| 摘要: |
| 钙化藻和微生物在造礁石珊瑚幼虫的附着变态过程中扮演着重要角色，对珊瑚礁生态系统的健康具有重要意义。对南海珊瑚礁区钙化藻的共附生细菌进行分离培养，一方面有利于发掘南海珊瑚礁的微生物资源，另一方面有利于进行微生物与珊瑚、钙化藻等珊瑚礁框架生物的相互作用研究。本研究分离获得孔石藻（Porolithon onkodes）表面共附生细菌，基于16S rRNA基因序列进行系统发育分析，并通过高效液相色谱和质谱对分离得到的假交替单胞菌属菌株的代谢产物进行比较分析。从孔石藻分离获得的369株细菌菌株分别隶属于变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）和厚壁菌门（Firmicutes）的5纲12目22科47属的97个种级类群。在属级水平上，假交替单胞菌属（Pseudoalteromonas）的菌株数量最多，分属于7个种。在假交替单胞菌属的代谢产物分析中，发现3株在系统发育树中聚为一簇的假交替单胞菌的代谢产物中存在四溴吡咯，而其余没有。研究结果不仅表明了钙化藻中含有丰富的可培养微生物和潜在新物种资源，还首次发现四溴吡咯在南海珊瑚礁区特定类群菌株的代谢产物中的存在，为珊瑚幼虫附着变态的化学信号研究提供基础。 |
| 关键词: 孔石藻 细菌多样性 假交替单胞菌 代谢产物 四溴吡咯 |
| DOI：10.14188/j.ajsh.2020.04.004 |
| 分类号:Q93 |
| 基金项目:国家自然科学基金（41806145）；中国科学院战略性先导科技专项（A类）（XDA13020203）；广州市科技计划项目（201707010174） |
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| Diversity of culturable bacteria isolated from Porolithon onkodes and metabolite tetrabromopyrrole |
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MO Jiahao1,2, YANG Fangfang1, WEI Zhangliang1, YIN Hao1, DONG Junde1, LONG Lijuan1
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1.Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, Guangdong, China;2.University of Chinese Academy of Sciences, Beijing 100049, China
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| Abstract: |
| Calcified algae and microorganisms play an important role in the process of settlement and metamorphosis of reef-building coral larvae and are of great significance to the health of coral reef ecosystems. Isolating the cultured bacteria from calcified algae of coral reefs in South China Sea (SCS) can help to discover the microbial resources of coral reefs in SCS. Moreover, it is beneficial to study the interaction between microorganisms and framework organisms such as corals and calcified algae in coral reefs. For this, phylogenetic analysis of cultured bacteria isolated from Porolithon onkodes was conducted based on 16S rRNA gene sequence, and the metabolites of the isolated bacteria were analyzed by HPLC and mass spectrometry. The results showed that a total of 369 bacterial strains were isolated, belonging to 5 classes, 12 orders, 22 families, 47 genera and 97 species in three phyla: Proteobacteria, Bacteroidetes and Firmicutes, containing 91 strains with 16S rRNA gene sequence similarity between 95%~98% and 6 strains with less than 95% similarity. At the genus level, Pseudoalteromonas has the highest proportion, which affiliated to 7 species. In the analysis of metabolites of Pseudoalteromonas, tetrabromopyrrole was detected in metabolites of 3 strains of Pseudoalteromonas clustered in the phylogenetic tree while the rest were not. The results not only indicate that calcified algae are rich in culturable microorganisms and potential new species resources, but also the first discovery of the presence of tetrabromopyrrole in the microbial metabolites of coral reefs in SCS, which promote future studies on chemical signals of coral larval settlement and metamorphosis. |
| Key words: Porolithon onkodes bacterial diversity Pseudoalteromonas metabolite tetrabromopyrrole |
