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fed batch

Yasuharu Kamachi, Takeshi Omasa
Cell culture platform processes are generally employed to shorten the duration of new product development. A fed-batch process with continuous feeding is a conventional platform process for monoclonal antibody production using Chinese hamster ovary (CHO) cells. To establish a simplified platform process, the feeding method can be changed from continuous feed to bolus feed. However, this change induces a rapid increase of osmolality by the bolus addition of nutrients. The increased osmolality suppresses cell culture growth, and the final product concentration is decreased...
December 7, 2017: Journal of Bioscience and Bioengineering
Joseph P Webb, S Alison Arnold, Scott Baxter, Stephen J Hall, Graham Eastham, Gill Stephens
Citramalic acid is a central intermediate in a combined biocatalytic and chemocatalytic route to produce bio-based methylmethacrylate, the monomer used to manufacture Perspex and other high performance materials. We developed an engineered E. coli strain and a fed-batch bioprocess to produce citramalate at concentrations in excess of 80 g l-1 in only 65 h. This exceptional efficiency was achieved by designing the production strain and the fermentation system to operate synergistically. Thus, a single gene encoding a mesophilic variant of citramalate synthase from Methanococcus jannaschii, CimA3...
December 12, 2017: Microbiology
Lukas Chrast, Radka Chaloupkova, Jiri Damborsky
Heterologous production of recombinant proteins is a cornerstone of microbiological and biochemical research as well as various biotechnological processes. Yields and quality of produced proteins have a tremendous impact on structural and enzymology studies, development of new biopharmaceuticals and establishing new biocatalytic processes. Majority of current protocols for recombinant protein expression in Escherichia coli exploit batch cultures with complex media, often providing low yields of the target protein due to oxygen transfer limitation, rapid depletion of carbon sources, and pH changes during the cultivation...
December 5, 2017: FEMS Microbiology Letters
Ping Liu, Xinggao Liu, Zeyin Zhang, Yalin Wang, Chunhua Yang, Weihua Gui
Since a very slight violation of constraint could cause process safety and product quality problems in biochemical processes, an adaptive approach of fed-batch reactor production optimization that can strictly satisfy constraints over the entire operating time is presented. In this approach, an improved smooth function is proposed such that the inequality constraints can be transformed into smooth constraints. Based on this, only an auxiliary state is needed to monitor violations in the augmented performance index...
December 8, 2017: Bioprocess and Biosystems Engineering
Leonie Marang, Mark C M van Loosdrecht, Robbert Kleerebezem
To enrich polyhydroxyalkanoate (PHA) producing microbial communities, generally, a feast-famine regime is applied. Here we investigated the impact of continuous substrate feeding on the enrichment of PHA-producing bacteria in two sequencing batch reactors (SBRs). In the first reactor, the substrate (acetate) was dosed continuously and Zoogloea sp. was enriched. The culture accumulated PHA upon exposure to excess carbon, but the PHA production rate and storage capacity (53wt.%) were one-fifth of that observed for enrichment cultures in a standard, pulse-fed SBR dominated by the PHA producer Plasticicumulans acidivorans...
December 5, 2017: New Biotechnology
Julia Tröndle, Christoph Albermann, Michael Weiner, Georg A Sprenger, Dirk Weuster-Botz
Usually perturbation of the metabolism of cells by addition of substrates is applied for metabolic analysis of production organisms, but perturbation studies are restricted to the endogenous substrates of the cells under study. The goal of this study was to overcome this limitation by making phosphoenolpyruvate (PEP) available for perturbation studies with Escherichia coli producing L-phenylalanine. A production strain overexpressing a PEP-transporter variant (UhpT-D388C) was applied in a standardized fed-batch production-process on a 42 L-scale...
December 8, 2017: Biotechnology Journal
Chan Woo Song, Chelladurai Rathnasingh, Jong Myoung Park, Julia Lee, Hyohak Song
Biologically produced 2,3-butanediol (2,3-BDO) has diverse industrial applications. In this study, schematic isolation and screening procedures were designed to obtain generally regarded as safe (GRAS) and efficient 2,3-BDO producers. Over 4,000 candidate strains were isolated by pretreatment and enrichment, and the isolated Bacillus strains were further screened by morphological, biochemical, and genomic analyses. The screened strains were then used to test the utilization of the most common carbon (glucose, xylose, fructose, sucrose) and nitrogen (yeast extract, corn steep liquor) sources for the economical production of 2,3-BDO...
December 8, 2017: Journal of Microbiology and Biotechnology
Matthias Müller, Wolfram Meusel, Ute Husemann, Gerhard Greller, Matthias Kraume
The application of biocalorimetry to fermentation processes offers advantageous insights, while being less complex compared to other,sophisticated PAT solutions. Although the general concept is established,calorimetric methods vary in detail. In this work, a special approach,called heat compensation calorimetry, was applied to an E. coli fed-batch process. Much work has been done for batch processes, proving the validity and accuracy of this calorimetric mode. However, the adaption of this strategy to fed-batch processes has some implications...
December 2, 2017: Journal of Biotechnology
R Kyle Bennett, Jacqueline E Gonzalez, W Brian Whitaker, Maciek R Antoniewicz, Eleftherios T Papoutsakis
Synthetic methylotrophy aims to develop non-native methylotrophic microorganisms to utilize methane or methanol to produce chemicals and biofuels. We report two complimentary strategies to further engineer a previously engineered methylotrophic E. coli strain for improved methanol utilization. First, we demonstrate improved methanol assimilation in the presence of small amounts of yeast extract by expressing the non-oxidative pentose phosphate pathway (PPP) from Bacillus methanolicus. Second, we demonstrate improved co-utilization of methanol and glucose by deleting the phosphoglucose isomerase gene (pgi), which rerouted glucose carbon flux through the oxidative PPP...
December 5, 2017: Metabolic Engineering
Tao Wu, Jinjin Zhao, Xianjun Mao
L-tryptophan, one of the aromatic amino acids, is widely used in the fields of medicine, food and feed additives. The phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS) plays an important role in glucose transport and phosphorylation in Escherichia coli. PTS-mediated regulation dominates the carbohydrates' uptake and metabolism in E. coli. We constructed L-tryptophan-producing bacteria containing two typical PTS mutations (ptsHIcrrglf⁻ glk⁺ and ptsG⁻) by Red homologous recombination system, and studied in 50 L jar fermenter using fed-batch fermentation...
November 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Wei Shu, Chao Li, Xiaoyun Liu, Jianye Xia, Yingping Zhuang
Isotope Dilution Mass Spectrometry (IDMS) is the most accurate method for high-throughput detection of intracellular metabolite concentrations, and the key is getting the corresponding fully uniformly(U) ¹³C-labeled metabolites to be measured. The conventional procedure for getting fully U ¹³C-labeled metabolites is through batch cultivation, but intracellular metabolites concentrations by this method are generally low. By applying U ¹³C-labeled glucose pulse, combined with fast sampling and quenching, mixture of fully U ¹³C-labeled intracellular metabolites was successfully extracted with higher concentration from Pichia pastoris G/DSEL fed with fully U ¹³C-labeled glucose as only carbon source...
November 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Julian Lange, Felix Müller, Kerstin Bernecker, Nicolaus Dahmen, Ralf Takors, Bastian Blombach
Background: A future bioeconomy relies on the efficient use of renewable resources for energy and material product supply. In this context, biorefineries have been developed and play a key role in converting lignocellulosic residues. Although a holistic use of the biomass feed is desired, side streams evoke in current biorefinery approaches. To ensure profitability, efficiency, and sustainability of the overall conversion process, a meaningful valorization of these materials is needed...
2017: Biotechnology for Biofuels
Xianhua Sun, Xianli Xue, Mengzhu Li, Fei Gao, Zhenzhen Hao, Huoqing Huang, Huiying Luo, Lina Qin, Bin Yao, Xiaoyun Su
Cellulase and mannase are both important enzyme additives of animal feeds. Expressing the two enzymes simultaneously within one microbial host could potentially lead to cost saving in animal feeding. For this purpose, we codon optimized the Aspergillus niger Man5A gene to the codon usage bias of Trichoderma reesei. By comparing the free energy and the local structure of the nucleotide sequences, one optimized sequence was finally selected and transformed into the T. reesei pyridine auxotrophic strain TU-6. The codon optimized gene was expressed to a higher level than the original one...
December 4, 2017: Journal of Agricultural and Food Chemistry
Elisa A Giustinianovich, José-Luis Campos, Marlene D Roeckel, Alejandro J Estrada, Anuska Mosquera-Corral, Ángeles Val Del Río
The performance of the partial nitritation/anammox processes was evaluated for the treatment of fish canning effluents. A sequencing batch reactor (SBR) was fed with industrial wastewater, with variable salt and total ammonium nitrogen (TAN) concentrations in the range of 1.75-18.00 g-NaCl L-1 and 112 - 267 mg-TAN L-1. The SBR operation was divided into two experiments: (A) progressive increase of salt concentrations from 1.75 to 18.33 g-NaCl L-1; (B) direct application of high salt concentration (18 g-NaCl L-1)...
November 24, 2017: Chemosphere
P De Cocker, Y Bessiere, G Hernandez-Raquet, S Dubos, I Mozo, G Gaval, M Caligaris, B Barillon, S E Vlaeminck, M Sperandio
This study compared two anammox sequencing batch reactors (SBR) for one year. SBRconstantT was kept at 30 °C while temperature in SBRloweringT was decreased step-wise from 30 °C to 20 °C and 15 °C followed by over 140 days at 12.5 °C and 10 °C. High retention of anammox bacteria (AnAOB) and minimization of competition with AnAOB were key. 5-L anoxic reactors with the same inoculum were fed synthetic influent containing 25.9 mg NH4+-N/L and 34.1 mg NO2--N/L (no COD). Specific ammonium removal rates continuously increased in SBRconstantT, reaching 785 mg NH4+-N/gVSS/d, and were maintained in SBRloweringT, reaching 82...
November 24, 2017: Bioresource Technology
Yunping Tang, Guomei Zhang, Zheng Wang, Dan Liu, Linglu Zhang, Yafeng Zhou, Ju Huang, Fangmiao Yu, Zuisu Yang, Guofang Ding
(S)-3-chloro-1-phenyl-1-propanol ((S)-CPPO) is an important chiral intermediate predominantly used in the synthesis of the chiral side chain of (S)-fluoxetine. In this study, carbonyl reductase (CBR) from Novosphingobium aromaticivorans was successfully expressed in recombinant E. coli. The enzymatic activity of the recombinant CBR was significantly increased to 1875 U/mL in the fed-batch fermentation in a 10 L fermenter and recombinant CBR was then purified and characterized. By regenerating NADH with glucose dehydrogenase, 100 g/L 3-chloro-1-phenyl-1-propanone (3-CPP) was successfully converted to (S)-CPPO with a conversion of 100% and ee value of 99...
November 1, 2017: Bioresource Technology
Di Wu, Xiaoyun Yi, Rong Tang, Chunhua Feng, Chaohai Wei
The use of several individual reactors for sequential removal of organic compounds and nitrogen, in addition to the required alkaline addition in aerobic reactors, remain outstanding technical challenges to the traditional biological treatment of coking wastewater. Here, we report the utilization of a single microbial fuel cell (MFC) reactor that performs simultaneous carbon and nitrogen removal with zero alkaline consumption, as evidenced by the results of the batch-fed and continuous-flow experiments. The MFC exhibited faster reaction kinetics for COD and total nitrogen (TN) removal than the same configured reactor analogous to the traditional aerobic biological reactor (ABR)...
November 28, 2017: Science of the Total Environment
Majdiah Othman, Arbakariya B Ariff, Helmi Wasoh, Mohd Rizal Kapri, Murni Halim
Lactic acid bacteria are industrially important microorganisms recognized for fermentative ability mostly in their probiotic benefits as well as lactic acid production for various applications. Fermentation conditions such as concentration of initial glucose in the culture, concentration of lactic acid accumulated in the culture, types of pH control strategy, types of aeration mode and different agitation speed had influenced the cultivation performance of batch fermentation of Pediococcus acidilactici. The maximum viable cell concentration obtained in constant fed-batch fermentation at a feeding rate of 0...
November 27, 2017: AMB Express
Jae Woong Choi, Sung Sun Yim, Ki Jun Jeong
Beyond its traditional role as an L-amino acid producer, Corynebacterium glutamicum has recently received significant attention regarding its use in the production of various biochemicals and recombinant proteins. However, despite these attributes, limitations in genetic tools are still hampering the engineering of C. glutamicum for use in more potential hosts. Here, we engineered a C. glutamicum via adaptive laboratory evolution to enhance the production of recombinant proteins. During the continuous cultivation, C...
November 25, 2017: Applied Microbiology and Biotechnology
Alexandra Hofer, Donya Kamravamanesh, Judit Bona-Lovasz, Andreas Limbeck, Bernhard Lendl, Christoph Herwig, Jens Fricke
Every biopharmaceutical production process aims for control strategies to achieve process robustness in order to ensure consistent product quality. Process variability can origin from process parameters, the biological nature as well as from high lot-to-lot variability of raw materials. In filamentous processes raw materials with very complex matrices, such as corn steep liquor (CSL), are used, which are especially challenging to characterize. In this study, CSL was characterized in detail for its ingredients presenting an overall composition of its matrix of 50 analyzed components (19 amino acids, 5 organic acids, 8 reducing sugars, 7 water-soluble vitamins and 11 trace elements/minerals) in order to facilitate analytical reduction to fingerprinting methods FT-MIR was evaluated as fast and non-destructive spectroscopic fingerprinting method for adequate assessment of CSL quality...
November 23, 2017: Journal of Biotechnology
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