Effect of Cultivating Conditions on gamma-Aminobutyric Acid Production by Lactobacillus brevis

To investigate the optimum culture conditions of γ-aminobutyric acid (GABA) production by a strain CC-W11 identified as Lactobacillus brevis in submerged fermentation, certain fermentation parameters involving inoculum volume of seeds, incubation temperature, initial pH value, period of cultivation and glutamate concentration in medium were investigated separately. The optimal cultivating conditions of GABA production in submerged fermentation were MRS medium with 5% monosodium glutamate (MSG), 32°C incubation temperature, 5% inoculum volume, 5.5 initial pH of medium, and 60 hours cultivation period. Under the optimized cultivation conditions, the maximum GABA production was 3.67±±0.23 g /L after 60 h of fermentation. This study also showed that industrial residues from seasoning corporation which contained approximately 400~450 g/L MSG could be used by Lactobacillus brevis as the substrate of glutamate decarboxylase for GABA biosynthesis and it was benefit to waste recycling.