两株海洋蛭弧菌的分离及生物学性质

Isolation and characterization of Bdellovibrio strains from the ocean

[目的]从深圳湾海泥中分离鉴定蛭弧菌，并对其生物学性质进行初步研究。[方法]通过稀释营养肉汤（dilute nutrient broth，DNB）双层平板法分离蛭弧菌，对所分离的菌株进行电镜形态观测，并进行16S rDNA测序分析，之后结合1994年版伯杰氏鉴定细菌学手册对菌株进行鉴定，最后通过生理试验对其生物学性质进行研究。[结果]从深圳湾海泥中分离出2株蛭弧菌，分别命名为5#-12和5#-sh06，它们可在20℃-35℃范围内生长，最适温度分别是25℃和30℃；生长pH范围6.1-8.6，最适pH均为7.2；2株蛭弧菌可分别裂解46和48株试验菌，各占总试验菌株数（58）的79.3%和82.8%；联合2株蛭弧菌，可裂解56株试验菌，占总试验菌株数的96.6%；同时，它们一起能将所有试验弧菌裂解。[结论]研究结果揭示了蛭弧菌作为一种生物净化因子具有极大的潜在应用价值。

[Objective] To isolate and identify the new Bdellovibrio strains from the sea mud of Shenzhen bay and to preliminarily study their biological characteristics. [Methods] We isolated Bdellovibrio strains by DNB（dilute nutrient broth） double-layer plate method. Their 16S rDNAs were sequenced and their morphologies were examined under electron microscope. We identified these strains according to the ninth edition of Bergey＇s manual of determinative bacteriology. We also studied their biological characteristics through physiological tests. [Results] We isolated 2 strains of Bdellovibrio sp. （5#-12 and 5#-sh06） from sea mud of Shenzhen bay. Both strains grew between 20℃ and 35℃, with 25℃ and 30℃ as optimal temperature for 5#-12 and 5#-sh06, respectively. They grew between pH 6.1 and 8.6, and the opti℃mal pH for both was 7.2. Lysis experiments on 58 strains of pathogens were conducted and the results showed that 5#-12 and 5#-sh06 lysed 46 and 48 strains, corresponding to 79.3% and 82.8% of lysis abilities. Taken both two Bdellovibrio strains together, they lysed 96.6% （56 strains） of tested pathogens and 100% of tested vibrios （39 strains）. [Conclusion] The results demonstrated that Bdellovibrio have potential and significant application prospect for elimination of pathogens.