Screening of potential probiotic lactic acid bacteria from fresh water fish intestine

Abstract

Probiotic, Lactic Acid Bacteria are associated with normal microbial ecosystem of gastrointestinal tract of human and fish and plays a vital role during in-vivo interactions occurring in Gastro Intestinal Tract (GI) of human beings, hence exert health benefits beyond inherent basic nutrition. In the recent study, some potential probiotic lactic acid bacteria were screened from fresh water fish intestine. Sixteen strains have been selected on the basis of growth in Lactobacillus selective media (MRS) and subjected to Gram staining, Catalase activity and Oxidase test. Out of these, 6 strains have been selected for further studies on the basis of morphology, Lactobacillus specific biochemical test and amplification of Lactobacillus genus specific gene. Five strains named (KTIT, KT2W, KT1B, KA2, FS) have been identified as Lactobacillus casei. Sixth strain has been identified and named as KT1, Lactobacillus delbrueckii on the basis of bergey's manual of systematic bacteriology. Out of these six strains KT1 has proved its probiotic credibility more by producing antimicrobial Bacteriocin-like compound, which were having inhibitory property against potential pathogenic strains. Strain KT1 was found to be more potential probiotic lactic acid bacteria after further identification by biochemical analysis and molecular identification (16s rDNA Sequencing) was done. The study is extremely promising, that underscores the important role of Lactobacillus strains, having probiotic effects, which may play an important role in food industry as starter-culture, co-culture and bio protective cultures to improve quality and safety of preserved food and beverages.