Division of Life Science, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China.
Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan.
Appl Environ Microbiol. 2018 Dec 13;85(1). doi: 10.1128/AEM.02032-18. Print 2019 Jan 1.
Hadal environments sustain diverse microorganisms. A few studies have investigated hadal microbial communities consisting of free-living or particle-associated bacteria and archaea. However, animal-associated microbial communities in hadal environments remain largely unexplored, and comparative analyses of animal gut microbiota between two isolated hadal environments have never been done so far. In the present study, 228 Gb of gut metagenomes of the giant amphipod from two hadal trenches, the Mariana Trench and Japan Trench, were sequenced and analyzed. Taxonomic analysis identified 49 microbial genera commonly shared by the gut microbiota of the two populations. However, the results of statistical analysis, in congruency with the alpha and beta diversity analyses, revealed significant differences in gut microbial composition across the two trenches. Abundance variation of , , and species was observed. Microbial cooccurrence was demonstrated for microbes that were overrepresented in the Mariana trench. Comparison of functional potential showed that the percentage of carbohydrate metabolic genes among the total microbial genes was significantly higher in the guts of specimens from the Mariana Trench. Integrating carbon input information and geological characters of the two hadal trenches, we propose that the differences in the community structure might be due to several selective factors, such as environmental variations and microbial interactions. The taxonomic composition and functional potential of animal gut microbiota in deep-sea environments remain largely unknown. Here, by performing comparative metagenomics, we suggest that the gut microbial compositions of two populations from the Mariana Trench and the Japan Trench have undergone significant divergence. Through analyses of functional potentials and microbe-microbe correlations, our findings shed light on the contributions of animal gut microbiota to host adaptation to hadal environments.
深渊环境中栖息着多种多样的微生物。有一些研究调查了由自由生活或颗粒相关细菌和古菌组成的深渊微生物群落。然而，深渊环境中动物相关的微生物群落在很大程度上仍未被探索，而且迄今为止，还从未对两个孤立的深渊环境中的动物肠道微生物群进行过比较分析。在本研究中，对来自马里亚纳海沟和日本海沟两个深渊海沟的巨型片脚类动物的 228 Gb 肠道宏基因组进行了测序和分析。分类分析确定了两个种群肠道微生物群中共同存在的 49 个微生物属。然而，统计分析的结果与 alpha 和 beta 多样性分析一致，表明两个海沟的肠道微生物组成存在显著差异。观察到 、 和 物种的丰度变化。对马里亚纳海沟中丰度较高的微生物进行了微生物共现分析。功能潜力的比较表明，马里亚纳海沟中 标本肠道内微生物基因总数中碳水化合物代谢基因的比例明显更高。整合两个深渊海沟的碳输入信息和地质特征，我们提出，群落结构的差异可能是由于环境变化和微生物相互作用等多种选择因素造成的。深海环境中动物肠道微生物的分类组成和功能潜力在很大程度上仍然未知。在这里，通过进行比较宏基因组学分析，我们表明，来自马里亚纳海沟和日本海沟的两个 种群的肠道微生物组成已经发生了显著的分歧。通过功能潜力和微生物-微生物相关性的分析，我们的研究结果揭示了动物肠道微生物群对宿主适应深渊环境的贡献。
