New Methane-Producing Microbe Found in Thawing Permafrost
The species and its relatives appear to be prevalent in areas of high methane flux worldwide.
The Science
Northern high-latitude ecosystems are rapidly changing amid rising temperatures, catalyzing the transition of many permafrost sites to wetlands. Researchers have used multiple techniques to understand the microbial decomposition of permafrost.
The Impact
A new species of archaea, Candidatus Methanoflorens stordalenmirensis, was found to dominate populations of methanogens (methane-producing microbes) in the thawing active layer of permafrost. The dominance of a single organism in CH4 production is a surprising finding. Given evidence for the global distribution of this type methanogen in thawing permafrost sites, these results may have wide-ranging implications for understanding climate change impacts.
Summary
As the organic carbon locked in permafrost thaws, it becomes accessible to decomposition by microbial communities. Understanding of these communities is limited, especially regarding functional processes that affect rates of carbon degradation and the balance of carbon dioxide (CO2) versus methane (CH4) released to the atmosphere. In a study supported by the U.S. Department of Energy’s Genomic Science program, researchers at the University of Arizona used a combination of metagenomics, metaproteomics, and geochemical flux measurements to characterize microbial community structure and function at a thawing permafrost site in northern Sweden. Using deep metagenomic sequencing, the research team was able to assemble a nearly complete genome for M. stordalenmirensis and identify the metabolic pathway for methanogenesis, the process by which microbes consume hydrogen and CO2 and produce CH4. Measurements of CH4 flux at the thawing permafrost site and quantitative in situ detection of M. stordalenmirensis methanogensis proteins suggest that this organism may perform the majority of methane production at these sites, especially during thawing. The team also searched published metagenomic libraries collected from permafrost sites across the northern hemisphere and detected high numbers of closely related methanogens at most of the sites.
Contact
Gene W. Tyson
Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, University of Queensland
g.tyson@uq.edu.au
Funding
This study was funded by the Genomic Science program of the Office of Biological and Environmental Research within the U.S. Department of Energy’s Office of Science (grant DE-SC0004632). Additional support for individual authors was provided by an Australian Postgraduate Award Scholarship, an ARC Discovery Outstanding Researcher Award (DP120103498), and an ARC Queen Elizabeth II fellowship (DP1093175).
Publications
Mondav, R., et al. “Discovery of a novel methanogen prevalent in thawing permafrost.” Nat. Commun. 5, 3212 (2014). [DOI: 10.1038/ncomms4212].
Highlight Categories
Performer: University
Additional: Collaborations , International Collaboration
