嗜盐噬菌弧菌BALOs10菌株的分离、鉴定及其裂解谱

Isolation, identification and prey range of Halobacteriovorax sp. BALOs10

摘要:

[目的]从海水中分离得到蛭弧菌类群（Bdellovibrio-and-like organisms，BALOs）新型菌株，丰富BALOs的种质资源。[方法]从中国深圳大亚湾取回海水样品后，使用本实验室分离得到的Vibrio alginolyticus LF TCBS 15作为宿主，通过海水双层平板法分离得到BALOs菌株，通过光学显微镜及透射电镜观察菌体形态，对16S rDNA序列进行系统发育分析，完成分子鉴定。采用双层平板滤纸片法分析NaCl浓度、pH及温度对菌株BALOs10生长的影响并测定菌株BALOs10对16株细菌的裂解效果。[结果]成功分离出一株以Vibrio alginolyticus LF TCBS 15为宿主的BALOs菌株BALOs10。噬菌斑呈圆形、透明且边缘光滑整齐，菌体为弧状，极生单鞭毛，菌体大小（0.21-0.44）μm×（1.25-1.87）μm。菌株最佳生长温度、NaCl浓度和pH范围分别为35-37℃、2%-3%（W/V）和7-8。菌株BALOs10可以裂解9株不同种的受试菌，占总试验菌株数（16株）的56.3%，主要是海杆菌属和弧菌属；菌株BALOs10的16S rDNA与最相近的典型菌株Halobacteriovorax marinus SJ的相似性只有92.14%，可能是一个全新的物种，将其命名为Halobacteriovorax sp.BALOs10。[结论]本文研究发现了Halobacteriovorax属（嗜盐噬菌弧菌属）的一个新型菌株，丰富了BALOs种质资源，为后续的应用及理论研究奠定物质基础。

Abstract:

[Objective] The purpose of the study was to isolate and identify Bdellovibrio-and-like organisms (BALOs) strains from seawater and increase the known species richness of BALOs. [Methods] Vibrio alginolyticus LF TCBS 15 was used as host bacterium to isolate BALOs from seawater samples with seawater agar double-layer plate method. The seawater samples were collected from Daya bay of Shenzhen, China. The morphology of the cells was observed by light microscopy and transmission electron microscopy. 16S rDNA was used for phylogenetic analysis to complete molecular identification. The prey range on 16 different strains and the effects of NaCl, pH and temperature on the growth of strain BALOs10 were determined by double-layer plate filter paper method.[Results] A novel strain, BALOs10, was isolated using V. alginolyticus LF TCBS 15 as prey. The plaques are round, transparent and the edges were smooth and tidy. The cells are curved (0.21-0.44 μm diameter×1.25-1.87 μm long) with a single polar flagellum. Optimum growth occurs at 35-37℃, pH 7-8 and in the presence of 2%-3% (W/V) NaCl. Prey range on 16 tested strains showed that strain BALOs10 lysed 9 different strains, corresponding to 56.3% of lysis rate, and was especially susceptive to Vibrio and Marinobacter. 16S rDNA sequence analysis indicates that BALOs10 was most closely related to Halobacteriovorax marinus SJ with 92.14% similarity, demonstrating that the strain may represent a novel species. Therefore, Halobacteriovorax sp. BALOs10 is proposed.[Conclusion] strain BALOs10 may represent a novel predator of genus Halobacteriovorax, which will enrich the species resource of BALOs and lay the material foundation for subsequent application and theoretical research.