Microbial survival strategies in ancient permafrost: insights from metagenomics

The ISME Journal
By: , and 



In permafrost (perennially frozen ground) microbes survive oligotrophic conditions, sub-zero temperatures, low water availability and high salinity over millennia. Viable life exists in permafrost tens of thousands of years old but we know little about the metabolic and physiological adaptations to the challenges presented by life in frozen ground over geologic time. In this study we asked whether increasing age and the associated stressors drive adaptive changes in community composition and function. We conducted deep metagenomic and 16 S rRNA gene sequencing across a Pleistocene permafrost chronosequence from 19 000 to 33 000 years before present (kyr). We found that age markedly affected community composition and reduced diversity. Reconstruction of paleovegetation from metagenomic sequence suggests vegetation differences in the paleo record are not responsible for shifts in community composition and function. Rather, we observed shifts consistent with long-term survival strategies in extreme cryogenic environments. These include increased reliance on scavenging detrital biomass, horizontal gene transfer, chemotaxis, dormancy, environmental sensing and stress response. Our results identify traits that may enable survival in ancient cryoenvironments with no influx of energy or new materials.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Microbial survival strategies in ancient permafrost: insights from metagenomics
Series title The ISME Journal
DOI 10.1038/ismej.2017.93
Volume 11
Year Published 2017
Language English
Publisher Nature Publishing Group
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description 14 p.
First page 2305
Last page 2318
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