Isolation and selection of high gamma aminobutyric acid-producing Lactobacillus strains from traditional fermented foods

Abstract

Gamma aminobutyric acid (GABA) is produced by microorganisms such as bacteria, yeast, and fungi. Lactic acid bacteria play crucial roles in processing and preserving Vietnamese traditional fermented foods. The study aims to isolate high GABA-producing Lactobacillus strains from traditional fermented foods. Eight bacterial strains, including BC3, BC4, BC5, BC6, BC7, K08, KC1, and KC2, were isolated from traditional fermented food sources (cabbage, pickled scallion, and kimchi). After 72 hrs of fermentation, the BC3 strain produced the highest GABA content (4.279 g/l). This strain was
identified as Lactobacillus fermentum by 16S rRNA analysis. The results from the investigation of the fermentation time and concentration of monosodium glutamate (MSG) showed that the BC3 strain producing the highest GABA with the value of 6.734 g/l was after 72 hrs of fermentation and the concentration of MSG 4%.