Niche separation of thaumarchaeotes from sea surface to hadal ocean.

Abstract:

Niche separation of the marine thaumarchaeal subgroups such as α (Nitrosopumiluscluster), β, γ and δ subgroups, along vertical water column has been observed in Arctic to tropical oceans (Sintes et al. 2013 and references therein). Availability of ammonia most likely influence on niche separation of thaumarchaeal communities, and thus the niche separation would be a signature of geochemical interface in oceanic environments.

In the Challenger Deep, thaumarchaeal communities in hadal water were distinct from those in the overlying abyssal water, and the niche separation of thaumarchaeotes was consistent with the enrichments of heterotrophic populations in the hadal water (Nunoura et al. 2015). Moreover, we have compared hadal microbial ecosystems in distinct trench environments at the Northwest Pacific; the Japan and Izu-Ogasawara Trenches, by using multiple molecular techniques including single-cell genomic analysis. A series of the molecular environmental studies for hadal environments provides novel insights into the molecular machineries of thaumarchaeotes that adapt and dominate in aphotic oceanic waters.