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. Tue, 07 Feb 2012 07:42:47 +0100 http://www.medworm.com/index.php?rid=5621735&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%3D22262086%26dopt%3DAbstract Authors: Zhu SC, Xu ZL, Meng HJ, Zhou J, Chen H Abstract The effect of static magnetic field on polyhydroxyalkanoates (PHAs) syntheses by activated sludge under aerobic dynamic feeding (ADF) was evaluated in sequence batch reactors (SBR), with magnetic field intensities of 42, 21, 11 and 7 millitesla (mT) exposure in the feast, feast-famine and famine periods, respectively, and one control group without magnetic field exposure. Under each level of magnetic field intensity, the effect of magnetic field exposed in the famine period to PHAs syntheses was most significant in comparison with that in the feast or feast-famine period. Maximal hydroxybutyrate (HB) and (HV) yield occurred at 21 and 11 mT, respectively, and the minimal yield occurred at 42 mT during exposure in the famine... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5621735 Fri, 20 Jan 2012 05:00:00 +0100 5621735 http://www.medworm.com/index.php?rid=5621738&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%3D22252419%26dopt%3DAbstract Authors: Kocabay O, Emregul E, Aras S, Emregul KC Abstract A novel, highly sensitive superoxide dismutase biosensor for the direct and simultaneous determination of superoxide radicals was developed by immobilization of superoxide dismutase within carboxymethylcellulose-gelatin on a Pt electrode surface. The parameters affecting the performance of the biosensor were investigated. The response of the CMC-G-SOD biosensor was proportional to O (2) (·-) concentration and the detection limit was 1.25 × 10(-3) mM with a correlation coefficient of 0.9994. The developed biosensor exhibited high analytical performance with wider linear range, high sensitivity and low response time. The biosensor retained 89.8% of its sensitivity after use for 80 ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5621738 Wed, 18 Jan 2012 05:00:00 +0100 5621738 http://www.medworm.com/index.php?rid=5621737&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%3D22252420%26dopt%3DAbstract Authors: Zhao X, Peng F, Du W, Liu C, Liu D Abstract Microbial lipid produced using yeast fermentation with inexpensive carbon sources such as lignocellulosic hydrolyzate can be an alternative feedstock for biodiesel production. Several inhibitors that can be generated during acid hydrolysis of lignocellulose were added solely or together into the culture medium to study their individual inhibitory actions and their synergistic effects on the growth and lipid accumulation of oleaginous yeast Rhodosporidium toruloides. When the inhibitors were present in isolation in the medium, to obtain a high cell biomass accumulation, the concentrations of formic acid, acetic acid, furfural and vanillin should be lower than 2, 5, 0.5 and 1.5 g/L, respectively. However, the synergistic effects o... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5621737 Wed, 18 Jan 2012 05:00:00 +0100 5621737 http://www.medworm.com/index.php?rid=5621736&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%3D22252421%26dopt%3DAbstract In this study, biological sulfide removal from natural gas in a continuous bioreactor is investigated for estimation of the optimal operational parameters. According to the carried out reactions, sulfide can be converted to elemental sulfur, sulfate, thiosulfate, and polysulfide, of which elemental sulfur is the desired product. A mathematical model is developed and was used for investigation of the effect of various parameters on elemental sulfur selectivity. The results of the simulation show that elemental sulfur selectivity is a function of dissolved oxygen, sulfide load, pH, and concentration of bacteria. Optimal parameter values are calculated for maximum elemental sulfur selectivity by using genetic algorithm as an adaptive heuristic search. In the optimal conditions, 87.76% of sulf... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5621736 Wed, 18 Jan 2012 05:00:00 +0100 5621736 http://www.medworm.com/index.php?rid=5621739&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%3D22249784%26dopt%3DAbstract Authors: Cheng YL, Wu AC, Wang PY, Tsai SW Abstract A new approach to the lipase-catalyzed hydrolytic resolution of (R,S)-azolyl carbamates for obtaining chiral azolyl carbamates and alcohol is described. With (R,S)-1-phenylethyl azolyl carbamates as the model substrates, the best reaction condition of using (R,S)-1-phenylethyl 4-bromopyrazole carbamate (1) as the substrate in water-saturated diisopropyl ether at 45 °C is selected. The kinetic constants, and hence enantiomeric ratio of 124, are then estimated from the kinetic analysis by considering the alcohol inhibition effect, with which theoretical time-course conversions for both enantiomers are numerically solved and agree with the experimental data. The thermodynamic parameters -ΔΔH and -ΔΔS satisfying a linear enthalp... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5621739 Tue, 17 Jan 2012 05:00:00 +0100 5621739 http://www.medworm.com/index.php?rid=5600507&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%3D22246535%26dopt%3DAbstract Authors: Whelan J, Murphy E, Pearson A, Jeffers P, Kieran P, McDonnell S, Glennon B Abstract The potential of focussed beam reflectance measurement (FBRM) as a tool to monitor changes in biomass concentration was investigated in a number of biological systems. The measurement technique was applied to two morphologically dissimilar plant cell suspension cultures, Morinda citrifolia and Centaurea calcitrapa, to a filamentous bacteria, Streptomyces natalensis, to high density cultures of Escherichia coli and to a murine Sp2/0 hybridoma suspension cell line, 3-2.19. In all cases, the biomass concentration proved to be correlated with total FBRM counts. The nature of the correlation varied between systems and was influenced by the concentration, nature, size and morphology of the partic... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5600507 Sun, 15 Jan 2012 05:00:00 +0100 5600507 http://www.medworm.com/index.php?rid=5600509&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%3D22237683%26dopt%3DAbstract Authors: Deive FJ, Alvarez MS, Morán P, Sanromán MA, Longo MA Abstract A lipolytic enzyme-producing thermophilic microorganism, recently isolated from a hot spring in Galicia (North Western Spain), has been investigated. First, the strain was genetically identified and tentatively named Bacillus thermoamylovorans CH6B. It produced significant levels (around 450 U/L) of extracellular lipolytic activity in shake flask cultures, and the most suitable conditions for this biological process were found at temperatures between 50 and 55 °C, and an initial pH value around 7.0. Next, a preliminary scaling up of the process was carried out in a 5-L stirred tank bioreactor, and it was concluded that operation at agitation and aeration rates of 300 rpm and 0.33 vvm, respectively, were a... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5600509 Thu, 12 Jan 2012 05:00:00 +0100 5600509 http://www.medworm.com/index.php?rid=5600508&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%3D22237684%26dopt%3DAbstract This study signifies the utility of Spilanthes suspension cultures for biosynthesis and constant production of spilanthol, throughout the year. The results of present study are useful for further scale-up process. PMID: 22237684 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5600508 Thu, 12 Jan 2012 05:00:00 +0100 5600508 http://www.medworm.com/index.php?rid=5578213&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%3D22228367%26dopt%3DAbstract Authors: Ramani K, Sekaran G Abstract The study demonstrates the production of lipase (LIP) from Pseudomonas gessardii using blood tissue lipid as the substrate for the hydrolysis of blood cholesterol and triglycerides. The lipase was purified with the specific activity of 828 U/mg protein and the molecular weight of 56 kDa. The maximum lipase activity was observed at the pH 7.0 and the temperature 37 °C. The amino acid composition of purified lipase was determined by HPLC. The mesoporous activated carbon (MAC) was used for the immobilization of lipase for the repeated use of the enzyme catalyst. The K (m) value of immobilized lipase (MAC-LIP) and the free lipase (LIP) was 0.182 and 1.96 mM, respectively. The V (max) value of MAC-LIP and LIP was 1.33 and 1.... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5578213 Tue, 10 Jan 2012 05:00:00 +0100 5578213 http://www.medworm.com/index.php?rid=5578214&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%3D22228298%26dopt%3DAbstract Authors: Liang ZX, Li L, Li S, Cai YH, Yang ST, Wang JF Abstract Propionic acid is an important chemical that is widely used in the food and chemical industries. To enhance propionic acid production, a fibrous-bed bioreactor (FBB) was constructed and Jerusalem artichoke hydrolysate was used as a low-cost renewable feedstock for immobilized fermentation. Comparison of the kinetics of immobilized-cell fermentation using the FBB with those of fed-batch free-cell fermentation showed that immobilized-cell fermentation gave a much higher propionic acid concentration (68.5 vs. 40.6 g/L), propionic acid yield (0.434 vs. 0.379 g/g) and propionic acid productivity (1.55 vs. 0.190 g/L/h) at pH 6.5. Furthermore, repeated batch fermentation, carried out to evaluate the stability of the FBB s... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5578214 Sat, 07 Jan 2012 05:00:00 +0100 5578214 http://www.medworm.com/index.php?rid=5578216&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%3D22218992%26dopt%3DAbstract Authors: Sousa M, Melo VM, Rodrigues S, Sant'ana HB, Gonçalves LR Abstract Glycerol, a co-product of biodiesel production, was evaluated as carbon source for biosurfactant production. For this reason, seven non-pathogenic biosurfactant-producing Bacillus strains, isolated from the tank of chlorination at the Wastewater Treatment Plant at Federal University of Ceara, were screened. The production of biosurfactant was verified by determining the surface tension value, as well as the emulsifying capacity of the free-cell broth against soy oil, kerosene and N-hexadecane. Best results were achieved when using LAMI005 and LAMI009 strains, whose biosurfactant reduced the surface tension of the broth to 28.8 ± 0.0 and 27.1 ± 0.1 mN m(-1), respectively. Additionally, at 72 h of cu... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5578216 Thu, 05 Jan 2012 05:00:00 +0100 5578216 http://www.medworm.com/index.php?rid=5578215&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%3D22218993%26dopt%3DAbstract Authors: Khan AA, Gaur RZ, Lew B, Diamantis V, Mehrotra I, Kazmi AA Abstract A simple, efficient and cost-effective method for municipal wastewater treatment is examined in this paper. The municipal wastewater is treated using an upflow anaerobic sludge bed (UASB) reactor followed by flash aeration (FA) as the post-treatment, without implementing aerobic biological processes. The UASB reactor was operated without recycle, at hydraulic retention time (HRT) of 8 h and achieved consistent removal of BOD, COD and TSS of 60-70% for more than 12 months. The effect of FA on UASB effluent post-treatment was studied at different HRT (15, 30 and 60 min) and dissolved oxygen (DO) concentrations (low DO = 1-2 mg/L and high DO = 5-6 mg/L). The optimum conditions for BOD, COD and sulfid... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5578215 Thu, 05 Jan 2012 05:00:00 +0100 5578215 http://www.medworm.com/index.php?rid=5578217&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%3D22212349%26dopt%3DAbstract Authors: Rosi PE, Miscoria SA, Bernik DL, Martín Negri R Abstract A specially designed electronic nose was coupled to an air-lift bioreactor in order to perform on-line monitoring of released vapors. The sensor array was placed at the top of the bioreactor sensing the headspace in equilibrium with the evolving liquor at any time without the need of aspiration and pumping of gases into a separated sensor chamber. The device was applied to follow the off-gas of a bioreactor with Acidithiobacillus thiooxidans grown on beds of elemental sulfur under aerobic conditions. Evolution was monitored by acid titration, pH and optical density measurements. The electronic nose was capable to differentiate each day of reactor evolution since inoculation within periods marked off culture medium r... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5578217 Tue, 03 Jan 2012 05:00:00 +0100 5578217 http://www.medworm.com/index.php?rid=5578218&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%3D22207186%26dopt%3DAbstract Authors: Al-Shannag M Abstract The current study investigated numerically the two-dimensional (2D) incompressible flow and mass transfer in a lid-driven cavity of annular geometry accompanied by enzymatic surface-reactions. The lid-driven bioreactor had a square cross-section of (H × H) and a radius of curvature of r (c). This flow configuration gives the opportunity to evaluate effects of curvature as well as operational parameters on the bioreactor performance. For forced-convection, conservation equations were solved numerically, using fourth-order finite volume schemes, to identify the 2D flow structure and concentration distribution of substrate within the bioreactor. For pure diffusion, analytical solution was obtained. Substrate transfer rates were presented in ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5578218 Fri, 30 Dec 2011 05:00:00 +0100 5578218 http://www.medworm.com/index.php?rid=5550022&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%3D22203267%26dopt%3DAbstract Authors: Deng Z, Sun S, Gang DD Abstract Stormwater runoff is one of the most common non-point sources of water pollution to rivers, lakes, estuaries, and coastal beaches. While most pollutants and nutrients, including nitrate-nitrogen, in stormwater are discharged into receiving waters during the first-flush period, no existing best management practices (BMPs) are specifically designed to capture and treat the first-flush portion of urban stormwater runoff. This paper presents a novel BMP device for highway and urban stormwater treatment with emphasis on numerical modeling of the new BMP, called first-flush reactor (FFR). A new model, called VART-DN model, for simulation of denitrification process in the designed first-flush reactor was developed using the variable residence time ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5550022 Wed, 28 Dec 2011 05:00:00 +0100 5550022 http://www.medworm.com/index.php?rid=5534750&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%3D22179413%26dopt%3DAbstract Authors: Shi Y, Chai L, Yang Z, Jing Q, Chen R, Chen Y Abstract A hexavalent chromium [Cr(VI)] reducing bacterial strain was isolated from chromium-containing slag. It was identified as Pannonibacter phragmitetus based on physiological, biochemical characteristics and 16S rRNA gene sequence analysis. This bacterium displayed great Cr(VI) reduction capability. The Cr(VI) could be completely removed in 24 h under anaerobic condition when the initial concentration was 1,917 mg L(-1), with the maximum reduction rate of 562.8 mg L(-1) h(-1). The Cr(VI) reduction rate increased with the increase of Cr(VI) concentration. P. phragmitetus was able to use many carbon sources such as lactose, fructose, glucose, pyruvate, citrate, formate, lactate, NADPH and NADH as electron donors, amon... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534750 Sun, 18 Dec 2011 05:00:00 +0100 5534750 http://www.medworm.com/index.php?rid=5534751&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%3D22170303%26dopt%3DAbstract Authors: Rosales E, Pérez-Paz A, Vázquez X, Pazos M, Sanromán MA Abstract In the present work, several samples from lab waste containers polluted with polycyclic aromatic hydrocarbons (PAHs) and heavy metals were investigated as potential sources of PAH-degrading microorganisms. After isolating, two fungal strains were selected as the best degrading microorganisms. Genetic identification by sequencing was carried out and they were identified as Trichoderma longibrachiatum and Byssochlamys spectabilis. Their degradation ability was determined in liquid cultures with 100 μM of benzo[a]anthracene. T. longibrachiatum cultures showed highest degradation values (around 97%) after 9 days, furthermore in a second batch the time was reduced to 6 days. To analyse the viability of indu... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534751 Thu, 15 Dec 2011 05:00:00 +0100 5534751 http://www.medworm.com/index.php?rid=5534753&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%3D22167463%26dopt%3DAbstract Authors: Sbarciog M, Loccufier M, Vande Wouwer A Abstract This paper presents an optimizing start-up strategy for a bio-methanator. The goal of the control strategy is to maximize the outflow rate of methane in anaerobic digestion processes, which can be described by a two-population model. The methodology relies on a thorough analysis of the system dynamics and involves the solution of two optimization problems: steady-state optimization for determining the optimal operating point and transient optimization. The latter is a classical optimal control problem, which can be solved using the maximum principle of Pontryagin. The proposed control law is of the bang-bang type. The process is driven from an initial state to a small neighborhood of the optimal steady state by switching the... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534753 Wed, 14 Dec 2011 05:00:00 +0100 5534753 http://www.medworm.com/index.php?rid=5534752&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%3D22167464%26dopt%3DAbstract Authors: Soundarrajan C, Sankari A, Dhandapani P, Maruthamuthu S, Ravichandran S, Sozhan G, Palaniswamy N Abstract The leaf extract of Ocimum sanctum was used as a reducing agent for the synthesis of platinum nanoparticles from an aqueous chloroplatinic acid (H(2)PtCl(6)·6H(2)O). A greater conversion of platinum ions to nanoparticles was achieved by employing a tulsi leaf broth with a reaction temperature of 100 °C. Energy-dispersive absorption X-ray spectroscopy confirmed the platinum particles as major constituent in the reduction process. It is evident from scanning electron microscopy that the reduced platinum particles were found as aggregates with irregular shape. Fourier-transform infrared spectroscopy revealed that the compounds such as ascorbic acid, gallic acid, terpen... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534752 Wed, 14 Dec 2011 05:00:00 +0100 5534752 http://www.medworm.com/index.php?rid=5534755&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%3D22160154%26dopt%3DAbstract Authors: Park DH, Lee SY PMID: 22160154 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534755 Sun, 11 Dec 2011 05:00:00 +0100 5534755 http://www.medworm.com/index.php?rid=5534754&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%3D22160186%26dopt%3DAbstract Authors: Bule MV, Singhal RS Abstract Ubiquinone (Coenzyme Q10, CoQ10), a yellow-to-orange-colored lipophilic substance having nutraceutical value, was extracted from dried biomass of Pseudomonas diminuta using supercritical carbon dioxide (SC-CO(2)). The effect of different operational parameters (temperature, pressure, and extraction time) and addition of co-solvent on SC-CO(2) extraction of CoQ10 was studied in detail. The solubility parameter of CoQ10, CO(2), and CO(2) with ethanol and methanol as co-solvents was calculated and validated with experimental results. Theoretically, ethanol and methanol had significant effect as co-solvent, and the difference between the two was only marginal. A maximum recovery of 22.33% was obtained using pure SC-CO(2) at 40 °C, 150 bar, and r... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534754 Thu, 08 Dec 2011 05:00:00 +0100 5534754 http://www.medworm.com/index.php?rid=5534756&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%3D22147105%26dopt%3DAbstract Authors: Al-Shorgani NK, Kalil MS, Yusoff WM Abstract Rice bran (RB) and de-oiled rice bran (DRB) have been treated and used as the carbon source in acetone-butanol-ethanol (ABE) production using Clostridium saccharoperbutylacetonicum N1-4. The results showed that pretreated DRB produced more ABE than pretreated RB. Dilute sulfuric acid was the most suitable treatment method among the various pretreatment methods that were applied. The highest ABE obtained was 12.13 g/L, including 7.72 g/L of biobutanol, from sulfuric acid. The enzymatic hydrolysate of DRB (ESADRB), when treated with XAD-4 resin, resulted in an ABE productivity and yield of 0.1 g/L h and 0.44 g/g, respectively. The results also showed that the choice of pretreatment method for RB and DRB is an important factor... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534756 Wed, 07 Dec 2011 05:00:00 +0100 5534756 http://www.medworm.com/index.php?rid=5534757&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%3D22139531%26dopt%3DAbstract In this study, two dilute pretreatments of 0.5% H(2)SO(4) and 1.0% NaOH were performed on Jatropha shells with subsequent simultaneous saccharification and fermentation (SSF) of the pretreated water-insoluble solids (WIS) to evaluate the effect of inhibitors in the pretreatment slurry. A cellulase loading of 15 FPU/g WIS, complimented with an excess of cellobiase (19.25 U/g), was used for SSF of either the washed WIS or the original slurry to determine the effect of inhibitors. Ethanol and glucose were monitored during SSF of 20 g of pretreated biomass. The unwashed slurry showed to have a positive effect on SSF efficiency for the NaOH-pretreated biomass. Maximum efficiencies of glucan conversion to ethanol in the WIS were 40.43% and 41.03% for the H(2)SO(4)- and NaOH-pretreated biomasses... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534757 Sun, 04 Dec 2011 05:00:00 +0100 5534757 http://www.medworm.com/index.php?rid=5534758&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%3D22139481%26dopt%3DAbstract Authors: Zou X, Xia JY, Chu J, Zhuang YP, Zhang SL Abstract The physiological response of erythromycin fermentation scale-up from 50 L to 132 m(3) scale was investigated. A relatively high oxygen uptake rate (OUR) in early phase of fermentation was beneficial for erythromycin biosynthesis. Correspondingly, the maximal consistency coefficient (K) reflecting non-Newtonian fluid characteristics in 50 L and 132 m(3) fermenter also appeared in same phase. Fluid dynamics in different scale bioreactor was further investigated by real-time computational fluid dynamics modeling. The results of simulation showed that the impeller combination in 50 L fermenter could provide more modest flow field environment compared with that in 132 m(3) fermenter. The decrease of oxygen transfer rate ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534758 Sat, 03 Dec 2011 05:00:00 +0100 5534758 http://www.medworm.com/index.php?rid=5534759&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%3D22130566%26dopt%3DAbstract Authors: Kundu P, Pramanik A, Mitra S, Choudhury JD, Mukherjee J, Mukherjee S Abstract Heterotrophic carbon utilizing microbes were acclimatized in the laboratory by inoculating sludge collected from the waste discharge pond of a small-scale rural abattoir in India in a nutrient solution intermittently fed with glucose and ammonium chloride. Cultures of 10 well-developed isolates were selected and grown in a basal medium containing glucose and ammonium chloride. Culture supernatants were periodically analyzed for ammonium nitrogen (NH(4) (+)-N) and chemical oxygen demand (COD). Polyphasic taxonomic study of the most active nitrifier (S18) was done. Half saturation concentration (K (s)), maximum rate of substrate utilization (k), yield coefficient (Y) and de... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534759 Thu, 01 Dec 2011 05:00:00 +0100 5534759 http://www.medworm.com/index.php?rid=5534760&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%3D22124780%26dopt%3DAbstract In this study, it was attempted for the first time to develop the SCAR marker for detecting the molecular phenotypes among Miscanthus species. Randomly amplified polymorphic DNA technique was applied for this study and one fragment which is unique to M. sacchariflorus was identified and then sequenced. Based on the specific fragment, one SCAR primer pair designated as MS62-5F and MS62-5R was designed to amplify an approximately 1,000 bp DNA fragment within the sequenced region. Diagnostic PCR was performed using the primer pair. Using this SCAR marker, approximately 1,000 bp and 1,200 bp DNA fragments were obtained in M. sacchariflorus and M. sinensis, respectively. Moreover, M. x giganteus was obtained both bands at the same time. The result showed that this SCAR marker can clearly disti... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534760 Tue, 29 Nov 2011 05:00:00 +0100 5534760 http://www.medworm.com/index.php?rid=5534761&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%3D22116528%26dopt%3DAbstract This study showed that the synergistic and depressing effects of co-cultivation of P. radiata, D. squalens and C. subvermispora on LMEs were species specific. PMID: 22116528 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534761 Fri, 25 Nov 2011 05:00:00 +0100 5534761 http://www.medworm.com/index.php?rid=5534762&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%3D22113359%26dopt%3DAbstract Authors: Jiang Z, Wu M, Liu G, Liang A Abstract In pH 8.9 Tris-HCl buffer solutions, alkaline phosphatase (ALP) catalyzed the hydrolysis of ascorbic acid 2-phosphate (AAP) substrate to form ascorbic acid. Then H(3)PO(4) was added to stop the enzymatic reaction and HAuCl(4) was used to react with ascorbic acid to generate gold nanoparticles that exhibited a resonance scattering (RS) peak at 600 nm. Under the selected conditions, when the activity of ALP increased, the formed ascorbic acid and gold nanoparticles also increased. Thus, the RS intensity at 600 nm enhanced linearly. The linear range was 0.06-22 U/L, with a detection limit of 0.03 U/L. The ALP in serum was analyzed, and the results were in agreement with those of the fluorescence method. PMID: 22113359 [PubMed - a... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534762 Thu, 24 Nov 2011 05:00:00 +0100 5534762 http://www.medworm.com/index.php?rid=5534763&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%3D22108897%26dopt%3DAbstract This study demonstrated the potential of expression of the antifungal peptide in yeast for the control of postharvest blue mold infections on pome fruits. PMID: 22108897 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534763 Wed, 23 Nov 2011 05:00:00 +0100 5534763 http://www.medworm.com/index.php?rid=5534764&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%3D22105931%26dopt%3DAbstract Authors: Liu XJ, Liu RS, Li HM, Tang YJ Abstract The dissolved oxygen tension of 20% of air saturation, pH-shift from 4.0 to 5.5 on day 3, and a moderate shear stress (calculated as an impeller tip speed, [Formula: see text]) were identified to be the key factors in scaling-up the mated fermentation of Blakeslea trispora NRRL 2895 (+) and 2896 (-) for lycopene production from a shake flask to a stirred-tank fermenter. The maximal lycopene production of 183.3 mg/L was obtained in 7.5-L stirred-tank fermenter, and then the mated fermentation process was successfully step-wise scaled-up from 7.5- to 200-L stirred-tank fermenter. The comparability of the fermentation process was well controlled and the lycopene production was maintained during the process scale-up. Furthermore, with t... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5534764 Tue, 22 Nov 2011 05:00:00 +0100 5534764 http://www.medworm.com/index.php?rid=5420283&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%3D22086290%26dopt%3DAbstract Authors: Kang KE, Jeong GT, Park DH Abstract Pretreatment method for rapeseed straw by sodium hydroxide was investigated for production of bioethanol and biobutanol. Various pretreatment parameters, including temperature, time, and sodium hydroxide concentration were optimized using a statistical method which is a central composite design of response surface methodology. In the case of sodium hydroxide pretreatment, optimal pretreatment conditions were found to be 7.9% sodium hydroxide concentration, 5.5 h of reaction time, and 68.4 °C of reaction temperature. The maximum glucose yield which can be recovered by enzymatic hydrolysis at the optimum conditions was 95.7% and the experimental result was 94.0 ± 4.8%. This experimental result was in agreement with the model predicti... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5420283 Wed, 16 Nov 2011 05:00:00 +0100 5420283 http://www.medworm.com/index.php?rid=5420284&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%3D22081050%26dopt%3DAbstract Authors: Liu D, Chen Y, Li A, Xie J, Xiong J, Bai J, Chen X, Niu H, Zhou T, Ying H Abstract A whole-cell biocatalytic process for uridine 5'-monophosphate (UMP) production from orotic acid by Saccharomyces cerevisiae was developed. To rationally redistribute the metabolic flux between glycolysis and pentose phosphate pathway, statistical methods were employed first to find out the critical factors in the process. NaH(2)PO(4), MgCl(2) and pH were found to be the important factors affecting UMP production significantly. The levels of these three factors required for the maximum production of UMP were determined: NaH(2)PO(4) 22.1 g/L; MgCl(2) 2.55 g/L; pH 8.15. An enhancement of UMP production from 6.12 to 8.13 g/L was achieved. A significant redistribution of metabolic fluxes was ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5420284 Tue, 15 Nov 2011 05:00:00 +0100 5420284 http://www.medworm.com/index.php?rid=5420285&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%3D22080938%26dopt%3DAbstract Authors: Sung IK, Han NS, Kim BS Abstract Cell retention culture of lactic acid bacterium Leuconostoc citreum was carried out in a fermentor equipped with an internal ceramic filtration system to co-produce biomass and metabolites. The filtration system was composed of porous ceramic filter module with pore size of 0.1 μm and total surface area of 330 cm(2). High cell density cultivation of L. citreum was achieved within the fermentor, while extracellular metabolites such as mannitol and D: -lactic acid were produced through the filter with high productivities. In batch culture of L. citreum using a medium containing 50 g/L of glucose and 100 g/L of fructose, the maximum optical density (OD) monitored at 660 nm was 13 with 65 g/L of mannitol and 38 g/L of lactic acid. In ce... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5420285 Sun, 13 Nov 2011 05:00:00 +0100 5420285 http://www.medworm.com/index.php?rid=5420286&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%3D22076402%26dopt%3DAbstract Authors: Monroy I, Villez K, Graells M, Venkatasubramanian V Abstract This paper investigates fault diagnosis in batch processes and presents a comparative study of feature extraction and classification techniques applied to a specific biotechnological case study: the fermentation process model by Birol et al. (Comput Chem Eng 26:1553-1565, 2002), which is a benchmark for advanced batch processes monitoring, diagnosis and control. Fault diagnosis is achieved using four approaches on four different process scenarios based on the different levels of noise so as to evaluate their effects on the performance. Each approach combines a feature extraction method, either multi-way principal component analysis (MPCA) or multi-way independent component analysis (MICA), with a classification m... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5420286 Fri, 11 Nov 2011 05:00:00 +0100 5420286 http://www.medworm.com/index.php?rid=5420287&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%3D22057949%26dopt%3DAbstract Authors: Liu J, Xu Y, Nie Y, Zhao GA Abstract Urea in alcoholic beverages is a precursor of ethyl carbamate, which is carcinogenic. Acid urease (EC 3.5.1.5) is regarded as a good approach to scavenge the urea. The acid urease of Enterobacter sp. R-SYB082, with lower optimum pH than the widely used commercial acid urease, exhibited a urea removal rate of 66.5% in Chinese rice wine, which was higher than that of the commercial acid urease (58.9%). The production of the acid urease was optimized from 1,100 to 2,504 U L(-1) by an approach which includes the optimization of initial glucose concentration, the elevation of anaerobic level of the reactor by charging CO(2) and in vitro natural activation of the target enzyme by simple cold storage (4°C). These would open up the possibili... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5420287 Sun, 06 Nov 2011 04:00:00 +0100 5420287 http://www.medworm.com/index.php?rid=5379725&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%3D22052232%26dopt%3DAbstract In this study, the productivity of the extracellular enzymes in the strain was evaluated by using empty palm fruit bunch fiber (EPFBF), a lignocellulosic biomass, as a substrate for solid-state bioconversion. The highest cellulase activities were observed after 6 days of fermentation at pH 6.0 and 30 °C. The enzymes were secreted as cellulosomes for the degradation of EPFBF as a sole carbon source. Focused ion beam analysis showed that P. verruculosum COKE4E produced cellulolytic enzymes that were able to effectively biodegrade EPFBF during solid-state fermentation. In this process, 6.5 U of CMCase, 6.8 U of Avicelase, and 8.8 U of xylanase per gram of dry solid EPFBF were produced. These results demonstrate that EPFBF may be a potential raw material in solid-state fermentation for t... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5379725 Fri, 04 Nov 2011 04:00:00 +0100 5379725 http://www.medworm.com/index.php?rid=5379724&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%3D22052233%26dopt%3DAbstract Authors: Zeng Y, Ji XJ, Chang SM, Nie ZK, Huang H Abstract To improve the arachidonic acid (ARA) accumulation in Mortierella alpina, a mixed B-group vitamin addition strategy was developed. The ARA titer reached up to 10.0 g/L, 1.7-fold of the control. At the same time, the highest specific activities of key enzymes involved in ARA biosynthesis, including malic enzyme, glucose-6-phosphate dehydrogenase and ATP: citrate lyase, were 63.3, 38.6 and 53.7% higher than the control, respectively. The possible vitamin triggered improved ARA accumulation mechanism was thus elucidated that B-group vitamins could function as the cofactors of the key enzymes involved in ARA biosynthesis, or precursors for the formation of NADPH and acetyl-CoA which were crucial for ARA synthesis, and strength... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5379724 Fri, 04 Nov 2011 04:00:00 +0100 5379724 http://www.medworm.com/index.php?rid=5379726&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%3D22042557%26dopt%3DAbstract Chloroform aerobic cometabolism by butane-growing Rhodococcus aetherovorans BCP1 in continuous-flow biofilm reactors. Bioprocess Biosyst Eng. 2011 Nov 1; Authors: Ciavarelli R, Cappelletti M, Fedi S, Pinelli D, Frascari D Abstract This work focuses on chloroform (CF) cometabolism by a butane-grown aerobic pure culture (Rhodococcus aetherovorans BCP1) in continuous-flow biofilm reactors. The goals were to obtain preliminary information on the feasibility of CF biodegradation by BCP1 in biofilm reactors and to evaluate the applicability of the pulsed injection of growth substrate and oxygen to biofilm reactors. The attached-cell tests were initially conducted in a 0.165-L bioreactor and, then, scaled-up to a 1.772-L bioreactor. Glass cylinders were utilized as biofil... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5379726 Tue, 01 Nov 2011 04:00:00 +0100 5379726 http://www.medworm.com/index.php?rid=5379727&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%3D22020865%26dopt%3DAbstract Authors: Findrik Z, Németh G, Gubicza L, Bélafi-Bakó K, Vasić-Rački D Abstract In this paper esterification of ethanol and lactic acid catalyzed by Candida antarctica B (Novozyme 435) in ionic liquid (Cyphos 104) was studied. The influence of different variables on lipase enantioselectivity and lactic acid conversion was investigated. The variables investigated were ionic liquid mass/lipase mass ratio, water content, alcohol excess and temperature. Using the Design Expert software 2(3) factorial experimental plan (two levels, three factors) was performed to ascertain the effect of selected variables and their interactions on the ethyl lactate enantiomeric excess and lactic acid conversion. The results of the experiments and statistical processing suggest that temperature and a... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5379727 Sat, 22 Oct 2011 04:00:00 +0100 5379727 http://www.medworm.com/index.php?rid=5345147&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%3D22011884%26dopt%3DAbstract Authors: Go S, Lee SJ, Jeong GT, Kim SK Abstract Biomass production and oil productivity in microalgae culture are the most important key factors for algal biodiesel production. However, proper culture condition for the biomass production of microalgae is different from that for the oil production of microalgae. A study on the biomass production of Tetraselmis suecica using various light intensities and nitrate concentrations as growth factors was carried out to evaluate proper culture conditions in 20-L batch culture. The effect of nitrate depletion on the oil accumulation was also evaluated with two-stage culture. It took 5 days to reach the stationary phase for the cultures of T. suecica on the light intensities of 108.9 and 133.1 μmol m(-2 )s(-1) with biomass of 0.89 and 0... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345147 Thu, 20 Oct 2011 04:00:00 +0100 5345147 http://www.medworm.com/index.php?rid=5345148&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%3D22009439%26dopt%3DAbstract Authors: Sarkar J, Ray S, Chattopadhyay D, Laskar A, Acharya K Abstract The development of an eco-friendly and reliable process for the synthesis of gold nanomaterials (AuNPs) using microorganisms is gaining importance in the field of nanotechnology. In the present study, AuNPs have been synthesized by bio-reduction of chloroauric acid (HAuCl(4)) using the fungal culture filtrate (FCF) of Alternaria alternata. The synthesis of the AuNPs was monitored by UV-visible spectroscopy. The particles thereby obtained were characterized by UV, dynamic light scattering (DLS), X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis, Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM) and transmission electron microscopy (TEM). Energy-dispersive X-ray study rev... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345148 Wed, 19 Oct 2011 04:00:00 +0100 5345148 http://www.medworm.com/index.php?rid=5345149&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%3D22002161%26dopt%3DAbstract Authors: Choi SP, Park YC, Lee J, Sim SJ, Chang HN Abstract Insulin-like growth factor 1 (IGF1), a therapeutic protein, is highly homologous to proinsulin in 3-dimensional structure. To highly express IGF1 in recombinant Escherichia coli, IGF1 was engineered to be fused with the 6-lysine tag and ubiquitin at its N-terminus (K6Ub-IGF1). Fed-batch fermentation of E. coli TG1/pAPT-K6Ub-IGF1 resulted in 60.8 g/L of dry cell mass, 18% of which was inclusion bodies composed of K6Ub-IGF1. Subsequent refolding processes were conducted using accumulated inclusion bodies. An environment of 50 mM bicine buffer (pH 8.5), 125 mM L: -arginine, and 4 °C was chosen to optimize the refolding of K6Ub-IGF1, and 240 mg/L of denatured K6Ub-IGF1 was refolded with a 32% yield. The positive effect ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345149 Sun, 16 Oct 2011 04:00:00 +0100 5345149 http://www.medworm.com/index.php?rid=5345150&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%3D22002101%26dopt%3DAbstract Authors: Wang CC, Zhu LW, Li HM, Tang YJ Abstract A neutralizing agent combination strategy was developed to enhance the succinic acid production by Actinobacillus succinogenes ATCC 55618. First, a maximal succinic acid production of 48.2 g/L was obtained at a culture pH of 7.5. Second, NaOH and KOH were screened to identify the optimal neutralizing agent for pH control. However, the production of succinic acid did not increase, and severe cell flocculation was observed due to a high concentration of metal ions when only one neutralizing agent was used to control pH. Finally, a neutralizing agent combination strategy was developed with a supply of neutralizing agents with OH(-) and carbonate. The cell flocculation was eliminated, and a maximum succinic acid production of 59.2 g/L... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345150 Sat, 15 Oct 2011 04:00:00 +0100 5345150 http://www.medworm.com/index.php?rid=5345154&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%3D21989636%26dopt%3DAbstract Authors: Lee M, Lee D, Cho JK, Cho J, Han J, Park C, Kim S Abstract The enzymatic synthesis of biodiesel by a high-pressure semi-continuous process in near-critical carbon dioxide (NcCO(2)) was studied. Biodiesel synthesis was evaluated in both batch and semi-continuous systems to develop an effective process. Batch processing demonstrated the advantageous properties of NcCO(2) as an alternative reaction medium. Three immobilized lipases (Novozym 435, Lipozyme RM IM, and Lipozyme TL IM from Novozymes) were tested, with Lipozyme TL IM the most effective, showing the highest conversion. Biodiesel conversion from several edible and non-edible oil feedstocks reached >92%. Higher conversion (99.0%) was obtained in a shorter time by employing repeated batch processes with optimized co... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345154 Wed, 12 Oct 2011 04:00:00 +0100 5345154 http://www.medworm.com/index.php?rid=5345153&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%3D21989637%26dopt%3DAbstract Authors: Kim DM, Choi SH, Ko BS, Jeong GY, Jang HB, Han JG, Jeong KH, Lee HY, Won Y, Kim IC Abstract Ethanol production using hemicelluloses has recently become a focus of many researchers. In order to promote D: -xylose fermentation, we cloned the bacterial xylA gene encoding for xylose isomerase with 434 amino acid residues from Agrobacterium tumefaciens, and successfully expressed it in Saccharomyces cerevisiae, a non-xylose assimilating yeast. The recombinant strain S. cerevisiae W303-1A/pAGROXI successfully colonized a minimal medium containing D: -xylose as a sole carbon source and was capable of growth in minimal medium containing 2% xylose via aerobic shake cultivation. Although the recombinant strain assimilates D: -xylose, its ethanol productivity is quite low during ferm... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345153 Wed, 12 Oct 2011 04:00:00 +0100 5345153 http://www.medworm.com/index.php?rid=5345152&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%3D21989638%26dopt%3DAbstract In this study, we investigated the growth and lipid contents of microalgae Nannochloris oculata under various environmental conditions for biodiesel production. Our results indicated that biomass productivities of N. oculata were correlated with increasing nitrogen concentrations up to 37.5 ppm. High irradiance using 230-250 μmol/m(2) led to higher biomass yields than low irradiance of 160-180 μmol/m(2). Biomass productivities increased further by manipulating surface to volume ratio (S/V), which in turn enhanced light penetration. Finally, optimal biomass productivities (1.04 g/l day) could be achieved by the supplementation of yeast extract. Lipid contents and fatty acid profiles of N. oculata were affected by the different growth conditions. Lipid contents of N. oculata decreased... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345152 Wed, 12 Oct 2011 04:00:00 +0100 5345152 http://www.medworm.com/index.php?rid=5345151&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%3D21989639%26dopt%3DAbstract Authors: Yoon S, Lee W, Kim M, Kim TD, Ryu Y Abstract S-adenosylmethionine synthetase (SAM-s) catalyzes the synthesis of S-adenosylmethionine (SAM), which is essential for methylation, transcription, proliferation, and production of secondary metabolites. Here SAM-s from Pichia ciferrii were selectively cloned using RNA CapFishing and rapid amplification of cDNA ends (RACE). The putative full-length cDNA of SAM-s encoded a 383 amino acid protein (42.6 kDa), which has highly conserved metal binding sites, a phosphate-binding site, and functionally important motifs. The corresponding enzyme was over-expressed in a heterologous host of Pichia pastoris, and then purified to a homogenous form. Enzyme kinetics, immunoblotting, circular dichroism (CD), high performance liquid chromatogra... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345151 Wed, 12 Oct 2011 04:00:00 +0100 5345151 http://www.medworm.com/index.php?rid=5345156&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%3D21987306%26dopt%3DAbstract Authors: Murthy GS, Johnston DB, Rausch KD, Tumbleson ME, Singh V Abstract Many mathematical models by researchers have been formulated for Saccharomyces cerevisiae which is the common yeast strain used in modern distilleries. A cybernetic model that can account for varying concentrations of glucose, ethanol and organic acids on yeast cell growth dynamics does not exist. A cybernetic model, consisting of 4 reactions and 11 metabolites simulating yeast metabolism, was developed. The effects of variables such as temperature, pH, organic acids, initial inoculum levels and initial glucose concentration were incorporated into the model. Further, substrate and product inhibitions were included. The model simulations over a range of variables agreed with hypothesized trends and to observa... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345156 Tue, 11 Oct 2011 04:00:00 +0100 5345156 http://www.medworm.com/index.php?rid=5345155&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%3D21987307%26dopt%3DAbstract The objective of this research was to determine the effects of the pelleting conditions on chemical composition and fermentable sugar yield of the biomass. Corn stover, wheat straw, big bluestem, and sorghum stalks were used for this study. Dilute sulfuric acid was used for biomass pretreatment. Accellerase 1500™ was used for cellulose hydrolysis. Effects of mill screen size, die thickness, and L/D ratio of die on chemical compositions and sugar yield were determined. Glucan content of the biomass was positively affected by die thickness and negatively affected by mill screen size. Opposite trend was observed for xylan content. Wheat straw pellets had the highest sugar yield (92.5-94.1%) and big bluestem pellets had the lowest sugar yield (83.6-91.1%). Optimum pelleting condition is 6.5�... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5345155 Tue, 11 Oct 2011 04:00:00 +0100 5345155 http://www.medworm.com/index.php?rid=5297421&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%3D21979859%26dopt%3DAbstract In this study, we investigated changes in protein expression of V. anguillarum in response to diverse stress conditions of temperature, pH, and NaCl. Proteins were separated by 2D-PAGE, differences in expression patterns under each of the above conditions were observed, and proteins were identified using MALDI-TOF MS/MS. We found an oxidoreductase short-chain dehydrogenase/reductase family protein (OSDR), commonly down-regulated under all applied stresses (temperature 15 °C, pH 5 or 10, and NaCl 2 M). Analysis at transcriptional level using RT-PCR showed that osdr gene expression was reduced over time under these stress conditions. Among the various stresses, pH 10 was the most effective for reduction of osdr mRNA transcription. Our findings provide a useful candidate protein for detect... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5297421 Fri, 07 Oct 2011 04:00:00 +0100 5297421 http://www.medworm.com/index.php?rid=5297423&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%3D21971607%26dopt%3DAbstract Use of sugarcane molasses "B" as an alternative for ethanol production with wild-type yeast Saccharomyces cerevisiae ITV-01 at high sugar concentrations. Bioprocess Biosyst Eng. 2011 Oct 5; Authors: Fernández-López CL, Torrestiana-Sánchez B, Salgado-Cervantes MA, García PG, Aguilar-Uscanga MG Abstract Molasses "B" is a rich co-product of the sugarcane process. It is obtained from the second step of crystallization and is richer in fermentable sugars (50-65%) than the final molasses, with a lower non-sugar solid content (18-33%); this co-product also contains good vitamin and mineral levels. The use of molasses "B" for ethanol production could be a good option for the sugarcane industry when cane sugar prices diminish in the market. In a complex medium like molasses, osm... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5297423 Wed, 05 Oct 2011 04:00:00 +0100 5297423 http://www.medworm.com/index.php?rid=5297422&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%3D21971608%26dopt%3DAbstract In this study, the effects of glutamate decarboxylase (gadA, gadB), glutamate/GABA antiporter (gadC) and GABA aminotransferase (gabT) on GABA production were investigated in Escherichia coli. Glutamate decarboxylase was overexpressed alone or with the glutamate/GABA antiporter to enhance GABA synthesis. GABA aminotransferase, which redirects GABA into the TCA cycle, was knock-out mutated. When gadB and gadC were co-overexpressed in the gabT mutant strain, a final GABA concentration of 5.46 g/l was obtained from 10 g/l of monosodium glutamate (MSG), which corresponded to a GABA yield of 89.5%. PMID: 21971608 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5297422 Wed, 05 Oct 2011 04:00:00 +0100 5297422 http://www.medworm.com/index.php?rid=5297424&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%3D21969058%26dopt%3DAbstract Authors: Ahmad I, Shim WY, Jeon WY, Yoon BH, Kim JH Abstract The yeast Candida tropicalis produces xylitol, a natural, low-calorie sweetener whose metabolism does not require insulin, by catalytic activity of NADPH-dependent xylose reductase. The oxidative pentose phosphate pathway (PPP) is a major basis for NADPH biosynthesis in C. tropicalis. In order to increase xylitol production rate, xylitol dehydrogenase gene (XYL2)disrupted C. tropicalis strain BSXDH-3 was engineered to co-express zwf and gnd genes which, respectively encodes glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6-PGDH), under the control of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoter. NADPH-dependent xylitol production was higher in the engineered strain, termed "PP"... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5297424 Tue, 04 Oct 2011 04:00:00 +0100 5297424 http://www.medworm.com/index.php?rid=5280241&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%3D21959580%26dopt%3DAbstract Authors: Oh BR, Seo JW, Heo SY, Hong WK, Luo LH, Son JH, Park DH, Kim CH Abstract We generated a genetically engineered Klebsiella pneumoniae strain (AK-VOT) to eliminate by-product formation during production of 1,3-propanediol (1,3-PD) from glycerol. In the present study, the glycerol-metabolizing properties of the recombinant strain were examined during fermentation in a 5 L bioreactor. As expected, by-product formation was completely absent (except for acetate) when the AK-VOT strain fermented glycerol. However, 1,3-PD productivity was severely reduced owing to a delay in cell growth attributable to a low rate of glycerol consumption. This problem was solved by establishing a two-stage process separating cell growth from 1,3-PD production. In addition, nutrient co-supplementat... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280241 Fri, 30 Sep 2011 04:00:00 +0100 5280241 http://www.medworm.com/index.php?rid=5280240&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%3D21959581%26dopt%3DAbstract We examined the growth of a novel oleaginous microalga, Aurantiochytrium sp. KRS101, using cellulosic materials as nutrients, and the resultant production of lipids containing high levels of docosahexaenoic acid (DHA). The microalgal strain could grow using either carboxymethylcellulose or cellobiose as a carbon source, and produced lipids containing high levels of DHA (49-58% of total fatty acids). In line with this growth behavior, carboxymethylcellulase and cellobiohydrolase activities were evident in both cell-free lysates and culture broths. Additionally, an industrial cellulosic biomass, palm oil empty fruit bunches (POEFB), a by-product of the palm oil industry, were utilized by the microalgal strain for cell growth and lipid production. PMID: 21959581 [PubMed - as supplied by p... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280240 Fri, 30 Sep 2011 04:00:00 +0100 5280240 http://www.medworm.com/index.php?rid=5280239&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%3D21959582%26dopt%3DAbstract Authors: Farnazo DM, Nisola GM, Han M, Yoo N, Chung WJ Abstract Biodegradations of methyl ethyl ketone and methyl isobutyl ketone were performed in intermittent biotrickling filter beds (ITBF) operated at two different trickling periods: 12 h/day (ITBF-12) and 30 min/day (ITBF-0.5). Ralstonia sp. MG1 was able to degrade both ketones as evidenced by growth kinetic experiments. Results show that trickling period is an important parameter to achieve high removal performance and to maintain the robustness of Ralstonia sp. MG1. Overall, ITBF-12 outperformed ITBF-0.5 regardless of the target compound. ITBF-12 had high performance recovery at various inlet gas concentrations. The higher carbon dioxide production rates in ITBF-12 suggest higher microbial activity than in ITBF-0.5. Additi... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280239 Fri, 30 Sep 2011 04:00:00 +0100 5280239 http://www.medworm.com/index.php?rid=5280238&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%3D21959583%26dopt%3DAbstract Authors: Meeuwse P, Akbari P, Tramper J, Rinzema A Abstract The production of lipids by oleaginous yeast and fungi becomes more important because these lipids can be used for biodiesel production. To understand the process of lipid production better, we developed a model for growth, lipid production and lipid turnover in submerged batch fermentation. This model describes three subsequent phases: exponential growth when both a C-source and an N-source are available, carbohydrate and lipid production when the N-source is exhausted and turnover of accumulated lipids when the C-source is exhausted. The model was validated with submerged batch cultures of the fungus Umbelopsis isabellina (formerly known as Mortierella isabellina) with two different initial C/N-ratios. Comparison with ch... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280238 Fri, 30 Sep 2011 04:00:00 +0100 5280238 http://www.medworm.com/index.php?rid=5280244&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%3D21947702%26dopt%3DAbstract Authors: Ilyas S, Chi R, Bhatti HN, Bhatti IA, Ghauri MA Abstract Present work describes the bioleaching potential of metals from low-grade mining ore containing smithsonite, sphaerocobaltite, azurite and talc as main gangue minerals with adapted consortium of Sulfobacillus thermosulfidooxidans strain-RDB and Thermoplasma acidophilum. Bioleaching potential improved markedly by added energy source, acid preleaching and adaptation of microbial consortium with mixed metal ions. During whole leaching period including acid preleaching stage of 960 h and bioleaching stage of 212 days about 76% Co, 70% Zn, 84% Cu, 72% Ni and 63% Fe leached out. PMID: 21947702 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280244 Tue, 27 Sep 2011 04:00:00 +0100 5280244 http://www.medworm.com/index.php?rid=5280243&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%3D21947703%26dopt%3DAbstract Authors: Gomaa AE, Hafez EE, Lim HS, Chung GH, Sun SM Abstract Insulin, in nature, has a stimulatory effect on microorganisms. These effects include the acceleration of sugar metabolism, triacylglycerol anabolism, growth rate, and formation of oils. We also observed that insulin may cause indirect activation of triacylglycerol lipase by forcing the cell to permanently require an energy source. Thus, cells can consume all of their accumulated internal fuel sources such as lipids, proteins, and carbohydrates. After studying the effects of using two types of insulin (Humulin 70/30, and human insulin expressed in yeast) at different concentrations on microalgae (Chlorella sp.), we found that with certain concentrations of insulin (1:3.3 ml unit Humulin 70/30 per ml; 1:2.6 ml unit yea... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280243 Tue, 27 Sep 2011 04:00:00 +0100 5280243 http://www.medworm.com/index.php?rid=5280242&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%3D21947704%26dopt%3DAbstract Authors: Xuan Z, Chang NB, Wanielista M Abstract A next generation septic tank media filter to replace or enhance the current on-site wastewater treatment drainfields was proposed in this study. Unit operation with known treatment efficiencies, flow pattern identification, and system dynamics modeling was cohesively concatenated in order to prove the concept of a newly developed media filter. A multicompartmental model addressing system dynamics and feedbacks based on our assumed microbiological processes accounting for aerobic, anoxic, and anaerobic conditions in the media filter was constructed and calibrated with the aid of in situ measurements and the understanding of the flow patterns. Such a calibrated system dynamics model was then applied for a sensitivity analysis under ch... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280242 Tue, 27 Sep 2011 04:00:00 +0100 5280242 http://www.medworm.com/index.php?rid=5280246&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%3D21947672%26dopt%3DAbstract Authors: Zhang LJ, Jin ZH, Chen XG, Jin QC, Feng MG Abstract Seven amino acids were tested as precursors to affect pristinamycin production by a mutant strain derived from Streptomyces pristinaespiralis ATCC25486. Of those, glycine was selected as the best precursor to facilitate both cell growth and pristinamycin production at the feeding time of 36-h incubation and the feeding rate of 0.75 g L(-1) flask culture. The optimized time and concentration of glycine feeding were applied to enlarged 3-L bioreactor fermentation with a resin added at the time of 20-h fermentation for in situ separation. As a result, a combination of the glycine feeding and the added resin resulted in the maximal pristinamycin yield of 616 mg L(-1) culture 12 h after glycine feeding. The yield from the... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280246 Sun, 25 Sep 2011 04:00:00 +0100 5280246 http://www.medworm.com/index.php?rid=5280245&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%3D21947673%26dopt%3DAbstract Authors: Wang JF, Liu XJ, Liu RS, Li HM, Tang YJ Abstract The mated fermentation process for the production of lycopene by Blakeslea trispora NRRL 2895 (+) and NRRL 2896 (-) was systematically optimized in shake flasks. The ratio of the (+) to (-) strains, the lycopene cyclase inhibitors piperidine and creatinine, the trisporic acid structural analog abscisic acid, the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) precursor leucine, and the mevalonate kinase enhancer penicillin were all identified as key factors affecting lycopene biosynthesis. With an optimal ratio of 5:1 for the (+) to (-) strains and the addition of 6 g/L creatinine on day 3, the highest lycopene production was 98.1 ± 15.5 mg/L. Based on the above result, the addition of 0.1 g/L penicillin on day 4, 150�... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280245 Sun, 25 Sep 2011 04:00:00 +0100 5280245 http://www.medworm.com/index.php?rid=5280249&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%3D21947600%26dopt%3DAbstract Authors: Andriani D, Sunwoo C, Ryu HW, Prasetya B, Park DH Abstract Bacillus subtilis TD6 was isolated from Takifugu rubripes, also known as puffer fish. Cellulase from this strain was partially purified by ammonium sulphate precipitation up to 80% saturation, entrapped in calcium alginate beads, and finally characterized using CMC as the substrate. For optimization, various parameters were observed, including pH maximum, temperature maximum, sodium alginate, and calcium chloride concentration. pH maximum of the enzyme showed no changes before and after immobilization and remained stable at 6.0. The temperature maximum showed a slight increase to 60 °C. Two percent sodium alginate and a 0.15 M calcium chloride solution were the optimum conditions for acquisition of enzyme with g... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280249 Sat, 24 Sep 2011 04:00:00 +0100 5280249 http://www.medworm.com/index.php?rid=5280248&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%3D21947624%26dopt%3DAbstract Authors: Kang HW, Kim Y, Kim SW, Choi GW Abstract In cellulosic ethanol production, use of simultaneous saccharification and fermentation (SSF) has been suggested as the favorable strategy to reduce process costs. Although SSF has many advantages, a significant discrepancy still exists between the appropriate temperature for saccharification (45-50 °C) and fermentation (30-35 °C). In the present study, the potential of temperature-shift as a tool for SSF optimization for bioethanol production from cellulosic biomass was examined. Cellulosic ethanol production of the temperature-shift SSF (TS-SSF) from 16 w/v% biomass increased from 22.2 g/L to 34.3 g/L following a temperature shift from 45 to 35 °C compared with the constant temperature of 45 °C. The glucose conversion yi... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280248 Wed, 21 Sep 2011 04:00:00 +0100 5280248 http://www.medworm.com/index.php?rid=5280247&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%3D21947625%26dopt%3DAbstract Authors: Chung CM, Cho KW, Kim YJ, Yamamoto K, Chung TH Abstract A modified ludzack ettinger reactor (MLE) combined with a post-denitrification reactor (PDMLE) using electroflotation (EF) as a secondary clarifier was investigated on its feasibility and process performance. Results indicated that higher mixed liquor suspended solids (MLSS) concentrations in bioreactor (5,350 ± 352 mg L(-1)) were maintained via the highly concentrated return sludge (16,771 ± 991 mg L(-1)) from the EF clarifier and the effluent suspended solids (SS) concentrations continued relatively low, representing effluent SS concentration of 1.71 ± 1.16 mg L(-1), compared with GS-A2O process during the operation of four months. The denitrification was improved by combining MLE process with post-denit... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5280247 Wed, 21 Sep 2011 04:00:00 +0100 5280247 http://www.medworm.com/index.php?rid=5247063&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%3D21932061%26dopt%3DAbstract Authors: Tahir MN, Adnan A, Strömberg E, Mischnick P Abstract O-Pentynyl dextran (PyD), an amphiphilic polysaccharide derivative with a degree of substitution (DS) of 0.43 was compared with ion exchange resins Lewatit VP OC 1600, Amberlite XAD 761 and Duolite A568 for immobilization of Lipase from Rhizopus arrhizus by adsorption method. The immobilized enzymes were employed for esterification of octanoic acid with geraniol in n-hexane as model reaction. PyD showed higher lipase adsorption and with 249 μmol min(-1 )g(-1) significant higher esterification activity than the other supports (67-83 μmol min(-1) g(-1)). Biocatalysts from all types of supports except PyD became completely inactive within 8 weeks storing at -10 °C while lipase immobilized on PyD retained its fu... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5247063 Tue, 20 Sep 2011 04:00:00 +0100 5247063 http://www.medworm.com/index.php?rid=5247062&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%3D21932062%26dopt%3DAbstract Authors: Yilmaz E Abstract Candida rugosa lipase was encapsulated within a sol-gel procedure and improved considerably by fluoride-catalyzed hydrolysis of mixtures of octyltriethoxysilane and tetraethoxysilane in the presence of magnetic sporopollenin. The catalytic properties of the immobilized lipases were evaluated into model reactions, i.e., the hydrolysis of p-nitrophenylpalmitate (p-NPP), and the enantioselective hydrolysis of racemic naproxen methyl ester, mandelic acid methyl ester or 2-phenoxypropionic acid methyl ester that were studied in aqueous buffer solution/isooctane reaction system. The encapsulated magnetic sporopollenin (Spo-M-E) was found to give 319 U/g of support with 342% activity yield. It has been observed that the percent activity yields and enantioselect... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5247062 Tue, 20 Sep 2011 04:00:00 +0100 5247062 http://www.medworm.com/index.php?rid=5247065&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%3D21928095%26dopt%3DAbstract In this study, a colorimetric whole-cell biosensor for cadmium (Cd) was designed using a genetically engineered red pigment producing bacterium, Deinococcus radiodurans. Based on the previous microarray data, putative promoter regions of highly Cd-inducible genes (DR_0070, DR_0659, DR_0745, and DR_2626) were screened and used for construction of lacZ reporter gene cassettes. The resultant reporter cassettes were introduced into D. radiodurans R1 to evaluate promoter activity and specificity. Among the promoters, the one derived from DR_0659 showed the highest specificity, sensitivity, and activity in response to Cd. The Cd-inducible activity was retained in the 393-bp deletion fragment (P0659-1) of the P0569 promoter, but the expression pattern of the putative promoter fragments inferred i... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5247065 Sun, 18 Sep 2011 04:00:00 +0100 5247065 http://www.medworm.com/index.php?rid=5231017&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%3D21922311%26dopt%3DAbstract In this study, NcXR codons were changed to those preferred in C. tropicalis. This codon-optimized NcXR gene (termed NXRG) was placed under control of a constitutive glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoter derived from C. tropicalis, and integrated into the genome of xylitol dehydrogenase gene (XYL2)-disrupted C. tropicalis. High expression level of NXRG was confirmed by determining XR activity in cells grown on glucose medium. The resulting recombinant strain, LNG2, showed high XR activity (2.86 U (mg of protein)(-1)), whereas parent strain BSXDH-3 showed no activity. In xylitol fermentation using glucose as a co-substrate with xylose, LNG2 showed xylitol production rate 1.44 g L(-1) h(-1) and xylitol yield of 96% at 44 h, which were 73 and 62%, respectively, higher t... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5231017 Fri, 16 Sep 2011 04:00:00 +0100 5231017 http://www.medworm.com/index.php?rid=5231020&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%3D21918837%26dopt%3DAbstract Authors: Jang JS, Cho Y, Jeong GT, Kim SK Abstract Ethanol was produced using the simultaneous saccharification and fermentation (SSF) method with macroalgae polysaccharide from the seaweed Saccharina japonica (Sea tangle, Dasima) as biomass. The seaweed was dried by hot air, ground with a hammer mill and filtered with a 200-mesh sieve prior to pretreatment. Saccharification was carried out by thermal acid hydrolysis with H(2)SO(4) and the industrial enzyme, Termamyl 120 L. To increase the yield of saccharification, isolated marine bacteria were used; the optimal saccharification conditions were 10% (w/v) seaweed slurry, 40 mM H(2)SO(4) and 1 g dcw/L isolated Bacillus sp. JS-1. Using this saccharification procedure, the reducing sugar concentration and viscosity were 45.6 ± 5... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5231020 Thu, 15 Sep 2011 04:00:00 +0100 5231020 http://www.medworm.com/index.php?rid=5231019&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%3D21918838%26dopt%3DAbstract In this study, pretreatment by soaking in aqueous ammonia was adopted for pretreatment of biomass for ethanol production. A central composite design of response surface methodology was used for optimization of the pretreatment condition of rapeseed straw, with respect to catalyst concentration, pretreatment time, and pretreatment temperature. The most optimal condition for pretreatment of rapeseed straw by soaking in aqueous ammonia was 19.8% of ammonia water, 14.2 h of pretreatment time, and a pretreatment temperature of 69.0 °C. Using these optimal factor values under experimental conditions, 60.7% of theoretical glucose was obtained, and this value was well within the range predicted by the model. SEM results showed that SAA pretreatment of rapeseed straw resulted in increased surfac... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5231019 Thu, 15 Sep 2011 04:00:00 +0100 5231019 http://www.medworm.com/index.php?rid=5231018&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%3D21918839%26dopt%3DAbstract This study aims to use a membrane bioreactor system to remove glycerol during biodiesel production. In addition, methanol inhibition can be reduced by continuously feeding methanol through the membrane system. This continuous membrane bioreactor system can be used for efficient biodiesel production. PMID: 21918839 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5231018 Thu, 15 Sep 2011 04:00:00 +0100 5231018 http://www.medworm.com/index.php?rid=5231022&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%3D21915672%26dopt%3DAbstract In this study, we developed a method for low-cost production of exopolysaccharide (EPS) that effectively screens components and optimizes medium composition using statistical methods (Plackett-Burman and Box-Behnken design). As a result, we obtained the following optimized medium: sucrose 165.73 g/L, sodium nitrate 3.08 g/L, dipotassium phosphate 1.00 g/L, potassium chloride 0.50 g/L, magnesium sulfate 0.50 g/L, ferrous sulfate 0.01 g/L, and 0.71 g/L of Ashbya gossypii extract. The maximum production of about 29 g/L EPS was achieved in the optimized medium during 84 h batch fermentation. PMID: 21915672 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5231022 Wed, 14 Sep 2011 04:00:00 +0100 5231022 http://www.medworm.com/index.php?rid=5231021&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%3D21915673%26dopt%3DAbstract In this study, we optimized immobilization of a facultative hydrogen producing microorganism, Enterobacter aerogenes, with the goal of developing biocatalysts that was appropriate for the continuous hydrogen production from glycerol. Several carriers were tested and agar was found to be the most effective. In addition, it was clearly shown that variables such as the carrier content and cell loading should be controlled for the immobilization of biocatalysts with high hydrogen productivity, stability, and reusability. After optimization of these variables, we were able to obtain reusable biocatalysts that could directly convert the byproduct stream from biodiesel processes into hydrogen in continuous processes. PMID: 21915673 [PubMed - as supplied by publisher] (Source: Bioprocess and B... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5231021 Wed, 14 Sep 2011 04:00:00 +0100 5231021 http://www.medworm.com/index.php?rid=5219025&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%3D21909937%26dopt%3DAbstract Authors: Park S, Lee K, Kim YS, Chi YT, Shin JS, Back K Abstract Tyramine, one of the various biogenic amines found in plants, is derived from the aromatic L: -amino acid tyrosine through the catalytic reaction of tyrosine decarboxylase (TYDC). Tyramine overproduction by constitutive expression of TYDC in rice plants leads to stunted growth, but an increased number of tillers. To regulate tyramine production in rice plants, we expressed TYDC under the control of a methanol-inducible plant tryptophan decarboxylase (TDC) promoter and generated transgenic T(2) homozygous rice plants. The transgenic rice plants showed normal growth phenotypes with slightly increased levels of tyramine in seeds relative to wild type. Upon treatment with 1% methanol, the transgenic rice leaves produced l... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219025 Sun, 11 Sep 2011 04:00:00 +0100 5219025 http://www.medworm.com/index.php?rid=5219024&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%3D21909938%26dopt%3DAbstract In this study, ethanol production from pure and crude glycerol using Enterobacter aerogenes ATCC 29007 was evaluated under anaerobic culture conditions. Inhibitory effects of substrate concentrations, pH, and salt concentrations were investigated based on crude glycerol components. Ethanol production was performed with pure glycerol concentrations ranging from 5 to 30 g/L to evaluate the effects of substrate concentration and osmotic pressure. The consumed glycerol was 5-14.33 g/L, and the yield of ethanol was higher than 0.75 mol ethanol/mol glycerol after 24 h of cultivation. To evaluate the inhibitory effects of salts (NaCl and KCl), experiments were performed with 0-20 g/L of each salt. Inhibitory effects of salts were strongest at high salt concentrations. The inhibitory effect o... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219024 Sun, 11 Sep 2011 04:00:00 +0100 5219024 http://www.medworm.com/index.php?rid=5219023&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%3D21909939%26dopt%3DAbstract Authors: Ahn DJ, Kim SK, Yun HS Abstract Alkaline-oxidative (A/O) pretreatment and enzymatic saccharification were optimized for bioethanol fermentation from water hyacinth by Saccharomyces cerevisiae. Water hyacinth was subjected to A/O pretreatment at various NaOH and H(2)O(2) concentrations and reaction temperatures for the optimization of bioethanol fermentation by S. cerevisiae. The most effective condition for A/O pretreatment was 7% (w/v) NaOH at 100 °C and 2% (w/v) H(2)O(2). The carbohydrate content was analyzed after reaction at various enzyme concentrations and enzyme ratios using Celluclast 1.5 L and Viscozyme L to determine the effective conditions for enzymatic saccharification. After ethanol fermentation using S. cerevisiae KCTC 7928, the concentration of glucose,... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219023 Sun, 11 Sep 2011 04:00:00 +0100 5219023 http://www.medworm.com/index.php?rid=5219043&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%3D21909666%26dopt%3DAbstract Authors: Li X, Kim TH Abstract A cascade type of fermentation, designated the cascade simultaneous saccharification and fermentation (CSSF), was studied to convert corn stover derived pentose and hexose to ethanol with reduced enzyme input. In detail, each step of CSSF utilizes two sequential SSF phases operating on pentose and hexose, i.e., pentose conversion using xylanase, endo-glucanase, and recombinant Escherichia coli (KO11) with minimal glucose conversion in the first phase SSF, and hexose conversion in the second phase SSF using cellulase, β-glucosidase, and Saccharomyces cerevisiae (D(5)A). In this cascade scheme, multiple stages of 1st and 2nd phase SSF were performed in series; enzymes are recycled from the fermentation broth of the last stage for the use of the next st... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219043 Sat, 10 Sep 2011 04:00:00 +0100 5219043 http://www.medworm.com/index.php?rid=5219042&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%3D21909667%26dopt%3DAbstract In this study, we estimated the effects of the slope of a V-shaped bottom design, the volumetric flow rate of air, height/diameter (H/D) ratio, and diameter of an air sparger on the performance of a photo-bioreactor. These parameters were selected because they are recognized as important factors effecting the mixing that produces increased cell density in the reactor. The mixing effect can be measured by changes in optical density in the bioreactor over a period of time. A 6 L indoor photo-bioreactor was prepared in a short time period of 24 h for the performance study. A bioreactor designed with a V-shaped bottom with a slope of 60° showed an optical density change of 0.052 at 680 nm, which was sixfold less than the change in a photo-bioreactor designed with a flat bottom. Studies exp... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219042 Sat, 10 Sep 2011 04:00:00 +0100 5219042 http://www.medworm.com/index.php?rid=5219041&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%3D21909668%26dopt%3DAbstract Authors: Yoo SY, Wan Daud WM, Lee MG Abstract The biodegradable oil absorption resin (B-PEHA) was prepared by suspension polymerization, and its preparation was confirmed by Fourier transform infrared analysis. The oil absorption capacities of the prepared B-PEHA were: chloroform 30.88, toluene 19.75, xylene, 18.78, THF 15.96, octane 11.43, hexane 9.5, diesel oil 12.80, and kerosene 13.79 g/g. The biodegradation of the prepared B-PEHA was also investigated by determination of reduced sugar produced after enzymatic hydrolysis, thermogravimetric analysis, and incubation with Aspergillus niger. The biodegradation of B-PEHA was ~18%. PMID: 21909668 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219041 Sat, 10 Sep 2011 04:00:00 +0100 5219041 http://www.medworm.com/index.php?rid=5219040&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%3D21909669%26dopt%3DAbstract Authors: Kim W, Park JM, Gim GH, Jeong SH, Kang CM, Kim DJ, Kim SW Abstract Culture conditions for the mass production of three green algae, Chlorella sp., Dunaliella salina DCCBC2 and Dunaliella sp., were optimized using a response surface methodology (RSM). A central composite design was applied to investigate the effects of initial pH, nitrogen and phosphate concentrations on the cultivation of microalgae. The optimal growth conditions estimated from the design are as follows: Chlorella sp. (initial pH 7.2, ammonium 17 mM, phosphate 1.2 mM), D. salina DCCBC2 (initial pH 8.0, nitrate 3.3 mM, phosphate 0.0375 mM) and Dunaliella sp. (initial pH 8.0, nitrate 3.7 mM, phosphate 0.17 mM). Culturing the microalgae with the optimized conditions confirmed that the maximum growth rat... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219040 Sat, 10 Sep 2011 04:00:00 +0100 5219040 http://www.medworm.com/index.php?rid=5219039&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%3D21909670%26dopt%3DAbstract In this study, hydrolysis of marine algal biomass Kappaphhycus alvarezii using two different acid catalysts was examined with the goal of identifying optimal reaction conditions for the formation of sugars and by-products. K. alvarezii were hydrolyzed by autoclave using sulfuric acid or hydrochloric acid as catalyst with different acid concentrations (0.1-1.0 M), substrate concentrations (1.0-13.5%), hydrolysis time (10-90 min) and hydrolysis temperatures (100-130 (°)C). A difference in galactose, glucose, reducing sugar and total sugar content was observed under the different hydrolysis conditions. Different by-product compounds such as 5-hydroxymethylfurfural and levulinic acid were also observed under the different reaction conditions. The optimal conditions for hydrolysis were achi... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219039 Sat, 10 Sep 2011 04:00:00 +0100 5219039 http://www.medworm.com/index.php?rid=5219038&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%3D21909671%26dopt%3DAbstract In this study, we investigated the effect of fermentation inhibitors to the K. alvarezii hydrolysate on cell growth and ethanol fermentation. In addition, detoxification of fermentation inhibitors was performed to decrease the fermentation inhibitory effect. 5-Hydroxymethylfurfural and levulinic acid, which are liberated from acidic hydrolysis, was also observed in the hydrolysate of K. alvarezii. These compounds inhibited ethanol fermentation. In order to remove these inhibitors, activated charcoal and calcium hydroxide were introduced. The efficiency of activated charcoals was examined and over-liming was used to remove the inhibitors. Activated charcoal was found to be more effective than calcium hydroxide to remove the inhibitors. Detoxification by activated charcoal strongly improved ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219038 Sat, 10 Sep 2011 04:00:00 +0100 5219038 http://www.medworm.com/index.php?rid=5219037&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%3D21909672%26dopt%3DAbstract Authors: Jung SH, Choi S, Kim YR, Jeon TJ Abstract An artificially created lipid bilayer is an important platform in studying ion channels and engineered biosensor applications. However, a lipid bilayer created using conventional techniques is fragile and short-lived, and the measurement of ion channels requires expertise and laborious procedures, precluding practical applications. Here, we demonstrate a storable droplet lipid bilayer precursor frozen with ion channels, resulting in a droplet interface bilayer upon thawing. A small vial with an aqueous droplet in organic solution was flash frozen in -80 °C methanol immediately after an aqueous droplet was introduced into the organic solution and gravity draws the droplet down to the interface upon thawing. A lipid bilayer created... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219037 Sat, 10 Sep 2011 04:00:00 +0100 5219037 http://www.medworm.com/index.php?rid=5219036&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%3D21909673%26dopt%3DAbstract Authors: Ha SH, Anh TV, Lee SH, Koo YM Abstract Although caffeic acid phenethyl ester (CAPE), an active flavonoid, plays an important role in the antioxidant activity of honeybee propolis, the isolation of CAPE from honeybee propolis is time-consuming due to wide variety of impurities present. Therefore, biochemical method to synthesize CAPE was investigated in this study. Since ionic liquids (ILs) possess some unique characteristics as appreciated alternatives to conventional solvents for certain biotransformation, the effect of ILs as reaction media for enzymatic synthesis of CAPE was assessed. Several factors including substrate molar ratio, and reaction temperature affecting the conversion yield of lipase-catalyzed CAPE synthesis were also investigated. Reaction yields were sig... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219036 Sat, 10 Sep 2011 04:00:00 +0100 5219036 http://www.medworm.com/index.php?rid=5219035&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%3D21909674%26dopt%3DAbstract Authors: Cho SS, Choi YH, Simkhada JR, Mander P, Park DJ, Yoo JC Abstract With the aim of isolating new microbes capable of producing strong antimicrobial substances, strain CS392 was screened from 700 soil isolates preserved in our laboratory. The strain was related to genus Streptomyces based on various characteristics. Three highly active antimicrobial compounds, C1, C2 and C3, produced by the strain were purified by solvent extraction followed by silica gel column chromatography. These compounds were highly active against various Gram-positive resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA), and vancomycin-resistant Enterococcus (VRE). Among three, C3 was the most active against MRSA and VRSA with ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219035 Sat, 10 Sep 2011 04:00:00 +0100 5219035 http://www.medworm.com/index.php?rid=5219034&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%3D21909675%26dopt%3DAbstract Authors: Cho SS, Park DJ, Simkhada JR, Hong JH, Sohng JK, Lee OH, Yoo JC Abstract In an attempt to isolate a biocatalyst able to catalyze biodiesel production from microbial source, Streptomyces sp. CS326 was screened from hundreds of soil isolates collected from various parts of Korea. In 16S rRNA sequence analysis, the strain showed high degree of similarity with Streptomyces xanthocidicus (99.79%); therefore, it is classified as Streptomyces sp. CS326. An extracellular lipase produced by the strain (LP326) was purified using a single step gel permeation chromatography on Sepharose CL-6B. Molecular weight of LP326 was estimated to be 17,000 Da by SDS-PAGE. The activity was optimum at 40 °C and pH 7.0 and was stable at pH 5.0-8.0 and below 50 °C. It preferred p-nitrophenyl pa... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219034 Sat, 10 Sep 2011 04:00:00 +0100 5219034 http://www.medworm.com/index.php?rid=5219033&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%3D21909676%26dopt%3DAbstract Authors: Simkhada JR, Yoo HY, Cho SS, Choi YH, Kim SW, Park DH, Yoo JC Abstract Fossil fuel is limited but its usage has been growing rapidly, thus the fuel is predicted to be completely running out and causing an unbearable global energy crisis in the near future. To solve this potential crisis, incorporating with increasing environmental concerns, significant attentions have been given to biofuel production in the recent years. With the aim of isolating a microbial biocatalyst with potential application in the field of biofuel, a lipase from Streptomyces sp. CS628, LP28, was purified using hydroxyapatite column chromatography followed by a gel filtration. Molecular weight of LP28 was estimated to be 32,400 Da by SDS-PAGE. The activity was the highest at 30 °C and pH 8.0 and wa... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219033 Sat, 10 Sep 2011 04:00:00 +0100 5219033 http://www.medworm.com/index.php?rid=5219032&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%3D21909677%26dopt%3DAbstract Authors: Yun JY, Lee JE, Yang KM, Cho S, Kim A, Kwon YE, Park JB Abstract The effects of structural modification of cell wall on the biotransformation capability by recombinant Corynebacterium glutamicum cells, expressing the chnB gene encoding cyclohexanone monooxygenase of Acinetobacter calcoaceticus NCIMB 9871, were investigated. Baeyer-Villiger oxygenation of 2-(2'-acetoxyethyl) cyclohexanone (MW 170 Da) into R-7-(2'-acetoxyethyl)-2-oxepanone was used as a model reaction. The whole-cell biotransformation followed Michaelis-Menten kinetics. The V (max) and K (S) values were estimated as 96.8 U g(-1) of dry cells and 0.98 mM, respectively. The V (max) was comparable with that of cyclohexanone oxygenation, whereas the K (S) was almost eightfold higher. The K (S) value of 2-(2'... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219032 Sat, 10 Sep 2011 04:00:00 +0100 5219032 http://www.medworm.com/index.php?rid=5219031&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%3D21909678%26dopt%3DAbstract Authors: Lee EJ, Khan SA, Park JK, Lim KH Abstract The morphology of gelatin nanoparticles loaded with three different drugs (Tizanidine hydrochloride, Gatifloxacin and Fluconazole) and their characteristics of entrapment and release from gelatin nanoparticles were investigated by the analysis on nanoparticle size distribution, SEM and FT-IR in this study. The particles were prepared by nanoprecipitation using water and ethanol as a solvent and a nonsolvent, respectively. The exclusion of a crosslinking agent from the procedure led the system to have an irregularly-shaped morphology. Nonetheless, the uncrosslinked case of Gatifloxacin loading generally led to a more homogeneous population of nanoparticles than the uncrosslinked case of Tizanidine hydrochloride loading. No loading w... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219031 Sat, 10 Sep 2011 04:00:00 +0100 5219031 http://www.medworm.com/index.php?rid=5219030&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%3D21909679%26dopt%3DAbstract In this study, S. cerevisiae was engineered to investigate the effects of the sole and double disruption of NADH-dependent glycerol-3-phosphate dehydrogenase 1 (GPD1) and NADPH-requiring glutamate dehydrogenase 1 (GDH1) on the production of glycerol and ethanol from glucose. Even though sole deletion of GPD1 or GDH1 reduced glycerol production, double deletion of GPD1 and GDH1 resulted in the lowest glycerol concentration of 2.31 g/L, which was 46.4% lower than the wild-type strain. Interestingly, the recombinant S. cerevisiae ∆GPD1∆GDH1 strain showed a slight improvement in ethanol yield (0.414 g/g) compared with the wild-type strain (0.406 g/g). Genetic engineering of the glycerol and glutamate metabolic pathways modified NAD(P)H-requiring metabolic pathways and exerted a positive... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219030 Sat, 10 Sep 2011 04:00:00 +0100 5219030 http://www.medworm.com/index.php?rid=5219029&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%3D21909680%26dopt%3DAbstract Authors: Kang HK, Kim D Abstract Rice straw is a lignocellulosic biomass that constitutes a renewable organic substance and alternative source of energy; however, its structure confounds the liberation of monosaccharides. Pretreating rice straw using a TiO(2)/UV system facilitated its hydrolysis with Accellerase 1000(™), suggesting that hydroxyl radicals (OH·) from the TiO(2)/UV system could degrade lignin and carbohydrates. TiO(2)/UV pretreatment was an essential step for conversion of hemicellulose to xylose; optimal conditions for this conversion were a TiO(2) concentration of 0.1% (w/v) and an irradiation time of 2 h with a UV-C lamp at 254 nm. After enzymatic hydrolysis, the sugar yields from rice straw pretreated with these parameters were 59.8 ± 0.7% of the theoretic... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219029 Sat, 10 Sep 2011 04:00:00 +0100 5219029 http://www.medworm.com/index.php?rid=5219028&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%3D21909681%26dopt%3DAbstract Authors: Kim DJ, Lee J Abstract Hydrolysis of waste activated sludge (WAS) has been regarded as the rate limiting step of anaerobic sludge digestion. Therefore, in this study, the effect of ultrasound and hydraulic residence time during sludge hydrolysis was investigated with the goal of enhancing methane production from anaerobic digestion (AD). WAS was ultrasonically disintegrated for hydrolysis, and it was semi-continuously fed to an anaerobic digesters at various hydraulic retention times (HRTs). The results of these experiments showed that the solids and chemical oxygen demand (COD) removal efficiencies when using ultrasonically disintegrated sludge were higher during AD than the control sludge. The longer the HRT, the higher the removal efficiencies of solids and COD, while m... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219028 Sat, 10 Sep 2011 04:00:00 +0100 5219028 http://www.medworm.com/index.php?rid=5219027&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%3D21909682%26dopt%3DAbstract Authors: Madeira JV, Macedo JA, Macedo GA Abstract The production of enzymes such as tannases and phytases by solid-state fermentation and their use in animal feed have become a subject of great interest. In the present work, Paecilomyces variotii was used to produce tannase and phytase simultaneously. Solid-state fermentation, a process initially designed for tannase production, was implemented here using orange pomace as substrate. Orange pomace is the waste product of the large orange juice industry in Brazil, and it has also been used as an ingredient in animal feed. In addition to enzymatic production, biotransformation of the phenolic content and antioxidant capacity of the orange pomace were analyzed after fermentation. Fermentation conditions, namely moisture level and tann... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219027 Sat, 10 Sep 2011 04:00:00 +0100 5219027 http://www.medworm.com/index.php?rid=5219026&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%3D21909683%26dopt%3DAbstract Authors: Chen XS, Ren XD, Dong N, Li S, Li F, Zhao FL, Tang L, Zhang JH, Mao ZG Abstract To improve the efficiency of ε-poly-L: -lysine (ε-PL) production by Streptomyces sp. M-Z18, batch and fed-batch fermentations with glucose and glycerol (co-fermentations) were performed. The batch fermentations showed that the initial ratio of glucose to glycerol plays an important role in glucose/glycerol co-fermentation. The optimal glucose/glycerol weight ratio was 30/30; this resulted in a maximum ε-PL productivity of 5.26 g/L/d. Glucose and glycerol were consumed synergistically during the co-fermentation process, and the length of time during which the substrate was exhausted was significantly shortened compared with the single carbon source fermentation. Under optimized conditions, f... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5219026 Sat, 10 Sep 2011 04:00:00 +0100 5219026 http://www.medworm.com/index.php?rid=5176117&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%3D21874514%26dopt%3DAbstract Authors: Kim DJ, Seo DW, Lee SH, Shipin O Abstract In a complete nitrification sequencing batch reactor (CNSBR), where ammonium containing wastewater (200-1,000 mg N/L) is completely oxidized to nitrate up to 2.4 kg NH(4) (+)-N/m(3) d, both ammonia oxidizers and nitrite oxidizers were enriched in the sludge granules. Quantitative fluorescence in situ hybridization analyses of the sludge granules of the CNSBR showed that ammonia oxidizers and nitrite oxidizers occupied 31 and 4.2% of total bacteria, respectively. Most of the nitrite oxidizers were Nitrobacter species (95% of the nitrite oxidizers) and the remainder was Nitrospira species. The population of nitrite oxidizers was significantly higher than that of partial nitrification SBR (PNSBR) where most of the ammonium was oxi... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5176117 Sat, 27 Aug 2011 23:00:00 +0100 5176117 http://www.medworm.com/index.php?rid=5176118&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%3D21870108%26dopt%3DAbstract Authors: Park J, Oh JH, Ellis TG Abstract An on-site pilot-scale static granular bed reactor (SGBR) system was evaluated for treating wastewater from a slaughterhouse in Iowa. The study evaluated SGBR reactor suitability for slaughterhose wastewater having high particulate COD concentration (7.9 ± 4.3 g COD/L) at 0.3-1.4 m(3)/m(2)/day of the surface loading rates. High organic removal efficiency (over 95% of TSS and VSS removal) was obtained due to the consistent treatability of SGBR system during operation at HRTs of 48, 36, 30, 24, and 20 h. The average effluent TSS, VSS, COD, soluble COD, and BOD(5) concentrations were 84, 71, 301,197, and 87 mg/L, respectively. An effective backwash procedure was performed once every 7-14 days to waste a portion of the accumulated solid... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5176118 Thu, 25 Aug 2011 23:00:00 +0100 5176118 http://www.medworm.com/index.php?rid=5157335&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%3D21858702%26dopt%3DAbstract In this study, under steady-state conditions, the anaerobic period of the cyclic SBR was found to allow the reductive decolorization of azo dye. Longer anaerobic periods resulted in higher color removal efficiencies, approximately 71% for the 3-h, 87% for 6-h and 92% for the 9-h duration. Total COD removal efficiencies were over 84% under each of the cyclic conditions and increased as the length of the anaerobic period was increased; however, the highest color removal rate was attained for the cycle with the shortest anaerobic period of 3 h. During the decolorization of RBV-5R, two sulfonated aromatic amines (benzene based and naphthalene based) were formed. Additionally, anaerobic azo reductase enzyme was found to be positively affected with the increasing duration of the anaerobic perio... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5157335 Sat, 20 Aug 2011 23:00:00 +0100 5157335 http://www.medworm.com/index.php?rid=5157340&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%3D21853329%26dopt%3DAbstract Authors: Bayramoglu G, Yakup Arica M Abstract In this work, a new methodology is developed for selection of affinity ligands towards the enzyme "trypsin" using quartz crystals microbalance (QCM) technique. To achieve this goal, the surface amination of gold plated QCM crystals was achieved in 13.56 MHz plasma polymerization system by using ethylenediamine. Three different ligands (i.e., 4-aminobenzamidine, 4-aminobenzoic acid, and phenylalanine) were immobilized on the aminated QCM crystals surface via glutaraldhyde coupling. All three ligand immobilized QCM crystals were characterized and compared under different experimental conditions. It was observed that the benzamidine ligand showed higher affinity to trypsin with a dissociation constant on the order of 1.76 × 10(-9) M, wh... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5157340 Thu, 18 Aug 2011 23:00:00 +0100 5157340 http://www.medworm.com/index.php?rid=5157336&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%3D21853330%26dopt%3DAbstract Authors: Li B, Chen X, Ren H, Li L, Xiong J, Bai J, Chen Y, Wu J, Ying H Abstract During ribonucleic acid fermentation, the fermentative processes were researched at pH controlled at 4.0 and under natural conditions. Unstructured models in a 50-L airlift fermentor were established for batch RNA production at pH 4.0 using the Verhulst equation for microbial growth, the Luedeking-Piret equation for product formation and a Luedeking-Piret-like equation for substrate uptake. Parameters of the kinetic models were determined using origin 7.5. Based on the models estimated above, another batch fermentation experiment was conducted in a 300-L airlift fermentor, which demonstrated that the models could be useful for RNA production on an industrial scale. Additionally, continuous fermentatio... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5157336 Thu, 18 Aug 2011 23:00:00 +0100 5157336 http://www.medworm.com/index.php?rid=5141420&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%3D21833619%26dopt%3DAbstract In this study, the high level expression of the BoNT/A-Hc was achieved by high cell density cultivation of recombinant Escherichia coli in a 2-l batch stirred-tank bioreactor. In order to maximize protein expression, post-induction time and IPTG inducer concentration were optimized by the Taguchi statistical design method. Results showed that the middle of the logarithmic phase and an IPTG concentration of 1 mM presented the optimum conditions for the maximum expression of BoNT/A-HC. High cell density cultivation was subsequently carried out as an effective strategy for the high level expression of recombinant BoNT/A-Hc. Consequently, soluble BoNT/A-Hc was produced at the maximum level of 486 mg l(-1), at 3 h post-induction, which was approximately 9.3 and 7.8 times higher than the lev... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5141420 Wed, 10 Aug 2011 23:00:00 +0100 5141420 http://www.medworm.com/index.php?rid=5141419&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%3D21833620%26dopt%3DAbstract In this study, a new-generation subsurface upflow wetland (SUW) system packed with the unique sorption media was introduced for nutrient removal. To explore the interface between hydraulic and environmental performance, a tracer study was carried out in concert with a transport model to collectively provide hydraulic retention time (7.1 days) and compelling evidence of pollutant fate and transport processes. Research findings indicate that our pollution-control media demonstrate smooth nutrient removal efficiencies across different sampling port locations given the appropriate size distribution conversant with the anticipated hydraulic patterns and layered structure among the sorption media components. The sizable capacity for nutrient removal in this bioprocess confirms that SUW is a pro... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5141419 Wed, 10 Aug 2011 23:00:00 +0100 5141419 http://www.medworm.com/index.php?rid=5141418&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%3D21833621%26dopt%3DAbstract Authors: Richetti A, Munaretto CB, Lerin LA, Batistella L, Vladimir Oliveira J, Dallago RM, Astolfi V, Luccio MD, Mazutti MA, de Oliveira D, Treichel H Abstract An experimental design was carried out to evaluate the effect of the concentrations of sodium alginate, glutaraldehyde and activated coal on the immobilization of inulinase from Kluyveromyces marxianus NRRL Y-7571. The experimental condition of 20 g/L of sodium alginate, 50 mL/L of glutaraldehyde and 30 g/L of activated coal led to the highest specific activity (2,063.5 U/mg of protein), corresponding to an enhancement of about 26 times compared to the activity of the free enzyme (79.1 U/mg of protein). The effect of pH and temperature on the immobilized enzyme activity was also evaluated, showing optimal activities at... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5141418 Wed, 10 Aug 2011 23:00:00 +0100 5141418 http://www.medworm.com/index.php?rid=5141421&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%3D21822961%26dopt%3DAbstract Authors: Ghaniyari-Benis S, Martín A, Borja R, Martín MA, Hedayat N Abstract A modelling of the anaerobic digestion process of molasses was conducted in a 70-L multistage anaerobic biofilm reactor or hybrid anaerobic baffled reactor with six compartments at an operating temperature of 26 °C. Five hydraulic retention times (6, 16, 24, 72 and 120 h) were studied at a constant influent COD concentration of 10,000 mg/L. Two different kinetic models (one was based on a dispersion model with first-order kinetics for substrate consumption and the other based on a modification of the Young equation) were evaluated and compared to predict the organic matter removal efficiency or fractional conversion. The first-order kinetic constant obtained with the dispersion model was 0.28 h(-1),... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5141421 Sat, 06 Aug 2011 23:00:00 +0100 5141421 http://www.medworm.com/index.php?rid=5103239&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%3D21796365%26dopt%3DAbstract Authors: Kapagiannidis AG, Zafiriadis I, Aivasidis A A continuous-flow anaerobic-anoxic (A2) activated sludge system was operated for efficient enhanced biological phosphorus removal (EBPR). Because of the system configuration with no aeration zones, phosphorus (P) uptake takes place solely under anoxic conditions with simultaneous denitrification. Basic operating conditions, namely biomass concentration, influent carbon to phosphorus ratio and anaerobic retention time were chosen as variables in order to assess their impact on the system performance. The experimental results indicated that maintenance of biomass concentration above 2,500 mg MLVSS/L resulted in the complete phosphate removal from the influent (i.e. 15 mg PO(4) (3-)-P/L) for a mean hydraulic residence time (HRT) of 15... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5103239 Wed, 27 Jul 2011 23:00:00 +0100 5103239 http://www.medworm.com/index.php?rid=5103241&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%3D21792564%26dopt%3DAbstract Authors: Lee JW, Hong YS, Suh C, Shin HS Online estimation of unknown state variables is a key component in the accurate modelling of biological wastewater treatment processes due to a lack of reliable online measurement systems. The extended Kalman filter (EKF) algorithm has been widely applied for wastewater treatment processes. However, the series approximations in the EKF algorithm are not valid, because biological wastewater treatment processes are highly nonlinear with a time-varying characteristic. This work proposes an alternative online estimation approach using the sequential Monte Carlo (SMC) methods for recursive online state estimation of a biological sequencing batch reactor for wastewater treatment. SMC is an algorithm that makes it possible to recursively construct the ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5103241 Tue, 26 Jul 2011 23:00:00 +0100 5103241 http://www.medworm.com/index.php?rid=5103240&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%3D21792565%26dopt%3DAbstract Authors: Ju X, Yu HL, Pan J, Xu JH We optimized culture medium and batch-fed fermentation conditions to enhance production of an acetyl esterase from Pseudomonas sp. ECU1011 (PSAE). This enzyme enantioselectively deacetylates α-acetoxyphenylacetic acid. The medium was redesigned by single-factor and statistical optimization. The addition of ZnSO(4) enhanced enzyme production by 37%. Yeast extract concentration was directly associated with the enzyme production. The fermentation was scaled up in a 5-l fermenter with the optimized medium, and the correlations between enzyme production and dissolved oxygen, pH, and feeding strategy were investigated. The fermentation process was highly oxygen-demanding, pH sensitive and mandelic acid-inducible. The fermentation pH was controlled at 7.5 b... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5103240 Tue, 26 Jul 2011 23:00:00 +0100 5103240 http://www.medworm.com/index.php?rid=5056532&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%3D21779888%26dopt%3DAbstract Authors: Batistella L, Ustra MK, Richetti A, Pergher SB, Treichel H, Oliveira JV, Lerin L, de Oliveira D Both stability and catalytic activity of two commercial immobilized lipases were investigated in the presence of different organic solvents in ultrasound-assisted system. In a general way, for Novozym 435, the use of ethanol as solvent led to a loss of activity of 35% after 10 h of contact. The use of iso-octane conducted to a gradual increase in lipase activity in relation to the contact time, reaching a maximum value of relative activity of 126%. For Lipozyme RM IM, after 5 h of exposure, the enzyme presented no residual activity when ethanol was used as solvent. The solvents tert-butanol and iso-octane showed an enhancement of about 20 and 17% in the enzyme activity in 6 h of ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5056532 Thu, 21 Jul 2011 23:00:00 +0100 5056532 http://www.medworm.com/index.php?rid=5056531&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%3D21779889%26dopt%3DAbstract Authors: Frigon JC, Roy C, Guiot SR The owners of farm-scale anaerobic digesters are relying on off-farm wastes or energy crops as a co-digestion feedstock with animal manure in order to increase their production of methane and thus revenues. Switchgrass represents an interesting feedstock for Canadian digesters owners as it is a high-yielding low-maintenance perennial crop, well adapted to northern climate. Methane potential assays in batch tests showed methane production of 19.4 ± 3.6, 28.3 ± 1.7, 37.3 ± 7.1 and 45.7 ± 0.8 L kg(-1), for raw manure, blended manure, manure and mulched switchgrass, manure and pretreated switchgrass, respectively. Two 6-L lab-scale anaerobic digesters were operated for 130 days in order to assess the benefit of co-digesting switchgrass wit... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5056531 Thu, 21 Jul 2011 23:00:00 +0100 5056531 http://www.medworm.com/index.php?rid=5056530&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%3D21779890%26dopt%3DAbstract Authors: Kuprijanov A, Schaepe S, Aehle M, Simutis R, Lübbert A An new cascade control system is presented that reproducibly keeps the cultivation part of recombinant protein production processes on its predetermined track. While the system directly controls carbon dioxide production mass and carbon dioxide production rates along their setpoint profiles in fed-batch cultivation, it simultaneously keeps the specific biomass growth rates and the biomass profiles on their desired paths. The control scheme was designed and tuned using a virtual plant environment based on the industrial process control system SIMATIC PCS 7 (Siemens AG). It is shown by means of validation experiments that the simulations in this straightforward approach directly reflect the experimentally observed controlle... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5056530 Thu, 21 Jul 2011 23:00:00 +0100 5056530 http://www.medworm.com/index.php?rid=5056529&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%3D21779891%26dopt%3DAbstract In this study, Lactobacillus rhamnosus, a renowned probiotic, was cultivated in fluctuating environment. Base gradients caused by a pH control in an industrial process and temperature gradients caused by uneven heating were simulated with a scale-down method. A pH gradient was created in a plug flow reactor (PFR). Expression of pH stress-related genes (atpA, aldB, cfa, groEL, hrcA and pstS) were studied as a relative gene expression study using ldhD as a reference gene. Expression measurements were carried out with the TRAC method. The responses of groEL, hrcA and atpA genes to temperature and pH changes were observed. The expression of phosphate uptake system-related pstS gene was induced almost linearly in the chemostat cultivation experiments when the base gradient in the PFR was increa... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5056529 Wed, 20 Jul 2011 23:00:00 +0100 5056529 http://www.medworm.com/index.php?rid=5056533&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%3D21766234%26dopt%3DAbstract Authors: Petrov K, Stoyanov A 1,3-Propanediol (1,3-PD) is a bivalent alcohol, used in a number of chemical syntheses. It could be produced from glycerol in course of microbial fermentation by Klebsiella pneumoniae along with more than five minor liquid products. With the purpose to enhance 1,3-PD production and to eliminate by-products formation, principally new pH control on the process was applied. The method, named "forced pH fluctuations" was realized by consecutive raisings of pH with definite ΔpH amplitude (ranging from 1.0 to 2.0) at time intervals between 2 and 4 h, during a series of fed batch processes. The fermentation performed by forced pH fluctuations with ΔpH = 1.0, risen at every 3 h was evaluated as the most successful. Increase by 10% of the maximal amount of 1,... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5056533 Fri, 15 Jul 2011 23:00:00 +0100 5056533 http://www.medworm.com/index.php?rid=5056534&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%3D21750920%26dopt%3DAbstract Authors: Fan J, Ding Y, Qiu Z, Li W, Lu S Soluble microbial products (SMPs) are considered as the main organic components in wastewater treatment plant effluent from biological wastewater treatment systems. To investigate and explore SMP metabolism pathway for further treatment and control, two innovative mechanistically based activated sludge models were developed by extension of activated sludge model no.3 (ASM3). One was the model by combining SMP formation and degradation (ASM3-SMP model) processes with ASM3, and the other by combining both SMP and simultaneous substrate storage and growth (SSSG) mechanisms with ASM3 (SSSG-ASM3-SMP model). The detailed schematic modification and process supplements were introduced for comprehensively understanding all the mechanisms involved in the... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5056534 Tue, 12 Jul 2011 23:00:00 +0100 5056534 http://www.medworm.com/index.php?rid=5056535&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%3D21744121%26dopt%3DAbstract Authors: Zhang DH, Lv YQ, Zhi GY, Yuwen LX Thermomyces lanuginosus lipase (Lipozyme TLIM)-catalyzed esterification of L: -ascorbic acid was studied. It was suggested that Lipozyme TLIM was a suitable biocatalyst for enzymatic esterification of L: -ascorbic acid. Three solvents were investigated for the reaction, and acetone was found to be a suitable reaction medium. Furthermore, it was found that water activity could notably affect the conversion. Moreover, pH memory of Lipozyme TLIM lipase for catalyzing L: -ascorbic acid esterification in acetone was observed and the effect of pH on the reaction was estimated. In addition, the influences of other parameters such as substrate mole ratio, enzyme loading, and reaction temperature and reusability of lipase on esterification of L: -ascor... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5056535 Fri, 08 Jul 2011 23:00:00 +0100 5056535 http://www.medworm.com/index.php?rid=5056536&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%3D21739170%26dopt%3DAbstract Authors: Badenes SM, Lemos F, Cabral JM The kinetics of the enzymatic transesterification between a mixture of triglycerides (oils) and methanol for biodiesel production in a bis(2-ethylhexyl) sodium sulfosuccinate (AOT)/isooctane reversed micellar system, using recombinant cutinase from Fusarium solani pisi as a catalyst, was investigated. In order to describe the results that were obtained, a mechanistic scheme was proposed, based on the literature and on the experimental data. This scheme includes the following reaction steps: the formation of the active enzyme-substrate complex, the addition of an alcohol molecule to the complex followed by the separation of a molecule of the fatty acid alkyl ester and a glycerol moiety, and release of the active enzyme. Enzyme inhibition and deact... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5056536 Thu, 07 Jul 2011 23:00:00 +0100 5056536 http://www.medworm.com/index.php?rid=5008868&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%3D21720965%26dopt%3DAbstract Authors: Zhang M, Yuan R, Chai Y, Li W, Zhong H, Wang C In this paper, a new glucose biosensor was prepared. At first, Prussian blue (PB) was electrodeposited on a glassy carbon electrode (GCE) modified by titanium dioxide-multiwall carbon nanotubes-chitosan (TiO(2)-MWNTs-CS) composite, and then gold nanoparticles functionalized by poly(diallyldimethylammonium chloride) (PDDA-Au) were adsorbed on the PB film. Finally, the negatively charged glucose oxidase (GOD) was self-assembled on to the positively charged PDDA-Au. The electrochemical performances of the modified electrodes had been studied by cyclic voltammetry (CV) and amperometric methods, respectively. In addition, the stepwise fabrication process of the as-prepared biosensor was characterized by scanning electron microscopy. PD... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5008868 Thu, 30 Jun 2011 23:00:00 +0100 5008868 http://www.medworm.com/index.php?rid=5008869&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%3D21706308%26dopt%3DAbstract Authors: Tawfik A, Wahab RA, Al-Asmer A, Matary F PMID: 21706308 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5008869 Sat, 25 Jun 2011 23:00:00 +0100 5008869 http://www.medworm.com/index.php?rid=5008871&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%3D21698347%26dopt%3DAbstract Authors: Wang XX, Zhao ZH, Chang TS, Liu JG Wastewater from avermectin production is refractory with high output, high chemical oxygen demand (COD) concentration and high cost further. The current wastewater treatment technology, with little reuse of the organic material, needs high dilution ratio during treatment. Yeast single cell protein was produced from the wastewater of avermectins fermentation in this research. First, the yeast strain (H-1) which show enough tolerance to avermectins residue was screened from the wastewater, and it was identified as being most closely related to Candida tropicalis (100%, EF120592.1) using 18S rDNA gene sequence analysis. Second, its growth characteristics in the avermectins wastewater were studied. The dry biomass reached the maximal point of 10�... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5008871 Wed, 22 Jun 2011 23:00:00 +0100 5008871 http://www.medworm.com/index.php?rid=5008870&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%3D21698348%26dopt%3DAbstract Authors: Kurochkina VB, Sklyarenko AV, Satarova JE, Yarotsky SV The article deals with experimental determination of ionization constants and solubility for the compounds (target products, initial β-lactams, acylating agents and by-products) involved in enzymatic synthesis of some therapeutically used aminopenicillins and aminocephalosporins, namely ampicillin, amoxicillin, cephalexin, cephadroxil, cephaloglycin, cefaclor, cefprozil, cefatrizine. Methodology of investigations and the evaluation of experimental data for the determination of ionization constants and solubility of the different type electrolytes are presented. Applications of the methods based on acid-base potentiometric titration and on determination of solubility-pH dependence of assayed substances are discussed. The o... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=5008870 Wed, 22 Jun 2011 23:00:00 +0100 5008870 http://www.medworm.com/index.php?rid=4961279&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%3D21681588%26dopt%3DAbstract Authors: Mitra S, Banerjee P, Gachhui R, Mukherjee J A polymethylmethacrylate (PMMA) conico-cylindrical flask (CCF) with an inner arrangement consisting of eight equidistantly spaced rectangular strips mounted radially on a circular disk to provide additional surface area for fungal attachment was employed for production of cellulase by Chaetomium crispatum and xylanase by Gliocladium viride. The design allowed comparison of production between CCFs with hydrophobic surface (PMMA-CCF), hydrophilic glass surface (GS-CCF) and 500-ml Erlenmeyer flask (EF). Compared with the EF, endo-β-1,4-glucanase and FPase (filter paper degradation) activities increased from 0.044 to 0.156 and from 0.008 to 0.021 IU/ml, respectively, in the PMMA-CCF, while growth of C. crispatum was higher by at most 1... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4961279 Thu, 16 Jun 2011 23:00:00 +0100 4961279 http://www.medworm.com/index.php?rid=4961280&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%3D21678044%26dopt%3DAbstract Authors: Rezić T, Zeiner M, Santek B, Novak S Industrial wastewaters polluted with toxic heavy metals are serious ecological and environmental problem. Therefore, in this study multi-heavy metals (Fe(2+), Cu(2+), Ni(2+) and Zn(2+)) removal process with mixed microbial culture was examined in the horizontal rotating tubular bioreactor (HRTB) by different combinations of process parameters. Hydrodynamic conditions and biomass sorption capacity have main impact on the removal efficiency of heavy metals: Fe(2+) 95.5-79.0%, Ni(2+) 92.7-54.8%, Cu(2+) 87.7-54.9% and Zn(2+) 81.8-38.1%, respectively. On the basis of experimental results, integral mathematical model of removal heavy metals in the HRTB was established. It combines hydrodynamics (mixing), mass transfer and kinetics to define biop... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4961280 Wed, 15 Jun 2011 23:00:00 +0100 4961280 http://www.medworm.com/index.php?rid=4961281&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%3D21674266%26dopt%3DAbstract This study was helpful in the construction of an E. coli system that can display selective metal binding peptides on the surface of the cell in response to exogenous zinc. The engineered bacterial system for monitoring exogenous zinc was successfully employed to detect levels of zinc as low as 0.001 mM, which directly activates the expression of chimeric ompC ( t )-zinc binding peptide gene to remove zinc by adsorbing a maximum of 163.6 μmol of zinc per gram of dry cell weight. These results indicate that the engineered bacterial strain developed in the present study can sense the specific heavy metal and activates a cell surface display system that acts to remove the metal. PMID: 21674266 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4961281 Tue, 14 Jun 2011 23:00:00 +0100 4961281 http://www.medworm.com/index.php?rid=4961282&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%3D21656156%26dopt%3DAbstract Authors: Jallouli W, Jaoua S, Zouari N For low-cost production of Photorhabdus temperata ssp. temperata strain K122 bioinsecticide, a cheap complex medium was optimized. Diluted seawater was used as the source of micronutrients, especially sodium chloride, involved in the improvement of cell density, culturability and oral toxicity of the bacterium P. temperata against Ephestia kuehniella larvae. Thus, the new formulated medium was composed only of 10 g/l of soya bean meal, used as the carbon and nitrogen main source, mixed in sevenfold diluted seawater. At such conditions, several limitations of P. temperata bioinsecticide productions were shown to be overcome. The appearance of variants small colony polymorphism was completely avoided. Thus, the strain K122 was maintained at the pri... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4961282 Wed, 08 Jun 2011 23:00:00 +0100 4961282 http://www.medworm.com/index.php?rid=4912438&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%3D21647681%26dopt%3DAbstract Authors: Facchini FD, Vici AC, Benassi VM, Freitas LA, Reis RA, Jorge JA, Terenzi HF, Polizeli MD Fibrolytic enzyme production by Aspergillus japonicus C03 was optimized in a medium containing agro-industrial wastes, supplemented with peptone and yeast extract. A 2(3) full factorial composite and response surface methodology were used to design the experiments and analysis of results. Tropical forages were hydrolyzed by A. japonicus C03 enzymatic extract in different levels, and they were also tested as enzymatic substrate. Optimal production to xylanase was obtained with soybean bran added to crushed corncob (1:3), 0.01% peptone, and 0.2% yeast extract, initial pH 5.0, at 30 °C under static conditions for 5 days of incubation. Optimal endoglucanase production was obtained with whea... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4912438 Mon, 06 Jun 2011 23:00:00 +0100 4912438 http://www.medworm.com/index.php?rid=4912441&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%3D21643974%26dopt%3DAbstract Authors: Román RC, Hernández OG, Urtubia UA Artificial neural networks (ANNs) have been used for the recognition of non-linear patterns, a characteristic of bioprocesses like wine production. In this work, ANNs were tested to predict problems of wine fermentation. A database of about 20,000 data from industrial fermentations of Cabernet Sauvignon and 33 variables was used. Two different ways of inputting data into the model were studied, by points and by fermentation. Additionally, different sub-cases were studied by varying the predictor variables (total sugar, alcohol, glycerol, density, organic acids and nitrogen compounds) and the time of fermentation (72, 96 and 256 h). The input of data by fermentations gave better results than the input of data by points. In fact, it was poss... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4912441 Sat, 04 Jun 2011 23:00:00 +0100 4912441 http://www.medworm.com/index.php?rid=4912440&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%3D21643975%26dopt%3DAbstract Authors: Zhang M, Lawlor PG, Wu G, Lynch B, Zhan X The performance of an intermittently aerated sequencing batch reactor (IASBR) technology was investigated in achieving partial nitrification, organic matter removal and nitrogen removal from separated digestate liquid after anaerobic digestion of pig manure. The wastewater had chemical oxygen demand (COD) concentrations of 11,540 ± 860 mg/L, 5-day biochemical oxygen demand (BOD(5)) concentrations of 2,900 ± 200 mg/L and total nitrogen (TN) concentrations of 4,041 ± 59 mg/L, with low COD:N ratios (2.9) and BOD(5):COD ratios (0.25). Synthetic wastewater, simulating the separated digestate liquid with similar COD and nitrogen concentrations but BOD(5) of 11,500 ± 100 mg/L, was also treated using the IASBR technology. At a ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4912440 Sat, 04 Jun 2011 23:00:00 +0100 4912440 http://www.medworm.com/index.php?rid=4912439&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%3D21643976%26dopt%3DAbstract In this study, effect of nitrogen limitation during acclimatization period of biomass on production of polyhydroxyalkanoate was investigated. Activated sludge was selected in two sequencing batch reactors operated with and without nitrogen limitation. Batch tests were performed to examine polymer productions of activated sludges acclimatized to different nitrogen regimes. Responses of biomass to different organic loading rates, organic acids, and carbon to nitrogen (C/N) ratios were studied by determining specific polymer storage rate, polymer storage yield, and sludge polymer content of biomasses. Results obtained from batch experiments showed that concentrations of polymer accumulated by two different sludges increased directly with initial substrate concentration. Observed highest polym... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4912439 Sat, 04 Jun 2011 23:00:00 +0100 4912439 http://www.medworm.com/index.php?rid=4912442&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%3D21643688%26dopt%3DAbstract Authors: Sun T, Wang L, Li N, Gan X A sensitive label-free electrochemical aptasensor was successfully fabricated for thrombin detection with nafion@graphene as platform. With electrostatic interaction between nafion and methylene blue (MB), positive charged MB was successfully assembled on nafion@graphene modified electrode surface, which provided amounts of redox probes for electrochemical aptasensor. In the presence of thrombin, the thrombin aptamer (TBA) on the electrode surface would catch the target on the electrode interface, which made a barrier for electrons and inhibits the electro-transfer, resulting in the decreased differential pulse voltammetry signals of MB. As a result, the proposed approach showed a high sensitivity and a wider linearity to thrombin in the range 0.01-5... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4912442 Fri, 03 Jun 2011 23:00:00 +0100 4912442 http://www.medworm.com/index.php?rid=4912443&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%3D21630078%26dopt%3DAbstract Authors: Dhillon GS, Brar SK, Valero JR, Verma M Studies were carried out for β-glucosidase production using apple pomace (AP) in solid-state fermentation using 2(4) factorial design and response surface methodology. The influence of four independent variables including initial moisture level and inducers [veratryl alcohol (VA), lactose (LAC) and copper sulfate (CS)] was studied. The experimental design showed that initial moisture level had significant negative effect on the response. Higher β-glucosidase activity of 64.18 IU/gram fermented substrate (gfs) was achieved in solid-state tray fermentation with optimum conditions having initial moisture level 55% (v/w), pH 4.5, 2 mM/kg VA, 2% (w/w) LAC and 1.5 mM/kg CS concentration, respectively,. The non-specific chitinase 70.28 ±... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4912443 Tue, 31 May 2011 23:00:00 +0100 4912443 http://www.medworm.com/index.php?rid=4865037&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%3D21604055%26dopt%3DAbstract Authors: Durmaz-Sam S, Sayar NA, Topal-Sarikaya A, Sayar AA The potential of the dried yeast, wild-type Schizosaccharomyces pombe, to remove Ni(II) ion was investigated in batch mode under varying experimental conditions including pH, temperature, initial metal ion concentration and biosorbent dose. Optimum pH for biosorption was determined as 5.0. The highest equilibrium uptake of Ni(II) on S. pombe, q (e), was obtained at 25 °C as 33.8 mg g(-1). It decreased with increasing temperature within a range of 25-50 °C denoting an exothermic behaviour. Increasing initial Ni(II) concentration up to 400 mg L(-1) also elevated equilibrium uptake. No more adsorption took place beyond 400 mg L(-1). Equilibrium data fitted better to Langmuir model rather than Freundlich model. Sips, Red... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4865037 Fri, 20 May 2011 23:00:00 +0100 4865037 http://www.medworm.com/index.php?rid=4865038&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%3D21573983%26dopt%3DAbstract Authors: Zheng Y, Yates M, Aung H, Cheng YS, Yu C, Guo H, Zhang R, Vandergheynst J, Jenkins BM Seasonally produced biomass such as sugar beet pulp (SBP) and tomato pomace (TP) needs to be stored properly to meet the demand of sustainable biofuel production industries. Ensilage was used to preserve the feedstock. The effect of moisture content (MC) on the performance of ensilage and the relationship between microorganism activities and MC were investigated. For SBP, MC levels investigated were 80, 55, 30, and 10% on a wet basis. For TP, MC levels investigated were 60, 45, 30, and 10%. Organic acids, ethanol, ammonia, pH and water soluble carbohydrates (WSC) were measured to evaluate the silage quality. Ensilage improved as the MC decreased from 80 to 55% for SBP and from 60 to 45% for T... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4865038 Sat, 14 May 2011 23:00:00 +0100 4865038 http://www.medworm.com/index.php?rid=4810680&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%3D21553014%26dopt%3DAbstract Authors: Zabot GL, Mecca J, Mesomo M, Silva MF, Prá VD, de Oliveira D, Oliveira JV, Castilhos F, Treichel H, Mazutti MA This work is focused on hybrid modeling of xanthan gum bioproduction process by Xanthomonas campestris pv. mangiferaeindicae. Experiments were carried out to evaluate the effects of stirred speed and superficial gas velocity on the kinetics of cell growth, lactose consumption and xanthan gum production in a batch bioreactor using cheese whey as substrate. A hybrid model was employed to simulate the bio-process making use of an artificial neural network (ANN) as a kinetic parameter estimator for the phenomenological model. The hybrid modeling of the process provided a satisfactory fitting quality of the experimental data, since this approach makes possible the incorpo... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810680 Fri, 06 May 2011 23:00:00 +0100 4810680 http://www.medworm.com/index.php?rid=4810681&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%3D21538015%26dopt%3DAbstract Authors: Meeuwse P, Tramper J, Rinzema A Lipid-accumulating fungi may be able to produce biodiesel precursors from agricultural wastes. As a first step in understanding and evaluating their potential, a mathematical model was developed to describe growth, lipid accumulation and substrate consumption of the oleaginous fungus Umbelopsis isabellina (also known as Mortierella isabellina) in submerged chemostat cultures. Key points of the model are: (1) if the C-source supply rate is limited, maintenance has a higher priority than growth, which has a higher priority than lipid production; (2) the maximum specific lipid production rate of the fungus is independent of the actual specific growth rate. Model parameters were obtained from chemostat cultures of U. isabellina grown on mineral medi... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810681 Mon, 02 May 2011 23:00:00 +0100 4810681 http://www.medworm.com/index.php?rid=4810682&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%3D21533792%26dopt%3DAbstract Authors: Lee JW, Suh C, Hong YS, Shin HS This work proposes a sequential modelling approach using an artificial neural network (ANN) to develop four independent multivariate models that are able to predict the dynamics of biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solid (SS), and total nitrogen (TN) removal in a wastewater treatment plant (WWTP). Suitable structures of ANN models were automatically and conveniently optimized by a genetic algorithm rather than the conventional trial and error method. The sequential modelling approach, which is composed of two parts, a process disturbance estimator and a process behaviour predictor, was also presented to develop multivariate dynamic models. In particular, the process disturbance estimator was first employed ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810682 Sat, 30 Apr 2011 23:00:00 +0100 4810682 http://www.medworm.com/index.php?rid=4810683&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%3D21516366%26dopt%3DAbstract Authors: Meeuwse P, Tramper J, Rinzema A A model that predicts cell growth, lipid accumulation and substrate consumption of oleaginous fungi in chemostat cultures (Meeuwse et al. in Bioproc Biosyst Eng. doi: 10.1007/s00449-011-0545-8 , 2011) was validated using 12 published data sets for chemostat cultures of oleaginous yeasts and one published data set for a poly-hydroxyalkanoate accumulating bacterial species. The model could describe all data sets well with only minor modifications that do not affect the key assumptions, i.e. (1) oleaginous yeasts and fungi give the highest priority to C-source utilization for maintenance, second priority to growth and third priority to lipid accumulation, and (2) oleaginous yeasts and fungi have a growth rate independent maximum specific lipid prod... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810683 Fri, 22 Apr 2011 23:00:00 +0100 4810683 http://www.medworm.com/index.php?rid=4810684&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%3D21509544%26dopt%3DAbstract Authors: García-Gutiérrez K, Poggi-Varaldo HM, Esparza-García F, Ibarra-Rendón J, Barrera-Cortés J PMID: 21509544 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering) Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810684 Wed, 20 Apr 2011 23:00:00 +0100 4810684 http://www.medworm.com/index.php?rid=4810687&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%3D21505813%26dopt%3DAbstract Authors: Liu C, Xu J, Wu Z ZnO hollow spheres were firstly prepared. A new type of amperometric hydrogen peroxide biosensor was fabricated by entrapping Hemoglobin (Hb) through the ZnO hollow spheres (ZHS) nanoparticles. The composition morphology and size were studied by transmission electron microscopy. The surface topography of the prepared films was imaged by atomic force microscope (AFM). Several techniques, including UV-vis absorption spectroscopy, cyclic voltammetry, chronoamperometry were employed to characterize the performance of the biosensor. The results indicated that the ZHS nanoparticles had enhanced the performance of the hydrogen peroxide sensors. The electrochemical parameters of Hb in the ZHS were calculated by the results of the electron-transfer coefficient (α) an... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810687 Tue, 19 Apr 2011 23:00:00 +0100 4810687 http://www.medworm.com/index.php?rid=4810686&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%3D21505814%26dopt%3DAbstract Authors: Zhong H, Yuan R, Chai Y, Li W, Zhang Y, Wang C An electrochemical biosensor for determination of hydrogen peroxide (H(2)O(2)) was fabricated, based on the electrostatic immobilization of horseradish peroxidase (HRP) with one-dimensional gold nanowires (Au NWs) and TiO(2) nanoparticles (nano-TiO(2)) on a gold electrode. The nano-TiO(2) can give a biocompatible microenvironment and compact film, and the Au NWs can provide fast electron transferring rate and greatly add the amount of HRP molecules immobilized on the electrode surface. Au NWs were characterized by ultraviolet-visible spectra and transmission electron microscope. The electrode modification process was probed by cyclic voltammetry and electrochemical impedance spectroscopy. Chronoamperometry was used to study the el... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810686 Tue, 19 Apr 2011 23:00:00 +0100 4810686 http://www.medworm.com/index.php?rid=4810685&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%3D21505815%26dopt%3DAbstract Authors: Sandadi S, Pedersen H, Bowers JS, Rendeiro D Large scale production of monoclonal antibodies has been accomplished using bioreactors with different length to diameter ratios, and diverse impeller and sparger designs. The differences in these physical attributes often result in dissimilar mass transfer, mechanical stresses due to turbulence and mixing inside the bioreactor that may lead to disparities in cell growth and antibody production. A rational analysis of impeller design parameters on cell growth, protein expression levels and subsequent antibody production is needed to understand such differences. The purpose of this study was to examine the impact of Rushton turbine and marine impeller designs on Chinese hamster ovary (CHO) cell growth and metabolism, and antibody pro... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810685 Tue, 19 Apr 2011 23:00:00 +0100 4810685 http://www.medworm.com/index.php?rid=4810719&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%3D21487698%26dopt%3DAbstract Authors: Valladares Juárez AG, Rost G, Heitmann U, Heger E, Müller R A novel biotechnological process for the production of high-quality flax fibers was developed. In this process, decorticated fibers from green flax were washed with 0.5% soda solution and treated with the pectinolytic strain Geobacillus thermoglucosidasius PB94A. Before drying the fibers, they were treated with the textile softener Adulcinol BUN. If the fibers contained contaminant shives, a bleaching step with hydrogen peroxide was performed before the softener treatment. In experiments where fibers were treated by the new process, and in which the bacterial solutions were reused seven times, the fiber quality was similar in all batches. The resolution of the treated fibers was 2.7 ± 0.4 and the fineness was 11.... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810719 Tue, 12 Apr 2011 23:00:00 +0100 4810719 http://www.medworm.com/index.php?rid=4810690&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%3D21487699%26dopt%3DAbstract Authors: Murthy GS, Johnston DB, Rausch KD, Tumbleson ME, Singh V Efficiency of the starch hydrolysis in the dry grind corn process is a determining factor for overall conversion of starch to ethanol. A model, based on a molecular approach, was developed to simulate structure and hydrolysis of starch. Starch structure was modeled based on a cluster model of amylopectin. Enzymatic hydrolysis of amylose and amylopectin was modeled using a Monte Carlo simulation method. The model included the effects of process variables such as temperature, pH, enzyme activity and enzyme dose. Pure starches from wet milled waxy and high-amylose corn hybrids and ground yellow dent corn were hydrolyzed to validate the model. Standard deviations in the model predictions for glucose concentration and DE valu... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810690 Tue, 12 Apr 2011 23:00:00 +0100 4810690 http://www.medworm.com/index.php?rid=4810735&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%3D21479596%26dopt%3DAbstract Authors: Horta AC, da Silva AJ, Sargo CR, Gonçalves VM, Zangirolami TC, de Campos Giordano R One of the most important events in fed-batch fermentations is the definition of the moment to start the feeding. This paper presents a methodology for a rational selection of the architecture of an artificial intelligence (AI) system, based on a neural network committee (NNC), which identifies the end of the batch phase. The AI system was successfully used during high cell density cultivations of recombinant Escherichia coli. The AI algorithm was validated for different systems, expressing three antigens to be used in human and animal vaccines: fragments of surface proteins of Streptococcus pneumoniae (PspA), clades 1 and 3, and of Erysipelothrix rhusiopathiae (SpaA). Standard feed-forward ne... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810735 Fri, 08 Apr 2011 23:00:00 +0100 4810735 http://www.medworm.com/index.php?rid=4810749&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%3D21472408%26dopt%3DAbstract Authors: Ahn S, Lee S, Cho Y, Chun W, Kim G Natural biopolymers, such as collagen or chitosan, are considered ideal for biomedical scaffolds. However, low processability of the materials has hindered the fabrication of designed pore structures controlled by various solid freeform-fabrication methods. A new technique to fabricate a biomedical three-dimensional collagen scaffold, supplemented with a sacrificial poly(ethylene oxide) mould is proposed. The fabricated collagen scaffold shows a highly porous surface and a three-dimensional structure with high porosity as well as mechanically stable structure. To show its feasibility for biomedical applications, fibroblasts/keratinocytes were co-cultured on the scaffold, and the cell proliferation and cell migration of the scaffold was more ... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810749 Wed, 06 Apr 2011 23:00:00 +0100 4810749 http://www.medworm.com/index.php?rid=4810762&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%3D21461947%26dopt%3DAbstract Authors: Gökgöz M, Yiğitoğlu M In this work, modified carboxymethylcellulose (CMC) was used as a new support material for production of ethanol. Crosslinked graft copolymers of CMC with N-vinyl-2-pyrrolidone (N-VP) were prepared in different grafting yields. The beads material was characterized by means of fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and swelling experiment. Saccharomyces cerevisiae was immobilized using entrapment method in the graft copolymers of carboxymethylcellulose-g-poly(N-vinyl-2-pyrrolidone) (CMC-g-PVP) for ethanol fermentation. The effects of grafting yield, initial glucose concentration and crosslinker concentration on the yield of ethanol process were investigated. Reusabili... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810762 Sat, 02 Apr 2011 23:00:00 +0100 4810762 http://www.medworm.com/index.php?rid=4810765&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%3D21461772%26dopt%3DAbstract Authors: García-Diéguez C, Salgado JM, Roca E, Domínguez JM A mathematical model describing the kinetics of the sequential production of lactic acid and xylitol from detoxified-concentrated vine trimming hemicellulosic hydrolysates by Lactobacillus rhamnosus and Debaryomyces hansenii, respectively, was developed from the basic principles of mass balance in two stages considering as main reactions: (1) glucose and xylose consumption by L. rhamnosus; and (2) xylitol and arabitol production by D. hansenii. The model allows to evaluate the yields and productivities under microaerobic and oxygen restricted conditions (in particular the effects caused by purging the oxygen with nitrogen), which were particularly important during the xylose to xylitol bioconversion by yeasts. The model was... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4810765 Fri, 01 Apr 2011 23:00:00 +0100 4810765 http://www.medworm.com/index.php?rid=4643520&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%3D21442419%26dopt%3DAbstract Authors: Sempere F, Martínez-Soria V, Palau J, Penya-Roja JM, San-Valero P, Gabaldón C The removal of styrene-polluted air emissions by biotrickling filtration was performed to evaluate the influence of using nitrate and urea as a nitrogen source in the nutrient solution supplied to two bioreactors run in parallel under the same operational conditions for 3 months. The use of urea resulted in less biomass content along the packed bed and better performance of the process, with a maximum elimination capacity (EC) of 57.6 g C m(-3 )h(-1) (removal efficiency (RE) of 88.3% and empty bed residence time (EBRT) of 60 s), which was around 54% higher than when using nitrate. EBRTs of 60, 30 and 15 s were evaluated with a urea-based nutrient supply. By decreasing the EBRT from 60 to 30�... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4643520 Sun, 27 Mar 2011 00:00:00 +0100 4643520 http://www.medworm.com/index.php?rid=4643522&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%3D21409450%26dopt%3DAbstract Authors: An HJ, Lee HJ, Jun SH, Hwang SY, Kim BC, Kim K, Lee KM, Oh MK, Kim J Lipase (LP) was immobilized on electrospun and ethanol-dispersed polystyrene-poly(styrene-co-maleic anhydride) (PS-PSMA) nanofibers (EtOH-NF) in the form of enzyme precipitate coatings (EPCs). LP precipitate coatings (EPCs-LP) were prepared in a three-step process, consisting of covalent attachment, LP precipitation, and crosslinking of precipitated LPs onto the covalently attached LPs via glutaraldehyde treatment. The LP precipitation was performed by adding various concentrations of ammonium sulfate (20-50%, w/v). EPCs-LP improved the LP activity and stability when compared to covalently attached LPs (CA-LP) and the enzyme coatings of LPs (EC-LP) without the LP precipitation. For example, the use of 40% (w/... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4643522 Wed, 16 Mar 2011 00:00:00 +0100 4643522 http://www.medworm.com/index.php?rid=4643521&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%3D21409451%26dopt%3DAbstract In this study, Candida antarctica lipase B (CalB) was fused with various polycationic amino acid tags and expressed in E. coli in order to increase a soluble expression level. By induction with 1.0 mM IPTG, the authentic and fused CalBs were expressed at 27-56% of total protein. The 10-arginine and 10-lysine tags fused at the C-terminal of CalB significantly increased the solubility of CalB by five- to ninefold, relative to the case of the authentic CalB expressed in a recombinant E. coli Origami 2(TM) (DE3) strain. Among a series of the C-terminal poly-arginine tags, the recombinant CalB combined with the 10-arginine tag (CalB-R10) possessed the highest lipase specific activity of 9.5 ± 0.03 U/mg protein, corresponding to a fourfold enhancement compared with the authentic CalB. P... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4643521 Wed, 16 Mar 2011 00:00:00 +0100 4643521 http://www.medworm.com/index.php?rid=4582178&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%3D21359535%26dopt%3DAbstract Authors: Tawfik A, Wahab RA, Al-Asmer A, Matary F Grey wastewater (GW) treatment via down-flow hanging sponge (DHS) system was the subject of the study. The reactor was operated at different hydraulic retention times (HRTs) of 11.7, 5.8 and 2.9 h, corresponding to organic loading rates (OLRs) of 1.9, 3.6 and 6.8 kgCOD/m(3) day, respectively. The results obtained revealed that decreasing the HRT from 11.7 to 2.9 h negatively affected on the performance of the DHS system. COD(total), COD(soluble), COD(particulate) and detergent removal efficiency were reduced from 96 ± 2.4 to 90 ± 2.3%, from 83 ± 10 to 69 ± 8%, from 98 ± 2 to 94 ± 3% and from 96 ± 12 to 88 ± 6.9%, respectively. However, the removal efficiency of the distinguished COD fractions and detergent re... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4582178 Sat, 26 Feb 2011 00:00:00 +0100 4582178 http://www.medworm.com/index.php?rid=4582180&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%3D21350955%26dopt%3DAbstract Authors: Jeong KJ, Rani M Previously, we isolated the M18 scFv, which is an affinity matured antibody against the anthrax toxin PA, and observed that its single chain antibody (scAb) form (M18 scAb) exhibited superior stability compared to the scFv. Here, we report high cell density cultivations for preparative scale production of M18 scAb in a 3.5 L fermenter. Briefly, a pH-stat feeding strategy was employed in fed-batch cultivation, and four different cell densities (OD(600) of 40, 80, 120, and 150) were examined for the induction of scAb gene expression. Among the four cell densities investigated, lower cell densities (OD(600) of 40) showed higher post-induction cell growth and production yields (665 mg/L of scAb). Even though lower solubility (51%) of scAb was achieved at lower c... Bioprocess and Biosystems Engineering journals http://www.medworm.com/rss/comments.php?id=4582180 Fri, 25 Feb 2011 00:00:00 +0100 4582180