Japan Collection of Microorganisms (JCM), RIKEN BioResource Research Center.
Ore Genesis Research Unit, Project Team for Development of New-generation Research Protocol for Submarine Resources, Japan Agency for Marine-Earth Science and Technology (JAMSTEC).
Microbes Environ. 2019 Sep 25;34(3):293-303. doi: 10.1264/jsme2.ME19021. Epub 2019 Aug 3.
Candidatus Hydrothermarchaeota, formally called Marine Benthic Group E, has often been detected in iron- and sulfur-rich marine environments, such as hydrothermal vents and cold seeps. However, their ecology and physiology remain unclear. Cultivated representatives of this group are still lacking and only several metagenome-assembled genomes (MAGs) and single-amplified genomes (SAGs) are available from two deep-sea hydrothermal areas, the Juan de Fuca Ridge (JdFR) and Guaymas Basin (GB), in the north-east Pacific. We herein report four MAGs of Ca. Hydrothermarchaeota recovered from hydrothermally-inactive metal sulfide deposits at the Southern Mariana Trough (SMT) in the north-west Pacific. A phylogenetic analysis indicated that the MAGs of the SMT were distinct from those of the JdFR and GB at the genus or potentially family level. Ca. Hydrothermarchaeota MAGs from the SMT commonly possessed putative genes for carboxydotrophic and hydrogenotrophic respiration using oxidized chemical species of sulfur as electron acceptors and also for carbon fixation, as reported previously in MAGs/SAGs from the JdFR and GB. This result strongly supports Ca. Hydrothermarchaeota containing anaerobic chemolithoautotrophs using carbon monoxide and/or hydrogen as electron donors. A comparative genome analysis highlighted differences in the capability of nitrogen fixation between MAGs from the SMT and the other fields, which are consistent with environmental differences in the availability of nitrogen sources for assimilation between the fields. Based on the wide distribution in various areas, abundance, and metabolic potential of Ca. Hydrothermarchaeota, they may play a role in the biogeochemical cycling of carbon, nitrogen, sulfur, and iron in marine environments, particularly in deep-sea hydrothermal fields.
产甲烷古菌，正式称为海洋底层群 E，经常在富含铁和硫的海洋环境中被检测到，例如热液喷口和冷泉。然而，它们的生态和生理学仍然不清楚。该群体的培养代表仍然缺乏，只有来自东北太平洋两个深海热液区——胡安·德富卡脊（JdFR）和瓜伊马斯盆地（GB）的几个宏基因组组装基因组（MAG）和单扩增基因组（SAG）可用。我们在此报告了从西北太平洋马里亚纳海沟（SMT）热液不活跃的金属硫化物矿床中回收的产甲烷古菌的四个 MAG。系统发育分析表明，SMT 的 MAG 与 JdFR 和 GB 的 MAG 在属或潜在的家族水平上存在明显差异。SMT 的 Ca. Hydrothermarchaeota MAG 通常具有使用氧化硫类作为电子受体进行羧化和氢营养呼吸以及固碳的假定基因，这在以前 JdFR 和 GB 的 MAG/SAG 中已有报道。这一结果强烈支持含有使用一氧化碳和/或氢气作为电子供体的厌氧化能自养生物的 Ca. Hydrothermarchaeota。比较基因组分析突出了 SMT 和其他领域之间固氮能力的差异，这与这些领域之间同化氮源可用性的环境差异一致。基于 Ca. Hydrothermarchaeota 在各个领域的广泛分布、丰度和代谢潜力，它们可能在海洋环境中碳、氮、硫和铁的生物地球化学循环中发挥作用，特别是在深海热液场中。
