Optimization and modeling of growth conditions for Lactobacillus brevis IBRC10818 for biosynthesis of gamma-aminobutyric acid, affected by ultrasonic shock

This study aimed to produce gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter in the nervous system, from Lactobacillus brevis IBRC 10818 using microbial biosynthesis and ultrasonic shock. Microbial biosynthesis is one of the best production methods compared to chemical synthesis. The response surface methodology (RSM) was used to optimize and model the GABA production under the influence of four shock factors: ultrasonic intensity, ultrasonic time, incubation period, and monosodium glutamate (MSG) concentration. The shock was applied during the lag phase. The optimal conditions for maximum GABA production were predicted to be 2.98 % MSG, 70.8 h incubation time, 6.30 min shock time, and 33 kHz frequency. Under these conditions, the GABA production was 266.19 mg/L, which was close to the predicted value of 212.2 mg/L. The model prediction was suitable with a high coefficient of determination (R2=0.96).