Updated: Discovery of Positive Methane Feedback from Permafrost Thaw

Update: As pointed out by one of the authors, Rhiannon […]

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Climate State

Date Posted:

February 22, 2014

Update: As pointed out by one of the authors, Rhiannon Mondav, the microbe is not considered an entire new discovery. (See comment below).

Phys.org explains: Scientists from The University of Queensland have discovered a microbe that is set to play a significant role in future global warming. UQ’s Australian Centre for Ecogenomics researcher Ben Woodcroft said the methane-producing micro-organism, known as a ‘methanogen’, was thriving in northern Sweden’s thawing permafrost in a thick subsurface layer of soil that has previously remained frozen.

Mr Woodcroft said no one knew of the microbe’s existence or how it worked before the research discovery. Fragments of the microbe’s DNA had been found during the last 20 years but no one knew how it worked before the new research discovery.

Mr Woodcroft said global warming trends meant vast areas of permafrost would continue to thaw, allowing the microbes to flourish in organic matter and drive methane gas release, which would further fuel global warming. “The micro-organism generates methane by using carbon dioxide and hydrogen from the bacteria it lives alongside,” Mr Woodcroft said.

Lead researcher and UQ’s Australian Centre for Ecogenomics Deputy Director Associate Professor Gene Tyson said the findings were significant. “This micro-organism is responsible for producing a substantial fraction of methane at this site,” he said. “Methane is a potent greenhouse gas with about 25 times the warming capacity of carbon dioxide.”

The researchers showed the organism and its close relatives live not just in thawing permafrost but in many other methane-producing habitats worldwide. The team made the discovery by using DNA from soil samples and reconstructing a near-complete genome of the microbe, bypassing traditional methods of cultivating microbes in the lab.

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The Study: Discovery of a novel methanogen prevalent in thawing permafrost

Rhiannon Mondav, et al. Nature Communications 5, Article number: 3212 DOI: 10.1038/ncomms4212

Abstract Thawing permafrost promotes microbial degradation of cryo-sequestered and new carbon leading to the biogenic production of methane, creating a positive feedback to climate change. Here we determine microbial community composition along a permafrost thaw gradient in northern Sweden. Partially thawed sites were frequently dominated by a single archaeal phylotype, Candidatus ‘Methanoflorens stordalenmirensis’ gen. nov. sp. nov., belonging to the uncultivated lineage ‘Rice Cluster II’ (Candidatus ‘Methanoflorentaceae’ fam. nov.). Metagenomic sequencing led to the recovery of its near-complete genome, revealing the genes necessary for hydrogenotrophic methanogenesis. These genes are highly expressed and methane carbon isotope data are consistent with hydrogenotrophic production of methane in the partially thawed site. In addition to permafrost wetlands, ‘Methanoflorentaceae’ are widespread in high methane-flux habitats suggesting that this lineage is both prevalent and a major contributor to global methane production. In thawing permafrost, Candidatus ‘M. stordalenmirensis’ appears to be a key mediator of methane-based positive feedback to climate warming.

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2 Comments

  1. Rhiannon Mondav March 5, 2014 at 2:12 pm - Reply

    Dear editor

    I am the listed first co-author on the paper mentioned in the press release ‘Newly discovered microbe holds key to global warming’. Due to some oversight I was neither mentioned nor contacted regarding the press release on this work. The UQ press release has now been ammended. I would like to take this oportunity to correct an error in the release. Mr Woodcroft’s statement that “no one knew of the microbe’s existence or how it worked before the research discovery” is incorrect. The correct statement should be “fragments of the microbe’s DNA had been found during the last 20 years but no one knew how it worked before the research discovery”. Please feel free to veryify this correction. That we were able to identify where in the world the microbe had previously been found and that we knew it was nicknamed “RCII” certainly lends credence to my correction. I would also appreciate it if my statement was accredited to me.

    http://rhiannonmondav.net/
    Best Regards
    Rhiannon Mondav

    • Profile photo ofadmin
      Climate State March 5, 2014 at 3:18 pm - Reply

      Thank you Rhiannon Mondav, i’ve updated the article accordingly.

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