Probiotic lactic acid bacteria isolated from traditional Korean fermented foods based on β-glucosidase activity

Abstract

This study was designed to isolate lactic acid bacteria (LAB) with β-glucosidase activity and probiotic properties from Korean fermented foods. Among nine isolates, four LAB strains had excellent survival rates at pH 2.5 with 0.3% (w/v) pepsin for 3 h and 0.3% (w/v) oxgall for 24 h. Four LAB strains did not produce β-glucuronidase and showed adhesion ability to HT-29 cells that was superior to that shown by the reference strain Lactobacillus rhamnosus GG. All four strains were sensitive to ampicillin, tetracycline, chloramphenicol, and doxycycline. These strains were identified as Leuconostoc mesenteroides H40, Lactobacillus plantarum FI10604, L. brevis FI10700, and L. perolens FI10842 by 16S rRNA gene sequence, respectively. It was found that L. perolens FI10842 produced the highest β-glucosidase activity (49.10 mU/mL). These results indicate that the four LAB strains could be used as potential probiotic. Especially L. perolens FI10842 could be used as a starter culture for fermentation.

Keywords: Korean fermented food; Lactic acid bacteria; Probiotic; Screening; β-Glucosidase.

Fig. 1

Adhesion ability of commercial and isolated LAB strains to human intestinal HT-29 cells. Error bars indicate the standard deviations from three independent experiments. The letters at the base of the bars denote statistical significance (p < 0.05), as determined by one-way analysis of variance and Duncan’s multiple range tests

Fig. 2

β-Glucosidase activity of potential probiotic strains at 37 °C for 24 h. Error bars indicate the standard deviations from three independent experiments. The letters at the base of the bars denote statistical significance (p < 0.05), as determined by one-way analysis of variance and Duncan’s multiple range tests