Characteristics of the bacteriocin produced by Lactococcus lactis subsp cremoris CTC 204 and the effect of this compound on the mesophilic bacteria associated with raw beef

> Screening for the bacteriocin production of strains of lactic acid bacteria from various meat and meat products resulted in the detection of a bacteriocin-producing Lactococcus lactis subsp. cremoris CTC 204, isolated from chicken. The bacteriocin inhibited not only closely related lactic acid bacteria (Lactobacillus helveticus), but also pathogenic microorganisms (Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, and Clostridium perfringens). It was inactivated by alpha-chymotrypsin, ficin, papain, and pronase E, but not by lipase or pepsin. This compound was heat stable even at autoclaving temperature (121 degrees C for 10 min) and was produced during refrigerated storage. It was also active over a wide pH range (2-10), but the highest activity was observed in the lower pH range. The results indicated that dipping raw beef in the bacteriocin produced by strain CTC 204 could contribute to the extension of the shelf life of refrigerated bovine meat.