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Journal of Biotechnology

Eric Lorenz, Dennis Runge, Anna-Maria Marbà-Ardébol, Maximilian Schmacht, Ulf Stahl, Martin Senz
The application of oleaginous yeast cells as feed supplement, for instance in aqua culture, can be a meaningful alternative for fish meal and oil additives. Therefore, a two-stage fed-batch process split into growth and lipogenesis phase was systematically developed to enrich the oleaginous yeast Rhodotorula glutinis Rh-00301 with high amounts of lipids at industrial relevant biomasses. Thereby, the different carbon sources glucose, sucrose and glycerol were investigated concerning their abilities to serve as a suited raw material for growth and/or lipid accumulation...
February 14, 2017: Journal of Biotechnology
Shuying Li, Zhonghao Jiang, Lichao Sun, Xin Liu, Ying Huang, Fengzhong Wang, Fengjiao Xin
FIP-dsq2, a new immunomodulatory protein, was identified in Basidiomycota Dichomitus squalens by gene mining. FIP-dsq2 contained 111 amino acids with a molecular weight of 12.51kDa. FIP-dsq2 had a homology range of 51-65% to the reported FIPs. The predicted 3-dimensional model had more similar identical folding patterns in LZ-8 than for FIP-fve. Evolutionary analysis indicated substantial phylogenetic differences were existed with the other FIPs. Overexpression of a 14.07kDa soluble rFIP-dsq2 was achieved in Rosetta (pGEX-6T-1) and the purified recombinant protein was homodimer verified by gel filtration chromatography analysis...
February 12, 2017: Journal of Biotechnology
Marc R Hayes, Kevin Bochinsky, Lisa S Seibt, Lothar Elling, Jörg Pietruszka
The synthesis of glycosidic structures by catalysis via glycosynthases has gained much interest due to the potential high product yields and specificity of the enzymes. Nevertheless, the characterisation and implementation of new glycosynthases is greatly hampered by the lack of high-throughput methods for reaction analysis and screening of potential glycosynthase variants. Fluoride detection, via silyl ether chemosensors, has recently shown high potential for the identification of glycosynthase mutants in a high-throughput manner, though limited by the low maximal detection concentration...
February 10, 2017: Journal of Biotechnology
Benjamin Dionne, Neha Mishra, Michael Butler
Glycosylation and intracellular assembly of monoclonal antibodies (MAbs) is important for glycan profile consistency. To better understand how these factors may be influenced by a lower redox potential, an IgG1-producing NS0 cell line was grown in the presence of varying concentrations of dithiothreitol (DTT). Cultures were monitored for growth and culture redox potential (CRP) with glycan heterogeneity determined using a HILIC-HPLC method. Macroheterogeneity was unchanged in all conditions whereas the Galactosylation Index (GI) decreased by as much as 50% in cultures with lower CRP or higher dithiothreitol levels...
February 11, 2017: Journal of Biotechnology
Priscila da Silva Delabona, Gisele Nunes Rodrigues, Mariane Paludetti Zubieta, Jonas Ramoni, Carla Aloia Codima, Deise Juliana Lima, Cristiane Sanchez Farinas, José Geraldo da Cruz Pradella, Bernhard Seiboth
This work investigates the influence of the positive regulator XYR1 of Trichoderma harzianum on the production of cellulolytic enzymes, using sugarcane bagasse as carbon source. Constitutive expression of xyr1 was achieved under the control of the strong Trichoderma reesei pki1 promoter. Five clones with xyr1 overexpression achieved higher xyr1 expression and greater enzymatic productivity when cultivated under submerged fermentation, hence validating the genetic construction for T. harzianum. Clone 5 presented a relative expression of xyr1 26-fold higher than the parent strain and exhibited 66, 37, and 36% higher values for filter paper activity, xylanase activity, and β-glucosidase activity, respectively, during cultivation in a stirred-tank bioreactor...
February 9, 2017: Journal of Biotechnology
Jingyang Guan, Sarah A Berlinger, Xiaozheng Li, Zhongmou Chao, Victor Sousa E Silva, Scott Banta, Alan C West
Electrofuels processes are potentially promising platforms for biochemical production from CO2 using renewable energy. When coupled to solar panels, this approach could avoid the inefficiencies of photosynthesis and there is no competition with food agriculture. In addition, these systems could potentially be used to store intermittent or stranded electricity generated from other renewable sources. Here we develop reactor configurations for continuous electrofuels processes to convert electricity and CO2 to isobutyric acid (IBA) using genetically modified (GM) chemolithoautotrophic Acidithiobacillus ferrooxidans...
February 6, 2017: Journal of Biotechnology
Lisa Mears, Stuart M Stocks, Gürkan Sin, Krist V Gernaey
A majority of industrial fermentation processes are operated in fed-batch mode. In this case, the rate of feed addition to the system is a focus for optimising the process operation, as it directly impacts metabolic activity, as well as directly affecting the volume dynamics in the system. This review covers a range of strategies which have been employed to use the feed rate as a manipulated variable in a control strategy. The feed rate is chosen as the focus for this review, as it is seen that this variable may be used towards many different objectives depending on the process of interest, the characteristics of the strain, or the product being produced, which leads to different drivers for process optimisation...
February 5, 2017: Journal of Biotechnology
Zijun Xiao, Wenlong Liang, Xiankun Zhu, Jing-Yi Zhao
Consumers prefer biotechnological food products with high nutritional values and good flavors. Solid-state fermentation is a commonly used technique with a long history. In the present study, Myroides sp. ZB35 was used in solid-state fermentative production of aroma volatiles on a rice medium. Using the headspace solid phase microextraction coupled with gas chromatography-mass spectrometry technique and authentic standards, 22 esters with molecular weight ranging from 102 to 172 were identified. At 192h, the esters reached a total concentration of 1774μg/kg...
February 4, 2017: Journal of Biotechnology
Bárbara Cunha, Tiago Aguiar, Sofia B Carvalho, Marta M Silva, Ricardo A Gomes, Manuel J T Carrondo, Patrícia Gomes-Alves, Cristina Peixoto, Margarida Serra, Paula M Alves
To deliver the required cell numbers and doses to therapy, scaling-up production and purification processes (at least to the liter-scale) while maintaining cells' characteristics is compulsory. Therefore, the aim of this work was to prove scalability of an integrated streamlined bioprocess compatible with current good manufacturing practices (cGMP) comprised by cell expansion, harvesting and volume reduction unit operations using human mesenchymal stem cells (hMSC) isolated from bone marrow (BM-MSC) and adipose tissue (AT-MSC)...
February 4, 2017: Journal of Biotechnology
Ingemar Nærdal, Roman Netzer, Marta Irla, Anne Krog, Tonje Marita Bjerkan Heggeset, Volker F Wendisch, Trygve Brautaset
Bacillus methanolicus is a methylotrophic bacterium with an increasing interest in academic research and for biotechnological applications. This bacterium was previously applied for methanol-based production of l-glutamate, l-lysine and the five-carbon diamine cadaverine by wild type, classical mutant and recombinant strains. The genomes of two different l-lysine secreting B. methanolicus classical mutant strains, NOA2#13A52-8A66 and M168-20, were sequenced. We focused on mutational mapping in genes present in l-lysine and other relevant amino acid biosynthetic pathways, as well as in the primary cell metabolism important for precursor supply...
February 2, 2017: Journal of Biotechnology
Juan M Bolivar, Christiane Luley-Goedl, Ernestine Leitner, Thornthan Sawangwan, Bernd Nidetzky
2-O-(α-d-Glucopyranosyl)-sn-glycerol (αGG) is a natural osmolyte. αGG is produced industrially for application as an active cosmetic ingredient. The biocatalytic process involves a selective transglucosylation from sucrose to glycerol catalyzed by sucrose phosphorylase (SPase). Here we examined immobilization of SPase (from Leuconostoc mesenteroides) on solid support with the aim of enabling continuous production of αGG. By fusing SPase to the polycationic binding module Zbasic2 we demonstrated single-step noncovalent immobilization of the enzyme chimera to different porous supports offering an anionic surface...
February 1, 2017: Journal of Biotechnology
Jian Sun, Wen-Hui Cui, Kun Du, Qian Gao, Mengmeng Du, Peijun Ji, Wei Feng
R-ɷ-transaminases transfer an amino group from an amino donor (e.g. (R)-1-phenylethylamine) onto an amino acceptor (e.g. pyruvate), resulting a co-product (e.g. d-alanine). This work intends to immobilize R-ɷ-Transaminase on MnO2 nanorods to achieve multienzyme catalysis. R-ɷ-Transaminase (RTA) and d-amino acid oxidase (DAAO) have been fused to an elastin-like polypeptide (ELP) separately through genetic engineering of the enzymes. ELP-RTA and ELP-DAAO have been separately immobilized on polydopamine-coated MnO2 nanorods...
January 31, 2017: Journal of Biotechnology
Samantha Wang, Scott Godfrey, Janani Ravikrishnan, Henry Lin, Jens Vogel, Jon Coffman
Achievement of a robust and scalable cell retention device remains a challenge in perfusion systems. Of the two filtration systems commonly used, tangential flow filtration (TFF) systems often have an inferior product sieving profile compared to alternating tangential flow filtration (ATF) systems, which is typically attributed to the ATF's unique alternating flow. Here, we demonstrate that observed performance differences between the two systems are a function of cell lysis and not the alternating flow as previously thought...
January 31, 2017: Journal of Biotechnology
Rodolfo Marques, Moritz von Stosch, Rui M C Portela, Cristiana A V Torres, Sílvia Antunes, Filomena Freitas, Maria A M Reis, Rui Oliveira
Enterobacter A47 is a bacterium that produces high amounts of a fucose-rich exopolysaccharide (EPS) from glycerol residue of the biodiesel industry. The fed-batch process is characterized by complex non-linear dynamics with highly viscous pseudo-plastic rheology due to the accumulation of EPS in the culture medium. In this paper, we study hybrid modeling as a methodology to increase the predictive power of models for EPS production optimization. We compare six hybrid structures that explore different levels of knowledge-based and machine-learning model components...
January 31, 2017: Journal of Biotechnology
Chun Su, Yibo Liu, Yan Sun, Zhi Li
Serratia sp. YD25 (KCTC 42987) was originally isolated from rhizosphere soil in a continuous cropping tobacco-planting farm. Here, we show that its metabolites efficiently suppress the growth of various important pathogenic fungi and bacteria, causing infection in both plants and humans. In addition, Serratia sp. YD25 has a special trait of simultaneous production of both serrawettin W2 and prodigiosin, two important bioactive secondary metabolites produced by Serratia strains. Such co-production has not been reported in other Serratia strains...
January 30, 2017: Journal of Biotechnology
Suah Jo, Jinkyung Yoon, Sun-Mi Lee, Youngsoon Um, Sung Ok Han, Han Min Woo
Xylose-negative Corynebacterium glutamicum has been engineered to utilize xylose as the sole carbon source via either the xylose isomerase (XI) pathway or the Weimberg pathway. Heterologous expression of xylose isomerase and overexpression of a gene encoding for xylulose kinase enabled efficient xylose utilization. In this study, we show that two functionally-redundant transcriptional regulators (GntR1 and GntR2) present on xylose repress the pentose phosphate pathway genes. For efficient xylose utilization, pentose phosphate pathway genes and a phosphoketolase gene were overexpressed through - with the XI pathway in C...
January 30, 2017: Journal of Biotechnology
Won-Heong Lee, Yong-Su Jin
Although simultaneous saccharification and fermentation (SSF) of cellulosic biomass can offer efficient hydrolysis of cellulose through alleviating feed-back inhibition of cellulases by glucose, supplementation of β-glucosidase is necessary because most fermenting microorganisms cannot utilize cellobiose. Previously, we observed that SSF of cellulose by an engineered Saccharomyces cerevisiae expressing a cellobiose transporter (CDT-1) and an intracellular β-glucosidase (GH1-1) without β-glucosidase could not be performed as efficiently as the traditional SSF with extracellular β-glucosidase...
January 28, 2017: Journal of Biotechnology
Nicolai Kallscheuer, Michael Vogt, Michael Bott, Jan Marienhagen
Plant polyphenols receive significant attention due to their anti-oxidative and health-promoting properties, and several microorganisms are currently engineered towards producing these valuable compounds. Previously, Corynebacterium glutamicum has been engineered for synthesizing polyphenol core structures such as the stilbene resveratrol and the (2S)-flavanone naringenin. Decoration of these compounds by O-methylation or hydroxylation would provide access to polyphenols of even higher commercial interest. In this study, introduction of a heterologous O-methyltransferase into a resveratrol-producing C...
January 28, 2017: Journal of Biotechnology
Yang Liu, Rudiyanto Gunawan
The performance of model-based bioprocess optimizations depends on the accuracy of the mathematical model. However, models of bioprocesses often have large uncertainty due to the lack of model identifiability. In the presence of such uncertainty, process optimizations that rely on the predictions of a single "best fit" model, e.g. the model resulting from a maximum likelihood parameter estimation using the available process data, may perform poorly in real life. In this study, we employed ensemble modeling to account for model uncertainty in bioprocess optimization...
January 27, 2017: Journal of Biotechnology
Andrey Yu Gulevich, Alexandra Yu Skorokhodova, Alexey V Sukhozhenko, Vladimir G Debabov
Enantiomers of 3-hydroxybutyric acid (3-HB) can be used as the chiral precursors for the production of various optically active fine chemicals, including drugs, perfumes, and pheromones. In this study, Escherichia coli was engineered to produce (S)-3-HB from glucose through the inverted reactions of the native aerobic fatty acid β-oxidation pathway. Expression of only specific genes encoding enzymes responsible for the conversion of acetyl-CoA to acetoacetyl-CoA, reduction of acetoacetyl-CoA to 3-hydroxybutyryl-CoA and subsequent hydrolysis of 3-hydroxybutyryl-CoA to 3-HB was directly upregulated in an engineered strain...
January 25, 2017: Journal of Biotechnology
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