以霍乱弧菌作为宿主菌,从南美白对虾养殖水体中分离到一株具有噬菌特性的菌株H2,通过对其形态观察、特异性聚合酶链式反应(PCR)鉴定与系统发育分析,证实菌株H2为噬菌弧菌(Bacteriovoraxsp.)(GenBank登录号:JXl22409),其16SrRNA序列与GenBank基因库中噬菌弧菌属菌株的16SrRNA序列有94%~98%的同源性,而且与噬菌弧菌菌株NE1(GenBank登录号:EF092445)的亲缘关系最近。此外,菌株H2对溶藻弧菌、哈维氏弧菌、创伤弧菌、副溶血弧菌、鳗弧菌等其他弧菌也具有良好的噬菌活性,在pH=7.5、亚硝酸盐氮为0.2mg/L时具有良好的噬菌活性,在氨氮≥0.2mg/L时的噬菌活性降低。确定了噬菌弧菌H2的分类地位,分析了噬菌弧菌H2对常见弧菌的噬菌效果以及水环境因子对其噬菌活性的影响,不仅丰富了弧菌寄生菌的微生物资源,而且为其在养殖水体弧菌消除中的应用奠定了基础。
A predatory bacterial strain H2 was isolated from the Litopenaeus vannamei farming water using Vibrio cholerae as the host bacterium. Strain H2 was identified as a Bacteriovorax sp. strain (GenBank accession No. JX122409) through morphology observation, specific PCR detection and phylogenetic analysis. The 16S rRNA se- quence of strain H2 had 94%-98% of homology with those of Bacteriovorax strains in GenBank,and was most close to Bacteriovorax strain NE1 (GenBank accession No. EF092445). In addition,strain H2 could lyze the other bacterial pathogens such as Vibrio alginolyticus , Vibrio harveyi , Vibrio vulni ficus , Vibrio parahaemolyticus and Vibrio an- guillarum ,and exhibited good lytic activity under pH 7.5 and 0.2 mg/L nitrite nitrogen. However,its lysis activity could be inhibited at ≥0.2 mg/L ammonia nitrogen. The present study determined the taxonomic position of strain H2,analyzed its lysis effects on well-known Vibrio, which not only enrich the predatory microbial resources against Vibrio,but laid a solid basis for its application in the removal of Vibrio in farming waters.