title: Efficient bioconversion of L-glutamate to γ-aminobutyric acid by Lactobacillus brevis resting cells.
abstract: This work investigated the efficient bioconversion process of L-glutamate to GABA by Lactobacillus brevis TCCC 13007 resting cells. The optimal bioconversion system was composed of 50 g/L 48 h cultivated wet resting cells, 0.1 mM pyridoxal phosphate in glutamate-containing 0.6 M citrate buffer (pH 4.5) and performed at 45 °C and 180 rpm. By 10 h bioconversion at the ratio of 80 g/L L-glutamic acid to 240 g/L monosodium glutamate, the final titer of GABA reached 201.18 g/L at the molar bioconversion ratio of 99.4 %. This process presents a potential for industrial and commercial applications and also offers a promising feasibility of continuous GABA production coupled with fermentation. Besides, the built kinetics model revealed that the optimum operating conditions were 45 °C and pH 4.5, and the bioconversion kinetics at low ranges of substrate concentration (0 < S < 80 g/L) was assumed to follow the classical Michaelis-Menten equation.
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Xiufeng
authors.initials: X
authors.lastname: Shi
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Chuanyou
authors.initials: C
authors.lastname: Chang
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Shenxi
authors.initials: S
authors.lastname: Ma
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China. gaoqiang@tust.edu.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gao
mesh_terms: D005285:Fermentation; D018698:Glutamic Acid / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D052196:Levilactobacillus brevis / Q000166:cytology / Q000378:metabolism*; D013696:Temperature; D005680:gamma-Aminobutyric Acid / Q000096:biosynthesis*
chemical_list: D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid
keywords: Bioconversion; Glutamate; Kinetics model; Lactobacillus brevis; γ-Aminobutyric acid