김치에서 분리된 젖산균의 β-glucosidase 활성 탐색

The β-glucosidase (E.C. 3.2.1.21) production capabilities of lactic acid bacteria isolated from a variety of kimchi (fermented vegetables) were examined. When grown in a medium containing cellobiose as carbon source, most lactic acid bacteria showed significantly higher intracellular levels of β-glucosidase than the extracellular levels. A maximum intracellular β-glucosidase activity of 3.7±0.5 (unit/mg protein) was obtained in the case of Weissella cibaria KFRI88010 isolated from kimchi. The optimum reaction conditions for W. cibaria KFRI88010 β-glucosidase activity were pH 5.0 and 37°C, and addition of divalent cations to the reaction mixture resulted in a notable decrease in enzyme activity. The β-glucosidase activity was enhanced twofold when W. cibaria KFRI88010 was grown in a medium containing fructose as compared with to a medium containing glucose or cellobiose.