title: Physiology-Oriented Engineering Strategy to Improve Gamma-Aminobutyrate Production in Lactobacillus brevis.
abstract: Gamma-aminobutyrate (GABA) is an important chemical in the pharmaceutical field. GABA-producing lactic acid bacteria (LAB) offer the opportunity of developing this health-oriented product. In this study, the gadA, gadB, gadC, gadCB, and gadCA gene segments of Lactobacillus brevis were cloned into pMG36e, and strain Lb. brevis/pMG36e-gadA was selected for thorough characterization in terms of GABA production after analysis of GAD activities. Subsequently, a physiology-oriented engineering strategy was adopted to construct an FoF1-ATPase deficient strain NRA6 with higher GAD activity. As expected, strain NRA6 could produce GABA at a concentration of 43.65 g/L with a 98.42% GABA conversion rate in GYP fermentation medium, which is 1.22-fold higher than that obtained by the wild-type strain in the same condition. This work demonstrates how the acid stress response mechanisms of LAB can be employed to develop cell factories with improved production efficiency and contributes to research into the development of the physiology-oriented engineering.
authors.affiliation: College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, China.|School of Biotechnology and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University , Ningbo 315100, China.
authors.forename: Chang-Jiang
authors.initials: CJ
authors.lastname: Lyu
authors.affiliation: School of Biotechnology and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University , Ningbo 315100, China.
authors.forename: Wei-Rui
authors.initials: WR
authors.lastname: Zhao
authors.affiliation: School of Biotechnology and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University , Ningbo 315100, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Hu
authors.affiliation: School of Biological and Chemical Engineering, Zhejiang University of Science and Technology , Hangzhou 310023, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.affiliation: College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Lu
authors.affiliation: School of Biotechnology and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University , Ningbo 315100, China.
authors.forename: Zhi-Hua
authors.initials: ZH
authors.lastname: Jin
authors.affiliation: College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, China.|School of Biotechnology and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University , Ningbo 315100, China.
authors.forename: Le-He
authors.initials: LH
authors.lastname: Mei
authors.affiliation: College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Shan-Jing
authors.identifier: http://orcid.org/0000-0003-3199-3044
authors.initials: SJ
authors.lastname: Yao
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D052196:Levilactobacillus brevis / Q000235:genetics / Q000378:metabolism*; D060847:Metabolic Engineering; D005680:gamma-Aminobutyric Acid / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D005680:gamma-Aminobutyric Acid
keywords: FoF1-ATPase; GABA; GAD system; Lb. brevis; physiology-oriented engineering