Abstract:Two hundred and eighteen bacteria strains isolated from intestinal tract of cultured Pelteobagrus fulvidraco were used for testing the producing zymogenicities of protease,lipase and amylase,the antagonistic against five common pathogenic bacterias and the antibiotic sensitivity.The toxicity of strain HS140 screened as potential probiotic for Pelteobagrus fulvidraco was evaluated.HS140 was identified according to its morphological,physiological and biochemical characteristics as well as homology analysis of 16S rRNA sequences.The results indicated that HS140 had high ectoenzyme-producing ability and could produce chemical substances inhibitor to Edwardsiella tarda,Aeromonas sobria and Vibrio anguillarum.HS140 was resistant to ampicillin,sulfamethoxazole,VI cefradine,but sensitive or medium sensitive to the other 13 kinds of antibiotics.It was safe for Pelteobagrus fulvidraco when they were challenged by a high immersion concentration of HS140 at 108cfu/mL.Morphology observation showed that HS140 was gram-positive,rod,motile.The results revealed that strain HS140 comprised sequences more related to Bacillus licheniformis(99.3%) from partial 16S rRNA sequences.The identification showed that strain HS140 was Bacillus licheniformis by the way of morphology,biochemistry characteristic and 16S rRNA sequence homology analysis.