Designing a cocktail containing redox enzymes to improve hemicellulosic hydrolysate fermentability by microorganisms
Publication date: Available online 10 December 2019Source: Enzyme and Microbial TechnologyAuthor(s): Robson Tramontina, Lívia Beatriz Brenelli, Amanda Sousa, Rafael Alves, Ana Maria Zetty Arenas, Viviane Marcos Nascimento, Sarita Cândida Rabelo, Sindélia Freitas, Roberto Ruller, Fabio SquinaAbstractBioproducts production using monomeric sugars derived from lignocellulosic biomass presents several challenges, such as to require a physicochemical pretreatment to improve its conversion yields. Hydrothermal lignocellulose pretreatment has several advantages and results in solid and liquid streams. The former is called hemic...
Source: Enzyme and Microbial Technology - December 11, 2019 Category: Biotechnology Source Type: research
Catalytic synthesis of 2,5-bis(hydroxymethyl)furan from 5-hydroxymethylfurfual by recombinant Saccharomyces cerevisiae
Publication date: Available online 11 December 2019Source: Enzyme and Microbial TechnologyAuthor(s): Zhi-Hao Xia, Min-Hua Zong, Ning LiAbstract2,5-Bis(hydroxymethyl)furan (BHMF) is a versatile building block in the synthesis of polymers, fuels, and macrocycle polyethers. In this work, alcohol dehydrogenases (ADHs) were identified from Meyerozyma guilliermondii SC1103 and were heterologously expressed in Saccharomyces cerevisiae for the synthesis of BHMF from 5-hydroxymethylfurfural (HMF). Of recombinant strains constructed, S. cerevisiae expressing an aryl ADH (AAD1669) was observed to be the best catalyst. Upon process op...
Source: Enzyme and Microbial Technology - December 11, 2019 Category: Biotechnology Source Type: research
High-yield and plasmid-free biocatalytic production of 5-methylpyrazine-2-carboxylic acid by combinatorial genetic elements engineering and genome engineering of Escherichia coli
Publication date: Available online 9 December 2019Source: Enzyme and Microbial TechnologyAuthor(s): Liuyan Gu, Haibo Yuan, Xueqin Lv, Guangsheng Li, Rigang Cong, Jianghua Li, Guocheng Du, Long LiuAbstract5-Methylpyrazine-2-carboxylic acid (MPCA) is an important pharmaceutical intermediate and is used in the production of hypoglycemic agents and lipid-lowering drugs. This work aimed to develop a whole-cell biocatalytic process for the efficient synthesis of MPCA from 2, 5-dimethylpyrazine (DMP). Firstly, a whole-cell biocatalyst Escherichia coli strain was constructed by plasmid-based expression of xylene monooxygenase (XMO...
Source: Enzyme and Microbial Technology - December 11, 2019 Category: Biotechnology Source Type: research
Increased Thermal Stability of a Glucose Oxidase Biosensor under High Hydrostatic Pressure
We report the effects of high hydrostatic pressure (HHP), immobilization in electrochemically generated poly-o-phenylenediamine nano-films, and reticulation with glutaraldehyde on the thermal stability of glucose oxidase (GOx). The pseudo-first-order rate constant of inactivation of immobilized GOx inactivated at 70 °C and atmospheric pressure was 20.6 times smaller than that of GOx in solution under the same conditions. Immobilized GOx inactivated at 70 °C and 180 MPa was 87.6 times more stable than GOx in solution inactivated at 70 °C and atmospheric pressure. However, applying high pressure during electropoly...
Source: Enzyme and Microbial Technology - December 8, 2019 Category: Biotechnology Source Type: research
Transcriptome analysis of Haematococcus pluvialis of multiple defensive systems against nitrogen starvation
Publication date: Available online 6 December 2019Source: Enzyme and Microbial TechnologyAuthor(s): Yue Zhao, Yuyong Hou, Wenjing Chai, Zhiyong Liu, Xuan Wang, ChunQing He, Zhipeng Hu, Shulin Chen, Weijie Wang, Fangjian chenAbstractHaematococcus pluvialis could accumulate large amounts of triacylglycerol (TAG) and astaxanthin under various environmental stresses. To gain insights into the multiple defensive systems for carbon metabolism against nitrogen starvation, transcriptome analysis was performed. It was found that the genes related to carbon fixation, glycolysis, fatty acid and carotenoid biosynthesis pathways were u...
Source: Enzyme and Microbial Technology - December 8, 2019 Category: Biotechnology Source Type: research
Overexpression of the transcription factor HAC1 improves nerolidol production in engineered yeast
This study provides an effective strategy for sesquiterpene production in yeast. (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - December 4, 2019 Category: Biotechnology Source Type: research
Profiles of plant core-fucosylated N-glycans of acid alpha-glucosidases produced in transgenic rice cell suspension cultures treated with eight different conditions
This study performed the comparison of the N-glycan profiles of rice cell-derived rhGAA to identify the core-fucosylated glycans using UPLC and tandem mass spectrometry. (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - December 1, 2019 Category: Biotechnology Source Type: research
Identification of key sites determining the cofactor specificity and improvement of catalytic activity of a steroid 5β-reductase from Capsella rubella
In this study a steroid 5β-reductase was identified in Capsella rubella (CrSt5βR1) and its function in steroid 5β-reduction was validated experimentally. CrSt5βR1 is capable of enantioselectively reducing the activated C = C bond of broad substrates such as steroids and enones by using NADPH as a cofactor and therefore has the potential as a biocatalyst in organic synthesis. However, for industrial purposes the cheaper NADH is the preferred cofactor. By applying rational design based on literature and complementary mutagenesis strategies, we successfully identified two key amino acid residues determining the cofact...
Source: Enzyme and Microbial Technology - December 1, 2019 Category: Biotechnology Source Type: research
A novel GH30 xylobiohydrolase from Acremonium alcalophilum releasing xylobiose from the non-reducing end
Publication date: Available online 30 November 2019Source: Enzyme and Microbial TechnologyAuthor(s): Katarína Šuchová, Vladimír Puchart, Nikolaj Spodsberg, Kristian B.R. Mørkeberg Krogh, Peter BielyAbstractXylanases of the GH30 family are grouped to subfamilies GH30-7 and GH30-8. The GH30-8 members are of bacterial origin and well characterized, while the GH30-7 members are from fungal sources and their properties are quite diverse. Here, a heterologous expression and characterization of the GH30-7 xylanase AaXyn30A from a cellulolytic fungus Acremonium alcalophilum is reported. From various polymeric and oligomeric s...
Source: Enzyme and Microbial Technology - December 1, 2019 Category: Biotechnology Source Type: research
Novel approach to produce biomass-derived oligosaccharides simultaneously by recombinant endoglucanase from Trichoderma reesei
Publication date: Available online 27 November 2019Source: Enzyme and Microbial TechnologyAuthor(s): Yuheng Tao, Lei Yang, Limin Yin, Chenhuan Lai, Caoxing Huang, Xin Li, Qiang YongAbstractThe recombinant endoglucanase gene (EG I) from Trichoderma reesei was successfully expressed in Pichia pastoris for the purpose of producing oligosaccharides from various biomass-derived substrates. Interestingly, the recombinant endoglucanase I (ReEG I) showed the catalytic activity towards both cellulose and xylan hydrolysis, yet it was more efficient with xylans. Among various glucans and xylans substrates (paper pulp, carboxymethylat...
Source: Enzyme and Microbial Technology - November 29, 2019 Category: Biotechnology Source Type: research
Production of isofloridoside from galactose and glycerol using α-galactosidase from Alicyclobacillus hesperidum
This study provides a possible feasible method for the biosynthesis of isofloridoside from low-cost glycerol and galactose. (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - November 28, 2019 Category: Biotechnology Source Type: research
Enzymatic synthesis and biological characterization of a novel mangiferin glucoside
In this study, novel mangiferin-(1→6)-α-D-glucopyranoside (Mg-G1) was enzymatically synthesized from mangiferin and sucrose using glucansucrase from Leuconostoc mesenteroides B-512F/KM, and optimized using response surface methodology. The water solubility of Mg-G1 was found to be 824.7 mM, which is more than 2,300-fold higher than that of mangiferin. Mg-G1 also showed DPPH radical scavenging activity and superoxide dismutase (SOD)-like scavenging activity, which were 4.77- and 3.71-fold higher than that of mangiferin, respectively. Mg-G1 displayed inhibitory activity against human intestinal maltase and COX-2. Thus, ...
Source: Enzyme and Microbial Technology - November 24, 2019 Category: Biotechnology Source Type: research
Efficient heterologous expression of nicotinate dehydrogenase in Comamonas testosteroni CNB-2 with transcriptional, folding enhancement strategy
Publication date: Available online 22 November 2019Source: Enzyme and Microbial TechnologyAuthor(s): Zhen-Hua Lu, Li-Rong Yang, Jian-Ping WuAbstractNicotinate dehydrogenase (NDHase) from Comamonas testosteroni JA1 catalyzes the C6 hydroxylation of 3-cyanopyridine with high regional selectivity, which is a very difficult and complex reaction for chemical synthesis. However, because NDHase is a membrane protein with three subunits (ndhS, ndhL and ndhM), it is difficult to express the enzyme in a functional form using common hosts such as Escherichia coli, Bacilus subtilis or Pichia pastoris. Furthermore, the enzyme require...
Source: Enzyme and Microbial Technology - November 22, 2019 Category: Biotechnology Source Type: research
Autodisplay of alpha amylase from Bacillus megaterium in E. coli for the bioconversion of starch into hydrogen, ethanol and succinic acid
Publication date: Available online 19 November 2019Source: Enzyme and Microbial TechnologyAuthor(s): Ana K. Gutiérrez-García, Cecilia Lizeth Alvarez-Guzmán, Antonio De Leon-RodriguezAbstractIn this work, the expression of an α-amylase from Bacillus megaterium on the cell surface of Escherichia coli strains WDHA (Δ hycA and Δ ldhA) and WDHFP (Δ hycA, Δ frdD and Δ pta) by the autodisplay adhesin involved in diffuse adherence (AIDA) system was carried out with the purpose to confer the ability to E. coli strains to degrade starch and thus produce hydrogen, ethanol and succinic acid. For the characterization of the bi...
Source: Enzyme and Microbial Technology - November 21, 2019 Category: Biotechnology Source Type: research
Expression, biochemical characterization, and mutation of a water forming NADH: FMN oxidoreductase from Lactobacillus rhamnosus
Publication date: Available online 17 November 2019Source: Enzyme and Microbial TechnologyAuthor(s): Fei-Long Li, Wen Bin Su, Qing-Lan Tao, Liao-Yuan Zhang, Ye-Wang ZhangAbstractEnzyme-catalyzed cofactor regeneration is a significant approach to avoid large quantities consumption of oxidized cofactor, which is vital in a variety of bioconversion reactions. NADH: FMN oxidoreductase is an ideal regenerating enzyme because innocuous molecular oxygen is required as an oxidant. But the by-product H2O2 limits its further applications at the industrial scale. Here, novel NADH: FMN oxidoreductase (LrFOR) from Lactobacillus rhamnos...
Source: Enzyme and Microbial Technology - November 18, 2019 Category: Biotechnology Source Type: research
