keyword
MENU ▼
Read by QxMD icon Read
search

fed batch

keyword
https://www.readbyqxmd.com/read/28528488/enhanced-production-of-para-hydroxybenzoic-acid-by-genetically-engineered-saccharomyces-cerevisiae
#1
Nils J H Averesch, Alex Prima, Jens O Krömer
Saccharomyces cerevisiae is a popular organism for metabolic engineering; however, studies aiming at over-production of bio-replacement precursors for the chemical industry often fail to overcome proof-of-concept stage. When intending to show real industrial attractiveness, the challenge is twofold: formation of the target compound must be increased, while minimizing the formation of side and by-products to maximize titer, rate and yield. To tackle these, the metabolism of the organism, as well as the parameters of the process, need to be optimized...
May 20, 2017: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/28523377/mining-lipolytic-enzymes-in-community-dna-from-high-andean-soils-using-a-targeted-approach
#2
Daniel Borda-Molina, José Salvador Montaña, María Mercedes Zambrano, Sandra Baena
Microbial enrichments cultures are a useful strategy to speed up the search for enzymes that can be employed in industrial processes. Lipases have gained special attention because they show unique properties such as: broad substrate specificity, enantio- and regio-selectivity and stability in organic solvents. A major goal is to identify novel lipolytic enzymes from microorganisms living in cold extreme environments such as high Andean soils, of relevance to our study being their capability be used in industrial processes...
May 18, 2017: Antonie Van Leeuwenhoek
https://www.readbyqxmd.com/read/28522198/efficient-production-of-2-3-butanediol-by-recombinant-saccharomyces-cerevisiae-through-modulation-of-gene-expression-by-cocktail-%C3%AE-integration
#3
Ryosuke Yamada, Kazuki Wakita, Ryosuke Mitsui, Riru Nishikawa, Hiroyasu Ogino
In this study, the expression of 4 genes encoding α-acetolactate synthase, α-acetolactate decarboxylase, 2,3-butanediol dehydrogenase, and NADH oxidase was modulated using a previously developed cocktail δ-integration strategy. The resultant strain, YPH499/dPdAdG/BD6-10, was used in a fed-batch cultivation for the production of 2,3-butanediol. The concentration, production rate, and yield obtained were 80.0g/L, 4.00g/L/h, and 41.7%, respectively. The production rate and yield of the compound obtained are higher for this strain compared to reports published for Saccharomyces cerevisiae so far...
May 10, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28521235/integrated-bioconversion-of-syngas-into-bioethanol-and-biopolymers
#4
Borja Lagoa-Costa, Haris Nalakath Abubackar, María Fernández-Romasanta, Christian Kennes, María C Veiga
Syngas bioconversion is a promising method for bioethanol production, but some VFA remains at the end of fermentation. A two-stage process was set-up, including syngas fermentation as first stage under strict anaerobic conditions using C. autoethanogenum as inoculum, with syngas (CO/CO2/H2/N2, 30/10/20/40) as gaseous substrate. The second stage consisted in various fed-batch assays using a highly enriched PHA accumulating biomass as inoculum, where the potential for biopolymer production from the remaining acetic acid at the end of the syngas fermentation was evaluated...
May 5, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28512676/different-fermentation-processes-produced-variants-of-an-anti-cd52-monoclonal-antibody-that-have-divergent-in-vitro-and-in-vivo-characteristics
#5
Chao Zhuang, Chen Zheng, Yantian Chen, Zheng Huang, Yanchao Wang, Qiang Fu, Chen Zeng, Tong Wu, Liming Yang, Nianmin Qi
The anti-CD52 antibody has already been approved for the treatment of patients with resistant chronic lymphocytic leukemia, relapsing-remitting multiple sclerosis, and has demonstrable efficacy against stem cell transplantation rejection. A CHO cell line expressing a humanized anti-CD52 monoclonal antibody (mAb-TH) was cultivated in both fed-batch and perfusion modes, and then purified. The critical quality attributes of these mAb variants were characterized and the pharmacokinetics (PK) properties were investigated...
May 16, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28512675/selection-and-characterization-of-an-anaerobic-microbial-consortium-with-high-adaptation-to-crude-glycerol-for-1-3-propanediol-production
#6
Jin-Jie Zhou, Jun-Tao Shen, Li-Li Jiang, Ya-Qin Sun, Ying Mu, Zhi-Long Xiu
Crude glycerol is an ideal feedstock for bioproduction of 1,3-propanediol (1,3-PDO) while pure culture always shows low substrate tolerance and limited productivity. In this study, an anaerobic microbial consortium for conversion of crude glycerol was selected and its 1,3-PDO production capacity was evaluated. The consortium was obtained from anaerobic activated sludge by 19 serial transfers and mainly consisted of 94.64% Clostridiaceae and 4.47% Peptostreptococcaceae. The consortium adapted well with high glycerol concentration of 120 g/L as well as wide substrate concentration fluctuation from 15 to 80 g/L, producing 60...
May 16, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28511681/chromosome-engineering-of-escherichia-coli-for-constitutive-production-of-salvianic-acid-a
#7
Liang Zhou, Qi Ding, Guo-Zhen Jiang, Zhen-Ning Liu, Hai-Yan Wang, Guang-Rong Zhao
BACKGROUND: Salvianic acid A (SAA), a valuable natural product from herbal plant Salvia miltiorrhiza, exhibits excellent antioxidant activities on food industries and efficacious therapeutic potential on cardiovascular diseases. Recently, production of SAA in engineered Escherichia coli was established via the artificial biosynthetic pathway of SAA on the multiple plasmids in our previous work. However, the plasmid-mediated system required to supplement expensive inducers and antibiotics during the fermentation process, restricting scale-up production of SAA...
May 16, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28506930/rewiring-the-reductive-tricarboxylic-acid-pathway-and-l-malate-transport-pathway-of-aspergillus-oryzae-for-overproduction-of-l-malate
#8
Jingjing Liu, Zhipeng Xie, Hyun-Dong Shin, Jianghua Li, Guocheng Du, Jian Chen, Long Liu
Aspergillus oryzae finds wide application in the food, feed, and wine industries, and is an excellent cell factory platform for production of organic acids. In this work, we achieved the overproduction of L-malate by rewiring the reductive tricarboxylic acid (rTCA) pathway and L-malate transport pathway of A. oryzae NRRL 3488. First, overexpression of native pyruvate carboxylase and malate dehydrogenase in the rTCA pathway improved the L-malate titer from 26.1gL(-1) to 42.3gL(-1) in shake flask culture. Then, the oxaloacetate anaplerotic reaction was constructed by heterologous expression of phosphoenolpyruvate carboxykinase and phosphoenolpyruvate carboxylase from Escherichia coli, increasing the L-malate titer to 58...
May 12, 2017: Journal of Biotechnology
https://www.readbyqxmd.com/read/28503195/strategies-for-improved-isopropanol-butanol-production-by-a-clostridium-strain-from-glucose-and-hemicellulose-through-consolidated-bioprocessing
#9
Fengxue Xin, Tianpeng Chen, Yujiang Jiang, Weiliang Dong, Wenming Zhang, Min Zhang, Hao Wu, Jiangfeng Ma, Min Jiang
BACKGROUND: High cost of traditional substrates and formation of by-products (such as acetone and ethanol) in acetone-butanol-ethanol (ABE) fermentation hindered the large-scale production of biobutanol. Here, we comprehensively characterized a newly isolated solventogenic and xylanolytic Clostridium species, which could produce butanol at a high ratio with elimination of ethanol and conversion of acetone to more value-added product, isopropanol. Ultimately, direct butanol production from hemicellulose was achieved with efficient expression of indigenous xylanase by the novel strain via consolidated bioprocessing...
2017: Biotechnology for Biofuels
https://www.readbyqxmd.com/read/28500546/quantitative-image-analysis-of-polyhydroxyalkanoates-inclusions-from-microbial-mixed-cultures-under-different-sbr-operation-strategies
#10
António L Amaral, Hugo Abreu, Cristiano Leal, Daniela P Mesquita, Luís M Castro, Eugénio C Ferreira
Polyhydroxyalkanoates (PHAs) produced from mixed microbial cultures (MMC), regarded as potential substitutes of petrochemical plastics, can be found as intracellular granules in various microorganisms under limited nutrient conditions and excess of carbon source. PHA is traditionally quantified by laborious and time-consuming chromatography analysis, and a simpler and faster method to assess PHA contents from MMC, such as quantitative image analysis (QIA), is of great interest. The main purpose of the present work was to upgrade a previously developed QIA methodology (as reported by Mesquita et al...
May 12, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28497288/novel-signal-peptides-improve-the-secretion-of-recombinant-staphylococcus-aureus-alpha-toxinh35l-in-escherichia-coli
#11
SooJin Han, Shushil Machhi, Mark Berge, Guoling Xi, Thomas Linke, Ronald Schoner
Secretion of heterologous proteins into Escherichia coli cell culture medium offers significant advantages for downstream processing over production as inclusion bodies; including cost and time savings, and reduction of endotoxin. Signal peptides play an important role in targeting proteins for translocation across the cytoplasmic membrane to the periplasmic space and release into culture medium during the secretion process. Alpha toxinH35L (ATH35L) was selected as an antigen for vaccine development against Staphylococcus aureus infections...
December 2017: AMB Express
https://www.readbyqxmd.com/read/28496068/the-use-of-a-gas-chromatography-milli-whistle-technique-for-the-on-line-monitoring-of-ethanol-production-using-microtube-array-membrane-immobilized-yeast-cells
#12
Ming-Ju Wu, Guan-Fu Ye, Ching-Hao Wang, Hong-Ting Victor Lin, Chien-Chung Chen, Cheng-Huang Lin
Hollow, poly(L-lactic acid) microtube array membranes (MTAM) were used in preparing membranes that contained immobilized yeast cells. To evaluate the performance of the developed system for continuous and fed-batch fermentation, a gas chromatography/milli-whistle device was used to on-line monitor the production of ethanol. The milli-whistle was connected to the outlet of a GC capillary, and when the fermentation gases and the GC carrier gas passed through it, a sound with a fundamental frequency was produced...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/28486197/on-site-cellulase-production-and-efficient-saccharification-of-corn-stover-employing-cbh2-overexpressing-trichoderma-reesei-with-novel-induction-system
#13
Yonghao Li, Xiaoyue Zhang, Liang Xiong, Muhammad Aamer Mehmood, Xinqing Zhao, Fengwu Bai
Although on-site cellulase production offers cost-effective saccharification of lignocellulosic biomass, low enzyme titer is still a barrier for achieving robustness. In the present study, a strain of T. reesei was developed for enhanced production of cellulase via overexpression of Cellobiohydrolase II. Furthermore, optimum enzyme production was achieved using a novel inducer mixture containing synthesized glucose-sophorose (MGD) and alkali pre-treated corn stover (APCS). Within 60h, a remarkably higher cellulase productivity and activity were achieved in the fed-batch fermentation using the optimized ratio of MGD and APCS in the inducer mixture, compared to those reported using cellulosic biomass as the sole inducer...
April 26, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28485588/h2o2-production-in-microbial-electrochemical-cells-fed-with-primary-sludge
#14
Dongwon Ki, Sudeep C Popat, Bruce E Rittmann, César Iván Torres
We developed an energy-efficient, flat-plate, dual-chambered microbial peroxide producing cell (MPPC) as an anaerobic energy-conversion technology for converting primary sludge (PS) at the anode and producing hydrogen peroxide (H2O2) at the cathode. We operated the MPPC with a 9-day HRT in the anode. A maximum H2O2 concentration of ~230 mg/L was achieved in 6 hours of batch cathode operation. This is the first demonstration of H2O2 production using PS in an MPPC, and the energy requirement for H2O2 production was low (~0...
May 9, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28480535/integrated-continuous-bioprocessing-economic-operational-and-environmental-feasibility-for-clinical-and-commercial-antibody-manufacture
#15
James Pollock, Jon Coffman, Sa V Ho, Suzanne S Farid
This paper presents a systems approach to evaluating the potential of integrated continuous bioprocessing for monoclonal antibody (mAb) manufacture across a product's lifecycle from pre-clinical to commercial manufacture. The economic, operational and environmental feasibility of alternative continuous manufacturing strategies were evaluated holistically using a prototype UCL decisional tool that integrated process economics, discrete-event simulation, environmental impact analysis, operational risk analysis and multi-attribute decision-making...
May 8, 2017: Biotechnology Progress
https://www.readbyqxmd.com/read/28479190/biosynthesis-of-plant-derived-ginsenoside-rh2-in-yeast-via-repurposing-a-key-promiscuous-microbial-enzyme
#16
Yu Zhuang, Guangyu Yang, Xiaohui Chen, Qian Liu, Xueli Zhang, Zixin Deng, Yan Feng
Ginsenoside Rh2 is a potential anticancer drug isolated from medicinal plant ginseng. Fermentative production of ginsenoside Rh2 in yeast has recently been investigated as an alternative strategy compared to extraction from plants. However, the titer was quite low due to low catalytic capability of the key ginseng glycosyltransferase in microorganisms. Herein, we have demonstrated high-level production of ginsenoside Rh2 in Saccharomyces cerevisiae via repurposing an inherently promiscuous glycosyltransferase, UGT51...
May 4, 2017: Metabolic Engineering
https://www.readbyqxmd.com/read/28472673/phenylalanine-ammonia-lyase-from-arabidopsis-thaliana-atpal2-a-potent-mio-enzyme-for-the-synthesis-of-non-canonical-aromatic-alpha-amino-acids-part-ii-application-in-different-reactor-concepts-for-the-production-of-s-2-chloro-phenylalanine
#17
Alana Dreßen, Thomas Hilberath, Ursula Mackfeld, Jens Rudat, Martina Pohl
Phenylalanine ammonia lyase (PAL) from Arabidopsis thaliana (AtPAL2) is in general a very good catalyst for the amination of fluoro- and chloro-cinnamic acid derivatives yielding halogenated (S)-phenylalanine derivatives with ≥85% conversion and excellent ee values >99%. We have studied the application of this enzyme as whole cell biocatalyst and immobilized on the cellulose carrier Avicel(®) for the production of the hypertension drug precursor (S)-2-chloro-phenylalanine using batch, fed-batch, as well as continuous membrane reactor and plug-flow reactor...
May 1, 2017: Journal of Biotechnology
https://www.readbyqxmd.com/read/28472077/improvement-of-uridine-production-of-bacillus-subtilis-by-atmospheric-and-room-temperature-plasma-mutagenesis-and-high-throughput-screening
#18
Xiaoguang Fan, Heyun Wu, Guoliang Li, Hui Yuan, Hongchao Zhang, Yanjun Li, Xixian Xie, Ning Chen
In the present study, a novel breeding strategy of atmospheric and room temperature plasma (ARTP) mutagenesis was used to improve the uridine production of engineered Bacillus subtilis TD12np. A high-throughput screening method was established using both resistant plates and 96-well microplates to select the ideal mutants with diverse phenotypes. Mutant F126 accumulated 5.7 and 30.3 g/L uridine after 30 h in shake-flask and 48 h in fed-batch fermentation, respectively, which represented a 4.4- and 8.7-fold increase over the parent strain...
2017: PloS One
https://www.readbyqxmd.com/read/28470602/high-yield-of-recombinant-protein-in-shaken-e-coli-cultures-with-enzymatic-glucose-release-medium-enpresso-b
#19
Kaisa Ukkonen, Antje Neubauer, Vinit J Pereira, Antti Vasala
Expression of recombinant proteins in sufficient quantities is essential for protein structure-function studies. The most commonly used method for recombinant protein production is overexpression in E. coli cultures. However, producing high yields of functional proteins in E. coli can be a challenge in conventional shaken cultures. This is often due to nonoptimal growth conditions, which result in low cell yields and insoluble or incorrectly folded target protein. To overcome the shortcomings of shake flask cultivation, we present a cultivation method based on enzymatic glucose delivery...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28466304/microbial-production-of-glutathione
#20
REVIEW
Maximilian Schmacht, Eric Lorenz, Martin Senz
Glutathione (GSH) is a non-coding tripeptide thiol with several important regulative and protective functions in eukaryotes and in most prokaryotes. The primary function of GSH is to maintain the redox potential of the cell, which is directly connected to GSH concentration, and to prevent cellular damages caused by reactive oxygen species or toxic heavy metals. Due to its antioxidant character, it is widely used in pharmaceutical, cosmetic and food industry. There have been different strategies to optimize GSH yield and productivity in bacteria and yeasts by means of metabolic and evolutionary engineering, media optimization and bioprocess engineering...
June 2017: World Journal of Microbiology & Biotechnology
keyword
keyword
60207
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"