马里亚纳海沟不同深度水样微生物分离与多样性分析

Microbial isolation and biodiversity analysis of water samples at different depth in the Mariana Trench

【背景】马里亚纳海沟挑战者深渊是地球表面最深点,认识其微生物群落结构和分离培养的微生物对挖掘新的微生物资源具有重要意义。【目的】对马里亚纳海沟不同深度水样进行细菌分离培养,并与这些样品的微生物群落结构进行比较,认识进一步要分离培养的微生物类型。【方法】采用不同培养基对马里亚纳海沟两个站位不同深度水样进行细菌分离培养,并通过Illumina MiSeq高通量测序分析各个水样的细菌和古菌的群落结构。【结果】从来自两个站位不同深度的6个水样样品中分离获得783株细菌,属于4个门6个纲28个属。其中,变形菌门占主导地位,67.8%的菌株属于γ-变形菌纲。分离获得的菌株主要属于亚硫杆菌属、假单胞菌属和交替假单胞菌属,它们在这些样品中广泛分布,且在高通量测序结果中也能检测到。高通量测序结果表明除浅层样品优势微生物为蓝细菌外,其他样品以变形菌门占主导;不同深度样品的微生物群落结构存在较大差异。【结论】马里亚纳海沟不同深度水样中不仅分离培养出了相对丰度较高的一些细菌属,也分离得到一些相对丰度较低的微生物类型。从马里亚纳海沟水样中分离培养获得的细菌菌株资源将用于功能微生物和功能酶挖掘等相关研究,这有利于深渊微生物资源挖掘。

[Background] The Challenger Deep in the Mariana Trench is the deepest known site in the earth’s ocean. Understanding of its microbial community structure and bacterial isolation are important for mining of deep-sea genetic resources. [Objective] Various types of bacteria were isolated from water samples at different depths in the Mariana Trench, and these microbes were compared with high-throughput sequencing results to know microbes that should be further isolated. [Methods] Different media were used to isolate bacteria from water samples, and Illumina MiSeq high-throughput sequencing system was used for the diversity analysis of bacteria and archaea. [Results] A total of 783 strains were isolated from 6 water samples at different depths and stations. These isolates belonged to 4 phyla, 6 classes and 28 genera. Among them, Proteobacteria was dominant and 67.8% of total strains belonged to Gammaproteobacteria. The microbes were mainly belonged to Sulfitobacter, Pseudomonas and Pseudoalteromonas. These types of microbes were widely distributed in all samples and detected by high-throughput sequencing. High-throughput sequencing results showed that Cyanobacteria was the major bacteria in samples at shallow depth and Proteobacteria were dominated in other samples. The microbial community structures of samples at different depths were quite different. [Conclusion] Not only bacteria with relatively high abundance in Mariana Trench water were isolated, but also some bacteria with relatively low abundance. The isolated microbes in the Mariana Trench water samples will be helpful for the mining of functional microbes and enzymes.