This study isolated a strain J2-2 from the bottom mud of loach aquaculture pond in Gongan County,Hubei Province,to screen the bacteria with potential antibacterial effect on Aeromonas veronii.Meanwhile,its char-acteristics were studied and the antibacterial active substances were preliminarily analyzed.The results showed that the strain J2-2 is Bacillus amyloliquefaciens,which has a broad bacteriostatic spectrum.The inhibition diameters of 6 aquatic pathogens,such as Elizabethella milieri and A.hydrophila,ranged from 9.6 to 29.5mm.The bacterio-static substances of strain J2-2 were insensitive to high temperature,acid,acid-base,and protease.The results of electron microscopy showed that the fermentation product of strain J2-2 had destructive effect on the cell mem-brane structure of A.veronii.Through LC-MC analysis,the antagonistic bacteria could produce at least 15 li-popeptide compounds such as Bacillomycin D,etc.The susceptibility test results showed that strain J2-2 was on-ly resistant to ampicillin and penicillin,moderately susceptible to clindamycin and highly susceptible to most anti-biotics.
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维普
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