Production and characterization of enterocin from Enterococcus faecium IJ-06 and IJ-21 isolated from indigenous dairy products

摘要

The study was conducted to investigate previously isolated Enterococcus faecium IJ-06 from local processed cheese and Enterococcus faecium IJ-21 from yoghurt for their bacteriocin production potential, antimicrobial activity and relevant virulence traits. Isolated stains were non hemolytic, susceptible to vancomycin and both strains possess genes for enterocin A (entA) and enterocin P (entP). Assessment of vanA, vanB genes and virulence determinants cyl were done through PCR. The enterocin was inhibitory towards Listeria monocytogenes, Staphylococcus aureus, Bacillus subtlis, Bacillus cereus and other enterococci. Characterization of enteriocins with specific treatment followed by residual activity assay showed its thermo-stability, with a wide pH range of activity and sensitivity to proteases. The molecular weight of partially purified enteocins was ~4.5-4.7 kDa as estimated by SDS-PAGE. It is promising for further investigation of the safe exploitation of these strains or their enterocins for microbial food safety.