Methane‐derived carbon flow through microbial communities in arctic lake sediments

Journal Article · Wed Mar 04 00:00:00 EST 2015 · Environmental Microbiology

DOI:https://doi.org/10.1111/1462-2920.12773· OSTI ID:1400898

He, Ruo ^[1]; Wooller, Matthew J. ^[2]; Pohlman, John W. ^[3]; Tiedje, James M. ^[4]; Leigh, Mary Beth ^[5]

---

1. Department of Environmental Engineering Zhejiang University Hangzhou 310058 China, Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK 99775 USA
2. Alaska Stable Isotope Facility Water and Environmental Research Center University of Alaska Fairbanks Fairbanks AK 99775 USA, School of Fisheries and Ocean Sciences Institute of Marine Science University of Alaska Fairbanks Fairbanks AK 99775 USA
3. Woods Hole Coastal and Marine Science Center U.S. Geological Survey Woods Hole MA 02543 USA
4. Center for Microbial Ecology Michigan State University East Lansing MI 48824 USA
5. Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK 99775 USA

Summary Aerobic methane ( CH ₄ ) oxidation mitigates CH ₄ release and is a significant pathway for carbon and energy flow into aquatic food webs. Arctic lakes are responsible for an increasing proportion of global CH ₄ emissions, but CH ₄ assimilation into the aquatic food web in arctic lakes is poorly understood. Using stable isotope probing ( SIP ) based on phospholipid fatty acids ( PLFA‐SIP ) and DNA ( DNA‐SIP ), we tracked carbon flow quantitatively from CH ₄ into sediment microorganisms from an arctic lake with an active CH ₄ seepage. When 0.025 mmol CH ₄ g ⁻¹ wet sediment was oxidized, approximately 15.8–32.8% of the CH ₄ ‐derived carbon had been incorporated into microorganisms. This CH ₄ ‐derived carbon equated to up to 5.7% of total primary production estimates for Alaskan arctic lakes. Type I methanotrophs, including Methylomonas , Methylobacter and unclassified Methylococcaceae , were most active at CH ₄ oxidation in this arctic lake. With increasing distance from the active CH ₄ seepage, a greater diversity of bacteria incorporated CH ₄ ‐derived carbon. Actinomycetes were the most quantitatively important microorganisms involved in secondary feeding on CH ₄ ‐derived carbon. These results showed that CH ₄ flows through methanotrophs into the broader microbial community and that type I methanotrophs, methylotrophs and actinomycetes are important organisms involved in using CH ₄ ‐derived carbon in arctic freshwater ecosystems.

• Sponsoring Organization: USDOE
• OSTI ID: 1400898
• Journal Information: Environmental Microbiology, Journal Name: Environmental Microbiology Vol. 17 Journal Issue: 9; ISSN 1462-2912
• Publisher: Wiley-Blackwell
• Country of Publication: United Kingdom
• Language: English