Enzymatic Bioconversion for γ-Ammobutyric Acid by Lactobacillus brevis CGMCC No. 3414 Resting Cells

摘要

In this work, y-aminobutyric acid (GABA) was prepared by the decar-boxylation of L-glutamate via L-glutamate decarboxylase in the resting cells of Lactobacillus brevis CGMCC No. 3414. The influence of cell concentration, cell age, buffer system, reaction time, and substrate concentration were investigated. The optimal composition of bioconversion system was composed of 50 g/L resting cells, cell age at 48 h fermentation, 0.2 M disodium hydrogen phosphate-citric acid buffer, and 25 mM monosodium glutamate. When the bioconversion system was performed at pH 4.6, 30°C, and 180 r/min shaking for 4 h, GABA production in biotransformation solution was 23.29 mM and the molar yield rate of bioconversion reached 93.15 %.