EVIDENCE FOR 2 BACTERIOCINS PRODUCED BY CARNOBACTERIUM-PISCICOLA AND CARNOBACTERIUM-DIVERGENS ISOLATED FROM FISH AND ACTIVE AGAINST LISTERIA-MONOCYTOGENES

Lactic acid bacteria (LAB) isolated from fish products (fresh fish, sm oked and marinated fish, fish intestinal tract) were screened for bact eriocin production and immunity in conditions eliminating the effects of organic acids and hydrogen peroxide. Twenty-two isolates which were found to produce bacteriocin-like compounds were identified as Carnob acteria, Lactococci and Enterococci on the basis of morphological exam ination, gas production from glucose, growth temperatures, configurati on of lactic acid, carbohydrates fermentation and deamination of argin ine. Two Carnobacteria named V1 and V41 were selected for further stud ies and identified by DNA-DNA hybridization as Carnobacterium piscicol a and Carnobacterium divergens, respectively. Their respective bacteri ocins named piscicocin V1 and divercin V41 were heat-resistant and sen sitive to various proteolytic enzymes. These bacteriocins were active against Listeria monocytogenes and exhibited a different spectrum of a ctivity against LAB. Both bacteriocins had a bactericidal and non-bact eriolytic mode of action. Maximum production of piscicocin V1 and dive rcin V41 in Man Rogosa Sharpe (MRS) medium broth occurred at the begin ning of the stationary phase and was higher at 20-degrees-C than at 30 -degrees-C. When the cultures were maintained at pH 6.5, bacteriocin p roduction was significantly increased.