Characterization of Bacteriocin like Inhibitory Substances from Enterococcus ratti MF183967.

This study was designed to characterize one Lactic acid bacteria (LAB), Enterococcus ratti showing admirable antimicrobial potential. Out of 54 LAB strains isolated from herbivores, cell free supernatant (CFS) of one strain E. ratti was active against wide range of pathogens including Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Clostridium perfringens, Listeria monocytogenes, Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Proteus mirabilis. PCR amplification of enterocin genes indicated presence of entL50 A and entP. Time kill assay of foodborne pathogens in the presence of CFS further confirmed its bactericidal property. The antimicrobial component was stable at a wide range of pH (4-10) and temperature (4-100°C). The loss of activity with proteinase k and pepsin treatment indicated its proteinaceous nature. SDS-PAGE analysis confirmed production of short peptides of 20 and 30KDa Bioautography revealed 20kDa fraction was active against MRSA. Scanning Electron Micrograph further indicated that its bactericidal action involves damage to the cell wall. Our findings suggest safe nature of E. ratti MF183967 for consumer health. [ABSTRACT FROM AUTHOR]