中国南海沉积环境可培养细菌多样性研究

【目的】探索海洋沉积环境中可培养细菌的多样性。【方法】采用纯培养分离及16S rRNA基因序列鉴定的方法,对我国南海海域20个沉积物样品进行细菌多样性分析。【结果】共获得200株细菌,分属于47个属,99个种。经系统进化分析,可培养菌株主要分布于4个类群:厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和拟杆菌门(Bacteroidetes),优势类群为Firmicutes,其中芽孢杆菌属(Bacillus)所占比例为55.6%;而Actinobacteria和Bacteroidetes两个类群获得菌株较少;在Firmicutes和Actinobacteria两个类群中发现8个潜在新种和3个潜在新属级类群。【结论】初步研究结果表明,南海海洋沉积环境可培养微生物资源丰富,新物种资源多样;其中,芽孢杆菌为海洋沉积环境中的优势类群,随着样品深度的增加,细菌多样性呈现递减的趋势,深度可能是影响细菌多样性的一个重要因素;其次,分离培养基和分离方法直接关系到样品中可培养微生物多样性的发现,有待深入研究。

Diversity of cultivable bacteria isolated from marine sediment environments in South China Sea

Objective] Investigating the diversity of the cultivable bacteria in marine sediment environments. Methods] Twenty sediment samples collected from South China Sea were used for bacterial diversity research by using the culture dependent method and 16S rRNA gene sequencing. Results] Total of 200 strains were obtained, which belong to 47 genera and 99 species and spread in four phyla: Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. The predominant group is phylum Firmicutes, in which genus Bacillus takes a great proportion of 55.6%. A few strains in phyla Actinobacteria and Bacteroidetes were also obtained. Eight potential new species and 3 potential new genera were discovered in phyla Firmicutes and Actinobacteria. Conclusion] The preliminary study indicates that genus Bacillus is the dominant group in sediment environments of South China Sea and bacterial diversity showed a decreasing trend with the increase of sampling depth. Sampling depth maybe is one of the important factors to influence the distribution of bacteria. Diversity of bacteria and novel bio-resources in the sediment environments are very abundant and need to be further researched. Isolating methods and isolation media are the crucial factors to recover the microorganisms inhabiting the sediment environments.