维氏气单胞菌拮抗菌株J2-2的筛选、鉴定与效果评价

Isolation,identification and effect evaluation of antagonistic strain J2-2 from Aeromonas veronii

为筛选对维氏气单胞菌(Aeromonas veronii)有潜在抑菌作用的菌株,本研究从湖北公安县泥鳅养殖池塘底泥中分离一株细菌J2-2,对其特性进行了研究,并对抑菌活性物质进行了初步分析。结果显示:菌株J2-2为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),具有抑菌广谱性,对米尔伊丽莎白菌(Elizabethella milieri)、嗜水气单胞菌(A.hydrophila)等6种水产病原菌的抑菌直径在9.6~29.5 mm。菌株J2-2的抑菌物质具有较好的酸碱稳定性、热稳定性和蛋白酶K处理的稳定性。电镜结果显示菌株J2-2的发酵产物对维氏气单胞菌的细胞膜结构具有破坏作用。通过LC-MC分析该拮抗细菌可产生至少15种不同的脂肽类化合物如杆菌霉素等。药敏试验结果显示,菌株J2-2对氨苄西林、青霉素具有耐药性,对克林霉素中度敏感,对大多数抗生素高度敏感。

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 characteristics 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 bacteriostatic 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 membrane structure of A.veronii.Through LC-MC analysis,the antagonistic bacteria could produce at least 15 lipopeptide compounds such as Bacillomycin D,etc.The susceptibility test results showed that strain J2-2 was only resistant to ampicillin and penicillin,moderately susceptible to clindamycin and highly susceptible to most antibiotics.