Gamma-aminobutyric acid (GABA) promotes characteristics of Levilactobacillus sp. LB-2

γ-Aminobutyric acid (GABA) is a pharmaceutical, bioactive amino acid that can be produced by lactic acid bacteria (LAB), but the yield of GABA is still limited by several reasons. In this study, a GABA-producing LAB strain Levilactobacillus sp. LB-2 (OP890629) was isolated from a Chinese traditional dough fermentation starter of Jiaozi. When subjected to GABA production optimization applying one-factor-at-a-time (OFAT) and response surface method (RSM), the temperature, pH, and L-monosodium glutamate (L-MSG) concentration for GABA production were set as 37 °C, pH 4.5, and 2.5 g/L, respectively. The maximum amount of GABA produced by strain Levilactobacillus sp. LB-2 was 49.42 g/L, which was 3.5-fold higher than that before optimization of 14.19 g/L. The GABA content of steamed bread made by Levilactobacillus sp. LB-2 significantly increased. Thus, strain Levilactobacillus sp. LB-2 could be used for the production of GABA or applied for the development and improvement of GABA-enriched foods.