Cargando…

Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes

Lakes are a natural source of methane to the atmosphere and contribute significantly to total emissions compared to the oceans. Controls on methane emissions from lake surfaces, particularly biotic processes within anoxic hypolimnia, are only partially understood. Here we investigated biological met...

Descripción completa

Detalles Bibliográficos
Autores principales: Oswald, Kirsten, Milucka, Jana, Brand, Andreas, Littmann, Sten, Wehrli, Bernhard, Kuypers, Marcel M. M., Schubert, Carsten J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4508055/
https://www.ncbi.nlm.nih.gov/pubmed/26193458
http://dx.doi.org/10.1371/journal.pone.0132574
_version_ 1782381882646724608
author Oswald, Kirsten
Milucka, Jana
Brand, Andreas
Littmann, Sten
Wehrli, Bernhard
Kuypers, Marcel M. M.
Schubert, Carsten J.
author_facet Oswald, Kirsten
Milucka, Jana
Brand, Andreas
Littmann, Sten
Wehrli, Bernhard
Kuypers, Marcel M. M.
Schubert, Carsten J.
author_sort Oswald, Kirsten
collection PubMed
description Lakes are a natural source of methane to the atmosphere and contribute significantly to total emissions compared to the oceans. Controls on methane emissions from lake surfaces, particularly biotic processes within anoxic hypolimnia, are only partially understood. Here we investigated biological methane oxidation in the water column of the seasonally stratified Lake Rotsee. A zone of methane oxidation extending from the oxic/anoxic interface into anoxic waters was identified by chemical profiling of oxygen, methane and δ(13)C of methane. Incubation experiments with (13)C-methane yielded highest oxidation rates within the oxycline, and comparable rates were measured in anoxic waters. Despite predominantly anoxic conditions within the zone of methane oxidation, known groups of anaerobic methanotrophic archaea were conspicuously absent. Instead, aerobic gammaproteobacterial methanotrophs were identified as the active methane oxidizers. In addition, continuous oxidation and maximum rates always occurred under light conditions. These findings, along with the detection of chlorophyll a, suggest that aerobic methane oxidation is tightly coupled to light-dependent photosynthetic oxygen production both at the oxycline and in the anoxic bottom layer. It is likely that this interaction between oxygenic phototrophs and aerobic methanotrophs represents a widespread mechanism by which methane is oxidized in lake water, thus diminishing its release into the atmosphere.
format Online
Article
Text
id pubmed-4508055
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-45080552015-07-24 Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes Oswald, Kirsten Milucka, Jana Brand, Andreas Littmann, Sten Wehrli, Bernhard Kuypers, Marcel M. M. Schubert, Carsten J. PLoS One Research Article Lakes are a natural source of methane to the atmosphere and contribute significantly to total emissions compared to the oceans. Controls on methane emissions from lake surfaces, particularly biotic processes within anoxic hypolimnia, are only partially understood. Here we investigated biological methane oxidation in the water column of the seasonally stratified Lake Rotsee. A zone of methane oxidation extending from the oxic/anoxic interface into anoxic waters was identified by chemical profiling of oxygen, methane and δ(13)C of methane. Incubation experiments with (13)C-methane yielded highest oxidation rates within the oxycline, and comparable rates were measured in anoxic waters. Despite predominantly anoxic conditions within the zone of methane oxidation, known groups of anaerobic methanotrophic archaea were conspicuously absent. Instead, aerobic gammaproteobacterial methanotrophs were identified as the active methane oxidizers. In addition, continuous oxidation and maximum rates always occurred under light conditions. These findings, along with the detection of chlorophyll a, suggest that aerobic methane oxidation is tightly coupled to light-dependent photosynthetic oxygen production both at the oxycline and in the anoxic bottom layer. It is likely that this interaction between oxygenic phototrophs and aerobic methanotrophs represents a widespread mechanism by which methane is oxidized in lake water, thus diminishing its release into the atmosphere. Public Library of Science 2015-07-20 /pmc/articles/PMC4508055/ /pubmed/26193458 http://dx.doi.org/10.1371/journal.pone.0132574 Text en © 2015 Oswald et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Oswald, Kirsten
Milucka, Jana
Brand, Andreas
Littmann, Sten
Wehrli, Bernhard
Kuypers, Marcel M. M.
Schubert, Carsten J.
Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes
title Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes
title_full Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes
title_fullStr Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes
title_full_unstemmed Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes
title_short Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes
title_sort light-dependent aerobic methane oxidation reduces methane emissions from seasonally stratified lakes
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4508055/
https://www.ncbi.nlm.nih.gov/pubmed/26193458
http://dx.doi.org/10.1371/journal.pone.0132574
work_keys_str_mv AT oswaldkirsten lightdependentaerobicmethaneoxidationreducesmethaneemissionsfromseasonallystratifiedlakes
AT miluckajana lightdependentaerobicmethaneoxidationreducesmethaneemissionsfromseasonallystratifiedlakes
AT brandandreas lightdependentaerobicmethaneoxidationreducesmethaneemissionsfromseasonallystratifiedlakes
AT littmannsten lightdependentaerobicmethaneoxidationreducesmethaneemissionsfromseasonallystratifiedlakes
AT wehrlibernhard lightdependentaerobicmethaneoxidationreducesmethaneemissionsfromseasonallystratifiedlakes
AT kuypersmarcelmm lightdependentaerobicmethaneoxidationreducesmethaneemissionsfromseasonallystratifiedlakes
AT schubertcarstenj lightdependentaerobicmethaneoxidationreducesmethaneemissionsfromseasonallystratifiedlakes