Isolation of lactic acid bacteria, producing γ-aminobutyric acid (GABA), from foods and plants in Toyama Prefecture

Abstract

Four strains of lactic acid bacteria which produce a high level of γ-aminobutyric acid （GABA） were isolated from foods and plants produced in Toyama Prefecture. These lactic acid bacteria were identified and the productive capacity of GABA in GYP liquid medium was examined. The obtained results are summarized as follows:

（1）These lactic acid bacteria were identified and named Lactobacillus brevis 0910, Lactobacillus buchneri 0912, Lactobacillus buchneri 1001 and Lactococcus lactis 1005 by 16S rRNA gene sequencing analysis. These strains were isolated from masuzushi, miso, kaburazushi and tulip, respectively.（2）There was a difference in the productive capacity of GABA among the four strains: Lb. buchneri 1001 showed the greatest capacity, while Lc. lactis 1005 did the least. （3） Lb. brevis 0910, Lb. buchneri 0912 and Lb. buchneri 1001 produced the largest amount of GABA on the condition of pH 4.5 or 5.0.（4）In the case of Lb. buchneri 1001, when the pH level of the medium was at 4.5, a maximum of 550 mM GABA was produced from 800 mM sodium glutamate concentration (GABA conversion rate: 69%).