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Wenjian Ma, Jianli Wang, Ye Li, Lianghong Yin, Xiaoyuan Wang
BACKGROUND: Co-production of polyhydroxyalkanoate (PHA) and amino acids makes bacteria effective microbial cell factories by secreting amino acids outside while accumulating PHA granules inside. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is one of the PHAs with biocompatibility and fine mechanical properties, but its production is limited by the low level of intracellular propionyl-CoA. RESULTS: L-Isoleucine producing Corynebacterium glutamicum strain WM001 were analyzed by genome and transcriptome sequencing...
June 15, 2018: Microbial Cell Factories
Baek-Rock Oh, Sung-Mok Lee, Sun-Yeon Heo, Jeong-Woo Seo, Chul Ho Kim
BACKGROUND: 1,3-Propanediol (1,3-PDO) is important building blocks for the bio-based chemical industry, Klebsiella pneumoniae can be an attractive candidate for their production. However, 1,3-PDO production is high but productivity is generally low by K. pneumoniae. In this study, repeated fed-batch cultivation by a lactate and 2,3-butanediol (2,3-BDO) deficient mutant of K. pneumoniae were investigated for efficient 1,3-PDO production from industrial by-products such as crude glycerol...
June 15, 2018: Microbial Cell Factories
Justus Hardegen, Adriel Latorre-Pérez, Cristina Vilanova, Thomas Günther, Manuel Porcar, Olaf Luschnig, Claudia Simeonov, Christian Abendroth
In this work, liquid and solid fractions of grass biomass were used as co-substrates for anaerobic co-digestion of sewage sludge. The input of grass biomass was increased gradually, and the underlying methanogenic microbiome was assessed by means of microscopy-based cell counting and full-length 16S rRNA gene high-throughput sequencing, proving for the first time the suitability of nanopore-based portable sequencers as a monitoring tool for anaerobic digestion systems. In both cases co-fermentation resulted in an increased number of bacteria and methanogenic archaea...
June 6, 2018: Bioresource Technology
Zora Váradyová, Dominika Mravčáková, Monika Holodová, Ľubomira Grešáková, Jana Pisarčíková, Marcin Barszcz, Marcin Taciak, Anna Tuśnio, Svetlana Kišidayová, Klaudia Čobanová
Two experiments were conducted on sheep to determine the effect of dietary supplementation with zinc and a medicinal plant mixture on haematological parameters and microbial activity in the rumen and large intestine. In Experiment 1, 24 male lambs were randomly divided into four groups: One group was fed an unsupplemented basal diet (control), and three groups were fed a diet supplemented with 70 mg Zn/kg diet in the form of Zn sulphate (ZnSO4 ), a Zn-chelate of glycine hydrate (Zn-Gly) or a Zn-proteinate (Zn-Pro), for five months...
June 14, 2018: Journal of Animal Physiology and Animal Nutrition
Brigitte Roy, Cécile Philippe, Martin J Loessner, Jacques Goulet, Sylvain Moineau
Applications for bacteriophages as antimicrobial agents are increasing. The industrial use of these bacterial viruses requires the production of large amounts of suitable strictly lytic phages, particularly for food and agricultural applications. This work describes a new approach for phage production. Phages H387 ( Siphoviridae ) and A511 ( Myoviridae ) were propagated separately using Listeria ivanovii host cells immobilised in alginate beads. The same batch of alginate beads could be used for four successive and efficient phage productions...
June 13, 2018: Viruses
Lan Anh Thi Hoang, Ha Cam Nguyen, Thom Thi Le, Thi Huong Quynh Hoang, Van Nhat Pham, Minh Hien Thi Hoang, Hoai Thu Thi Ngo, Dang Diem Hong
Schizochytrium mangrovei strain PQ6 was investigated for co-production of docosahexaenoic acid (C22: 6ω-3, DHA) and squalene using a 30 L bioreactor with a working volume of 15 L under various batch and fed-batch fermentation process regimes. The fed-batch process was a more efficient cultivation strategy for achieving higher biomass production rich in DHA and squalene. The final biomass, total lipid, unsaponifiable lipid content and DHA productivity were 105.25 g · L-1 , 43.40% of dry cell weight, 8.58% total lipid and 61...
June 11, 2018: Journal of Phycology
Nayaret Acosta, Jo De Vrieze, Verónica Sandoval, Danny Sinche, Isabella Wierinck, Korneel Rabaey
The aim of this work was to evaluate the bioenergy potential of cocoa residue via anaerobic digestion. Batch and fed-batch lab-scale reactors were operated under low and high solids conditions. In the batch tests, 59 ± 4% of Chemical Oxygen Demand (COD) was recovered as methane. This corresponded with an average methane yield of 174 (wet) and 193 (dry) L kg-1 volatile solids fed, whereas a series of fed-batch reactors produced 70 ± 24 (wet) and 107 ± 39 (dry) L CH4  kg-1 volatile solids fed during stable conditions...
May 31, 2018: Bioresource Technology
Shruti Bindal, Vikas Kumar Dagar, Meenu Saini, Yogender Pal Khasa, Rani Gupta
Increasing demand of microbial γ-glutamyl transpeptidase (GGT) in food and pharmaceutical sectors raised the need for process development for high level production of the enzyme. In this respect, GGT from Bacillus licheniformis ER15 (SBLGGT) was cloned along with its native secretion signal and expressed in E. coli using different expression vectors. Native signal of the enzyme assistedits extracellular translocationin E. coli.Maximum enzyme expression was shown by construct pET51b-sblggt,in comparison to other clones, in E...
September 2018: Enzyme and Microbial Technology
Giovanna Lovato, Roberta Albanez, Marianne Triveloni, Suzana M Ratusznei, José A D Rodrigues
The most common approach to deal with vinasse (sugarcane stillage) is fertigation, but this technique compromises soil structure and surrounding water bodies. A possible solution is to transport vinasse to local cheese whey producers and perform the co-digestion of these wastewaters together, reducing their organic load and generating bioenergy. Therefore, this study investigated the application of an AnSBBR (anaerobic sequencing batch biofilm reactor) operated in batch and fed-batch mode, co-digesting vinasse and whey at 30 °C...
June 7, 2018: Applied Biochemistry and Biotechnology
Ye Hou, Hang Su, Zhiying Luo, Mingying Li, Xiaonan Ma, Ningning Ma
Phosphorylation and hydroxylation are post translational modifications (PTMs) rarely observed or reported in biopharmaceuticals. While developing a stable CHO cell line and a fed-batch process to produce a biosimilar dulaglutide, a GLP1-Fc fusion protein, we identified both serine phosphorylation and lysine hydroxylation. While the innovator dulaglutide contains less than 2% phosphorylated and only approximately 6.5% hydroxylated GLP1-Fc molecules, the clones that we obtained in the platform fed-batch process had approximately 20% phosphorylated and 25% hydroxylated GLP1-Fc molecules...
June 7, 2018: Biotechnology Journal
Lijie Cao, Dongmei Liang, Panlong Hao, Qianqian Song, Ershu Xue, Qinggele Caiyin, Zihao Cheng, Jianjun Qiao
Cell wall is closely related to bacterial robustness and adsorption capacity, playing crucial roles in nisin production in Lactococcus lactis. Peptidoglycan (PG), the essential component of cell wall, is usually modified with MurNAc O-acetylation and GlcNAc N-deacetylation, catalyzed by YvhB and XynD, respectively. In this study, increasing the two modifications in L. lactis F44 improved autolysis resistance by decreasing the susceptibility to PG hydrolases. Furthermore, both modifications were positively associated with overall cross-linkage, contributing to cell wall integrity...
June 6, 2018: Journal of Industrial Microbiology & Biotechnology
Shuai Luo, Xin-Ai Chen, Xu-Ming Mao, Yong-Quan Li
Production of secondary metabolites in Streptomyces is regulated by a complex regulatory network precisely, elaborately, and hierarchically. One of the main reasons for the low yields of some high-value secondary metabolites is the repressed expression of their biosynthetic gene clusters, supposedly by some gene cluster out-situated negative regulators. Identification of these repressors and removal of the inhibitory effects based on the regulatory mechanisms will be an effective way to improve their yields...
June 6, 2018: Applied Microbiology and Biotechnology
Clément Flayac, Eric Trably, Nicolas Bernet
Microbial community structure of anodic biofilms plays a key role in bioelectrochemical systems (BESs). When ecosystems are used as inocula, many bacterial species having interconnected ecological interactions are present. The aim of the present study was to identify these interactions for the conversion of single substrates into electrical current. Dual-chamber reactors were inoculated with activated sludge and fed in batch mode with acetate, lactate, butyrate and propionate at 80 mMe- equivalents in quadruplicate...
May 28, 2018: Bioelectrochemistry
Guneet Kaur, Hung-Chi Cheung, Wei Xu, Jun Vic Wong, For Fan Chan, Yingxue Li, Larry McReynolds, Linfeng Huang
Small interfering RNAs (siRNAs) are invaluable research tools for studying gene functions in mammalian cells. siRNAs are mainly produced by chemical synthesis or by enzymatic digestion of dsRNAs produced in vitro. Recently bacterial cells, engineered with ectopic plant viral siRNA binding protein p19, have enabled the production of 'recombinant' siRNAs (pro-siRNAs). Here we describe an optimized methodology for the production of milligram amount of highly potent recombinant pro-siRNAs from Escherichia coli cells...
June 5, 2018: Biotechnology and Bioengineering
Hana Raschmanová, Leona Paulová, Barbora Branská, Zdeněk Knejzlík, Karel Melzoch, Karin Kovar
Pharmaceutical grade trypsin is in ever-increasing demand for medical and industrial applications. Improving the efficiency of existing biotechnological manufacturing processes is therefore paramount. When produced biotechnologically, trypsinogen-the inactive precursor of trypsin-is advantageous, since active trypsin would impair cell viability. To study factors affecting cell physiology and the production of trypsinogen in fed-batch cultures, we built a fusion protein of porcine trypsinogen and enhanced green fluorescent protein (EGFP) in Pichia pastoris...
June 5, 2018: Folia Microbiologica
Jérôme Maury, Soumya Kannan, Niels B Jensen, Fredrik K Öberg, Kanchana R Kildegaard, Jochen Forster, Jens Nielsen, Christopher T Workman, Irina Borodina
For an industrial fermentation process, it can be advantageous to decouple cell growth from product formation. This decoupling would allow for the rapid accumulation of biomass without inhibition from product formation, after which the fermentation can be switched to a mode where cells would grow minimally and primarily act as catalysts to convert substrate into desired product. The switch in fermentation mode should preferably be accomplished without the addition of expensive inducers. A common cell factory Saccharomyces cerevisiae is a Crabtree-positive yeast and is typically fermented at industrial scale under glucose-limited conditions to avoid the formation of ethanol...
2018: Frontiers in Bioengineering and Biotechnology
Ajeet Kumar Mohanty, Praveen Balabaskaran Nina, Shuvankar Ballav, Smita Vernekar, Sushma Parkar, Maria D'souza, Wenyun Zuo, Edwin Gomes, Laura Chery, Shripad Tuljapurkar, Neena Valecha, Pradipsinh K Rathod, Ashwani Kumar
BACKGROUND: As much as 80% of global Plasmodium vivax infections occur in South Asia and there is a shortage of direct studies on infectivity of P. vivax in Anopheles stephensi, the most common urban mosquito carrying human malaria. In this quest, the possible effects of laboratory colonization of mosquitoes on infectivity and development of P. vivax is of interest given that colonized mosquitoes can be genetically less divergent than the field population from which they originated. METHODS: Patient-derived P...
June 5, 2018: Malaria Journal
Rohan Jain, Sirpa Peräniemi, Norbert Jordan, Manja Vogel, Stephan Weiss, Harald Foerstendorf, Aino-Maija Lakaniemi
This study demonstrated the removal and recovery of uranium(VI) in a fed-batch stirred tank reactor (STR) using waste digested activated sludge (WDAS). The batch adsorption experiments showed that WDAS can adsorb 200 (±9.0) mg of uranium(VI) per g of WDAS. The maximum adsorption of uranium(VI) was achieved even at an acidic initial pH of 2.7 which increased to a pH of 4.0 in the equilibrium state. Desorption of uranium(VI) from WDAS was successfully demonstrated from the release of more than 95% of uranium(VI) using both acidic (0...
May 24, 2018: Water Research
Christian Reitz, Qin Fan, Peter Neubauer
In E. coli the non-canonical amino acids acids norvaline, norleucine, and β-methylnorleucine, which derive from an off-pathway of the branched-chain amino acid synthesis route are synthesized and incorporated into cellular and recombinant proteins. The synthesis of these amino acids is supported by a high flux of glucose through the glycolytic pathway in combination with a derepression of the enzymes of the branched chain amino acid pathway, for example, when leucine-rich proteins are produced. Avoiding the synthesis and misincorporation of these amino acids has been challenging, especially in large-scale pharmaceutical processes where the problem is boosted by the typical fed-batch production and the technical limitation of mass transfer in the bioreactors...
June 2, 2018: Current Opinion in Biotechnology
Natalia L Rojas, Elizabeth S Lewkowicz, Matias L Nobile
An industrial-scale, profitable method for production of the most widely used bioinsecticide, Bacillus thuringiensis (Bt), is challenging because of its widespread application. The aim of this study is to present a strategy to develop a low-cost, large-scale bioprocess to produce Bt H14. This study was first focused on the design of a culture medium composed of economical and available components, such as glycerol and lysed Saccharomyces cerevisiae. The production goal of 1200 ITU was achieved using a medium composed of 20:20 g L-1 of glycerol:lysed yeast in batch cultures...
June 5, 2018: Journal of Environmental Science and Health. Part. B, Pesticides, Food Contaminants, and Agricultural Wastes
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