Inhibitory effect of bacteriocin-producing Lactobacillus brevis DF01 and Pediococcus acidilactici K10 isolated from kimchi on enteropathogenic bacterial adhesion

Abstract

The inhibitory effect of Lactobacillus brevis DF01 and Pediococcus acidilactici K10, which had been isolated from kimchi, on enteropathogenic bacterial adhesion to intestinal epithelial cells as well as their probiotic potential was studied. After the incubation of Lb. brevis DF01 and P. acidilactici K10 in simulated gastrointestinal juice, they showed higher tolerance to acidic juice (pH 3.0) and porcine bile extract (0.3%) than Lb. rhamnosus GG. Both Lb. brevis DF01 and P. acidilactici K10 also showed high percentages of autoaggregation and coaggregation with the enteropathogenic bacteria Salmonella Typhimurium and Escherichia coli O157:H7 at 37 degrees C after 24 h-incubation. It was shown that P. acidilactici K10 showed the highest adhesion to a human intestinal epithelial cell line, HT-29, followed by Lb. brevis DF01 and Lb. rhamnosus GG. In addition, the ability of Lb. brevis DF01 and P. acidilactici K10 to inhibit the adhesion of S. Typhimurium and E. coli O157:H7 to HT-29 cells was also evaluated. P. acidilactici K10 showed the strongest inhibitory effect on the adhesion of S. Typhimurium and E. coli O157:H7 on the basis of competition, displacement and exclusion assays. Lb. brevis DF01 was also shown to effectively inhibit the adhesion of S. Typhimurium and E. coli O157:H7, in particular, inhibition by exclusion. The results suggested that Lb. brevis DF01 and P. acidilactici K10 can be considered as promising probiotic candidates with antimicrobial activities against enteropathogenic bacteria.