Biopreservation potential of E. faecalis isolated from Italian traditional raw milk cheeses

Mediterranean area. The genetic diversity of 38 E. faecalis isolates obtained from raw milk products in Italy was assessed through RAPD-PCR and Rep-PCR. The isolates were then screened for their antimicrobial activity against 5 food-borne spoilage and pathogenic bacteria, but also 13 technologically useful micro-organisms, commonly used as dairy starter cultures. Investigation was made to identify the bacteriocinogenic potential by searching for bacteriocin-encoding genes. Inhibitory effects against harmful or detrimental microbial species, including Bacillus cereus (44.7% of strains), Escherichia coli (18.4%), Listeria monocytogenes (15.8%), Staphylococcus aureus (2.6%), and Clostridium sporogenes (21.1%), were detected. Moderate antagonism towards lactic acid bacteria was found. Only gene for enterocin AS-48 was identified, suggesting that the antimicrobial activity of the phenotypically positive isolates should be necessarily due to another enterocin or non-enterocin factor. A deeper insight into biopreservation potential of dairy E. faecalis was provided.