EFFECT OF BACTERIOCIN FROM SELECTED LACTIC ACID BACTERIA ON SOME TEST ORGANISMS

Abstract

Lactic acid bacteria (LAB) are a group of Gram positive, fastidious bacteria having some members capable of
producing bacteriocin-a ribosomally synthesized antimicrobial peptide. The study is aimed at determining the effect
of bacteriocin from selected LAB isolates on some test organisms. Samples (cow and goat milk, kunu, nunu, cheese
and fermented locust beans) were obtained from Malete, Kwara State. LABs were isolated under aseptic condition
using spread plate method. After biochemical characterization, the isolates obtained were screened for their ability to
produce bacteriocin using standard procedures. The isolates that produced bacteriocin with the widest zone of
inhibition were then identified using 16SrRNA gene sequencing analysis. The antibacterial activity of the bacteriocin
was tested against Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus
cereus. A total of thirty-six isolates were obtained out of which nine produced bacteriocin, however, two of these
isolates produced bacteriocin with the widest zone of inhibition against the test organism and these were identified as
Lactobacillus plantarum SJC103 and L. apis HBAm1. Using bacteriocin from L. apis the highest mean zone of
inhibition of 15.00 ± 1.00 mm was obtained against S. aureus and the least of 10.00 ± 0.00 mm against P. aeruginosa
and Salmonella typhi while for bacteriocin from L. plantarum the highest mean zone of inhibition of 17.00 ± 0.00 mm
was obtained against S. aureus and the least of 7.50 ± 0.50 mm against Salmonella typhi. It was concluded that LAB
bacteriocin produced inhibitory effect on the test organisms.