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Xiaolong Han, Guodong Liu, Wenxia Song, Yinbo Qu
The production of sodium gluconate by enzymatic catalysis of delignified corn cob residue (DCCR) hydrolysate was studied. Penicillium oxalicum I1-13 was used for the production of cellulase with high β-glucosidase activity. A fed-batch saccharification process was developed to obtain high yields of glucose. At the end of hydrolysis, the concentration of glucose reached 145.80g/L. Glucose oxidase and catalase were co-immobilized to catalyze DCCR hydrolysate to produce sodium gluconate. Under the optimum conditions, 166...
June 23, 2017: Bioresource Technology
N Jarrige, G Cazeau, E Morignat, M Chanteperdrix, E Gay
The development of antimicrobial resistance has made it necessary to measure antimicrobial usage in animal production sectors. France is a major European producer of white veal calves, but few data were previously available for that sector, even though these young animals are particularly susceptible to infection and considered as a reservoir of antimicrobial resistance. A cross-sectional study was conducted on 186 batches of French calves to estimate the exposure of white veal calves to antimicrobials and identify the potential risk factors related to antimicrobial usage...
September 1, 2017: Preventive Veterinary Medicine
P Philip, K Meier, D Kern, J Goldmanns, F Stockmeier, C Bähr, J Büchs
BACKGROUND: The initial part of process development involves extensive screening programs to identify optimal biological systems and cultivation conditions. For a successful scale-up, the operation mode on screening and production scale must be as close as possible. To enable screening under fed-batch conditions, the membrane-based fed-batch shake flask was developed. It is a shake flask mounted with a central feed reservoir with an integrated rotating membrane tip for a controlled substrate release...
July 17, 2017: Microbial Cell Factories
Xiuping Su, Xinwei Geng, Meixian Fu, Yeqing Wu, Longfei Yin, Fukun Zhao, Wei Chen
EG27I is an endogenous glucanase belonging to glycoside hydrolase family (GHF) 45 from the Mollusca, Ampullaria crossean. In this study, the EG27I mature peptide gene fused to HFBII secretion signal of Trichoderma reesei was expressed under GAP promoter of Pichia pastoris in SMD1163 strain. Bioactive EG27I with a molecular weight of 27 kDa was successfully expressed and secreted into the culture medium. When high cell density fermentation of the recombinant Pichia pastoris was performed by a fed-batch strategy for totally 132 h in a 7...
July 12, 2017: Protein Expression and Purification
A Val Del Río, A Stachurski, R Méndez, J L Campos, J Surmacz-Górska, A Mosquera-Corral
The effects of orange azo dye over ammonia oxidizing bacteria (AOB) and anammox bacteria activities were tested. Performed batch tests indicated that concentrations lower than 650 mgorange/L stimulated AOB activity, while anammox bacteria activity was inhibited at concentrations higher than 25 mgorange/L. Long-term performance of a continuous stirred tank reactor (CSTR) for the partial nitritation and a sequencing batch reactor (SBR) for the anammox process was tested in the presence of 50 mgorange/L. In the case of the partial nitritation process, both the biomass concentration and the specific AOB activity increased after 50 days of orange azo dye addition...
July 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Marco Stoller, Javier Miguel Ochando-Pulido, Robert Field
In the last decades, membrane processes have gained a significant share of the market for wastewater purification. Although the product (i.e., purified water) is not of high added value, these processes are feasible both technically and from an economic point of view, provided the flux is relatively high and that membrane fouling is strongly inhibited. By controlling membrane fouling, the membrane may work for years without service, thus dramatically reducing operating costs and the need for membrane substitution...
July 14, 2017: Membranes
Jun Li, Chi Zhang, Poyi Huang, Erkin Kuru, Eliot T C Forster-Benson, Taibo Li, George M Church
Reconstituted cell-free protein synthesis systems such as the Protein synthesis Using Recombinant Elements (PURE) system give high-throughput and controlled access to in vitro protein synthesis. Here we show that compared with the commercial S30 crude extract based RTS 100 E. coli HY system, the PURE system has less mRNA degradation and produces up to ∼6-fold full-length proteins. However the majority of polypeptides PURE produces are partially translated or inactive since the signal from firefly luciferase (Fluc) translated in PURE is only ∼2/3(rd) of that measured using the RTS 100 E...
2017: Translation
Jonas Burgard, Minoska Valli, Alexandra B Graf, Brigitte Gasser, Diethard Mattanovich
BACKGROUND: Industrial processes for recombinant protein production challenge production hosts, such as the yeast Pichia pastoris, on multiple levels. During a common P. pastoris fed-batch process, cells experience strong adaptations to different metabolic states or suffer from environmental stresses due to high cell density cultivation. Additionally, recombinant protein production and nutrient limitations are challenging in these processes. RESULTS: Pichia pastoris producing porcine carboxypeptidase B (CpB) was cultivated in glucose or methanol-limited fed-batch mode, and the cellular response was analyzed using microarrays...
July 11, 2017: Microbial Cell Factories
Eik Czarnotta, Mariam Dianat, Marcel Korf, Fabian Granica, Juliane Merz, Jérôme Maury, Simo Abdessamad Baallal Jacobsen, Jochen Förster, Birgitta E Ebert, Lars M Blank
Microbial production of plant derived, biologically active compounds has the potential to provide economic and ecologic alternatives to existing low productive, plant-based processes. Current production of the pharmacologically active cyclic triterpenoid betulinic acid is realized by extraction from the bark of plane tree or birch. Here, we reengineered the reported betulinic acid pathway into S. cerevisiae and used this novel strain to develop efficient fermentation and product purification methods. Fed-batch cultivations with ethanol excess, using either an ethanol-pulse feed or controlling a constant ethanol concentration in the fermentation medium, significantly enhanced production of betulinic acid and its triterpenoid precursors...
July 8, 2017: Biotechnology and Bioengineering
Yu Zhang, Jingyi Cai, Xiuling Shang, Bo Wang, Shuwen Liu, Xin Chai, Tianwei Tan, Yun Zhang, Tingyi Wen
BACKGROUND: Corynebacterium glutamicum is an important platform organism for industrial biotechnology to produce amino acids, organic acids, bioplastic monomers, and biofuels. The metabolic flexibility, broad substrate spectrum, and fermentative robustness of C. glutamicum make this organism an ideal cell factory to manufacture desired products. With increases in gene function, transport system, and metabolic profile information under certain conditions, developing a comprehensive genome-scale metabolic model (GEM) of C...
2017: Biotechnology for Biofuels
Maohua Yang, Ruonan Chen, Tingzhen Mu, Xiang Zhang, Jianmin Xing
Due to the decrease of intracellular NADH availability, gluconate metabolism is more conducive to pyruvate production than glucose. Transcriptome analysis revealed that the Entner-Doudoroff (ED) pathway was activated by gluconate in Escherichia coli YP211 (MG1655 ΔldhA ΔpflB Δpta-ackA ΔpoxB Δppc ΔfrdBC). To construct a new pyruvate producing strain with glucose metabolism via ED pathway, the genes ppsA, ptsG, pgi and gnd were deleted sequentially to reduce the demand for PEP and block the Embden-Meyerhor-Parnas pathway and Pentose-Phosphate pathway...
June 29, 2017: Journal of Bioscience and Bioengineering
Andrea Schievano, Alessandra Colombo, Alessandra Cossettini, Andrea Goglio, Vincenzo D'Ardes, Stefano Trasatti, Pierangela Cristiani
In anaerobic digesters (AD), volatile fatty acids (VFAs) concentration is a critical operative parameter, which is usually manually monitored to prevent inhibition of microbial consortia. An on-line VFAs monitoring system as early-warning for increasing concentrations would be of great help for operators. Here, air-cathode membraneless microbial fuel cells (MFCs) were investigated as potential biosensors, whose electrical signal instantaneously moves from its steady value with the accumulation of VFAs in the anodic solution...
June 27, 2017: Waste Management
Juan Zhang, Yanqiu Cai, Guocheng Du, Jian Chen, Miao Wang, Zhen Kang
Cutinase as a promising biocatalyst has been intensively studied and applied in processes targeted for industrial scale. In this work, the cutinase gene tfu from Thermobifida fusca was artificially synthesized according to codon usage bias of Saccharomyces cerevisiae and investigated in Saccharomyces cerevisiae. Using the α-factor signal peptide, the T. fusca cutinase was successfully overexpressed and secreted with the GAL1 expression system. To increase the cutinase level and overcome some of the drawbacks of induction, four different strong promoters (ADH1, HXT1, TEF1, and TDH3) were comparatively evaluated for cutinase production...
July 2017: Journal of Microbiology / the Microbiological Society of Korea
Michal Dabros, Giorgio Genasci, Lucien Blanchard, Samuel Unterhofer, Olivier Vorlet, Ramón Mira de Orduña Heidinger, Jean-Pascal Bourgeois
The fermentation of yeast in fed-batch mode shows great potential in winemaking because it allows the concentration of sugars to be kept low and constant throughout the process which, in turn, reduces cell stress and leads to a significant decrease in the production of unwanted secondary metabolites. The implementation of this technique requires reliable on-line analysis of sugar and a robust control strategy to maintain sugar concentrations at defined levels over the course of the fermentation. In this study, a laboratory-scale setup was used to implement and assess a fully automated fed-batch fermentation of Saccharomyces cerevisiae in grape must...
December 21, 2016: Chimia
Ross Varin, John Novak, Charles Bott
  Acidogenic codigestion of fats, oils, and greases (FOG) was studied using suspended growth sludge digesters operated as batch fed reactors that were fed twice daily. The digesters were maintained at a 2-day retention time and at 37 °C to mimic the acid phase of an acid-gas digestion system. As FOG loading rates increased, volatile fatty acid (VFA) production was found to increase, although the percentage of VFA production compared to theoretical values decreased exponentially to just 20% at the highest loading rates...
November 1, 2016: Water Environment Research: a Research Publication of the Water Environment Federation
Jianjun Pei, Anna Chen, Linguo Zhao, Fuliang Cao, Gang Ding, Wei Xiao
Hyperoside exhibits many biological properties and is more soluble in water than quercetin. A uridine 5'-diphosphate (UDP) galactose regeneration system and one-pot synthesis of hyperoside was described herein. Glycine max sucrose synthase (GmSUS) was coupled with Escherichia coli UDP-galactose 4-epimerase (GalE) to regenerate UDP-galactose from sucrose and UDP. Petunia hybrida glycosyltransferase (PhUGT) with high activity toward quercetin was used to synthesize hyperoside via the UDP-galactose regeneration system...
July 10, 2017: Journal of Agricultural and Food Chemistry
Guangyuan Wang, Lin Liu, Wenxing Liang
Microbial oils are among the most attractive alternative feedstocks for biodiesel production. In this study, a newly isolated yeast strain, AM113 of Papiliotrema laurentii, was identified as a potential lipid producer, which could accumulate a large amount of intracellular lipids from hydrolysates of inulin. P. laurentii AM113 was able to produce 54.6% (w/w) of intracellular oil in its cells and 18.2 g/l of dry cell mass in a fed-batch fermentation. The yields of lipid and biomass were 0.14 and 0.25 g per gram of consumed sugar, respectively...
June 27, 2017: Applied Biochemistry and Biotechnology
Somruethai Bouyam, Wanna Choorit, Sarote Sirisansaneeyakul, Yusuf Chisti
The green microalga Chlorella sp. TISTR 8990 was grown heterotrophically in the dark using various concentrations of a basal glucose medium with a carbon-to-nitrogen mass ratio of 29:1. The final biomass concentration and the rate of growth were highest in the 5-fold concentrated basal glucose medium (25 g L(-1) glucose, 2.5 g L(-1) KNO3 ) in batch operations. Improving oxygen transfer in the culture by increasing the agitation rate and decreasing the culture volume in 500 mL shake flasks improved growth and glucose utilization...
June 27, 2017: Biotechnology Progress
Soo-Jung Kim, Hee-Jin Sim, Jin-Woo Kim, Ye-Gi Lee, Yong-Cheol Park, Jin-Ho Seo
The aim of this study was to produce 2,3-butanediol (2,3-BDO) from xylose efficiently by modulation of the xylose metabolic pathway in engineered Saccharomyces cerevisiae. Expression of the Scheffersomyces stipitis transaldolase and NADH-preferring xylose reductase in S. cerevisiae improved xylose consumption rate by a 2.1-fold and 2,3-BDO productivity by a 1.8-fold. Expression of the Lactococcus lactis noxE gene encoding NADH oxidase also increased 2,3-BDO yield by decreasing glycerol accumulation. Additionally, the disadvantage of C2-dependent growth of pyruvate decarboxylase-deficient (Pdc(-)) S...
June 9, 2017: Bioresource Technology
Glen R Bolton, Alex J Apostolidis
Fed-batch and perfusion cell culture processes used to produce therapeutic proteins can utilize microfilters for product harvest. In this study, new explicit mathematical models of sieving loss due to internal membrane fouling, external membrane fouling, or a combination of the two were generated. The models accounted for membrane and cake structures and hindered solute transport. Internal membrane fouling was assumed to occur due to the accumulation of foulant on either membrane pore walls (pore-retention model) or membrane fibers (fiber-retention model)...
June 26, 2017: Biotechnology Progress
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