Increases in temperature and nutrient availability positively affect methane-cycling microorganisms in Arctic thermokarst lake sediments
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 sedimen...
Published in: | Environmental Microbiology |
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Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2018
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Subjects: | |
Online Access: | https://research.vu.nl/en/publications/ffa6139b-e0ec-4a1a-b87d-f44bcb81d0c0 https://doi.org/10.1111/1462-2920.14345 https://hdl.handle.net/1871.1/ffa6139b-e0ec-4a1a-b87d-f44bcb81d0c0 http://www.scopus.com/inward/record.url?scp=85053372633&partnerID=8YFLogxK http://www.scopus.com/inward/citedby.url?scp=85053372633&partnerID=8YFLogxK |
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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