ANTIMICROBIAL COMPOUNDS FROM LACTOBACILLUS-CASEI AND LACTOBACILLUS-HELVETICUS

Three strains of Lactobacillus casei and one of Lactobacillus helvetic us were examined for antagonistic activity toward twenty five indicato r strains of different species. Under conditions eliminating the effec ts of organic acid and hydrogen peroxide, culture supernatants of all the Lactobacillus strains exhibited a wide spectrum of inhibitory acti vity toward microorganisms of different genera. The inhibitory compoun d secreted by one strain of L. casei was active against Clostridium ty robutyricum. The active components were insensitive to proteolytic enz yme and heat treatment.