Characterisation of anti-Listeria monocytogenesbacteriocins fromEnterococcus faeciumstrains isolated from dairy products

Bacteriocin‐producing lactic acid bacteria were isolated from 34 samples of dairy products. Nine bacteriocin producers were phenotypically and genotypically identified as Enterococcus faecium . By means of PCR‐techniques, enterocin A was characterised in all of the nine bacteriocin‐producing Enterococcus isolates. Enterocin‐producing lactic acid bacteria were the most abundant in dairy products collected from different areas in Iran. Maximum bacteriocin production by Enterococcus faecium strains was detected in the stationary phase of growth. Bacteriocins produced by all isolates were found to have anti‐listerial activity in sterile milk. The purified bacteriocins were identified as <6.5 kDa peptide by sodium dodecyl sulphate‐polyacrylamide gel (SDS‐PAGE). The molecular weights of bacteriocins were found to be the same in all strains. This bacteriocin might be useful as a natural preservative.