T, Shanmughapriya S A sponge-associated marine actinomycetes Nocardiopsis alba MSA10 was screened and evaluated for the production of biosurfactant. Biosurfactant production was confirmed by conventional screening methods including hemolytic activity, drop collapsing test, oil displacement method, lipase production and emulsification index. The active compound was extracted with three solvents including ethyl acetate, diethyl ether and dichloromethane. The diethyl ether extract was fractionated by TLC and semi-preparative HPLC to isolate the pure compound. In TLC, a single discrete spot was obtained with the R (f) 0.60 and it was extrapolated as valine. Based on the chemical characterization, the active compound... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2275167 Sat, 14 Mar 2009 04:00:00 +0100 2275167 http://www.medworm.com/index.php?rid=2261147&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19280224%26dopt%3DAbstract Authors: Ren LJ, Huang H, Xiao AH, Lian M, Jin LJ, Ji XJ Docosahexaenoic acid (DHA) production in Schizochytrium sp. HX-308 was evaluated by detecting enzymatic activities of ATP:citrate lyase (EC 4.1.3.8), malic enzyme (EC 1.1.1.40) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) at different fermentation stages. According to the analysis, a regulation strategy was proposed which reinforced acetyl-CoA and NADPH supply at a specific fermentation stage. DHA content of total fatty acids was increased from 35 to 60% by the addition of 4 g/L malic acid at the rapid lipid accumulation stage. Total lipid content also showed an apparent increase of 35% and reached 19 g/L when 40 mL ethanol/L was added at the late lipid accumulation stage. PMID: 19280224 [PubMed - as supplied by publis... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2261147 Thu, 12 Mar 2009 04:00:00 +0100 2261147 http://www.medworm.com/index.php?rid=2261155&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19277720%26dopt%3DAbstract Authors: Wu S, Zhang H, Yu X, Chen J The gene dehalA encoding a novel dichloromethane dehalogenases (DehalA), has been cloned from Bacillus circulans WZ-12 CCTCC M 207006. The open reading frame of dehalA, spanning 864 bp, encoded a 288-amino acid protein that showed 85.76% identity to the dichloromethane dehalogenases of Hyphomicrobium sp. GJ21 with several commonly conserved sequences. These sequences could not be found in putative dichloromethane (DCM) dehalogenases reported from other bacteria and fungi. DehalA was expressed in Escherichia coli BL21 (DE3) from a pET28b(+) expression system and purified. The subunit molecular mass of the recombinant DehalA as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was approximately 33 kDa. Subsequent enzymatic charact... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2261155 Wed, 11 Mar 2009 04:00:00 +0100 2261155 http://www.medworm.com/index.php?rid=2261156&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19271244%26dopt%3DAbstract This study describes the production of xylanases from Aspergillus niveus, A. niger, and A. ochraceus under solid-state fermentation using agro-industrial residues as substrates. Enzyme production was improved using a mixture of wheat bran and yeast extract or peptone. When a mixture of corncob and wheat bran was used, xylanase production from A. niger and A. ochraceus increased by 18%. All cultures were incubated at 30 degrees C at 70-80% relative humidity for 96 h. For biobleaching assays, 10 or 35 U of xylanase/g dry cellulose pulp were incubated at pH 5.5 for 1 or 2 h, at 55 degrees C. The delignification efficiency was 20%, the brightness (percentage of ISO) increased two to three points and the viscosity was maintained confirming the absence of cellulolytic activity. These results ind... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2261156 Sat, 07 Mar 2009 05:00:00 +0100 2261156 http://www.medworm.com/index.php?rid=2242623&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19259705%26dopt%3DAbstract Authors: Kiran AU, Jana AK Cell growth and metabolite production greatly depend on the feeding of the nutrients in fed-batch fermentations. A strategy for controlling the glucose feed rate in fed-batch baker's yeast fermentation and a novel controller was studied. The difference between the specific carbon dioxide evolution rate and oxygen uptake rate (Q (c) - Q (o)) was used as controller variable. The controller evaluated was neural network based model predictive controller and optimizer. The performance of the controller was evaluated by the set point tracking. Results showed good performance of the controller. PMID: 19259705 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2242623 Wed, 04 Mar 2009 05:00:00 +0100 2242623 http://www.medworm.com/index.php?rid=2235189&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19253022%26dopt%3DAbstract Authors: Pai TY, Wang SC, Chiang CF, Su HC, Yu LF, Sung PJ, Lin CY, Hu HC Three types of adaptive network-based fuzzy inference system (ANFIS) in which the online monitoring parameters served as the input variable were employed to predict suspended solids (SS(eff)), chemical oxygen demand (COD(eff)), and pH(eff) in the effluent from a biological wastewater treatment plant in industrial park. Artificial neural network (ANN) was also used for comparison. The results indicated that ANFIS statistically outperforms ANN in terms of effluent prediction. When predicting, the minimum mean absolute percentage errors of 2.90, 2.54 and 0.36% for SS(eff), COD(eff) and pH(eff) could be achieved using ANFIS. The maximum values of correlation coefficient for SS(eff), COD(eff), and pH(eff) were 0.97, 0... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2235189 Sun, 01 Mar 2009 05:00:00 +0100 2235189 http://www.medworm.com/index.php?rid=2224194&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19247693%26dopt%3DAbstract Authors: Laobusnanant P, Lee SH, Anceno AJ, Ghosh GC, Kim DJ, Pathak BK, Shipin OV Biological N-removal treatment of piggery wastewater in the upflow anaerobic-anoxic-aerobic floating filter (UA(3)FF) bioreactor based on the concept of nitritation-denitritation was studied along with the changes in internal recycle ratio and dissolved oxygen concentration (DO). Consecutive changes in the recirculation ratio between the anoxic and aerobic reactors has resulted in abundance and composition shifts of N-cycling bacteria as well as other bacterial groups, reflecting different survival strategies across (bio/physico)chemical milieu. The DO concentration was optimized to achieve nitritation in the aerobic reactor and denitritation in the anoxic reactor. Optimal nitritation-denitritation (270 ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2224194 Fri, 27 Feb 2009 05:00:00 +0100 2224194 http://www.medworm.com/index.php?rid=2212407&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19234861%26dopt%3DAbstract Authors: Ramesh S, Rajesh M, Mathivanan N Totally 191 different marine actinomycetes were isolated from 256 different marine samples collected from the Bay of Bengal and its associated Pulicat lake and Pichavaram mangrove, India. Among them, 157 produced caseinase, 113 produced gelatinase and 108 produced both the protease enzymes. An isolate coded as MML1614 was selected for further study as it exhibited high proteolytic activity. The MML1614 was identified as Streptomyces fungicidicus based on polyphasic taxonomical approach including 16S rRNA sequence analysis. The culture conditions were standardized for the growth and protease production in S. fungicidicus MML1614. The protease was isolated from a 6-day-old culture filtrate of S. fungicidicus MML1614 and partially purified up to 4... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2212407 Sun, 22 Feb 2009 05:00:00 +0100 2212407 http://www.medworm.com/index.php?rid=2196044&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19221805%26dopt%3DAbstract Authors: Grieco SH, Lee S, Dunbar WS, Macgillivray RT, Curtis SB Filamentous phage such as M13 and fd consist of a circular, single-stranded DNA molecule surrounded by several different coat proteins. These phages have been used extensively as vectors in phage display where one of the phage coat proteins is genetically engineered to contain a unique peptide surface loop. Through these peptide sequences, a phage collection can be screened for individual phage that binds to different macromolecules or small organic and inorganic molecules. Here, we use computer-controlled bioreactors to produce large quantities of filamentous phage in the bacterial host Escherichia coli. By measuring phage yield and bacterial growth while changing the growth medium, pH and dissolved oxygen concentration,... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2196044 Tue, 17 Feb 2009 05:00:00 +0100 2196044 http://www.medworm.com/index.php?rid=2196043&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19221806%26dopt%3DAbstract Authors: Liu K, Yuan R, Chai Y, Tang D, An H [AuCl(4)](-) was initially deposited by electrochemical reduction on a glassy carbon electrode (GCE) to form porous nanogold layer, then prussian blue (PB) was electrodeposited onto the as-prepared nanogold layer, and then secondary nanogold particles were fabricated again on the PB surface by electrochemical reduction for the immobilization of anti-CEA antibodies. The presence of double-layer porous gold nanoparticles enhanced the immobilized amount of biomolecules, and improved the sensitivity of the immunoassay. PB, as a good redox probe, was facile to electrochemical analysis and measurement. Under optimal conditions, the developed immunoassay exhibited dynamic range from 3.0 to 80.0 ng/mL with a detection limit of 0.9 ng/mL CEA (S/N = 3... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2196043 Tue, 17 Feb 2009 05:00:00 +0100 2196043 http://www.medworm.com/index.php?rid=2184639&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19205747%26dopt%3DAbstract Authors: Liu L, Du G, Chen J, Wang M, Sun J Three different dissolved oxygen (DO) control approaches were proposed to improve hyaluronic acid (HA) production: a three-stage agitation speed control approach, a two-stage DO control approach, and an oxygen vector perfluorodecalin (PFC) applied approach. In the three-stage agitation speed control approach, agitation speed was 200 rpm during 0-8 h, 400 rpm during 8-12 h, and 600 rpm during 12-20 h. In the two-stage DO control strategy, DO was controlled at above 10% during 0-8 h and at 5% during 8-20 h. In the PFC applied approach, PFC (3% v/v) was added at 8 h. HA production reached 5.5 g/L in the three-stage agitation speed control culture model, and 6.3 g/L in two-stage DO control culture model, and 6.6 g/L in the PFC applied culture mod... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2184639 Wed, 11 Feb 2009 05:00:00 +0100 2184639 http://www.medworm.com/index.php?rid=2184638&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19205748%26dopt%3DAbstract Authors: Tae H, Sohng JK, Park K Polyketides have diverse biological activities, including pharmacological functions such as antibiotic, antitumor and agrochemical properties. They are biosynthesized from short carboxylic acid precursors by polyketide synthases (PKSs). As natural polyketide products include many clinically important drugs and the volume of data on polyketides is rapidly increasing, the development of a database system to manage polyketide data is essential. MapsiDB is an integrated web database formulated to contain data on type I polyketides and their PKSs, including domain and module composition and related genome information. Data on polyketides were collected from journals and online resources and processed with analysis programs. Web interfaces were utilized to co... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2184638 Wed, 11 Feb 2009 05:00:00 +0100 2184638 http://www.medworm.com/index.php?rid=2184640&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19205746%26dopt%3DAbstract Authors: Xue J, Wang A, Zhou C, Shen S To enhance penicillin acylase (PA) performance, it was immobilized in mesocellular silica foams (MCFs) depended on macromolecular crowding and applied to catalysis in non-aqueous medium. Ficoll 70, dextran 10,000, dextran 40,000 and bovine serum albumin were co-assembled with PA. It was observed that specific activity of PA assembled in MCFs with dextran 10,000 in 80% cyclohexane (v/v) was 233.2 U/mg, 200% as that of PA assembled in MCFs in 80% cyclohexane and 323.5% as that of free PA in full aqueous medium. As content of alkane increased, activity of PA in MCFs with macromolecules varied slightly. In addition, PA co-immobilized with dextran 10 in MCFs retained 58.2% of its initial activity after heating at 50 degrees C for 4 h, 1.2 times higher ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2184640 Tue, 10 Feb 2009 05:00:00 +0100 2184640 http://www.medworm.com/index.php?rid=2117150&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19152099%26dopt%3DAbstract Authors: Beshay U, Miksch G, Friehs K, Flaschel E PMID: 19152099 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2117150 Wed, 21 Jan 2009 09:28:05 +0100 2117150 http://www.medworm.com/index.php?rid=2090680&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130092%26dopt%3DAbstract Authors: Naidoo K, Ayyachamy M, Permaul K, Singh S Xanthomonas campestris pv phaseoli produced an extracellular endoinulinase (9.24 +/- 0.03 U mL(-1)) in an optimized medium comprising of 3% sucrose and 2.5% tryptone. X. campestris pv. phaseoli was further subjected to ethylmethanesulfonate mutagenesis and the resulting mutant, X. campestris pv. phaseoli KM 24 demonstrated inulinase production of 22.09 +/- 0.03 U mL(-1) after 18 h, which was 2.4-fold higher than that of the wild type. Inulinase production by this mutant was scaled up using sucrose as a carbon source in a 5-L fermenter yielding maximum volumetric (21,865 U L(-1) h(-1)) and specific (119,025 U g(-1) h(-1)) productivities of inulinase after 18 h with an inulinase/invertase ratio of 2.6. A maximum FOS production of 11.9 g ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2090680 Thu, 08 Jan 2009 05:00:00 +0100 2090680 http://www.medworm.com/index.php?rid=2084889&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19125301%26dopt%3DAbstract In this study, using DNA microarray analysis, we performed comprehensive expression profiling of two strains of Saccharomyces cerevisiae, i.e., the ethanol-adapted strain that shows active growth under the ethanol stress condition and its parental strain used as the control. By comparing the expression profiles of these two strains under the ethanol stress condition, we found that the genes related to ribosomal proteins were highly up-regulated in the ethanol-adapted strain. Further, genes related to ATP synthesis in mitochondria were suggested to be important for growth under ethanol stress. We expect that the results will provide a better understanding of ethanol tolerance of yeast. PMID: 19125301 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2084889 Tue, 06 Jan 2009 05:00:00 +0100 2084889 http://www.medworm.com/index.php?rid=2084888&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19125302%26dopt%3DAbstract Authors: de Andrade RR, Rivera EC, Atala DI, Filho RM, Filho FM, Costa AC The accurate description of the kinetics and robust modeling of biotechnological processes can only be achieved by incorporating reliable methodologies to easily update the model when there are changes in operational conditions. The purpose of this work is to provide a systematic approach with which to perform model parameters screening and updating in biotechnological processes. Batch experiments are performed to develop a mechanistic model, considering the effect of temperature on the kinetics, and further experiments (batch fermentations using sugar cane molasses from a different harvest) are used to validate the effectiveness of screening before parameters updating. The reduction in the number of kinetic para... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2084888 Tue, 06 Jan 2009 05:00:00 +0100 2084888 http://www.medworm.com/index.php?rid=2076412&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19115065%26dopt%3DAbstract Authors: Tang YJ, Li Y, Zhong JJ A novel biotransformation process of podophyllotoxin (1) to produce picropodophyllotoxin (2) and podophyllic acid (3) was developed in this work. Eight bacteria which could modify the structure of podophyllotoxin were screened out from the tested fourteen bacteria. The highest conversion of podophyllotoxin (i.e., 70.2 +/- 8.0%) was obtained when Pseudomonas aeruginosa CCTCC AB93066 was used as biocatalyst, so P. aeruginosa was selected as a typical biocatalyst in the following study. Product (2) and (3) were separated through D312 macroporous resin and sephadex LH-20 gel column chromatograph. On the basis of (1)H NMR, (13)C NMR, ESI-MS and Elemental Analysis, product (2) and (3) were identified as picropodophyllotoxin (2) and podophyllic acid (3), respe... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2076412 Tue, 30 Dec 2008 05:00:00 +0100 2076412 http://www.medworm.com/index.php?rid=2076410&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19115067%26dopt%3DAbstract Authors: Li ZL, Wang YH, Chu J, Zhuang YP, Zhang SL Bitespiramycin, a group of 4''-O-acylated spiramycins with 4''-O-isovalerylspiramycins as the major components, is produced by recombinant spiramycin-producing strain Streptomyces spiramyceticus harboring a 4''-O-acyltransferase gene from a carbomycin-producing strain S. mycarofaciens 1748. The effects of leucine feeding on the bitespiramycin fermentation, especially the synthesis of isovalerylspiramycin components, were investigated. The experiment was initially performed in flask culture under the condition of feeding 15.4 mmol/l of leucine at 72 h fermentation, and the culture without leucine feeding was used as control. When 15.4 mmol/l leucine was fed at 72 h, 51.3 +/- 0.33% total isovalerylspiramycins was recorded compared to 40... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2076410 Tue, 30 Dec 2008 05:00:00 +0100 2076410 http://www.medworm.com/index.php?rid=2076411&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19115066%26dopt%3DAbstract In this study, the ammonia removal efficiency for high ammonia-containing wastewaters was evaluated via partial nitrification. A nitrifier biocommunity was first enriched in a fill-and-draw batch reactor with a specific ammonium oxidation rate of 0.1 mg NH(4) (-)-N/mg VSS.h. Partial nitrification was established in a chemostat at a hydraulic retention time (HRT) of 1.15 days, which was equal to the sludge retention time (SRT). The results showed that the critical HRT (SRT) was 1.0 day for the system. A maximum specific ammonium oxidation rate was achieved as 0.280 mg NH(4) (-)-N/mg VSS.h, which is 2.8-fold higher than that obtained in the fill-and-draw reactor, indicating that more adaptive and highly active ammonium oxidizers were enriched in the chemostat. Dynamic modeling of partial nit... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2076411 Thu, 25 Dec 2008 05:00:00 +0100 2076411 http://www.medworm.com/index.php?rid=2062862&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19101734%26dopt%3DAbstract Authors: Li J, Yang Y, Chen H, Jiang F, Ling J, Liu M, Yan F, Xu J The saccharification process of swine manure by conventional and microwave-assisted acid pretreated were investigated using cellulose enzymes, respectively. The optima for microwave-assisted acid pretreated swine manure is achieved when swine manure of 50 g l(-1) of substrate concentration and water amount 40 ml was pretreated by 4% H(2)SO(4) concentration with 445 W microwave powers for 30 min at pretreatment period, and temperature 50 degrees C, enzyme loading 2 mg g(-1) substrate, substrate concentration 5 g l(-1) and initial medium pH 4.8 at enzymes hydrolysis period by microwave-assisted acid pretreated, respectively. The optimal conditions by conventional acid pretreated is obtained when 50 g l(-1) swine manure wa... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2062862 Sat, 20 Dec 2008 05:00:00 +0100 2062862 http://www.medworm.com/index.php?rid=2054413&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19093135%26dopt%3DAbstract Authors: Silva CS, Bovarotti E, Rodrigues MI, Hokka CO, Barboza M The purification of clavulanic acid (CA), which is an important beta-lactam antibiotic produced by submerged cultivation of Streptomyces clavuligerus, was studied through the use of phosphate and polyethylene glycol-based aqueous two-phase systems. The parameters' effect on the yield and purification was evaluated through an experimental design and the preliminary results showed that the polyethylene molecular mass and tie-line length and phase volume ratio exerted the strongest effect on the yield and distribution coefficient in the range tested. In addition, the response surface methodology was used to optimize the distribution coefficient, yield, and purification factor. The optimal conditions of yield and purificatio... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2054413 Thu, 18 Dec 2008 05:00:00 +0100 2054413 http://www.medworm.com/index.php?rid=2042217&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19083018%26dopt%3DAbstract Authors: Zhan X, Healy MG, Li J The aim of this study was to examine nitrogen removal from slaughterhouse wastewater in a laboratory-scale sequencing batch reactor (SBR) operated at low dissolved oxygen (DO) levels under two aeration strategies: intermittent aeration (IA) and continuous aeration (CA). Under the IA strategy, during the aeration periods, the maximum DO was controlled at 10% saturation; under the CA strategy, in the first hour of the react phase, the DO was maintained at 10% saturation, and then it was kept at 2-3% saturation in the remaining react phase. Total nitrogen removals of up to 95 and 91% were achieved under the IA and CA aeration strategies, respectively. It is proposed that in situ measurement of oxygen utilization rates can be used to control the operation of... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2042217 Sun, 14 Dec 2008 05:00:00 +0100 2042217 http://www.medworm.com/index.php?rid=2042218&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19083017%26dopt%3DAbstract Authors: Guerrero-Germán P, Prazeres DM, Guzmán R, Montesinos-Cisneros RM, Tejeda-Mansir A A new bioprocess using mainly membrane operations to obtain purified plasmid DNA from Escherechia coli ferments was developed. The intermediate recovery and purification of the plasmid DNA in cell lysate was conducted using hollow-fiber tangential filtration and tandem anion-exchange membrane chromatography. The purity of the solutions of plasmid DNA obtained during each process stage was investigated. The results show that more than 97% of RNA in the lysate was removed during the process operations and that the plasmid DNA solution purity increased 28-fold. One of the main characteristics of the developed process is to avoid the use of large quantities of precipitating agents such as s... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2042218 Sat, 13 Dec 2008 05:00:00 +0100 2042218 http://www.medworm.com/index.php?rid=2042220&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19082632%26dopt%3DAbstract Authors: Uyar B, Schumacher M, Gebicki J, Modigell M Rhodobacter capsulatus was used for the phototrophic hydrogen production on effluent solution derived from the thermophilic fermentation of Miscanthus hydrolysate by Thermotoga neapolitana. Pretreatments such as centrifugation, dilution, buffer addition, pH adjustment and sterilization were suggested for the effluent before being fed to the photofermentation. Batch-wise experiments showed that R. capsulatus grows and produces hydrogen on the pretreated effluent solution. Moreover, it was found that the hydrogen yield increased from 0.3 to 1.0 L/L(culture) by addition of iron to the effluent solution. PMID: 19082632 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2042220 Fri, 12 Dec 2008 05:00:00 +0100 2042220 http://www.medworm.com/index.php?rid=2042219&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19082843%26dopt%3DAbstract Authors: Wang Q, Fan X, Hu Y, Yuan J, Cui L, Wang P Greater attention has been given to enzymatic processes of textiles as effective alternatives to conventional chemical treatments because of the non-toxic and eco-friendly characteristics of enzymes as well as the increasingly important requirement for reducing pollution in textile production. A new functionalization method for wool fabrics based on immobilization of lysozymes was investigated in this paper. Wool fabric was first activated with glutaraldehyde, and then employed to covalently immobilize lysozymes. Main immobilization parameters were optimized in terms of the activity of immobilized enzyme. A high activity of the immobilized enzyme was obtained when the fabric was activated at 25 degrees C for 6 h in a bath containing w... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2042219 Fri, 12 Dec 2008 05:00:00 +0100 2042219 http://www.medworm.com/index.php?rid=2012129&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19050933%26dopt%3DAbstract Authors: Wellerdiek M, Winterhoff D, Reule W, Brandner J, Oldiges M Representative and valid cytoplasmic concentrations are essential for ensuring the significance of results in the field of metabolome analysis. One of the most crucial points in this respect is the sampling itself. A rapid and sudden stopping of the metabolism on a timescale that is much faster than the conversion rates of investigated metabolites is worthwhile. This can be achieved by applying of cold methanol quenching combined with reproducible, fast, and automated sampling. Unfortunately, quenching the metabolism by a sharp temperature shift leads to what is known as cold shock or the cell-leakage effect. In the present work, we applied a microstructure heat exchanger to analyze the cold shock effect using Coryneba... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2012129 Wed, 03 Dec 2008 05:00:00 +0100 2012129 http://www.medworm.com/index.php?rid=2007709&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19048295%26dopt%3DAbstract This study investigated the contribution of microfiltration to phosphorus removal in the sequencing anoxic/anaerobic membrane bioreactor. The phosphorus content in activated sludge was fractionated by the Schmidt-Thannhauser-Schneider method. The size distribution of phosphorus in the influent was analyzed to estimate the portion of particulate phosphorus rejected physically by the 0.2 mum microfiltration. The result was that along with the high removal of phosphorus (83%) the phosphorus content of activated sludge was measured as 58.66 mgP/gVSS corresponding to 5.87% on dry weight basis. About 9% of total phosphorus was chemically precipitated phosphates while 56% was stored inside the microbial cell by activity of PAOs, and 35% was the sum of minor intracellular compositions and the part... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=2007709 Tue, 02 Dec 2008 05:00:00 +0100 2007709 http://www.medworm.com/index.php?rid=1976897&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19018576%26dopt%3DAbstract Authors: Hidai C, Kitano H, Kokubun S Developing methods that result in targeting of therapeutic molecules in gene therapies to target tissues has importance, as targeting can increase efficacy and decrease off target-side-effects. Work from my laboratory previously showed that the extracellular matrix protein Del1 is organized in the extracellular matrix (ECM) via the Del1 deposition domain (DDD). In this work, a fusion protein with DDD was made to assay the ability to immobilize an enzyme without disrupting enzymatic function. A prostatic cancer-derived cell line LNCap that grows in an androgen-dependent manner was used with 3alpha-hydroxysteroid dehydrogenase (3 alphaHD), which catalyzes dihydrotestosterone (DHT). Plasmids encoding a 3alphaHD:DDD fusion were generated and transfecte... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1976897 Wed, 19 Nov 2008 05:00:00 +0100 1976897 http://www.medworm.com/index.php?rid=1970502&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19015890%26dopt%3DAbstract Authors: Barrios AF, Covo V, Medina LM, Vives-Florez M, Achenie L The discovery of quorum sensing as a mechanism for regulating specific phenotypes in bacteria based on population density has conveyed attention to find molecules capable of interfering quorum sensing networks (QSN) in a process coined quorum quenching. Here, we examined the dynamics of Escherichia coli AI-2 and Pseudomonas aeruginosa QSN exposed to signal degraders or competitors for binding transcriptional regulators. Stability analysis was performed for E. coli and P. aeruginosa finding no multistability in E. coli. However, our model allowed to discern that quenchers influence P. aeruginosa QSN multistability by reducing the interval of the amount of molecules of the extracellular signal that originate several steady... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1970502 Tue, 18 Nov 2008 05:00:00 +0100 1970502 http://www.medworm.com/index.php?rid=1962214&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19005684%26dopt%3DAbstract Authors: Patnaik PR Cognitive (or intelligent) models are often superior to mechanistic models for nonideal bioreactors. Two kinds of cognitive models-cybernetic and neural-were applied recently to fed-batch fermentation by Ralstonia eutropha in a bioreactor with optimum finite dispersion. In the present work, these models have been applied in simulation studies of co-cultures of R. eutropha and Lactobacillus delbrueckii. The results for both cognitive and mechanistic models have been compared with single cultures. Neural models were the most effective for both types of cultures and mechanistic models the least effective. Simulations with co-culture fermentations predicted more PHB than single cultures with all three types of models. Significantly, the predicted enhancements in PHB con... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1962214 Thu, 13 Nov 2008 05:00:00 +0100 1962214 http://www.medworm.com/index.php?rid=1944161&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18989707%26dopt%3DAbstract Authors: Ma L, Yuan R, Chai Y, Chen S, Ling S A novel amperometric hydrogen peroxide biosensor based on the immobilization of hemoglobin on the 2,6-pyridinedicarboxylic acid (PDC) polymer, thionine and nano-Au was successfully fabricated. In this strategy, PDC polymer acted as the matrices to covalently immobilize the thionine, and then hemoglobin was successfully adsorbed on the nano-Au which was electro-deposited on to thionine modified electrode surface. The preparation process of modified electrode was characterized with electrochemical impedance spectroscopy and atomic force microscope. The analytical performance of proposed biosensor toward H(2)O(2) was investigated by cyclic voltammetry and chronoamperometry. The resulted biosensor exhibited fast amperometric response (within 6 ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1944161 Fri, 07 Nov 2008 05:00:00 +0100 1944161 http://www.medworm.com/index.php?rid=1940677&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18987898%26dopt%3DAbstract Authors: Padoley KV, Mudliar SN, Pandey RA Biodegradation of pyridine and alpha-picoline (2-methyl pyridine) by Pseudomonas pseudoalcaligenes-KPN and Nocardia sp. isolated from garden soil were investigated in batch culture experiments. Pyridine and alpha-picoline (50-200 mg L(-1)) were used as sole source of carbon and energy in the investigation. The kinetic constants were evaluated for pyridine and alpha-picoline degradation under optimized nutritional (C, N, P) and environmental (pH, temperature) conditions. The values of bio-kinetic constant obtained in the present investigation indicate the usefulness of both the cultures for treatment of waste containing pyridine and its derivatives. PMID: 18987898 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engine... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1940677 Thu, 06 Nov 2008 05:00:00 +0100 1940677 http://www.medworm.com/index.php?rid=1934984&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18982356%26dopt%3DAbstract Authors: Wang Y, Wu Y, Wang J, Di J A novel disposable biosensor based on direct electron transfer of superoxide dismutase (SOD) was fabricated for the determination of superoxide anion. The biosensor was constructed by electrodeposition of gold nanoparticles (GNPs) on the indium tin oxide (ITO) electrode and then immobilization of SOD in silica sol-gel (SG) network in the presence of cysteine on GNPs/ITO modified electrode surface. The distribution of GNPs on ITO electrode surface was examined by scanning electron microscopy (SEM). The immobilized SOD exhibited high catalytical activity towards superoxide anion. Parameters affecting the performance of the biosensor were also investigated. A linear calibration curve was obtained over the range from 0.08 to 0.64 muM with a correlation c... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1934984 Tue, 04 Nov 2008 05:00:00 +0100 1934984 http://www.medworm.com/index.php?rid=1931196&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18979122%26dopt%3DAbstract Authors: Vu KD, Tyagi RD, Valéro JR, Surampalli RY Different pH control agents (NaOH/H(2)SO(4)-SodSulp, NaOH/CH(3)COOH-SodAcet, NH(4)OH/CH(3)COOH-AmmoAcet and NH(4)OH/H(2)SO(4)-AmmoSulp) were used to investigate their effects on growth, enzyme production (alkaline protease and amylase), and entomotoxicity of Bacillus thuringiensis var. kurstaki HD-1 (Btk) against eastern spruce budworm larvae (Choristoneura fumiferana) using starch industry wastewater (SIW) as a raw material in a 15-l fermentor. AmmoSulp and SodSulp were found to be the best pH control agents for alkaline protease and amylase production, respectively; whereas, the fermented broth obtained by using SodAcet as pH control agents recorded the highest delta-endotoxin production of 1043.0 mg/l and entomotoxicity value 1... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1931196 Sat, 01 Nov 2008 04:00:00 +0100 1931196 http://www.medworm.com/index.php?rid=1925448&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18975015%26dopt%3DAbstract Authors: Ye R, Wang Q, Zhou X Based on the report that the introduction of the biosynthetic precursor of lincomycin, propylproline, could increase the production of lincomycin (Bruce et al. in US Patent 3,753,859, 1973), a mutant strain pro10-20, with resistance of feedback suppression of proline (an analog of propylproline) was thus selected and lincomycin production increased by 10%. The addition of three amino acids (L: -proline, L: -tyrosine, L: -alanine) which are the precursors of propylproline to the fermentation medium was found to enhance the accumulation of L: -dopa through different pathways and was favorable to lincomycin biosynthesis. The production of lincomycin was increased by 23, 10, 13%, respectively, with the addition of 0.05 g L(-1) L: -proline at 60 h, 0.005 g L(-1... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1925448 Fri, 31 Oct 2008 04:00:00 +0100 1925448 http://www.medworm.com/index.php?rid=1903185&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18941796%26dopt%3DAbstract Authors: Zhang L, Yi M The report is on an electrochemical biosensor with remarkably improved sensitivity toward nitrite. In this strategy, positively charged gold nanoparticle (PCNA) is used in combination with multiwall carbon nanotubes (MWCNT) by electrostatic adsorption for fabricating PCNA/MWCNT films. Then hemoglobin (Hb) biocatalyst will easily be attached to the surface of the combination films aforementioned. After that, the Hb/PCNA films are immobilized onto the Hb/PCNA/MWCNT films through layer-by-layer assembly technique. The (Hb/PCNA)(2)/MWNT/GC electrode thus prepared exhibits enhanced electrocatalytic behavior to the reduction of nitrite at -0.10 V versus SCE in 0.05 M H(2)SO(4) solution(.) On condition of the low detecting potential and low pH, interference caused by di... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1903185 Wed, 22 Oct 2008 04:00:00 +0100 1903185 http://www.medworm.com/index.php?rid=1903184&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18941797%26dopt%3DAbstract Authors: Tang YJ, Li HM, Hamel JF Heat-shock protein glycoprotein (gp96) serves as a natural adjuvant for chaperoning antigenic peptide into the immune surveillance pathway. In our laboratory, MethA tumor cell suspension culture process has been recently developed for gp96 production in spinner flask. In this work, effects of dissolved oxygen tension (DOT) and agitation rate on this process were studied in stirred-tank bioreactor. The optimal conditions for gp96 production were different with those for MethA tumor cell growth. MethA tumor cell growth pattern was not much changed by various levels of DOT and agitation rate, while gp96 biosynthesis was more sensitive to DOT and agitation rate. Compared with 50% of DOT, the production and specific productivity of gp96 was increased by 27 ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1903184 Wed, 22 Oct 2008 04:00:00 +0100 1903184 http://www.medworm.com/index.php?rid=1884244&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18923846%26dopt%3DAbstract Authors: Sanchez-Gonzalez Y, Cameleyre X, Molina-Jouve C, Goma G, Alfenore S Dynamic Saccharomyces cerevisiae responses to increasing ethanol stresses were investigated to monitor yeast viability and to optimize bioprocess performance when gradients occurred due to the specific configuration of multi-stage bioreactors with cell recycling or of large volume industrial bioreactors inducing chemical heterogeneities. Twelve fed-batch cultures were carried out with initial ethanol concentrations (P (in)) ranging from 5 g l(-1) to 110 g l(-1) with three different inoculums in different physiological states in terms of viability and quantity of ethanol produced (P (o)). For a given initial cell viability of 50%, the time to reach the maximum growth rate and maximum ethanol production rate was... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1884244 Thu, 16 Oct 2008 04:00:00 +0100 1884244 http://www.medworm.com/index.php?rid=1884243&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18923847%26dopt%3DAbstract Authors: Ling S, Yuan R, Chai Y, Zhang T A novel and convenient immunosensor, based on the electrostatic adsorption characteristics between the positively charged MnO(2) nanoparticles (nano-MnO(2)) and chitosan (CS) composite membrane (nano-MnO(2) + CS) and the negatively charged prussian blue (PB), was prepared for the detection of carcinoembryonic antigen (CEA). Firstly, PB was electro-deposited on the surface of the gold electrode in the constant potential, and then nano-MnO(2) + CS was adsorbed onto PB-modified electrode surface. Subsequently, Gold nanoparticles (nano-Au) were electro-deposited on the nano-MnO(2) + CS-modified electrode to immobilize antibody CEA (anti-CEA). Finally, bovine serum albumin (BSA) was employed to block sites against nonspecific binding. In our study, c... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1884243 Thu, 16 Oct 2008 04:00:00 +0100 1884243 http://www.medworm.com/index.php?rid=1877086&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18853193%26dopt%3DAbstract Authors: Fontes CP, Honorato TL, Rabelo MC, Rodrigues S The use of agriculture excess as substrate in industrial fermentations became an interesting alternative to reduce production costs and to reduce negative environmental impact caused by the disposal of these products. In this work, a kinetic study of mannitol production using cashew apple juice as substrate was studied. The carbohydrates of cashew apple juice are glucose and fructose. Sucrose addition favored the yield of mannitol (85%) at the expense of lower productivity. The best results were obtained applying only cashew apple juice as substrate, containing 50 g L(-1) of total reducing sugar (28 g L(-1) of fructose), yielding 18 g L(-1) of mannitol with 67% of fructose conversion into mannitol and productivity of 1.8 g L(-1) h... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1877086 Tue, 14 Oct 2008 04:00:00 +0100 1877086 http://www.medworm.com/index.php?rid=1877085&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18853194%26dopt%3DAbstract Authors: Temoçin Z, Yiğitoğlu M Having been activated with glutaraldehyde, modified poly(ethylene terephthalate) grafted acrylamide fiber was used for the immobilization of horseradish peroxidase (HRP). Both the free HRP and the immobilized HRP were characterized by determining the activity profile as a function of pH, temperature, thermal stability, effect of organic solvent and storage stability. The optimum pH values of the enzyme activity were found as 8 and 7 for the free HRP and the immobilized HRP respectively. The temperature profile of the free HRP and the immobilized HRP revealed a similar behaviour, although the immobilized HRP exhibited higher relative activity in the range from 50 to 60 degrees C. The immobilized HRP showed higher storage stability than th... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1877085 Tue, 14 Oct 2008 04:00:00 +0100 1877085 http://www.medworm.com/index.php?rid=1877084&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18853195%26dopt%3DAbstract Authors: Junker B, Walker A, Hesse M, Lester M, Vesey D, Christensen J, Burgess B, Connors N A pilot-scale fermentation was developed for an antifungal compound produced by a filamentous fungus. Replacement of galactose with lactose (20-fold cost savings) and a threefold phosphate reduction (15 to 5 g/L) improved productivity 2.5-fold. Addition of supplements-glycine, cobalt chloride, and trace elements-resulted in a further twofold productivity increase, greater process robustness, and less foaming which reduced antifoam addition tenfold (30 to <3 mL/L). Mid-cycle lactose limitations were addressed by raising initial lactose levels (40 to 120 g/L) resulting in another twofold productivity increase. Overall, peak titers increased tenfold from 45 +/- 9 to 448 +/- 39 mg/L, and product... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1877084 Tue, 14 Oct 2008 04:00:00 +0100 1877084 http://www.medworm.com/index.php?rid=1863630&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18841395%26dopt%3DAbstract Authors: Resa P, Elvira L, Montero de Espinosa F, González R, Barcenilla J In this work, fundamental aspects on the ultrasonic velocity monitoring of alcoholic fermentations in synthetic broths (glucose, fructose and sucrose) and natural media (must and wort) are reported. Results are explained in terms of monosaccharide catabolism, polysaccharide hydrolysis, gas production and microorganism growth. The effect of each one of these subprocesses upon ultrasonic velocity has been independently studied. It is shown that, regarding the sound propagation, the simplest systems behave as ternary dissolutions of sugar and ethanol in water, where, in the course of time, substrates are transformed into metabolites according to the fermentation reaction. A semi-empirical approach, based on th... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1863630 Wed, 08 Oct 2008 04:00:00 +0100 1863630 http://www.medworm.com/index.php?rid=1841875&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18825419%26dopt%3DAbstract Authors: Kwon KH, Yeom SH Pseudomonas fluorescence KNU417 was able to degrade up to 700 mg/L of phenol in 65 h but could not degrade 1,000 mg/L of phenol. Phenol degradation rate was noticeably enhanced by pre-adaptation. In addition, the cell was able to degrade up to 1,300 mg/L of phenol by pre-adapting to 700 mg/L of phenol. Repeated adaptations to the same concentration of phenol showed negligible increase in degradation rate. Also, relatively low concentration of phenol (100-700 mg/L) required only one pre-adaptation while high concentration (1,000 mg/L) did two consecutive stepwise pre-adaptations for rapid degradation. Optimal adaptation routes were suggested for the fast phenol degradation. For example, 1,000 mg/L of phenol was degraded as fast as in 48 h when the cell was pre-... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1841875 Tue, 30 Sep 2008 04:00:00 +0100 1841875 http://www.medworm.com/index.php?rid=1838410&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18820951%26dopt%3DAbstract Authors: Treichel H, Mazutti MA, Filho FM, Rodrigues MI The present work aimed to study the viability of the use of sugarcane molasses and corn steep liquor (CSL) in a sequential inulinase production performing an up-stream pretreatment of these agroindustrial residues. A sequential strategy was used applying three central composite rotatable designs (CCRDs) to optimise medium composition, followed by a down-stream step. The medium containing 150 g L(-1) molasses, 50 g L(-1) CSL and 6 g L(-1) yeast extract, yielded a maximum inulinase production of 1,294 +/- 7 U mL(-1), after 72 h of fermentation. A down-stream evaluation was carried out using an expanded bed of Streamline DAE resin (Pharmacia), with and without the up-stream treatment. The results showed that the enzyme could not be r... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1838410 Sat, 27 Sep 2008 04:00:00 +0100 1838410 http://www.medworm.com/index.php?rid=1803608&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18797932%26dopt%3DAbstract Authors: Bernardez LA A rotating disk apparatus was used to investigate the biodegradation of PAHs from non-aqueous phase liquids to solutions of Brij 35. The mass transfer of PAHs in absence of surfactant solution was not large enough to replenish the degraded PAHs. The addition of surfactant resulted in an overall enhancement of biodegradation rates compared to that observed in pure aqueous solution. This is because surfactant partition significant amount of PAHs into the bulk phase, where uptake occurs but the supply of PAHs to the aqueous phase through micellar solubilization at latter period limited biodegradation rates. It was demonstrated the relationship between biodegradation rate and surfactant dose and the mechanisms controlling the mass transfer of PAH from NAPLs. The satis... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1803608 Wed, 17 Sep 2008 04:00:00 +0100 1803608 http://www.medworm.com/index.php?rid=1780439&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18779980%26dopt%3DAbstract Authors: Teng Y, Xu Y, Wang D In order to control suitable mycelium morphology to obtain high lipase productivity by Rhizopus chinensis in submerged fermentation, the effects of fungal morphology on the lipase production by this strain both in shake flask and fermentor were investigated. Different inoculum level and shear stress were used to develop distinctive morphologies. Analyses and investigations both on micromorphology and macromorphology were performed. Study of micromorphology reveals that micromorphologies for dispersed mycelia and aggregated mycelia are different in cell shape, biosynthetic activity. Macromorphology and broth rheology study in fermentor indicate that pellet formation results in low broth viscosity. Under this condition, the oil can disperse sufficiently in b... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1780439 Tue, 09 Sep 2008 04:00:00 +0100 1780439 http://www.medworm.com/index.php?rid=1755798&cid=s_37612_169_f&fid=37612&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18762989%26dopt%3DAbstract Authors: Huang HC, Chen CI, Hung CN, Liu YC The effect of corn oil addition on mycelium growth and polysaccharide productions in the medicinal mushroom Ganoderma lucidum was studied. The results showed that when a level of 2% corn oil was added at the beginning of culture, the biomass and polysaccharide productions reached a maximum of 12.9 and 1.038 g/L, respectively, during 13-day cultivation. The pH variation along with morphology observation in culture provided an indirect inference to the promotional effect of oil addition. Moreover, a curve fitting analysis was carried out to assay the elevated effect on biomass and exopolysaccharide productions in oil added culture. The experimental data of substrates consumption and products formation in culture with oil addition were predicted... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=1755798 Tue, 02 Sep 2008 04:00:00 +0100 1755798