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https://www.readbyqxmd.com/read/27922181/evaluation-of-gas-and-carbon-transport-in-a-methanogenic-bioelectrochemical-system-bes
#1
Christy M Dykstra, Spyros G Pavlostathis
Bioelectrochemical systems (BESs) may be used to upgrade anaerobic digester biogas by directly converting CO2 to CH4 .The objective of this study was to evaluate gas (N2 , CO2 , CH4 , and H2 ) and carbon transport within a methanogenic BES. Four BES configurations were evaluated: abiotic anode with abiotic cathode (AAn-ACa), bioanode with abiotic cathode (BAn-ACa), abiotic anode with biocathode (AAn-BCa), and bioanode with biocathode (BAn-BCa). Transport of N2 , a gas commonly used for flushing anoxic systems, out of the anode headspace ranged from 3...
December 6, 2016: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/27919791/biosensor-assisted-transcriptional-regulator-engineering-for-methylobacterium-extorquens-am1-to-improve-mevalonate-synthesis-by-increasing-the-acetyl-coa-supply
#2
Wei-Fan Liang, Lan-Yu Cui, Jin-Yu Cui, Kai-Wen Yu, Song Yang, Chong Zhang, Xin-Hui Xing
Acetyl-CoA is not only an important intermediate metabolite for cells but also a significant precursor for production of industrially interesting metabolites. Methylobacterium extorquens AM1, a model strain of methylotrophic cell factories using methanol as carbon source, is of interest because it produces abundant coenzyme A compounds capable of directing to synthesis of different useful compounds from methanol. However, acetyl-CoA always does not efficiently accumulate in M.extorquens AM1, as it is located in the center of three cyclic central metabolic pathways...
December 2, 2016: Metabolic Engineering
https://www.readbyqxmd.com/read/27919692/improved-production-of-2-fucosyllactose-in-engineered-escherichia-coli-by-expressing-putative-%C3%AE-1-2-fucosyltransferase-wcfb-from-bacteroides-fragilis
#3
Young-Wook Chin, Ji-Yeong Kim, Jae-Han Kim, Sang-Min Jung, Jin-Ho Seo
2'-Fucosyllactose (2-FL) is one of most abundant oligosaccharides in human milk, which is involved in many biological functions for infant health. Since 2-FL has a great potential in application to functional food materials and pharmaceuticals, several microbial systems for mass production of 2-FL have been developed in recent years. Microbial production of 2-FL was suggested to be influenced by a number of factors including fucosylation activity of α-1,2-fucosyltransferase. In the present study, the wcfB gene coding for α-1,2-fucosyltransferase from Bacteroides fragilis was screened from eleven candidates of putative α-1,2-fucosyltransferase...
December 2, 2016: Journal of Biotechnology
https://www.readbyqxmd.com/read/27918882/metabolic-engineering-of-corynebacterium-glutamicum-for-the-production-of-3-hydroxypropionic-acid-from-glucose-and-xylose
#4
Zhen Chen, Jinhai Huang, Yao Wu, Wenjun Wu, Ye Zhang, Dehua Liu
3-Hydroxypropionic acid (3-HP) is a promising platform chemical which can be used for the production of various value-added chemicals. In this study,Corynebacterium glutamicumwas metabolically engineered to efficiently produce 3-HP from glucose and xylose via the glycerol pathway. A functional 3-HP synthesis pathway was engineered through a combination of genes involved in glycerol synthesis (fusion ofgpdandgppfromSaccharomyces cerevisiae) and 3-HP production (pduCDEGHfromKlebsiella pneumoniaeand aldehyde dehydrogenases from various resources)...
December 2, 2016: Metabolic Engineering
https://www.readbyqxmd.com/read/27913170/effects-of-the-feeding-ratio-of-food-waste-on-fed-batch-aerobic-composting-and-its-microbial-community
#5
Xiaojun Wang, Songqing Pan, Zhaoji Zhang, Xiangyu Lin, Yuzhen Zhang, Shaohua Chen
To determine the suitable feeding ratio for fed-batch aerobic composting, four fermenters were operated by adding 0%, 5%, 10% or 15% of food waste every day. The results showed that the 5% and 10% treatments were able to maintain continuous thermophilic conditions, while the 15% treatment performed badly in regard to composting temperature, which was probably due to the negative effects of excessive moisture on microbial activity. As composting proceeded, both the 5% and the 10% treatments reached maturity and achieved weight losses of approximately 65%...
November 22, 2016: Bioresource Technology
https://www.readbyqxmd.com/read/27900626/selection-of-chemically-defined-media-for-cho-cell-fed-batch-culture-processes
#6
Xiao Pan, Mathieu Streefland, Ciska Dalm, René H Wijffels, Dirk E Martens
Two CHO cell clones derived from the same parental CHO(BC®) cell line and producing the same monoclonal antibody (BC-G, a low producing clone; BC-P, a high producing clone) were tested in four basal media in all possible combinations with three feeds (=12 conditions) in fed-batch cultures. Higher amino acid feeding did not always lead to higher mAb production. The two clones showed differences in cell physiology, metabolism and optimal medium-feed combinations. During the phase transitions of all cultures, cell metabolism showed a shift represented by lower specific consumption and production rates, except for the specific glucose consumption rate in cultures fed by Actifeed A/B...
November 29, 2016: Cytotechnology
https://www.readbyqxmd.com/read/27900494/semi-industrial-scale-30%C3%A2-m-3-fed-batch-fermentation-for-the-production-of-d-lactate-by-escherichia-coli-strain-hbut-d15
#7
Xiangmin Fu, Yongze Wang, Jinhua Wang, Erin Garza, Ryan Manow, Shengde Zhou
D(-)-lactic acid is needed for manufacturing of stereo-complex poly-lactic acid polymer. Large scale D-lactic acid fermentation, however, has yet to be demonstrated. A genetically engineered Escherichia coli strain, HBUT-D, was adaptively evolved in a 15% calcium lactate medium for improved lactate tolerance. The resulting strain, HBUT-D15, was tested at a lab scale (7 L) by fed-batch fermentation with up to 200 g L(-1) of glucose, producing 184-191 g L(-1) of D-lactic acid, with a volumetric productivity of 4...
November 29, 2016: Journal of Industrial Microbiology & Biotechnology
https://www.readbyqxmd.com/read/27900444/effect-of-humic-acid-on-anaerobic-digestion-of-cellulose-and-xylan-in-completely-stirred-tank-reactors-inhibitory-effect-mitigation-of-the-inhibition-and-the-dynamics-of-the-microbial-communities
#8
Samet Azman, Ahmad F Khadem, Caroline M Plugge, Alfons J M Stams, Sabina Bec, Grietje Zeeman
Inhibition effect of humic acid (HA) on anaerobic digestion of cellulose and xylan and the mitigation potential of the inhibition were evaluated in controlled fed batch reactors at 30 °C and a hydraulic retention time (HRT) of 20 days. Reactor performances were evaluated by biogas production and metabolite measurements for 220 days. Microbial population dynamics of the reactors were monitored with next-generation 16S rRNA gene sequencing at nine different sampling times. Our results showed that increasing levels of HA inhibited the hydrolysis efficiency of the digestion by 40% and concomitantly reduced the methane yield...
November 29, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27898898/effects-of-molasses-and-crude-glycerol-combined-in-a-liquid-supplement-on-ruminal-fermentation-in-beef-steers-consuming-bermudagrass-hay
#9
F M Ciriaco, D D Henry, V R G Mercadante, T M Schulmeister, M Ruiz-Moreno, G C Lamb, N DiLorenzo
Two experiments were performed to evaluate the effects of 1) increasing supplementation doses of a 50:50 (as-fed) liquid supplement of molasses and crude glycerol (M:G) on ruminal fermentation parameters and blood urea nitrogen (BUN) in beef steers consuming Tifton 85 bermudagrass ( spp.) hay and 2) different proportions of molasses and crude glycerol in a liquid supplement on in vitro fermentation and gas production kinetics. For Exp. 1, 8 ruminally cannulated, Angus-crossbred steers were used in a duplicated 4 × 4 Latin square design, had ad libitum access to Tifton 85 bermudagrass hay, and were randomly assigned to 1 of 4 treatments: 1) CTRL, no supplementation; 2) SUP1, 0...
September 2016: Journal of Animal Science
https://www.readbyqxmd.com/read/27898878/effects-of-dietary-fiber-on-the-ideal-standardized-ileal-digestible-threonine-lysine-ratio-for-twenty-five-to-fifty-kilogram-growing-gilts
#10
J K Mathai, J K Htoo, J E Thomson, K J Touchette, H H Stein
Four experiments were conducted to determine effects of fiber on the ideal Thr:Lys ratio for 25- to 50-kg gilts. In Exp. 1, the objective was to determine the requirement for standardized ileal digestible Lys for gilts from 25 to 50 kg BW. Seventy gilts (24.54 ± 3.28 kg BW) were used in a growth assay with 2 pigs per pen, 5 diets, and 7 replicate pens per diet. The 5 diets were based on corn and soybean meal and contained between 0.80 and 1.32% SID Lys. Results indicated that 1.09% SID Lys was needed to optimize ADG and G:F...
October 2016: Journal of Animal Science
https://www.readbyqxmd.com/read/27889801/production-and-purification-of-an-untagged-recombinant-pneumococcal-surface-protein-a-pspa4pro-with-high-purity-and-low-endotoxin-content
#11
Douglas B Figueiredo, Eneas Carvalho, Mauricio P Santos, Stefanie Kraschowetz, Rafaela T Zanardo, Gilson Campani, Gabriel G Silva, Cíntia R Sargo, Antonio Carlos L Horta, Roberto de C Giordano, Eliane N Miyaji, Teresa C Zangirolami, Joaquin Cabrera-Crespo, Viviane Maimoni Gonçalves
Streptococcus pneumoniae is the main cause of pneumonia, meningitis, and other conditions that kill thousands of children every year worldwide. The replacement of pneumococcal serotypes among the vaccinated population has evidenced the need for new vaccines with broader coverage and driven the research for protein-based vaccines. Pneumococcal surface protein A (PspA) protects S. pneumoniae from the bactericidal effect of human apolactoferrin and prevents complement deposition. Several studies indicate that PspA is a very promising target for novel vaccine formulations...
November 26, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27881075/modelling-microbial-metabolic-rewiring-during-growth-in-a-complex-medium
#12
Marco Fondi, Emanuele Bosi, Luana Presta, Diletta Natoli, Renato Fani
BACKGROUND: In their natural environment, bacteria face a wide range of environmental conditions that change over time and that impose continuous rearrangements at all the cellular levels (e.g. gene expression, metabolism). When facing a nutritionally rich environment, for example, microbes first use the preferred compound(s) and only later start metabolizing the other one(s). A systemic re-organization of the overall microbial metabolic network in response to a variation in the composition/concentration of the surrounding nutrients has been suggested, although the range and the entity of such modifications in organisms other than a few model microbes has been scarcely described up to now...
November 24, 2016: BMC Genomics
https://www.readbyqxmd.com/read/27875768/high-efficiency-succinic-acid-production-from-glycerol-via-in-situ-fibrous-bed-bioreactor-with-an-engineered-yarrowia-lipolytica
#13
Chong Li, Xiaofeng Yang, Shi Gao, Huaimin Wang, Carol Sze Ki Lin
In this study, in situ fibrous bed bioreactor (isFBB) was developed at the first time for efficient succinic acid (SA) production by Yarrowia lipolytica. After optimization, SA titer, productivity and yield of 51.9g/L, 1.46g/L/h and 0.42g/g were obtained respectively via isFBB fermentation under conditions of 750cm(2) cotton towel, 120g/L initial glycerol and 3L/min aeration rate. By fed batch strategy, SA titer raised up to 198.2g/L was achieved, which was the highest value ever reported. In operation stability study, SA productivity showed no obvious decrease after 12 repeated batches of 460h fermentation, and cell viability even recovered within two repeated batches after intentional interruption...
November 12, 2016: Bioresource Technology
https://www.readbyqxmd.com/read/27869296/segmented-linear-modeling-of-cho-fed-batch-culture-and-its-application-to-large-scale-production
#14
Bassem Ben Yahia, Boris Gourevitch, Laetitia Malphettes, Elmar Heinzle
We describe a systematic approach to model CHO metabolism during biopharmaceutical production across a wide range of cell culture conditions. To this end, we applied the metabolic steady state concept. We analyzed and modeled the production rates of metabolites as a function of the specific growth rate. First, the total number of metabolic steady state phases and the location of the breakpoints were determined by recursive partitioning. For this, the smoothed derivative of the metabolic rates with respect to the growth rate were used followed by hierarchical clustering of the obtained partition...
November 7, 2016: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/27861744/omega-3-production-by-fermentation-of-yarrowia-lipolytica-from-fed-batch-to-continuous
#15
Dongming Xie, Edward Miller, Pamela Sharpe, Ethel Jackson, Quinn Zhu
The omega-3 fatty acid, cis-5,8,11,14,17-eicosapentaenoic acid (C20:5; EPA) has wide-ranging benefits in improving heart health, immune function, and mental health. A sustainable source of EPA production through fermentation of metabolically engineered Yarrowia lipolytica has been developed. In this paper, key fed-batch fermentation conditions were identified to achieve 25% EPA in the yeast biomass, which is so far the highest EPA titer reported in the literature. Dynamic models of the EPA fermentation process were established for analyzing, optimizing, and scaling up the fermentation process...
November 14, 2016: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/27858135/expression-in-pichia-pastoris-and-characterization-of-two-novel-dirigent-proteins-for-atropselective-formation-of-gossypol
#16
Isabelle Effenberger, Michael Harport, Jens Pfannstiel, Iris Klaiber, Andreas Schaller
We established an efficient fed-batch fermentation process for two novel dirigent proteins from cotton plants, GbDIR2 from Gossypium barbadense and GhDIR3 from G. hirsutum, using the engineered Pichia pastoris GlycoSwitch® SuperMan5 strain to prevent hyperglycosylation. The two (His)6-tagged proteins were purified by metal-chelate affinity chromatography and obtained in quantities of 12 and 15 mg L(-1) of culture volume, respectively. Glycosylation sites were identified for the native and for the enzymatically deglycosylated proteins by mass spectrometry, confirming five to six of the seven predicted glycosylation sites in the NxS/T sequence context...
November 17, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27854078/optimal-feed-profile-for-the-rhamnolipid-kinetic-models-by-using-tabu-search-metabolic-view-point
#17
J Satya Eswari, Kannekanti Kavya
Rhamnolipids are bio surfactants which are extra-cellular glycolipids composed of L-rhamnose and 3-hydroxyalkanoics. Rhamnolipids are produced through fermentation process by using Pseudomonas sp. as the species. An alteration to the traditional procedures in order to achieve increase in the production of biosurfactants, a numerous process technologies have been adopted in fed batch mode. Fed batch mode facilitates the high production of product by avoiding the substrate or product inhibition line of attack...
December 2016: AMB Express
https://www.readbyqxmd.com/read/27853308/comparison-of-high-titer-lactic-acid-fermentation-from-naoh-and-nh3-h2o2-pretreated-corncob-by-bacillus-coagulans-using-simultaneous-saccharification-and-fermentation
#18
Zhenting Zhang, Yuejiao Xie, Xiaolan He, Xinli Li, Jinlong Hu, Zhiyong Ruan, Shumiao Zhao, Nan Peng, Yunxiang Liang
Lignocellulose is one of the most abundant renewable feedstocks that has attracted considerable attention as a substrate for biofuel and biochemical production. One such biochemical product, lactic acid, is an important fermentation product because of its great potential for the production of biodegradable and biocompatible polylactic acid. High-titer lactic acid production from lignocellulosic materials has been achieved recently; however, it requires biodetoxification or results in large amounts of waste washing water...
November 17, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27852252/a-novel-pyruvate-kinase-and-its-application-in-lactic-acid-production-under-oxygen-deprivation-in-corynebacterium-glutamicum
#19
Xin Chai, Xiuling Shang, Yu Zhang, Shuwen Liu, Yong Liang, Yun Zhang, Tingyi Wen
BACKGROUND: Pyruvate kinase (Pyk) catalyzes the generation of pyruvate and ATP in glycolysis and functions as a key switch in the regulation of carbon flux distribution. Both the substrates and products of Pyk are involved in the tricarboxylic acid cycle, anaplerosis and energy anabolism, which places Pyk at a primary metabolic intersection. Pyks are highly conserved in most bacteria and lower eukaryotes. Corynebacterium glutamicum is an industrial workhorse for the production of various amino acids and organic acids...
November 16, 2016: BMC Biotechnology
https://www.readbyqxmd.com/read/27845720/a-novel-application-for-low-frequency-electrochemical-impedance-spectroscopy-as-an-online-process-monitoring-tool-for-viable-cell-concentrations
#20
Christoph Slouka, David J Wurm, Georg Brunauer, Andreas Welzl-Wachter, Oliver Spadiut, Jürgen Fleig, Christoph Herwig
New approaches in process monitoring during industrial fermentations are not only limited to classical pH, dO₂ and offgas analysis, but use different in situ and online sensors based on different physical principles to determine biomass, product quality, lysis and far more. One of the very important approaches is the in situ accessibility of viable cell concentration (VCC). This knowledge provides increased efficiency in monitoring and controlling strategies during cultivations. Electrochemical impedance spectroscopy-EIS-is used to monitor biomass in a fermentation of E...
November 11, 2016: Sensors
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