Characterization of Enterococcus faecium EO1 isolated from mutton and activity of bacteriocin-like substances in the control of Listeria monocytogenes in fresh mutton sausage

The aim of this study was to isolate and characterize bacteriocinogenic lactic acid bacteria (LAB) from mutton carcasses after slaughter. The study also evaluated the activity of bacteriocin-like substances (BLS) for control of Listeria monocytogenes in fresh mutton sausage. The cell-free supernatant (CFS) was obtained and its antimicrobial activity was quantified. The presence of genes encoding enterocin was evaluated by molecular techniques. Another aspect assessed was the action in situ of BLS produced by these isolates for control of Listeria monocytogenes in fresh mutton sausage, experimentally contaminated. Six isolates presented phenotypic and genotypic characteristics of safety. Also, the antibacterial peptides present in the CFS showed stability at different temperatures, pH, NaCl and cure salt concentrations, as well as potential against L. monocytogenes Scott A. The isolate identified as Enterococcus faecium EO1 showed gene coding for the production of enterocin A and produced bacteriocin after 6 h of growth (400 AU. mL(-1)). Based on this, the CFS of EO1 (5 and 10%) was applied in fresh mutton sausage, being significantly effective for control of L. monocytogenes during 21 days of refrigerated storage (4.07 log CFU.g(-1)). Therefore, the potential for preservation of food has been demonstrated through the use of CFS containing bacteriocin-like substances from E. faecium EO1 in fresh mutton sausage.