Isolation of two lactobacilli, producers of two new bacteriocin-like substances (BLS) for potential food-preservative use

The fermentation of meat by lactic acid bacteria (LAB) is a traditional practice in many countries of Europe. LAB are already used for probiotic use and/or their bacteriocins can be used as a food preservative. 21 LABs were isolated from ham samples and identified by PCR; in particular, L. plantarum-GS16 and L. paraplantarum-GS54 were identified as the best bacteriocin-like substance (BLS) producers, active against spoilage and pathogenic bacteria, Gram negative included. In these strains, the presence of virulence factors, antibiotic and gastrointestinal resistance was investigated. The kinetics of growth and the BLS biosynthesis was also evaluated at different pH values. Finally, both bacteriocin substances were partially characterized and included in the IIa class of Klaenhammer; as a potential application, both BLSs can be successfully used as food preservatives.