Enhanced production of γ-aminobutyric acid (GABA) using Lactobacillus plantarum EJ2014 with simple medium composition

gamma-Aminobutyric acid (GABA) is an amino acid not present in proteins. GABA participates in a variety of physiological functions and has received significant attention in the medical and food industries. In this study, GABA production was investigated using Lactobacillus plantarum. We designed a synthetic medium consisting of the simplest medium components such as yeast extract (nitrogen source), glucose (carbon source), and monosodium L-glutamate (MSG; substrate for GABA) and optimized their proportions to efficiently produce GABA. As a result, 19.8 g/L GABA was obtained under an optimal synthetic medium composition of 100 g/L yeast extract, 10 g/L glucose, and 2.25% MSG, which is the highest among previous studies using L. plantarum. Interestingly, 159.7% of theoretical maximum yield based on initial MSG content was obtained since yeast extract acts as a secondary source of substrate. By proper optimization with the simplest medium using L. plantarum, it can produce a high titer of GABA as well as might help various functional foods containing GABA to develop.

Automated summary

In this study, a synthetic medium was used to efficiently produce high titer of GABA using Lactobacillus plantarum. The optimized medium composition resulted in the highest GABA production compared to previous studies. The use of yeast extract as a secondary substrate source also contributed to achieving a yield exceeding the theoretical maximum.