Abstract: The purpose of this study is to isolate lactic acid bacteria (LAB) capable of producing γ-aminobutyric acid (GABA) from Yujiangsuan, a unique traditional fermented condiment in Qiandongnan, Guizhou Province, China, and analyze the fermentation characteristics of the strains. The GABA-producing strains were identified by thin-layer chromatography (TLC) and the Berthelot colorimetric method, and their fermentation characteristics such as acid tolerance, bile salt tolerance, amino acid decarboxylase activity, antibacterial activity, growth curve, pH, and acid production rate were evaluated. The results showed that a total of 387 strains were isolated from different stages of fermentation. Fifteen typical GABA-producing strains were selected from the 387 strains, including two strains of Weissella cibaria, one strain of Weissella bombi, 11 strains of Lactobacillus plantarum and one strain of L. spentosus. Among them, strain Y113 produced the highest amount of GABA (0.239 mg/mL). The GABA production ability and fermentation characteristics among the 15 strains were clearly separately by principal component analysis (PCA). Strains Y279 and Y64 were highly tolerant to acid and bile salt, exhibited good antibacterial activity, and had high growth rate and acid production rate but no amino acid decarboxylase activity. Due to its excellent fermentation characteristics, probiotic characteristics and GABA-producing capacity, strain Y279 shows great potential to be used as an excellent strain for industrial and standardized production of Yujiangsuan.

Key words: Yujiangsuan; γ-aminobutyric acid; lactic acid bacteria; separation and identification