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Shifts in identity and activity of methanotrophs in arctic lake sediments in response to temperature changes

Applied and Environmental Microbiology

By:
, , , , , and
DOI: 10.1128/AEM.00853-12

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Abstract

Methane (CH4) flux to the atmosphere is mitigated via microbial CH4 oxidation in sediments and water. As arctic temperaturesincrease, understanding the effects of temperature on the activity and identity of methanotrophs in arctic lake sediments is importantto predicting future CH4 emissions. We used DNA-based stable-isotope probing (SIP), quantitative PCR (Q-PCR), andpyrosequencing analyses to identify and characterize methanotrophic communities active at a range of temperatures (4°C, 10°C,and 21°C) in sediments (to a depth of 25 cm) sampled from Lake Qalluuraq on the North Slope of Alaska. CH4 oxidation activitywas measured in microcosm incubations containing sediments at all temperatures, with the highest CH4 oxidation potential of37.5 mol g1 day1 in the uppermost (depth, 0 to 1 cm) sediment at 21°C after 2 to 5 days of incubation. Q-PCR of pmoA and ofthe 16S rRNA genes of type I and type II methanotrophs, and pyrosequencing of 16S rRNA genes in 13C-labeled DNA obtained bySIP demonstrated that the type I methanotrophs Methylobacter, Methylomonas, and Methylosoma dominated carbon acquisitionfrom CH4 in the sediments. The identity and relative abundance of active methanotrophs differed with the incubation temperature.Methylotrophs were also abundant in the microbial community that derived carbon from CH4, especially in the deeper sediments(depth, 15 to 20 cm) at low temperatures (4°C and 10°C), and showed a good linear relationship (R0.82) with the relativeabundances of methanotrophs in pyrosequencing reads. This study describes for the first time how methanotrophiccommunities in arctic lake sediments respond to temperature variations.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Shifts in identity and activity of methanotrophs in arctic lake sediments in response to temperature changes
Series title:
Applied and Environmental Microbiology
DOI:
10.1128/AEM.00853-12
Volume
78
Issue:
13
Year Published:
2012
Language:
English
Publisher:
American Society of Microbiology
Contributing office(s):
Woods Hole Coastal and Marine Science Center
Description:
9 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Applied and Environmental Microbiology
First page:
4715
Last page:
4723
Country:
United States
State:
Alaska
Other Geospatial:
Brooks Range