| 摘要: |
| 深海弯曲菌(Thalassolituus)是一类海洋专属的石油降解菌.为认识其多样性与地理分布、获取石油降解菌资源，本研究对西太平洋和厦门近海的表层海水分别通过石油烃富集和直接涂布石油烃平板，对获取的菌株进行了分离鉴定.在此基础上，对GenBank数据库中该属的可培养和未培养菌株信息，进行了系统进化与物种多样性分析.结果表明，从西太富集菌群分离得到的32个菌株中，主要优势菌为假单孢菌(Pseudomonas)和海杆菌(Marinobacter)；其次是食烷菌(Alcanivorax) 和弧菌(Vibrio).深海弯曲菌仅有2株，但它们代表1个潜在的新种，它们与模式菌株T. marinus IMCC1826T 的同源性仅为96.9%和97.0%.从厦门表层海水中分离到1株深海弯曲菌，与模式菌株T. marinus IMCC1826T 的相似度为99.66%.基于本研究分离菌株及GenBank可培养及未培养菌株的16S rRNA基因序列开展的系统发育分析表明，该属存在3个明显的进化分支，即2个模式种 T. oleivorans 与 T. marinus 分别代表的2个分支和1个独立分支；此外，不同分支呈现明显的地理分布特征，即来自同一纬度范围的菌株或序列多聚类于同一分支中.我们推测，深海弯曲菌在进化过程中，可能因适应不同纬度海域的温度等环境因子，逐步进化出3个不同环境适应性的分支.本研究加深了对深海弯曲菌在不同温度海洋环境中种类多样性分布特征的认识，为海洋石油污染生物修复提供了新资源. |
| 关键词: 海洋生物学 深海弯曲菌 种类多样性 地理分布特征 表层海水 石油烃 生物降解 |
| DOI：10.3969/J.ISSN.2095-4972.2017.04.014 |
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| 基金项目:国家自然科学基金资助项目（41206158）；中国大洋专项资助项目（DY135-15-R-01）；国家微生物资源平台资助项目（NIMR-2017-9） |
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| Species diversity and biogeographic distribution of marine oil-degrading bacteria Thalassolituus spp. |
| LIU Ren-ju,DONG Chun-ming,LI Deng-feng,SHAO Zong-ze |
| (School of Marine Sciences, Ningbo University，Ningbo 315211，China;Key Laboratory of Marine Genetic Resources，Third Institute of Oceanography，SOA，Xiamen 361005，China) |
| Abstract: |
| To detect the diversity and geographical distribution of Thalassolituus bacteria, surface seawater was collected from western Pacific Ocean and Xiamen coastal sea, and enriched with crude oil or directly spread on agar plate. Then, the identified with 16S rRNA gene and subjected to phylogenetic analysis, together with all the sequences retrieved GenBank database. As a result, 32 bacterial strains were isolated in this study，including two belonging to Thalassolituus, while Pseudomonas and Marinobacter were the most dominant oildegrading bacteria, and followed by Alcanivorax and Vibrio. These two Thalassolituusstrains showed 96.9% and 97.0% sequence similarities with type strain T. marinus IMCC1826T in 16S rRNA gene, indicating that they were potential novel species within genus Thalassolituus. In addition, one Thalassolituus strain was isolated from Xiamen coastal seawater on the ONR7a plate supplemented with crude oil. The phylogenetic analysis showed that all Thalassolituus 16S rRNA gene sequences could be clustered into three distinct groups, i.e. T. oleivorans, T. marinus，and one independent group. They exhibited obvious biogeographic distribution in that bacteria clustered in the same group were associated with the areas they were from, especially the latitude. Temperature is suggested to have played an important role in their distribution. This report for the first time describes the species diversity and geographic distribution of Thalassolituus species in various marine environments. |
| Key words: marine biology Thalassolituus species diversity biogeographic distribution characteristics surface seawater petroleum hydrocarbon biodegradation |
