CHARACTERISTICS AND GENETIC-DETERMINANTS OF BACTERIOCIN ACTIVITIES PRODUCED BY CARNOBACTERIUM-PISCICOLA CP5 ISOLATED FROM CHEESE

Carnobacterium piscicola CP5, isolated from a French mold-ripened soft cheese, produced a bacteriocin activity named carnocin CP5, which inh ibited Carnobacterium, Enterococcus and Listeria spp. strains, and amo ng the Lactobacillus spp. only Lactobacillus delbrueckii spp. [24]. Th e activity was purified by ammonium sulfate precipitation, anion excha nge, and hydrophobic interaction chromatography followed by reverse-ph ase high-performance liquid chromatography (RP-HPLC). This latter step separated two peaks with anti-listerial activity (CP51 and CP52). Car nocin CP51 was partially sequenced, and the N-terminal part revealed t he presence of the ''pediocin-like consensus'' sequence-Tyr-Gly-Asn-Gl y-Val-. Then, a degenerated 24-mer oligonucleotide probe was construct ed from the N-terminal sequence and used to detect the structural gene . It was localized on a plasmid of about 40 kb. Cloning of restriction fragments of this one, followed by DNA sequencing, revealed the prese nce of the second anti-listeria bacteriocin gene (CP52). By comparing sequences in data banks and confirming results with PCR reactions, car nocin CP51 shared homologies with carnobacteriocin BM1, and carnocin C P52 was similar to carnobacteriocin B2, both produced by C. piscicola LV17 [2]. However, carnobacteriocin A from C. piscicola LV17 gene was lacking in C. piscicola CP5, and the two microorganisms have been isol ated from different ecological environments: C. piscicola CP5 and C. p iscicola LV17 were isolated from soft cheese and vacuum-packed meat re spectively. This fact could allow different application perspectives f or C. piscicola CP5.