This paper re notes the antagonistic substances produced by lactic bacteria and their activity against spoilage and pathogenic organisms.Non proteinaceous substances considered include organic acids,diacteyl,hydrogen peroxide,returein and the antimicrobial agents specially produced by L.plantarum.Bacteriocins are proteinaceous substances posing inhibitory effects towards related species.The LAB antimicrobial agents identified have been grouped into 3 main classes based on their biochemical and genetic ch...