Vertically distinct microbial communities in the Mariana and Kermadec trenches

• Published in: PloS one Vol. 13; no. 4; p. e0195102
• Main Authors: Peoples, Logan M, Donaldson, Sierra, Osuntokun, Oladayo, Xia, Qing, Nelson, Alex, Blanton, Jessica, Allen, Eric E, Church, Matthew J, Bartlett, Douglas H
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 05.04.2018; Public Library of Science (PLoS)
• Subjects: Analysis; Bacteria; Biodiversity; Biology and Life Sciences; Columns (structural); Communities; Community structure; Deep sea; Earth Sciences; Ecology and Environmental Sciences; Halomonas; Hydrostatic pressure; Marine biology; Microbial activity; Microbial colonies; Microbiomes; Microorganisms; Ocean trenches; Oceanography; Organic matter; Phylogenetics; Physical Sciences; Pseudomonas; Research and Analysis Methods; Soil sciences; Taxa; Taxonomy; Trenches; Water column; Pacific Ocean; New Zealand; La Jolla California; California; United States > US; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0195102

Hadal trenches, oceanic locations deeper than 6,000 m, are thought to have distinct microbial communities compared to those at shallower depths due to high hydrostatic pressures, topographical funneling of organic matter, and biogeographical isolation. Here we evaluate the hypothesis that hadal trenches contain unique microbial biodiversity through analyses of the communities present in the bottom waters of the Kermadec and Mariana trenches. Estimates of microbial protein production indicate active populations under in situ hydrostatic pressures and increasing adaptation to pressure with depth. Depth, trench of collection, and size fraction are important drivers of microbial community structure. Many putative hadal bathytypes, such as members related to the Marinimicrobia, Rhodobacteraceae, Rhodospirilliceae, and Aquibacter, are similar to members identified in other trenches. Most of the differences between the two trench microbiomes consists of taxa belonging to the Gammaproteobacteria whose distributions extend throughout the water column. Growth and survival estimates of representative isolates of these taxa under deep-sea conditions suggest that some members may descend from shallower depths and exist as a potentially inactive fraction of the hadal zone. We conclude that the distinct pelagic communities residing in these two trenches, and perhaps by extension other trenches, reflect both cosmopolitan hadal bathytypes and ubiquitous genera found throughout the water column.