Enhancement of γ-Amminobutyric Acid Production by Lactobacillus sakei B2-16 Expressing Glutamate Decarboxylase from Lactobacillus plantarum ATCC 14917

To enhance gamma-amminobutyric acid (GABA) production using genetically engineered lactic acid bacteria, glutamate decarboxylase gene was isolated from Lactobacillus plantarum ATCC 14917 and cloned into Lactobacilli-E. coli shuttle-expression vector (pTRKH2) to yield pTRKH2GAD, which was expressed in L. sakei B2-16 isolated from Kimchi. The recombinant L. sakei B2-16 showed 1.35- and 1.42-fold higher GABA production compared to the untransformed strain in 500-mL flask and 5-L fermentor scale, respectively. The maximum GABA concentration was 265.3 mM.