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Title: Metagenomic profiles of archaea and bacteria within thermal and geochemical gradients of the Guaymas Basin deep subsurface
Previous studies of microbial communities in subseafloor sediments reported that microbial abundance and diversity decrease with sediment depth and age, and microbes dominating at depth tend to be a subset of the local seafloor community. However, the existence of geographically widespread, subsurface-adapted specialists is also possible. Here, we usemetagenomic and metatranscriptomic analyses of the hydrothermally heated, sediment layers of Guaymas Basin (Gulf of California, Mexico) to examine the distribution and activity patterns of bacteria and archaea along thermal, geochemical and cell count gradients. We find that the composition and distribution of metagenome-assembled genomes (MAGs), dominated by numerous lineages of Chloroflexota and Thermoproteota, correlate with biogeochemical parameters as long as temperatures remain moderate, but downcore increasing temperatures beyond ca. 45 ºC override other factors. Consistently, MAG size and diversity decrease with increasing temperature, indicating a downcore winnowing of the subsurface biosphere. By contrast, specific archaeal MAGs within the Thermoproteota and Hadarchaeota increase in relative abundance and in recruitment of transcriptome reads towards deeper, hotter sediments, marking the transition towards a specialized deep, hot biosphere.  more » « less
Award ID(s):
2046799
NSF-PAR ID:
10484195
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Nature Communications
Date Published:
Journal Name:
Nature communications
Volume:
14
Issue:
7768
ISSN:
2041-1723
Subject(s) / Keyword(s):
["Deep Biosphere","hydrothermalism","metatranscriptomes","adaptation","survival"]
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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