Twenty strains of lactic acid bacteria (LAB) were isolated from 20 samples of wild elephant faeces from the Kui Buri District, in Prachuap Khiri Khan Province. Five strains of lactic acid bacteria showed antibacterial activity as follows: strain P115 showed antibacterial activity on Salmonella enteritidis serovar Enteritidis, Vibrio cholerae, and Escherichia coli, strain P124 showed antibacterial activity on Salmonella enteritidis serovar Enteritidis, and Vibrio cholerae, strain P322 showed antibacterial activity on Vibrio cholerae, Salmonella enteritidis serovar Enteritidis and Shigella dysenteriae, strain P911 showed antibacterial activity on Vibrio cholerae and Salmonella enteritidis serovar Enteritidis, and strain P1112 showed antibacterial activity on Staphylococcus aureus.
Strain P322 had higher antibacterial activity than P115. Antibacterial activity on Vibrio cholerae, Salmonella Enteritidis and Shigella dysenteriae was about 400 AU/ml for all test
strains. Strain P115 showed antibacterial activity on Salmonella enteritidis serovar Enteritidis, Vibrio cholerae, and Escherichia coli at 400, 400, and 200 AU/ml, respectively. Strain P115 and strain P322 were identified by Bergey’s Manual of Systemic Bacteriology and Biochemical test kit API 20 Strep (BioMerieux) as Lactobacillus casei strain P115, and Lactococcus lactis subsp. lactis strain P322, respectively. Antibacterial substances, cell free culture neutralized supernatant (CFNS) of Lactobacillus casei strain P115 and Lactococcus
lactis subsp. lactis strain P322 were digested by proteolytic enzyme with a consequent loss of antibacterial activity, thus the antibacterial substances are bacteriocins. The bacteriocins showed thermostable properties: 100% after treatment at 100°C for 10 minutes.