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Permafrost Microbiology

DIMENSIONS: Genetic, phylogenetic, and functional microbial diversity in permanently frozen aquatic sediments over geological time

Funded by the National Science Foundation, Directorate for Biological Sciences, Division of Environmental Biology (DEB) – Dimensions of Biodiversity

Sediments, soils, or rocks that remain at or below 0ºC for at least 2 consecutive years are defined as permafrost. Permafrost regions are geologically and ecologically diverse and occupy over 20% of the Earth’s land surface. Conditions within permafrost are shown to be amenable for preservation of microbial communities. The current literature presents contradictory interpretations on a major unresolved question in microbial ecology – whether microbes recovered from deep sediments are living fossils, representing an ancient surface community preserved through time, or an active extant community that has been interacting and evolving continuously since becoming buried. The resolution of this debate is critically important for determining past versus present microbial diversity in deep sediments and also in determining molecular evolution within bacterial taxa.

The current project aims to document temporal evolution of taxonomic, genetic and functional biodiversity in 5 thousand years to 3 million years permanently frozen sediments collected from the Siberian Kolyma-Indigirka Lowland. These permafrost sediments of lake-alluvial or marine origin have never completely thawed since they were frozen and most likely they contain a mixture of active, dormant, and truly extinct microbes. The project will expand our understanding of the extant and extinct microbial communities in young to ancient permanently frozen sediments with respect to evolutionary trends over time and the low temperature survivability and adaptation of psychrophilic microorganisms.

The team had a successful 2015 summer field season drilling cores across permafrost sediments of lake-alluvial origin in remote sites located on the Alazeya River in Northeastern Siberia. To extend public knowledge on the Siberian permafrost area including the tundra landscape and the life of the local people, the team produced a short video of the field site, local support personnel, and music of local artists [link to video].

International Workshop on Biology and Biotechnology of Thermophilic Microorganisms

Deep Freeze” in the Tennessee Alumnus magazine

UT Scientists Revive Microscopic Life from Frost” in the Daily Beacon newsletter

For more information, contact Tatiana Vishnivetskaya at tvishniv@utk.edu or 865-974-8080

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