Isolation, identification and characterization of Leuconostoc mesenteroides as a new probiotic from intestine of snakehead fish (Channa striatus)

Abstract

The intestinal microflora of snakehead ( Channa striatus ) fish was studied to isolate and identify lactic acid bacteria as new probiotic. A total of five lactic acid bacteria were isolated from intestine to evaluate with probiotic properties. Leuconostoc mesenteroides sp. mesenteroides with more ability to inhibit growth o f Aeromonas hydrophila was selected and identified by conventional and molecular techniques. This strain was able to survive and grow from pH 3 to 8 with the highest viability and growth rate at neutral conditions (pH 7). In addition, L. mesenteroides tolerated 0, 0.15 and 0.3% bile salt concentrations. This bacterium also, showed inhibitory activity against three tested fish pathogens which included; A. hydrophila, Pseudomonas aeruginosa and Shewanella putrefaciens . Antibiotic sensitivity test indicated that this strain was resistant to Streptomycin, intermediate to Amoxicillin and Kanamycin and sensitive to Gentamycin, Tetracycline, Chloramphenicol, and Ampicillin. Keywords : Isolation, characterization, probiotic, intestine, Leuconostoc mesenteroides , snakehead fish.