期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：11
页码：E1230-E1236
DOI：10.1073/pnas.1421816112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceAlthough many microbial explorations for hadal sediments began in the 1950s, the hadal water is the least-explored microbial biosphere. In this study, unexpected microbial ecosystems associated with the hadal trench water were discovered down to a 10,257-m water depth in the Challenger Deep of the Mariana Trench, which is the deepest ocean on Earth. We found the enrichment of heterotrophic population in the hadal water (6,000 [~]10,257 m) microbial communities, whereas the chemolithotrophic populations were more abundant in the upper abyssal waters. This observation suggested that the hadal microbial biosphere was supported by the endogenous recycling of organic matter in the hadal waters associated with the trench geomorphology. Hadal oceans at water depths below 6,000 m are the least-explored aquatic biosphere. The Challenger Deep, located in the western equatorial Pacific, with a water depth of [~]11 km, is the deepest ocean on Earth. Microbial communities associated with waters from the sea surface to the trench bottom (0 [~]10,257 m) in the Challenger Deep were analyzed, and unprecedented trench microbial communities were identified in the hadal waters (6,000 [~]10,257 m) that were distinct from the abyssal microbial communities. The potentially chemolithotrophic populations were less abundant in the hadal water than those in the upper abyssal waters. The emerging members of chemolithotrophic nitrifiers in the hadal water that likely adapt to the higher flux of electron donors were also different from those in the abyssal waters that adapt to the lower flux of electron donors. Species-level niche separation in most of the dominant taxa was also found between the hadal and abyssal microbial communities. Considering the geomorphology and the isolated hydrotopographical nature of the Mariana Trench, we hypothesized that the distinct hadal microbial ecosystem was driven by the endogenous recycling of organic matter in the hadal waters associated with the trench geomorphology.
