Increases in temperature and nutrient availability positively affect methane‐cycling microorganisms in Arctic thermokarst lake sediments

Summary Arctic permafrost soils store large amounts of organic matter that is sensitive to temperature increases and subsequent microbial degradation to methane (CH 4 ) and carbon dioxide (CO 2 ). Here, we studied methanogenic and methanotrophic activity and community composition in thermokarst lake...

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Bibliographic Details
Published in:Environmental Microbiology
Main Authors: de Jong, Anniek E. E., in ’t Zandt, Michiel H., Meisel, Ove H., Jetten, Mike S. M., Dean, Joshua F., Rasigraf, Olivia, Welte, Cornelia U.
Other Authors: H2020 European Research Council, Nederlandse Organisatie voor Wetenschappelijk Onderzoek
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2018
Subjects:
Arctic
Barrow
Climate change
permafrost
Thermokarst
Alaska
Online Access:http://dx.doi.org/10.1111/1462-2920.14345
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2F1462-2920.14345
https://onlinelibrary.wiley.com/doi/pdf/10.1111/1462-2920.14345
https://onlinelibrary.wiley.com/doi/full-xml/10.1111/1462-2920.14345
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Summary:Summary Arctic permafrost soils store large amounts of organic matter that is sensitive to temperature increases and subsequent microbial degradation to methane (CH 4 ) and carbon dioxide (CO 2 ). Here, we studied methanogenic and methanotrophic activity and community composition in thermokarst lake sediments from Utqiag˙vik (formerly Barrow), Alaska. This experiment was carried out under in situ temperature conditions (4°C) and the IPCC 2013 Arctic climate change scenario (10°C) after addition of methanogenic and methanotrophic substrates for nearly a year. Trimethylamine (TMA) amendment with warming showed highest maximum CH 4 production rates, being 30% higher at 10°C than at 4°C. Maximum methanotrophic rates increased by up to 57% at 10°C compared to 4°C. 16S rRNA gene sequencing indicated high relative abundance of Methanosarcinaceae in TMA amended incubations, and for methanotrophic incubations Methylococcaeae were highly enriched. Anaerobic methanotrophic activity with nitrite or nitrate as electron acceptor was not detected. This study indicates that the methane cycling microbial community can adapt to temperature increases and that their activity is highly dependent on substrate availability.

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