Screening of Probiotic Lactic Acid Bacteria from Piglet Feces

Abstract

The aim of this research was to screen for potential probiotic lactic acid bacteria (LAB) from piglet feces. A total of 317 LAB were isolated from 136 samples of pig feces. Preliminary screening was based on antimicrobial activity against eight pathogenic bacteria. A total of 171 isolates, which exhibited antimicrobial activity against at least three of the indicator strains, were selected and tested for acid and bile tolerance, bile salt hydrolase (BSH) activity and antibiotic susceptibility. Only five isolates, one identified as Lactobacillus amylovorus and four as Lactobacillus reuteri by sequence analysis of 16S rDNA, showed high survival rates under simulated gastric and intestinal conditions, and were selected for further characterization. These five selected isolates also exhibited bile salt hydrolase activity and the ability to adhere to epithelial cells. All five isolates were resistant to penicillin G, oxytetracyclin, neomycin, lincomycin and vancomycin, but sensitive to rifampicin and bacitracin. Based on their probiotic properties, one strain of L. amylovorus and four strains of L. reuteri were considered as potential candidate probiotics for animal feed.