Wang Li, Shen Ziyi, Cheng Xinyi, Hwang Jiang-Shiou, Guo Yizhe, Sun Mingye, Cao Junwei, Liu Rulong, Fang Jiasong
Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China.
Institute of Marine Biology, National Taiwan Ocean University, Keelung, Taiwan.
Front Microbiol. 2022 Nov 30;13:992034. doi: 10.3389/fmicb.2022.992034. eCollection 2022.
Hydrothermal vent (HTV) systems are important habitats for understanding the biological processes of extremophiles on Earth and their relative contributions to material and energy cycles in the ocean. Current understanding on hydrothermal systems have been primarily focused on deep-sea HTVs, and little is known about the functions and metabolisms of microorganisms in shallow-water HTVs (SW-HTVs), which are distinguished from deep-sea HTVs by a depth limit of 200 m. In this study, we analyzed metagenomes of sulfur-rich sediment samples collected from a SW-HTV of Kueishan Island, located in a marginal sea of the western Pacific Ocean. Comparing with a previously published report of pelagic samples from the nearby sampling site, microbial communities in the SW-HTV sediments enriching with genes of both aerobic and anaerobic respiration inferred variable environments in the tested sediments. Abundant genes of energy metabolism encoding sulfur oxidation, H oxidation, and carbon fixation were detected from the sediment samples. Sixty-eight metagenome-assembled-genomes (MAGs) were reconstructed to further understand the metabolism and potential interactions between different microbial taxa in the SW-HTVs sediment. MAGs with the highest abundant were chemolithotrophic sulfur-oxidization bacteria, including represented Campylobacteria involved multienzyme, sulfide oxidation genes and rTCA cycle, and Gammaproteobacteria involved gene and CBB cycle. In addition, Desulfobacterota with the potential to participate in sulfur-disproportionating processes also had higher abundance than the sample's overall mean value. The interaction of these bacterial groups allows the microbial communities to efficiently metabolize a large variety of sulfur compounds. In addition, the potential to use simple organic carbon, such as acetate, was found in chemolithotrophic Campylobacterial MAGs. Collectively, our results revealed the complexity of environmental conditions of the vent sediment and highlight the interactive relationships of the dominant microbial populations in driving sulfur cycles in the SW-HTV sediments off Kueishan Island.
热液喷口（HTV）系统是了解地球上嗜极生物的生物学过程及其对海洋物质和能量循环的相对贡献的重要栖息地。目前对热液系统的认识主要集中在深海热液喷口，而对于浅水热液喷口（SW-HTV）中微生物的功能和代谢了解甚少，浅水热液喷口与深海热液喷口的区别在于深度限制为200米。在本研究中，我们分析了从位于西太平洋边缘海的龟山岛一个浅水热液喷口采集的富硫沉积物样本的宏基因组。与之前发表的来自附近采样点的远洋样本报告相比，浅水热液喷口沉积物中的微生物群落富含需氧和厌氧呼吸基因，这表明测试沉积物中的环境多变。从沉积物样本中检测到了大量编码硫氧化、氢氧化和碳固定的能量代谢基因。重建了68个宏基因组组装基因组（MAG），以进一步了解浅水热液喷口沉积物中不同微生物类群之间的代谢和潜在相互作用。丰度最高的MAG是化能自养硫氧化细菌，包括参与多酶、硫化物氧化基因和还原性三羧酸循环的弯曲杆菌，以及参与卡尔文循环基因的γ-变形菌。此外，有参与硫歧化过程潜力的脱硫杆菌门的丰度也高于样本的总体平均值。这些细菌群体的相互作用使微生物群落能够有效地代谢多种硫化合物。此外，在化能自养弯曲杆菌MAG中发现了利用简单有机碳（如乙酸盐）的潜力。总的来说，我们的结果揭示了喷口沉积物环境条件的复杂性，并突出了龟山岛附近浅水热液喷口沉积物中优势微生物种群在驱动硫循环中的相互作用关系。
