title: A novel approach to improve poly-γ-glutamic acid production by NADPH Regeneration in Bacillus licheniformis WX-02.
abstract: Poly-γ-glutamic acid (γ-PGA) is an important biochemical product with a variety of applications. This work reports a novel approach to improve γ-PGA through over expression of key enzymes in cofactor NADPH generating process for NADPH pool. Six genes encoding the key enzymes in NADPH generation were over-expressed in the γ-PGA producing strain B. licheniformis WX-02. Among various recombinants, the strain over-expressing zwf gene (coding for glucose-6-phosphate dehydrogenase), WX-zwf, produced the highest γ-PGA concentration (9.13 g/L), 35% improvement compared to the control strain WX-pHY300. However, the growth rates and glucose uptake rates of the mutant WX-zwf were decreased. The transcriptional levels of the genes pgsB and pgsC responsible for γ-PGA biosynthesis were increased by 8.21- and 5.26-fold, respectively. The Zwf activity of the zwf over expression strain increased by 9.28-fold, which led to the improvement of the NADPH generation, and decrease of accumulation of by-products acetoin and 2,3-butanediol. Collectively, these results demonstrated that NADPH generation via over-expression of Zwf is as an effective strategy to improve the γ-PGA production in B. licheniformis.
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, China.
authors.forename: Dongbo
authors.initials: D
authors.lastname: Cai
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, China.
authors.forename: Penghui
authors.initials: P
authors.lastname: He
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, China.
authors.forename: Xingcheng
authors.initials: X
authors.lastname: Lu
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, China.
authors.forename: Chengjun
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.|Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa 50011, United States.
authors.forename: Zhiyou
authors.initials: Z
authors.lastname: Wen
authors.affiliation: Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, College of Life Sciences, Hubei University, Wuhan 430062, China.
authors.forename: Shouwen
authors.initials: S
authors.lastname: Chen
mesh_terms: D000093:Acetoin / Q000378:metabolism; D000069976:Bacillus licheniformis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002072:Butylene Glycols / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D007700:Kinetics; D053858:Metabolic Networks and Pathways / Q000235:genetics; D009154:Mutation; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics / Q000378:metabolism; D009249:NADP / Q000096:biosynthesis*; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000096:biosynthesis; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D002072:Butylene Glycols; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; C026978:2,3-butylene glycol; D009249:NADP; D000093:Acetoin; D005954:Glucosephosphate Dehydrogenase; D017351:N-Acetylglucosaminyltransferases; D005947:Glucose