PURIFICATION AND CLONING OF PISCICOLIN-61, A BACTERIOCIN FROM CARNOBACTERIUM-PISCICOLA-LV61

Piscicolin 61, a bacteriocin produced by Carnobactelium piscicola LV61 , inhibits the growth of strains of Camobacterium, Lactobncillus, and Enterococcus. The bacteriocin was purified to homogeneity by ammonium sulfate precipitation and sequential hydrophobic interaction and rever sed-phase chromatography. The N-terminal amino acid sequence of piscic olin 61 was determined by Edman degradation. The plasmid-located struc tural gene encoding piscicolin (psc61) was cloned and sequenced. It en coded a primary translation product of 71 amino acid residues, which i s cleaved between amino acid residues 18 and 19 to yield the active ba cteriocin. The calculated M, from the deduced protein sequence, 5052.6 , agreed with that obtained by mass spectrometry. Piscicolin 61 did no t show any sequence similarities to other known bacteriocins. However, the leader sequence resembled those of the pediocin-like bacteriocins . Piscicolin 61 may be able to form amphiphilic helices and may thus a ct on the membrane of sensitive cells.