Probiotic are non-pathogenic, low-GC containing, acid-tolerant, and Generally Recognized As Safe (GRAS) microorganisms. Viability and metabolic activities are important characteristics of probiotic microorganisms. They secrete substances that inhibit pathogenic bacteria which is known as BLIS (Bacteriocin Like Inhibitory Substance). Probiotics includes the genera Lactobacillus, Bifidobacterium, Pediococcus etc. The present work explores the isolation of potential probiotic from GIT of marine Lethrinus conchyliatus (Emperor Fish) and fresh water fish Oreochromis mossambicus (Tilapia), Probiotic characteristics (acid, bile salt and salt tolerant), growth in varied temperature, antibiotic profile and screening of bacteriocin producing organisms. We extracted and partially purified the bacteriocin by ammonium precipitation and dialysis method. Lactobacillus sp. (EF2) showed the best results in bacteriocin production. The Partially Purified Bacteriocin (PPB) was analysed for its preservative capability on the raw fish as bacteriocin would be a future organic preservator in food industries.
