DETECTION AND ACTIVITY OF PLANTARICIN-F AN ANTIBACTERIAL SUBSTANCE FROM LACTOBACILLUS-PLANTARUM BF001 ISOLATED FROM PROCESSED CHANNEL CATFISH

Lactobacillus plantarum BF001 isolated from chilled processed channel catfish produced an antimicrobial substance active against selected bacteria from the genera Lactobacillus, Lactococcus, Listeria, Micrococcus, Leuconostocs, Pediococcus, Staphylococcus, Streptococcus, Salmonella and Pseudomonas. The antimicrobial effect did not result from acidic fermentation products or hydrogen peroxide. Culture extracts showed a bactericidal mode of action, displayed optimal activity at pH 3.5, and retained full activity after 30 min at 100 degrees C (pH 3.5). It was not conclusively proved that the substance, named plantaricin F, was sensitive to proteolytic enzymes. Its molecular weight was estimated by ultrafiltration studies to be under 10,000 daltons. The ability of plantaricin F to inhibit a wide-range of bacteria, including grampositive and gram-negative foodborne pathogens, is of potential interest for food safety, and plantaricin F may have future applications as a food preservative.