Journal
ENVIRONMENTAL MICROBIOLOGY
Volume 22, Issue 2, Pages 766-782Publisher
WILEY
DOI: 10.1111/1462-2920.14886
Keywords
-
Categories
Funding
- Soehngen Institute of Anaerobic Microbiology (SIAM) Gravitation grant [024.002.002]
- Netherlands Organisation for Scientific Research (NWO)
Ask authors/readers for more resources
Methanotrophic bacteria play a key role in limiting methane emissions from lakes. It is generally assumed that methanotrophic bacteria are mostly active at the oxic-anoxic transition zone in stratified lakes, where they use oxygen to oxidize methane. Here, we describe a methanotroph of the genera Methylobacter that is performing high-rate (up to 72 mu M day(-1)) methane oxidation in the anoxic hypolimnion of the temperate Lacamas Lake (Washington, USA), stimulated by both nitrate and sulfate addition. Oxic and anoxic incubations both showed active methane oxidation by a Methylobacter species, with anoxic rates being threefold higher. In anoxic incubations, Methylobacter cell numbers increased almost two orders of magnitude within 3 days, suggesting that this specific Methylobacter species is a facultative anaerobe with a rapid response capability. Genomic analysis revealed adaptations to oxygen-limitation as well as pathways for mixed-acid fermentation and H-2 production. The denitrification pathway was incomplete, lacking the genes narG/napA and nosZ, allowing only for methane oxidation coupled to nitrite-reduction. Our data suggest that Methylobacter can be an important driver of the conversion of methane in oxygen-limited lake systems and potentially use alternative electron acceptors or fermentation to remain active under oxygen-depleted conditions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available