Screening of lactic acid bacteria with inhibitory activity isolated from intestinal of cold water fish and analysis of its physiological property

9 strains of lactic acid bacteria with inhibitory activity were screened from 24 lactic acid bacteria isolated from cold water fish intestinal by using oxford cup method. 6 strains belonged to Lacterococcus genus and 3 strains belonged to Enterococcus genus by phylogenic analysis based on their partial 16S rDNA gene sequences. Cell-free fermenting supematants (CFSs) from 9 strains were performed to determine the inhibitory compounds and the proteninaceous nature of inhibitors. The result showed that CFSs of 9 lactic acid bacteria still exhibit different degree of inhibitory activity against Listeria monocytogenes after eliminating the effect of organic acid and hydrogen peroxide;the inhibitory activity of strains MHY3-2 and MD-2 were strongly dependent on the organic acid, whereas the influence of organic acid produced by strains MB2-1 and MD-1on the inhibitory activity were negligible. CFSs of strains MB2-1 and MD-1 after eliminating organic acid and hydrogen peroxide show significant antibacterial activity against Listeria monocytogenes among 9 strains. The activity of all tested strains was lost by treating with pepsin and trysin but strains MB2-2 and MD-1 not sensitive to trypsin. The results demonstrated that the inhibitory compound was proteinaceous in nature and likely is bacterion-like or bacterion. In addition, antibiotic resistance of 9 strains of lactic acid bacteria was preliminarily tested. 9 strains were sensitive to ampicillin, vancomycin, erythromycin, chloramphenicol, ciprofloxacin and norfloxacin. The safety aspects of strains with inhibitory activity studied could provid basis for exploitarion and application of lactic acid bacteria isolated from the intestine of cold water fish.