Microbial communities in the northern permafrost wetlands are central to understanding current and future global carbon cycling. Northern permafrost wetlands contribute a tenth of global methane (CH4) emissions and contain a quarter of the global soil carbon. This is particularly important as methane is a very efficient greenhouse gas; it is 25 times more efficient at trapping the sun’s radiation in our atmosphere than carbon dioxide. As permafrost thaws, methane emissions will increase and are likely to cause a positive feedback loop where increased atmospheric warming causes more thawing. It is critical to understand how methane is cycled in these permafrost wetlands so we can predict the impact thawing permafrost will have on global climate change and the carbon cycle.
Wetland methane cycling is mediated by microorganisms, but the connection between microbial population dynamics, genomics and ecosystem‐scale fluxes is still unknown. Recent advances in high‐throughput DNA sequencing and improved resolution of biogeochemical isotope measurements now permit a uniquely comprehensive approach to opening the microbial “black boxes” of permafrost wetland methane cycling.
The specific aims of this project are to:
1.Investigate the meta-genomes and meta-transcriptomes of permafrost samples collected at different degrees of thawing
2.Develop a novel experimental method using quantum dot and BONCAT labelling to visualize and isolate the microbes responsible for key carbon transformations
Two microbial communities of interest include the methanogens that use hydrogen or acetate to produce methane, and the methanotrophs that use methane as their carbon and energy source. Methanotrophs will capture methane before it reaches the atmosphere, reducing methane emissions. Thus far our project has identified and sequenced novel genomes of both methanogens and methanotrophs, as well as approximately 1500 population genomes of previously undiscovered bacteria and archaea from the permafrost environment. Overall, the data gathered will augment our knowledge of the global carbon cycle, including energy transformations and the important role microbial communities play in a thawing world.