Methane ‘eating’ bacteria that live in symbiosis with peat-moss occur worldwide. This was demonstrated by researchers from Radboud University Nijmegen, Utrecht University and the Royal Netherlands Institute for Sea Research. These bacteria consume large quantities of the methane produced by the mosses. This process is therefore responsible for methane emission reduction in peat bogs across the world. This study was published in Nature Geoscience on 22 August.

Carbon storage

Peat bogs store up to a third of all terrestrial carbon on Earth, and are one of the largest natural sources of atmospheric methane. Anaerobic degradation of submerged Sphagnum species—mosses that are prevalent in peat bogs across the globe—produces significant quantities of methane in these systems. A large fraction of this methane is consumed by aerobic methane-oxidizing bacteria, known as methanotrophs. In return, the methanotrophs provide Sphagnum mosses with carbon. In the article it was demonstrated that Sphagnum associated methane oxidation occurs ubiquitously across the globe.

Mosses across the world

Sphagnum mosses have been collected from pools, lawns and hummocks in nine Sphagnum-dominated peatlands across the world. In a series of laboratory incubations their capacity to oxidize methane was measured. All mosses were capable of oxidizing methane. The rate of methane oxidation increased with temperature, and was most pronounced in submerged mosses, collected from peatland pools.

Symbiosis

According to DNA microarray analyses, the methanotrophic community responsible for methane oxidation was highly diverse. 13C labeling revealed that methane-derived carbon was incorporated into plant lipids when mosses were submerged, indicative of a mutually beneficial symbiosis between mosses and methanotrophs. The findings suggest that the interaction between methanotrophs and Sphagnum species may play a role in carbon recycling in waterlogged Sphagnum vegetation, potentially reducing methane emissions.

Nature Geoscience

Title: Global prevalence of methane oxidation by symbiotic bacteria in peat-moss ecosystems, Nature Geoscience, 22 augustus 2010.
Authors: Nardy Kip, Julia F. van Winden, Yao Pan, Levente Bodrossy, Gert-Jan Reichart, Alfons J. P. Smolders, Mike S. M. Jetten, Jaap S. Sinninghe Damsté, Huub J. M. Op den Camp.

Contact

Prof. dr. Mike Jetten, 024 3652941 or 06 24703662, m.jetten@science.ru.nl.

Nardy Kip, n.kip@science.ru.nl.