In vitro characterization of Lactobacillus brevis KU15006, an isolate from kimchi, reveals anti-adhesion activity against foodborne pathogens and antidiabetic properties.

Abstract

This study aimed at evaluating the functional and probiotic properties of three lactic acid bacterial (LAB) strains isolated from kimchi. The selected LAB strains, which had potential probiotic functions, were identified by 16S rRNA sequence analysis as Lactobacillus brevis G1, L. brevis KU15006, and Lactobacillus curvatus KCCM 200173. All LAB strains were able to tolerate incubation at pH 2.5 with 0.3% pepsin for 3 h and with 0.3% Oxgall for 24 h and showed similar enzyme production levels, antimicrobial activities, and antibiotic susceptibilities. L. brevis G1 and KU15006 presented higher adhesion ability, auto-aggregation, and cell surface hydrophobicity than Lactobacillus rhamnosus KCTC 12202BP, a commercial strain used as positive control. All LAB strains showed 50-60% co-aggregation activity with selected foodborne pathogens. L. brevis KU15006 showed anti-adhesion activity against Escherichia coli and Salmonella Typhimurium. In addition, cell-free supernatant and cell-free extract from L. brevis KU15006 displayed the highest inhibitory activities against α-glucosidase. These results indicate that L. brevis KU15006 has the best properties, with pathogen antagonistic and antidiabetic activity, for use in probiotic products.

Keywords: Antagonistic activity; Antidiabetic activity; Kimchi; Lactobacillus; Probiotics.