Bioprocess and Biosystems EngineeringThis is an RSS file. You can use it to subscribe to this data in your favourite RSS reader, such as GoogleReader, or to display this data on your own website or blog. Subscribe to this data using MyMedWorm.Subscribe to this data using GoogleReader.Subscribe to this data using Bloglines.Subscribe to this data using MyYahoo.

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Identification of cultivation condition to produce correctly folded form of a malaria vaccine based on Plasmodium falciparum merozoite surface protein-1 in Escherichia coli.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The C-terminal, 19-kDa domain of Plasmodium falciparum merozoite surface protein-1 (PfMSP-1(19)) is among the leading vaccine candidate for malaria due to its essential role in erythrocyte invasion by the parasite. We designed a synthetic gene for optimal expression of recombinant PfMSP-1(19) in Escherichia coli and developed a scalable process to obtain high-quality PfMSP-1(19). The synthetic gene construct yielded a fourfold higher expression level of PfMSP-1(19) in comparison to the native gene construct. Optimization of cultivation conditions in the bioreactor indicated important role of yeast extract and substrate...
Source: Bioprocess and Biosystems Engineering - November 18, 2009 Category: Biomedical Engineering Authors: Mazumdar S, Sachdeva S, Chauhan VS, Yazdani SS Tags: Bioprocess Biosyst Eng Source Type: journals

Maintaining high anaerobic succinic acid productivity by product removal.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
During dual-phase fermentations using Escherichia coli engineered for succinic acid production, the productivity and viable cell concentration decrease as the concentration of succinic acid increases. The effects of succinic acid on the fermentation kinetics, yield, and cell viability were investigated by resuspending cells in fresh media after selected fermentation times. The cellular succinic acid productivity could be restored, but cell viability continuously decreased throughout the fermentations by up to 80% and subsequently the volumetric productivity was reduced. Omitting complex nutrients in the resuspension me...
Source: Bioprocess and Biosystems Engineering - November 17, 2009 Category: Biomedical Engineering Authors: Andersson C, Petrova E, Berglund K, Rova U Tags: Bioprocess Biosyst Eng Source Type: journals

Process optimization for the production of diosgenin with Trichoderma reesei.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Based on the response surface methodology, an effective microbial system for diosgenin production from enzymatic pretreated Dioscorea zingiberensis tubers with Trichoderma reesei was studied. The fermentation medium was optimized with central composite design (3(5)) depended on Plackett-Burmann design which identified significant impacts of peptone, K(2)HPO(4) and Tween 80 on diosgenin yield. The effects of different fermentation conditions on diosgenin production were also studied. Four parameters, i.e. incubation period, temperature, initial pH and substrate concentration were optimized using 4(5) central composite d...
Source: Bioprocess and Biosystems Engineering - November 15, 2009 Category: Biomedical Engineering Authors: Zhu Y, Ni J, Huang W Tags: Bioprocess Biosyst Eng Source Type: journals

Estimating the cellular maintenance coefficient and its use in the design of two-phase partitioning bioscrubbers.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
One of the key roles of an organic solvent has emerged to be the enhancement of oxygen transfer in two-phase partitioning bioscrubbers (TPPBs). In order to determine an optimum organic fraction for a given VOCs loading, the oxygen demand of the total cell mass must be estimated, which depends upon the magnitude of the cellular maintenance coefficient. We have estimated the dynamics of the maintenance coefficient for benzene degradation by Achromobacter xylosoxidans Y234 in a TPPB and found that the maintenance coefficient generally decreased as cells accumulated in the TPPB but converged to a specific value of 1.750 x ...
Source: Bioprocess and Biosystems Engineering - November 14, 2009 Category: Biomedical Engineering Authors: Yeom SH, Daugulis AJ, Nielsen DR Tags: Bioprocess Biosyst Eng Source Type: journals

Nonlinear process modeling of fructosyltransferase (FTase) using bootstrap re-sampling neural network model.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Recently, the increased demand of fructooligosaccharides (FOS) as a functional food has alarmed researchers to screen and identify new strains capable of producing fructosyltransferase (FTase). FTase is the enzyme that converts the substrate (sucrose) to glucose and fructose. The characterization of complex sugar such as table sugar, brown sugar, molasses, etc. will be carried out and the sugar that contained the highest sucrose concentration will be selected as a substrate. Eight species of macro-fungi will be screened for its ability to produce FTase and only one strain with the highest FTase activity will be selecte...
Source: Bioprocess and Biosystems Engineering - November 14, 2009 Category: Biomedical Engineering Authors: Ahmad Z, Mat Don M, Mortan SH, Mat Noor RA Tags: Bioprocess Biosyst Eng Source Type: journals

Kinetics of enzymatic trans-esterification of glycerides for biodiesel production.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this paper, the reaction of enzymatic trans-esterification of glycerides with ethanol in a reaction medium containing hexane at a temperature of 37 degrees C has been studied. The enzyme was Lipase from Mucor miehei, immobilized on ionic exchange resin, aimed at achieving high catalytic specific surface and recovering, regenerating and reusing the biocatalyst. A kinetic analysis has been carried out to identify the reaction path; the rate equation and kinetic parameters have been also calculated. The kinetic model has been validated by comparison between predicted and experimental results. Mass transport resistances...
Source: Bioprocess and Biosystems Engineering - November 10, 2009 Category: Biomedical Engineering Authors: Calabrò V, Ricca E, De Paola MG, Curcio S, Iorio G Tags: Bioprocess Biosyst Eng Source Type: journals

Batch and fed-batch fermentation of Bacillus thuringiensis using starch industry wastewater as fermentation substrate.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Bacillus thuringiensis var. kurstaki biopesticide was produced in batch and fed-batch fermentation modes using starch industry wastewater as sole substrate. Fed-batch fermentation with two intermittent feeds (at 10 and 20 h) during the fermentation of 72 h gave the maximum delta-endotoxin concentration (1,672.6 mg/L) and entomotoxicity (Tx) (18.5 x 10(6) SBU/mL) in fermented broth which were significantly higher than maximum delta-endotoxin concentration (511.0 mg/L) and Tx (15.8 x 10(6) SBU/mL) obtained in batch process. However, fed-batch fermentation with three intermittent feeds (at 10, 20 and 34 h) of the fermenta...
Source: Bioprocess and Biosystems Engineering - November 4, 2009 Category: Biomedical Engineering Authors: Vu KD, Tyagi RD, Valéro JR, Surampalli RY Tags: Bioprocess Biosyst Eng Source Type: journals

Enzymatic synthesis of poly-L: -lactide and poly-L: -lactide-co-glycolide in an ionic liquid.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The syntheses of poly-L: -lactide (PLLA) and poly-L: -lactide-co-glycolide (PLLGA) is reported in the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate [HMIM][PF(6)] mediated by the enzyme lipase B from Candida antarctica (Novozyme 435). The highest PLLA yield (63%) was attained at 90 degrees C with a molecular weight (M ( n )) of 37.8 x 10(3) g/mol determined by size exclusion chromatography. This procedure produced relatively high crystalline polymers (up to 85% PLLA) as determined by DSC. In experiments at 90 degrees C product synthesis also occurred without biocatalyst, however, PLLA synthesis in [HMIM][...
Source: Bioprocess and Biosystems Engineering - November 4, 2009 Category: Biomedical Engineering Authors: Chanfreau S, Mena M, Porras-Domínguez JR, Ramírez-Gilly M, Gimeno M, Roquero P, Tecante A, Bárzana E Tags: Bioprocess Biosyst Eng Source Type: journals

Improvement of laccase production and its properties by low-energy ion implantation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Low-energy ion implantation was employed to breed laccase producing strain Paecilomyces sp. WSH-L07 and a mutant S152 that exhibited an activity of more than three times over the wild strain was obtained. The optimum substrate of both the wild and mutant laccases was 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate), and followed by guaiacol with optimal pH at 3.4 and 5.0, respectively, while the mutant laccase exhibited a broader active pH range. The mutant laccase had a higher optimal catalytic temperature (60-65 degrees C) than the wild one (55 degrees C), and the wild laccase deactivated rapidly when temperature i...
Source: Bioprocess and Biosystems Engineering - October 31, 2009 Category: Biomedical Engineering Authors: Liu Z, Zhang D, Hua Z, Li J, Du G, Chen J Tags: Bioprocess Biosyst Eng Source Type: journals

Anaerobic treatment of winery wastewater in fixed bed reactors.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The treatment of winery wastewater in three upflow anaerobic fixed-bed reactors (S9, S30 and S40) with low density floating supports of varying size and specific surface area was investigated. A maximum OLR of 42 g/l day with 80 +/- 0.5% removal efficiency was attained in S9, which had supports with the highest specific surface area. It was found that the efficiency of the reactors increased with decrease in size and increase in specific surface area of the support media. Total biomass accumulation in the reactors was also found to vary as a function of specific surface area and size of the support medium. The Stover-K...
Source: Bioprocess and Biosystems Engineering - October 30, 2009 Category: Biomedical Engineering Authors: Ganesh R, Rajinikanth R, Thanikal JV, Ramanujam RA, Torrijos M Tags: Bioprocess Biosyst Eng Source Type: journals

Preparation of a composite film electrochemically deposited with chitosan and gold nanoparticles for the determination of alpha-1-fetoprotein.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A novel amperometric immunosensor based on chitosan-gold nanoparticles (Chit-GNPs) composite film and thionine (Thi) was prepared for the determination of alpha-1-fetoprotein (AFP). The immunosensor was prepared by electro-depositing a Chit-GNPs composite matrix on the surface of the glass carbon electrode, then Thi was immobilized onto the Chit-GNPs film using glutaraldehyde as a cross-linker. Furthermore, the GNPs were chemisorbed onto Thi film for immobilization of alpha-1-fetoprotein antibody. The procedure of the immunosensor was characterized by means of cyclic voltammograms. The performance and influencing facto...
Source: Bioprocess and Biosystems Engineering - October 27, 2009 Category: Biomedical Engineering Authors: Liu Y, Yuan R, Chai Y, Hong C, Guan S Tags: Bioprocess Biosyst Eng Source Type: journals

Enhancement of human granulocyte-colony stimulating factor production in recombinant E. coli using batch cultivation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Development of inexpensive and simple culture media is always favorable for recombinant protein over-expression in E. coli. The effects of medium composition on the production of recombinant human granulocyte-colony stimulating factor (rh-GCSF) were investigated in batch culture of E. coli BL21 (DE3) [pET23a-hgcsf]. First, the optimum medium for production of rh-GCSF was determined; and, then it was shown that mixture of amino acid addition at induction time, which was determined on the basis of amino acids frequency in the recombinant protein, increases recombinant protein expression level significantly. Furthermore, ...
Source: Bioprocess and Biosystems Engineering - October 27, 2009 Category: Biomedical Engineering Authors: Babaeipour V, Pesaran Haji Abbas M, Sahebnazar Z, Alizadeh R Tags: Bioprocess Biosyst Eng Source Type: journals

beta-Glucosidase coating on polymer nanofibers for improved cellulosic ethanol production.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
beta-Glucosidase (betaG) can relieve the product inhibition of cellobiose in the cellulosic ethanol production by converting cellobiose into glucose. For the potential recycled uses, betaG was immobilized and stabilized in the form of enzyme coating on polymer nanofibers. The betaG coating (EC-betaG) was fabricated by crosslinking additional betaG molecules onto covalently attached betaG molecules (CA-betaG) via glutaraldehyde treatment. The initial activity of EC-betaG was 36 times higher than that of CA-betaG. After 20 days of incubation under shaking, CA-betaG and EC-betaG retained 33 and 91% of each initial activit...
Source: Bioprocess and Biosystems Engineering - October 23, 2009 Category: Biomedical Engineering Authors: Lee SM, Jin LH, Kim JH, Han SO, Na HB, Hyeon T, Koo YM, Kim J, Lee JH Tags: Bioprocess Biosyst Eng Source Type: journals

Design of a new rotating drum bioreactor operated at atmospheric pressure on the bioremediation of a polluted soil.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This paper reports the effect of the operation and design characteristics of rotating drum bioreactors (RDBs) aerated by natural convection and applied to the treatment of a soil highly polluted with weathered total petroleum hydrocarbons (TPH) (55,000 +/- 2,600 mg/kg). The parameters studied were length to diameter ratio (L/D), rotating speed (N) and lifter type. The highest TPH removal (59.6 +/- 0.7%) was obtained with the RDB of the lowest L/D ratio (1.5). Removals diminished by 27, 36 and 56%, with a ratio increment of 2.1, 3.1 and 5.1, respectively. Increment of the N, at an optimal value and lifter change from st...
Source: Bioprocess and Biosystems Engineering - October 21, 2009 Category: Biomedical Engineering Authors: Rodríguez-Meza MA, Chávez-Gómez B, Poggi-Varaldo HM, Ríos-Leal E, Barrera-Cortés J Tags: Bioprocess Biosyst Eng Source Type: journals

Separation characteristics of animal cells using a dielectrophoretic filter.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The separation characteristics of a wire-wire type dielectrophoretic (DEP) filter were evaluated using animal cells. The separation of cells with different activities was examined using a DEP filter. The specific growth rate of the cells in retention liquid was larger than that in permeation liquid. From the culture results of the separated cells, it becomes clear that the specific growth rate of the cells of the retention liquid was higher than that of the cells of the permeation liquid. Furthermore, as a result of separating cells two kinds of cell suspensions using the DEP filter, the difference between the retentio...
Source: Bioprocess and Biosystems Engineering - October 16, 2009 Category: Biomedical Engineering Authors: Hirota Y, Hakoda M, Wakizaka Y Tags: Bioprocess Biosyst Eng Source Type: journals

Enzymatic production of linalool esters in organic and solvent-free system.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This work investigated the influence of temperature, enzyme concentration, substrates molar ratio, in the absence and presence of organic solvent, at two molar ratios of the substrates on the enzymatic production of linalil esters using the immobilized lipase Novozym 435 as catalyst, different acids and linalool and Ho-Sho essential oil as substrates. The best reaction conversion was obtained at the highest temperature (70 degrees C), for both solvent free (3.81%) and with solvent addition (2.25%), for a solvent to substrates molar ratio of 2:1, enzyme concentration of 5 wt% and acid to alcohol molar ratio of 1:1. The ...
Source: Bioprocess and Biosystems Engineering - October 14, 2009 Category: Biomedical Engineering Authors: Paroul N, Biasi A, Rovani AC, Prigol C, Dallago R, Treichel H, Cansian RL, Oliveira JV, de Oliveira D Tags: Bioprocess Biosyst Eng Source Type: journals

Impact of oxygen level in gaseous phase on gene transcription and ganoderic acid biosynthesis in liquid static cultures of Ganoderma lucidum.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Liquid static cultivation of Ganoderma lucidum was previously found to be very efficient for improving the production of its valuable antitumor compound ganoderic acid (GA) (Fang and Zhong in Biotechnol Prog 18:51-54, 2002). In this work, effects of oxygen concentration within the range of 21-100% (v/v) in the gaseous phase on the mycelia growth, GA production, and gene transcription of key enzymes for GA biosynthesis in liquid static cultures of G. lucidum were investigated. A high cell density of 29.8 +/- 1.7 g/l DW and total GA production of 1427.2 +/- 74.2 mg/l were obtained under an optimal gaseous O(2) level of 8...
Source: Bioprocess and Biosystems Engineering - October 6, 2009 Category: Biomedical Engineering Authors: Zhang WX, Tang YJ, Zhong JJ Tags: Bioprocess Biosyst Eng Source Type: journals

Production of D: -arabitol by a newly isolated Kodamaea ohmeri.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A new yeast, isolated from natural osmophilic sources, produces D: -arabitol as the main metabolic product from glucose. According to 18S rRNA analysis, the NH-9 strain belongs to the genus Kodamaea. The optimal culture conditions for inducing production of D: -arabitol were 37 degrees C, neutral pH, 220 rpm shaking, and 5% inoculum. The yeast produced 81.2 +/- 0.67 g L(-1) D: -arabitol from 200 g L(-1) D: -glucose in 72 h with a yield of 0.406 g g(-1) glucose and volumetric productivity [Formula: see text] of 1.128 g L(-1) h(-1). Semi-continuous repeated-batch fermentation was performed in shaker-flasks to enhance the...
Source: Bioprocess and Biosystems Engineering - September 18, 2009 Category: Biomedical Engineering Authors: Zhu HY, Xu H, Dai XY, Zhang Y, Ying HJ, Ouyang PK Tags: Bioprocess Biosyst Eng Source Type: journals

Monitoring bioreactors using principal component analysis: production of penicillin G acylase as a case study.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The complexity of biological processes often makes impractical the development of detailed, structured phenomenological models of the cultivation of microorganisms in bioreactors. In this context, data pre-treatment techniques are useful for bioprocess control and fault detection. Among them, principal component analysis (PCA) plays an important role. This work presents a case study of the application of this technique during real experiments, where the enzyme penicillin G acylase (PGA) was produced by Bacillus megaterium ATCC 14945. PGA hydrolyzes penicillin G to yield 6-aminopenicilanic acid (6-APA) and phenyl acetic...
Source: Bioprocess and Biosystems Engineering - September 1, 2009 Category: Biomedical Engineering Authors: Nucci ER, Cruz AJ, Giordano RC Tags: Bioprocess Biosyst Eng Source Type: journals

Single cell protein production from yacon extract using a highly thermosensitive and permeable mutant of the marine yeast Cryptococcus aureus G7a and its nutritive analysis.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The intracellular protein in the highly thermosensitive and permeable mutant can be easily released when they are incubated both in the low-osmolarity water and at the non-permissive temperature (usually 37 degrees C). After the mutant was grown in the yacon extract for 45 h, the crude protein content in the highly thermosensitive and permeable mutant Z114 was 59.1% and over 61% of the total protein could be released from the cells treated at 37 degrees C. The mutant cells grown in the yacon extract still contained high level of essential amino acids and other nutrients. This means that the yacon extract could be used ...
Source: Bioprocess and Biosystems Engineering - August 31, 2009 Category: Biomedical Engineering Authors: Zhao CH, Zhang T, Chi ZM, Chi Z, Li J, Wang XH Tags: Bioprocess Biosyst Eng Source Type: journals

Artificial chaperone-assisted refolding in a microchannel.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Protein refolding using a simple dilution method in a microchannel often led to the formation of protein aggregates, which bound to the microchannel wall, resulting in low refolding yields. To inhibit aggregation and improve refolding yields, an artificial chaperone-assisted (ACA) refolding, which employed detergents and beta-cyclodextrin was used. Model proteins, hen egg white lysozyme and yeast alpha-glucosidase, were successfully refolded in a microchannel. The microscopic observation showed that the ACA method suppressed protein aggregation and facilitated the refolding of lysozyme, whereas significant aggregation ...
Source: Bioprocess and Biosystems Engineering - August 29, 2009 Category: Biomedical Engineering Authors: Yamamoto E, Yamaguchi S, Sasaki N, Kim HB, Kitamori T, Nagamune T Tags: Bioprocess Biosyst Eng Source Type: journals

Development of glucose sensor using two-photon adsorbed photopolymerization.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A novel glucose sensor was constructed, and its analytical potential examined. A chip-type three-electrode system for use in a flow-type electrochemical glucose sensor was fabricated using a UV lithography technique on a glass slide. An Ag/AgCl reference electrode was made by electroplating silver onto a Pt electrode and dipping in a saturated KCl solution for 30 min. In addition, a glucose-sensing electrode was fabricated using a two-photon adsorbed photopolymerization technique with a photo-reactive resin containing a glucose oxidase enzyme, ferrocene mediator, non-ionic surfactant, and carbon nanotubes. The cyclic v...
Source: Bioprocess and Biosystems Engineering - August 28, 2009 Category: Biomedical Engineering Authors: Kim JM, Park JJ, Lee HJ, Kim WS, Muramatsu H, Chang SM Tags: Bioprocess Biosyst Eng Source Type: journals

Glucoamylase by recombinant Kluyveromyces lactis cells: production and modelling of a fed batch bioreactor.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A cultural system, aimed at the production of glucoamylase with cells of a non-conventional yeast transformed for the enzyme expression, Kluyveromyces lactis JA6-GAA was realised. Glucoamylase production was accomplished in a reactor operating in fed batch mode to avoid limitations with respect to oxygen transfer, and achieve high cell density. A mathematical model able to describe batch and fed batch operations was developed. The theoretical and experimental approach permitted to catch sight of possible physiological changes in the producer strain and set up a suitable fed-batch run to achieve a higher cell density. ...
Source: Bioprocess and Biosystems Engineering - August 28, 2009 Category: Biomedical Engineering Authors: Paciello L, Romano F, de Alteriis E, Parascandola P, Romano V Tags: Bioprocess Biosyst Eng Source Type: journals

L: -Ribose from L: -arabinose by epimerization and its purification by 3-zone simulated moving bed chromatography.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
L: -Ribose has recently received attention as the starting material for nucleoside drugs. As it is not found in nature, it is being produced by enzymatic or epimerization reaction. We investigated an epimerization reaction by molybdenium oxide and examined the effects of temperature, solvent, and molybdenum oxide amount on epimerization. L: -Ribose has a yield of 22% under the conditions of 100 kg/m(3) L: -arabinose, 20% methanol, 5 kg/m(3) MoO(3), and 90 degrees C. In addition, simulated moving bed (SMB) that was equipped with three NH(2)-HPLC columns was used to separate L: -arabinose and L: -ribose resulting from L:...
Source: Bioprocess and Biosystems Engineering - August 27, 2009 Category: Biomedical Engineering Authors: Jeon YJ, Park MB, Kim IH Tags: Bioprocess Biosyst Eng Source Type: journals

Optimization of the enzymatic one pot reaction for the synthesis of uridine 5'-diphosphogalactose.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Five recombinant Escherichia coli extracts harboring overexpressed galactokinase, galactose-1-phosphate uridyltransferase, UDP-glucose pyrophophorylase, UMP kinase, and acetate kinase (AK) were utilized for the production of UDP-galactose (UDP-Gal). We analyzed the parameters which limit the yield of UDP-Gal in the reaction, and the reaction was optimized by increasing the concentration of AK. AK was used for the ATP regeneration as well as the conversion of UDP to UTP. The activities of four overexpressed enzymes were identically fixed, and then we increased the activity of AK to 20 times higher than others. The extra...
Source: Bioprocess and Biosystems Engineering - August 27, 2009 Category: Biomedical Engineering Authors: Lee JH, Chung SW, Lee HJ, Jang KS, Lee SG, Kim BG Tags: Bioprocess Biosyst Eng Source Type: journals

Construction of simultaneous SPR and QCM sensing platform.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To construct a novel simultaneous SPR and QCM sensing system, an AT-cut quartz crystal is fabricated by sputtering 250 nm of ITO on one side of the quartz plate over a 5-nm thick underlay of titanium, while a 50-nm thick layer of gold is sputter-deposited on the other side to induce a total light reflection of an incident laser beam on the thin gold layer. The signals of the sensing system are detected using a Handy-SPR and QCA922 when dropping 200 muL of Milli-Q water into the sensing cell. A decrease in the SPR reflected light intensity is clearly identified. In the same experiment, the changes in the resonant freque...
Source: Bioprocess and Biosystems Engineering - August 25, 2009 Category: Biomedical Engineering Authors: Kim J, Kim S, Ohashi T, Muramatsu H, Chang SM, Kim WS Tags: Bioprocess Biosyst Eng Source Type: journals

Biological synthesis of platinum nanoparticles using Diopyros kaki leaf extract.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The leaf extract of Diopyros kaki was used as a reducing agent in the ecofriendly extracellular synthesis of platinum nanoparticles from an aqueous H(2)PtCl(6).6H(2)O solution. A greater than 90% conversion of platinum ions to nanoparticles was achieved with a reaction temperature of 95 degrees C and a leaf broth concentration of >10%. A variety of methods was used to characterize the platinum nanoparticles synthesized: inductively coupled plasma spectrometry, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). ...
Source: Bioprocess and Biosystems Engineering - August 22, 2009 Category: Biomedical Engineering Authors: Song JY, Kwon EY, Kim BS Tags: Bioprocess Biosyst Eng Source Type: journals

Cell-free production of functional antibody fragments.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Botulinum neurotoxin serotype B (BoNT/B)-specific Fab was expressed in a cell-free protein synthesis system derived from an E. coli extract. The cell-free synthesized antibody fragment was found to be effective in neutralizing the toxicity of BoNT/B in animal studies. Expression of functional Fab required an appropriately controlled and stably maintained redox potential. Under an optimized redox condition, the cell extract, whose disulfide reducing activity had been exhausted, could generate bio-functional Fab molecules. Use of a cell extract enriched with molecular chaperones (GroEL/ES) and disulfide bond isomerases w...
Source: Bioprocess and Biosystems Engineering - August 22, 2009 Category: Biomedical Engineering Authors: Oh IS, Lee JC, Lee MS, Chung JH, Kim DM Tags: Bioprocess Biosyst Eng Source Type: journals

Electrochemical aptasensor for tetracycline detection.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
An electrochemical aptasensor was developed for the detection of tetracycline using ssDNA aptamer that selectively binds to tetracycline as recognition element. The aptamer was highly selective for tetracycline which distinguishes minor structural changes on other tetracycline derivatives. The biotinylated ssDNA aptamer was immobilized on a streptavidin-modified screen-printed gold electrode, and the binding of tetracycline to aptamer was analyzed by cyclic voltammetry and square wave voltammetry. Our results showed that the minimum detection limit of this sensor was 10 nM to micromolar range. The aptasensor showed hig...
Source: Bioprocess and Biosystems Engineering - August 22, 2009 Category: Biomedical Engineering Authors: Kim YJ, Kim YS, Niazi JH, Gu MB Tags: Bioprocess Biosyst Eng Source Type: journals

In vitro microscale systems for systematic drug toxicity study.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
After administration, drugs go through a complex, dynamic process of absorption, distribution, metabolism and excretion. The resulting time-dependent concentration, termed pharmacokinetics (PK), is critical to the pharmacological response from patients. An in vitro system that can test the dynamics of drug effects in a more systematic way would save time and costs in drug development. Integration of microfabrication and cell culture techniques has resulted in 'cells-on-a-chip' technology, which is showing promise for high-throughput drug screening in physiologically relevant manner. In this review, we summarize current...
Source: Bioprocess and Biosystems Engineering - August 22, 2009 Category: Biomedical Engineering Authors: Sung JH, Shuler ML Tags: Bioprocess Biosyst Eng Source Type: journals

Optical device for parallel online measurement of dissolved oxygen and pH in shake flask cultures.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We describe a new device with parallel optical measurement of dissolved oxygen (DO) and pH in up to nine shake flasks applicable in any conventional shaking incubator. Measurement ranges are 0-500% of air saturation for oxygen and 5.5-8.5 for pH. It was used to characterize growth profiles of different L: -lysine producing strains of Corynebacterium glutamicum, of Saccharomyces cerevisiae and of Escherichia coli. Cultures in unbaffled flasks were highly reproducible. Oxygen limitation was indicated online which is particularly important when cultivating fast growing cells as E. coli. C. glutamicum strains showed distinct c...
Source: Bioprocess and Biosystems Engineering - August 22, 2009 Category: Biomedical Engineering Authors: Schneider K, Schütz V, John GT, Heinzle E Tags: Bioprocess Biosyst Eng Source Type: journals

Sequence optimization in a sequencing batch reactor for biological nutrient removal from domestic wastewater.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The purpose of this work was to determine optimum sequence retention times for nutrient removal with low-cost using very short aeration time in an SBR treating domestic wastewater. During the study, four different CYCLEs were evaluated, with the highest removal efficiencies recorded for the CYCLE with fill, anaerobic, aerobic1, anoxic, aerobic2, settle, and decant sequences operated at retention times of 0.5, 2, 2, 1, 0.75, 1, and 0.5 h, respectively. For this CYCLE, the removal efficiencies of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), ammonia nitrogen (NH(3)-N), total phosphorus (TP), and ortho-phos...
Source: Bioprocess and Biosystems Engineering - August 18, 2009 Category: Biomedical Engineering Authors: Debik E, Manav N Tags: Bioprocess Biosyst Eng Source Type: journals

Optimization of lipase-catalyzed glucose ester synthesis in ionic liquids.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Lipase-catalyzed esterification of glucose with fatty acids in ionic liquids (ILs) mixture was investigated by using supersaturated glucose solution. The effect of ILs mixture ratio, substrate ratio, lipase content, and temperature on the activity and stability of lipase was also studied. The highest yield of sugar ester was obtained in a mixture of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([Bmim][TfO]) and 1-methyl-3-octylimidazolium bis[(trifluoromethyl)-sulfonyl]amide ([Omim][Tf(2)N]) with a volume ratio of 9:1, while Novozym 435 (Candida antarctica type B lipase immobilized on acrylic resin) showed the...
Source: Bioprocess and Biosystems Engineering - August 12, 2009 Category: Biomedical Engineering Authors: Ha SH, Hiep NM, Lee SH, Koo YM Tags: Bioprocess Biosyst Eng Source Type: journals

Enzymatic synthesis of glutathione using yeast cells in two-stage reaction.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In the present study, permeated yeast cells were used as the catalyst to synthesize glutathione. When waste cells of brewer's yeast were incubated with the three precursor amino acids and glucose for 36 h, 899 mg/L of glutathione were produced. To release the feedback inhibition of gamma-glutamylcysteine synthetase caused by glutathione, two-stage reaction was adopted. In the first stage, glycine was omitted from the reaction mixture and only gamma-glutamylcysteine was formed. Glycine was then added in the second stage, and 1,569 mg/L of glutathione were produced. The conditions of the two-stage reaction were optimized...
Source: Bioprocess and Biosystems Engineering - August 12, 2009 Category: Biomedical Engineering Authors: Li W, Li Z, Ye Q Tags: Bioprocess Biosyst Eng Source Type: journals

Metabolic modelling of syntrophic-like growth of a 1,3-propanediol producer, Clostridium butyricum, and a methanogenic archeon, Methanosarcina mazei, under anaerobic conditions.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Clostridium butyricum can convert glycerol into 1,3-propanediol, thereby generating unfortunately a high amount of acetate, formate and butyrate as inhibiting by-products. We have proposed a novel mixed culture comprising C. butyricum and a methane bacterium, Methanosarcina mazei, to relieve the inhibition and to utilise the by-products for energy production. In order to examine the efficiency of such a mixed culture, metabolic modelling of the culture system was performed in this work. The metabolic networks for the organisms were reconstructed from genomic and physiological data. Several scenarios were analysed to ex...
Source: Bioprocess and Biosystems Engineering - August 12, 2009 Category: Biomedical Engineering Authors: Bizukojc M, Dietz D, Sun J, Zeng AP Tags: Bioprocess Biosyst Eng Source Type: journals

Fed-batch culture of astaxanthin-rich Haematococcus pluvialis by exponential nutrient feeding and stepwise light supplementation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A fed-batch culture process followed by subsequent photoautotrophic induction was established for the high density culture of astaxanthin-rich Haematococcus pluvialis using a CO(2)-fed flat type photobioreactor under unsynchronized illumination. Fed-batch culture was performed with an exponential feeding strategy of the growth-limiting nutrients, nitrate and phosphate, concurrently with the stepwise supplementation of light depending on the cell concentration. During the growth phase, a biomass of 1.47 g/L was obtained at a biomass productivity of 0.33 g/L/day. Photoautotrophic induction of the well-grown vegetative ce...
Source: Bioprocess and Biosystems Engineering - August 6, 2009 Category: Biomedical Engineering Authors: Kang CD, Han SJ, Choi SP, Sim SJ Tags: Bioprocess Biosyst Eng Source Type: journals

Quantifying transcriptional regulatory networks by integrating sequence features and microarray data.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Genome-wide transcriptional regulatory networks (TRNs) specify the interactions between transcription factors (TFs) and their target genes. Many methods have been proposed to reconstruct regulatory networks from gene expression datasets and/or genome sequences, but most of them can only infer qualitative regulation relationships. Thus, developing a quantitative model that can estimate the kinetic parameters of transcriptional regulatory functions is an urgent and important task. In this paper I propose REMBE, a regulatory model based on binding energy, to quantify transcriptional regulatory networks. My model combines ...
Source: Bioprocess and Biosystems Engineering - August 5, 2009 Category: Biomedical Engineering Authors: Liu H Tags: Bioprocess Biosyst Eng Source Type: journals

Removal of potassium chloride by nanofiltration from ion-exchanged solution containing potassium clavulanate.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, nanofiltration with NF200 membrane was employed to remove KCl from ion-exchanged solutions containing potassium clavulanate. The pore radius of NF200 membrane was estimated to be around 0.39 nm. The effects of operating pressure on separation performance were investigated in a range of 100-400 psig. The influences of cross-flow velocity (0.14-0.70 cm/s), temperature (4-25 degrees C), and feed composition were also investigated. In all experiments, clavulanate rejection showed high levels from 0.91 to 0.99, while chloride rejection ranged from 0.06 to 0.54. In a case at an operating pressure of 50 psig and 25...
Source: Bioprocess and Biosystems Engineering - August 1, 2009 Category: Biomedical Engineering Authors: Kim HH, Kim JH, Chang YK Tags: Bioprocess Biosyst Eng Source Type: journals

Reactor scale up for biological conversion of cellulosic biomass to ethanol.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The absence of a systematic scale-up approach for biological conversion of cellulosic biomass to commodity products is a significant bottleneck to realizing the potential benefits offered by such conversion. Motivated by this, we undertook to develop a scale-up approach for conversion of waste paper sludge to ethanol. Physical properties of the system were measured and correlations were developed for their dependence upon cellulose conversion. Just-suspension of solid particles was identified as the scale up criterion based on experiments at lab scale. The impeller speed for just solids suspension at large scale was pr...
Source: Bioprocess and Biosystems Engineering - August 1, 2009 Category: Biomedical Engineering Authors: Shao X, Lynd L, Bakker A, Laroche R, Wyman C Tags: Bioprocess Biosyst Eng Source Type: journals

Effective and stable porcine interferon-alpha production by Pichia pastoris fed-batch cultivation with multi-variables clustering and analysis.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Efficient porcine interferon-alpha (pIFN-alpha) expression in high density recombinant Pichia pastoris cultivation was achieved in a 5 l bench-scaled bioreactor. The results indicated that a high and stable oxygen uptake rate (OUR) during induction phase was closely related with pIFN-alpha production efficiency. The multi-variables clustering and analysis results showed that the achievement of a high and stable OUR relied on a higher glycerol consumption rate during fed-batch culture phase and a moderate methanol level (around 10 g/l) during induction phase. In the high and stable OUR environments (200-300 mmol/l/h), t...
Source: Bioprocess and Biosystems Engineering - August 1, 2009 Category: Biomedical Engineering Authors: Yu R, Dong S, Zhu Y, Jin H, Gao M, Duan Z, Zheng Z, Shi Z, Li Z Tags: Bioprocess Biosyst Eng Source Type: journals

Kinetic study on succinic acid and acetic acid formation during continuous cultures of Anaerobiospirillum succiniciproducens grown on glycerol.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Succinic acid-producing Anaerobiospirillum succiniciproducens was anaerobically grown in a glycerol-fed continuous bioreactor in order to investigate the physiological responses of the cell to different pH values (5.9, 6.2, or 6.5) and various dilution rates, D. In these experiments, A. succiniciproducens showed a pH-dependent glycerol consumption behavior. When pH was maintained at 5.9 or 6.5, glycerol started to accumulate even at a very low D of 0.027 h(-1). Succinic acid yield was not significantly affected by the pH of the culture or the Ds. However, more acetic acid formation was observed when the growth rate of ...
Source: Bioprocess and Biosystems Engineering - July 30, 2009 Category: Biomedical Engineering Authors: Lee PC, Lee SY, Chang HN Tags: Bioprocess Biosyst Eng Source Type: journals

Enhanced immobilization of hexa-arginine-tagged esterase on gold nanoparticles using mixed self-assembled monolayers.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we examined the formation of MSAMs on gold nanoparticles (AuNPs) and the immobilization of hexa-arginine-tagged esterase (Arg(6)-esterase) on the surfaces of the resulting particles. The functionalization of AuNPs with MSAMs was achieved by introducing a mixture of tethering and shielding ligands into an AuNP solution. The formation of self-assembled monolayers (SAMs) on the AuNP surface was characterized by UV/visible spectroscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. Arg(6)-esterase was immobilized in a highly specific manner onto AuNPs treated with mixed SAMs (MSA...
Source: Bioprocess and Biosystems Engineering - July 28, 2009 Category: Biomedical Engineering Authors: Jeong J, Lee CS, Chung SJ, Chung BH Tags: Bioprocess Biosyst Eng Source Type: journals

In vitro cytotoxicity screening of water-dispersible metal oxide nanoparticles in human cell lines.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we present in vitro cytotoxicity of iron oxide (Fe(3)O(4)) and manganese oxide (MnO) using live/dead cell assay, lactate dehydrogenase assay, and reactive oxygen species detection with variation of the concentration of nanoparticles (5-500 mug/ml), incubation time (18-96 h), and different human cell lines (lung adenocarcinoma, breast cancer cells, and glioblastoma cells). The surface of nanoparticles is modified with polyethyleneglycol-derivatized phospholipid to enhance the biocompatibility, water-solubility, and stability under an aqueous media. While the cytotoxic effect was negligible for 18 h incubation...
Source: Bioprocess and Biosystems Engineering - July 27, 2009 Category: Biomedical Engineering Authors: Choi JY, Lee SH, Na HB, An K, Hyeon T, Seo TS Tags: Bioprocess Biosyst Eng Source Type: journals

Chiral resolution of phenylalanine by D: -Phe imprinted membrane considering rejection property.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
An enantio-selective D: -Phe imprinted P(AA-co-AN) membrane was prepared using the wet-phase inversion method. The membrane not only selectively adsorbed phenylalanine but also rejected it with a rejection selectivity of 0.82-0.64 and 0.91-0.63 during the filtration of 100 and 10 ppm (g m(-3)) racemate solutions, respectively. The fluxes of D: -Phe and L: -Phe during filtration of 10 ppm racemate solution were 0.0077-0.0229 and 0.0064-0.0208 mg m(-2) s(-1), respectively, and the fluxes of D: -Phe and L: -Phe during filtration of 100 ppm racemate solution were 0.1287-0.2522 and 0.1174-0.2458 mg m(-2) s(-1), respectively...
Source: Bioprocess and Biosystems Engineering - July 14, 2009 Category: Biomedical Engineering Authors: Ul-Haq N, Park JK Tags: Bioprocess Biosyst Eng Source Type: journals

Production and characterization of monoclonal antibody and its recombinant single chain variable fragment specific for a food-born mycotoxin, fumonisin B(1).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Fumonisin B(1) (FMB(1)) is a food-born mycotoxin produced by Fusarium moniliforme. Monoclonal antibody against FMB(1) (anti-FMB(1) mAb) was produced in the hybridoma DV9, which was established from a BALB/c mouse immunized with bovine serum albumin conjugated FMB(1) (FMB(1)-BSA). A competitive direct enzyme-linked immunosorbent assay (ELISA) showed that anti-FMB(1) mAb has about 10 ppb of minimum FMB(1) detection concentration and 220 ppb of 50% inhibition concentration (IC(50)). Much lower cross-reactivity of anti-FMB(1) mAb on ochratoxin A, aflatoxin B(1) and deoxynivalenol provided that anti-FMB(1) mAb was specific ...
Source: Bioprocess and Biosystems Engineering - July 11, 2009 Category: Biomedical Engineering Authors: Min WK, Cho YJ, Park JB, Bae YH, Kim EJ, Park K, Park YC, Seo JH Tags: Bioprocess Biosyst Eng Source Type: journals

Enhanced antibody production following intermediate addition based on flux analysis in mammalian cell continuous culture.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Generally, mammalian cells utilize glucose and glutamine as primary energy sources. To investigate the effect of energy sources on metabolic fluxes and antibody production, glucose- or glutamine-limited serum-free continuous culture of hybridoma 3A21 cells, which produce anti-ribonuclease A antibody, was carried out. The cell volume and dry cell weight were evaluated under various steady-state conditions. The specific consumption and production rates were evaluated on the basis of dry cell weight. On the basis of these results, the fluxes of the metabolic pathway were calculated. It was found that increasing the specif...
Source: Bioprocess and Biosystems Engineering - July 9, 2009 Category: Biomedical Engineering Authors: Omasa T, Furuichi K, Iemura T, Katakura Y, Kishimoto M, Suga KI Tags: Bioprocess Biosyst Eng Source Type: journals

Hydrophobic modification of sodium alginate and its application in drug controlled release.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Sodium alginate was hydrophobically modified by coupling of polybutyl methacrylate onto the alginate. The polybutyl methacrylate was previously prepared through polymerization of butyl methacrylate in the presence of 2-amino-ethanethiol as a chain transfer agent. The structure of the product was characterized by Fourier-transformed infrared spectrometry, nuclear magnetic resonance ((1)HNMR) and thermogravimetry. The result of fluorescence analysis showed that the hydrophobicity of the modified alginate was obviously increased. The modified alginate conjugate was used for immobilization of bovine serum albumin in the pr...
Source: Bioprocess and Biosystems Engineering - July 3, 2009 Category: Biomedical Engineering Authors: Yao B, Ni C, Xiong C, Zhu C, Huang B Tags: Bioprocess Biosyst Eng Source Type: journals

Specificity of odorant-binding proteins: a factor influencing the sensitivity of olfactory receptor-based biosensors.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, OBPs originating from rat and pig were cloned into a mammalian expression vector, pcDNA3, and expressed in HEK-293 cells, and their specificity for odorants and olfactory receptors was examined. Results suggest that OBPs have a high affinity for the olfactory receptors when both the OBP and receptor originate from the same species. The rat OBPs were bound not only to the rat olfactory receptor I7 but also to the odorant specific to I7. The solubility of the odorant was increased by both OBP2 and OBP3, which originate from rat, but with different efficiencies. These results demonstrate that OBPs specifically ...
Source: Bioprocess and Biosystems Engineering - July 1, 2009 Category: Biomedical Engineering Authors: Ko HJ, Lee SH, Oh EH, Park TH Tags: Bioprocess Biosyst Eng Source Type: journals

Predictive modelling of Fe(III) precipitation in iron removal process for bioleaching circuits.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study demonstrates that ANNs and regression models are robust tools for predicting iron precipitation in the integrated process and can thus be used in the management of such systems. PMID: 19572153 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering)
Source: Bioprocess and Biosystems Engineering - July 1, 2009 Category: Biomedical Engineering Authors: Nurmi P, Ozkaya B, Kaksonen AH, Tuovinen OH, Puhakka JA Tags: Bioprocess Biosyst Eng Source Type: journals

Ho Nam Chang Special Issue: Life of a great biochemical engineer and his life-time contribution to high cell density culture.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
PMID: 19565273 [PubMed - as supplied by publisher] (Source: Bioprocess and Biosystems Engineering)
Source: Bioprocess and Biosystems Engineering - June 29, 2009 Category: Biomedical Engineering Authors: Lee SY Tags: Bioprocess Biosyst Eng Source Type: journals