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Diversity of active aerobic methanotrophs along depth profiles of arctic and subarctic lake water column and sediments

ISME Journal

By:
, , , , ,
DOI: 10.1038/ismej.2012.34

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Abstract

Methane (CH4) emitted from high-latitude lakes accounts for 2–6% of the global atmospheric CH4 budget. Methanotrophs in lake sediments and water columns mitigate the amount of CH4 that enters the atmosphere, yet their identity and activity in arctic and subarctic lakes are poorly understood. We used stable isotope probing (SIP), quantitative PCR (Q-PCR), pyrosequencing and enrichment cultures to determine the identity and diversity of active aerobic methanotrophs in the water columns and sediments (0–25 cm) from an arctic tundra lake (Lake Qalluuraq) on the north slope of Alaska and a subarctic taiga lake (Lake Killarney) in Alaska's interior. The water column CH4 oxidation potential for these shallow (~2m deep) lakes was greatest in hypoxic bottom water from the subarctic lake. The type II methanotroph, Methylocystis, was prevalent in enrichment cultures of planktonic methanotrophs from the water columns. In the sediments, type I methanotrophs (Methylobacter, Methylosoma and Methylomonas) at the sediment-water interface (0–1 cm) were most active in assimilating CH4, whereas the type I methanotroph Methylobacter and/or type II methanotroph Methylocystis contributed substantially to carbon acquisition in the deeper (15–20 cm) sediments. In addition to methanotrophs, an unexpectedly high abundance of methylotrophs also actively utilized CH4-derived carbon. This study provides new insight into the identity and activity of methanotrophs in the sediments and water from high-latitude lakes.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Diversity of active aerobic methanotrophs along depth profiles of arctic and subarctic lake water column and sediments
Series title:
ISME Journal
DOI:
10.1038/ismej.2012.34
Volume
6
Issue:
10
Year Published:
2012
Language:
English
Publisher:
Nature Publishing Group
Publisher location:
Washington, D.C.
Contributing office(s):
Woods Hole Coastal and Marine Science Center
Description:
12 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
1937
Last page:
1948
Number of Pages:
53
Country:
United States
State:
Alaska
Other Geospatial:
Lake Qalluuraq;Lake Kilarney