Optimizing Levilactobacillus brevis NPS-QW 145 Fermentation for Gamma-Aminobutyric Acid (GABA) Production in Soybean Sprout Yogurt-like Product

Gamma-aminobutyric acid (GABA) is a non-protein amino acid with various physiological functions. Levilactobacillus brevis NPS-QW 145 strains active in GABA catabolism and anabolism can be used as a microbial platform for GABA production. Soybean sprouts can be treated as a fermentation substrate for making functional products. This study demonstrated the benefits of using soybean sprouts as a medium to produce GABA by Levilactobacillus brevis NPS-QW 145 when monosodium glutamate (MSG) is the substrate. Based on this method, a GABA yield of up to 2.302 g L(−1) was obtained with a soybean germination time of one day and fermentation of 48 h with bacteria using 10 g L(−1) glucose according to the response surface methodology. Research revealed a powerful technique for producing GABA by fermentation with Levilactobacillus brevis NPS-QW 145 in foods and is expected to be widely used as a nutritional supplement for consumers.