First evidence for cold-adapted anaerobic oxidation of methane in deep sediments of thermokarst lakes

M Winkel, A Sepulveda-Jauregui, K Martinez-Cruz, J K Heslop, R Rijkers, F Horn, S Liebner, K M Walter Anthony

    Research output: Contribution to JournalArticleAcademicpeer-review

    Abstract

    Microbial decomposition of thawed permafrost carbon in thermokarst lakes leads to the release of ancient carbon as the greenhouse gas methane (CH 4), yet potential mitigating processes are not understood. Here, we report δ 13 C-CH 4 signatures in the pore water of a thermokarst lake sediment core that points towards in situ occurrence of anaerobic oxidation of methane (AOM). Analysis of the microbial communities showed a natural enrichment in CH 4-oxidizing archaeal communities that occur in sediment horizons at temperatures near 0 °C. These archaea also showed high rates of AOM in laboratory incubations. Calculation of the stable isotopes suggests that 41 to 83% of in situ dissolved CH 4 is consumed anaerobically. Quantification of functional genes (mcrA) for anaerobic methano-trophic communities revealed up to 6.7±0.7×10 5 copy numbers g −1 wet weight and showed similar abundances to bacterial 16S rRNA gene sequences in the sediment layers with the highest AOM rates. We conclude that these AOM communities are fueled by CH 4 produced from permafrost organic matter degradation in the underlying sediments that represent the radially expanding permafrost thaw front beneath the lake. If these communities are widespread in thermokarst environments, they could have a major mitigating effect on the global CH 4 emissions.
    Original languageEnglish
    Article number021002
    JournalEnvironmental Research Communications
    Volume1
    Issue number2
    DOIs
    Publication statusPublished - 3 Apr 2019

    Funding

    We thank Sam Skidmore for granting access to Vault Lake and Anke Saborowski for laboratory support. Funding for M Winkel and K M Walter Anthony was provided by the National Science Foundation ARCSS-1500931. K Martinez-Cruz was funded by Conacyt (Grant no. 330197/233369). The Helmholtz Young Investigators Group of S Liebner is funded by the Helmholtz Gemeinschaft (HGF) (VH-NG-919). We deposited sequences of the thermokarst lake permafrost metagenome at the NCBI Sequence Read Archive (SRA) with the Project number BioProject ID# PRJNA381521, accession numbers for archaeal 16S rRNA gene sequences were SRX3047230-SRX3047235 and for bacterial 16S rRNA gene sequences were SRX3047223-SRX3047228. We thank Sam Skidmore for granting access to Vault Lake and Anke Saborowski for laboratory support. Funding for M Winkel and K M Walter Anthony was provided by the National Science Foundation ARCSS-1500931. K Martinez-Cruz was funded by Conacyt (Grant no. 330197/233369). The Helmholtz Young Investigators Group of S Liebner is funded by the Helmholtz Gemeinschaft (HGF)(VH-NG-919). We deposited sequences of the thermokarst lake permafrost metagenome at the NCBI Sequence Read Archive (SRA) with the Project number BioProject ID# PRJNA381521, accession numbers for archaeal 16S rRNA gene sequences were SRX3047230-SRX3047235 and for bacterial 16S rRNA gene sequences were SRX3047223-SRX3047228.

    FundersFunder number
    NCBIPRJNA381521, SRX3047223-SRX3047228, SRX3047230-SRX3047235
    National Science FoundationARCSS-1500931
    Consejo Nacional de Ciencia y Tecnología330197/233369
    Helmholtz AssociationVH-NG-919

      Fingerprint

      Dive into the research topics of 'First evidence for cold-adapted anaerobic oxidation of methane in deep sediments of thermokarst lakes'. Together they form a unique fingerprint.

      Cite this