Enterococcus faecalis B3A-B3B produces the bacteriocin B3A-B3B with activity against Listeria monocytogenes， Staphylococcus aureus， methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium perfringens， but apparently not against fungi or Gram-negative bacteria， except for Salmonella Newport. B3A-B3B enterocin has two different nucleotides but similar amino acid composition to the class IIb MR10A-MR10B enterocin. B3A-B3B consists of two peptides of predicted molecular mass of 5176.31 Da (B3A) and 5182.21 Da (B3B). Importantly， B3A-B3B impeded biofilm formation of the foodborne pathogen L. monocytogenes 162 grown on stainless steel. The antimicrobial treatment of stainless steel with nisin (1 or 16 mg ml) decreased the cell numbers by about 2 log CFU ml， thereby impeding the biofilm formation by L. monocytogenes 162 or its nisin-resistant derivative strain L. monocytogenes 162R. Furthermore， the combination of nisin and B3A-B3B enterocin reduced the MIC required to inhibit this pathogen grown in planktonic or biofilm cultures.