CHARACTERISTICS AND ANTAGONISTIC ACTIVITY OF LACTIC-ACID BACTERIA ISOLATED FROM CHILLED FISH PRODUCTS

In fish products, contrary to other foods, the commercial use of start er cultures is relatively unexploited. In this study, 61 isolates of l actic acid bacteria from lightly preserved, chilled fish products were characterized with special emphasis on their antagonistic activity an d their possible use as starter cultures. The strains were phenotypica lly identified and characterized with regard to gas production, carboh ydrate fermentations, production of off odours, H2O2-production, antag onistic activity and growth at 2, 5 and 10-degrees-C. Growth at 10-deg rees-C was detected for all strains within 4 days. At 5-degrees-C, 90% of the isolates were growing within 3-9 days. At 2-degrees-C only 33% of the strains were growing within 9 days. Fourteen strains were sele cted for further testing of antagonistic activity against spoilage- an d pathogenic bacteria at different pH in a disc assay. Two strains, a Leuconostoc spp. (V 6) and a Lactobacillus plantarum (LKE 5), differed from the other lactic acid bacteria by a very wide inhibitory spectru m for V 6 and by very distinct inhibition zones for LKE 5. The mechani sms of their inhibitory effects are discussed.