Permafrost Microbes Could Make Impacts of Arctic Warming Worse
In Earth’s Arctic regions, frozen soils (permafrost) sequester an estimated 1.6 trillion metric tons of carbon, more than 250 times the amount of greenhouse gas emissions attributed to the United States in 2009. Concerns are growing about the potential impact on the global carbon cycle when rising temperatures thaw the permafrost and release the trapped carbon. Microbes may significantly influence the eventual outcome through their involvement in carbon cycling. New research on permafrost microbes has discovered a previously unknown, yet abundant microbe that produces methane, a far more potent greenhouse gas than carbon dioxide. A draft of this microbe’s genome was determined by assembling DNA fragments isolated from permafrost. The DOE Joint Genome Institute (JGI) had previously identified several microbes that produced methane (“methanogens”) as a metabolic byproduct, and used this knowledge to identify enough fragments of the new microbe’s DNA to assemble a draft of its genome. The abundance of this novel methanogen implies that it could be an important factor in methane production under permafrost thawing conditions. The research, published in Nature, was carried out by scientists at JGI, Lawrence Berkeley National Laboratory, and U.S. Geological Survey.
Mackelprang, R., et al. 2011. “Metagenomic Analysis of a Permafrost Microbial Community Reveals a Rapid Response to Thaw,” Nature 480, 368-71. DOI: 10.1038/nature10576.