Microbial survival strategies in ancient permafrost: insights from metagenomics

• DOI: 10.1038/ismej.2017.93
• Publication Date: 2017-07-11T14:01:30Z
• Authors: Rachel Mackelprang; Alexander Burkert; Monica Haw; Tara Mahendrarajah; Christopher H Con...; Thomas A Douglas; Mark P Waldrop
• Keywords: Chronosequence; Geomicrobiology

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