澄黄滨珊瑚和丛生盔型珊瑚非培养放线菌多样性

【目的】研究澄黄滨珊瑚(Porites lutea)和丛生盔型珊瑚(Galaxea fascicularis)联合放线菌物种多样性。【方法】实验提取两种珊瑚的总DNA,利用放线菌特异性引物对样品总DNA进行扩增,通过构建16S rRNA基因克隆文库和系统发育分析,对三亚鹿回头岸礁区优势物种澄黄滨珊瑚和丛生盔型珊瑚联合放线菌的多样性和群落结构进行研究。【结果】118个从澄黄滨珊瑚克隆文库中随机挑选的阳性克隆子归为58个OTUs,主要分布于酸微菌亚目、棒状杆菌亚目、微球菌亚目、丙酸杆菌亚目和未知类群。丛生盔型珊瑚克隆文库共获得96个序列,归为31个OTUs,主要分布于酸微菌亚目和未知的放线菌类群。多样性指数和稀疏度曲线分析结果显示澄黄滨珊瑚联合放线菌物种多样性比丛生盔型珊瑚更高。【结论】澄黄滨珊瑚和丛生盔型珊瑚拥有较高水平的放线菌物种多样性和复杂的群落结构,并隐藏着大量的高等级放线菌新分类单元。

Diversity of actinobacteria associated with coral Porites lutea and Galaxea fascicularis

Objective] The aim of this study was to uncover the diversity of actinobacteria associated with corals Porites lutea and Galaxea fascicularis. Methods] Total DNA of coral samples was extracted for PCR amplification with the primers of class actinobacteria. Two clone libraries were constructed for P. lutea and G. fascicularis coral samples. We carried out phylogenetic and statistic analysis based on 16S rRNA gene sequences in order to investigate the communities of actinobacteria associated with corals P. lutea and G. fascicularis. Results] One hundred and eighteen clones of the P. lutea library were sequenced. They were classified into 58 OTUs, which distributed in suborders Acidimicrobineae, Corynebacterineae, Micrococcineae, Propionibacterineae and unclassified groups. Ninety-six clone sequences were retrieved from G. fasctercicularis library. They were classified into 31 OTUs, which were distributed in Acidimicrobineae and unclassified groups. Results of diversity index and rarefaction curve analysis suggested that coral P. lutea harbored more diverse actinobacteria than G. fascicularis. Conclusion] Actinobacteria associated with corals P. lutea and G. fascicularis showed a high level of diversity. There were a large number of unknown Actinobacteria taxa in this environment.