Riverbed methanotrophy sustained by high carbon conversion efficiency

Trimmer, Mark and Shelley, Felicity C. and Purdy, Kevin J. and Maanoja, Susanna T. and Chronopoulou, Panagiota-Myrsini and Grey, Jonathan (2015) Riverbed methanotrophy sustained by high carbon conversion efficiency. ISME Journal, 9 (10). pp. 2304-2314. ISSN 1751-7362

Full text not available from this repository.

Abstract

Our understanding of the role of freshwaters in the global carbon cycle is being revised, but there is still a lack of data, especially for the cycling of methane, in rivers and streams. Unravelling the role of methanotrophy is key to determining the fate of methane in rivers. Here we focus on the carbon conversion efficiency (CCE) of methanotrophy, that is, how much organic carbon is produced per mole of CH4 oxidised, and how this is influenced by variation in methanotroph communities. First, we show that the CCE of riverbed methanotrophs is consistently high (~50%) across a wide range of methane concentrations (~10–7000 nM) and despite a 10-fold span in the rate of methane oxidation. Then, we show that this high conversion efficiency is largely conserved (50%± confidence interval 44–56%) across pronounced variation in the key functional gene (70 operational taxonomic units (OTUs)), particulate methane monooxygenase (pmoA), and marked shifts in the abundance of Type I and Type II methanotrophs in eight replicate chalk streams. These data may suggest a degree of functional redundancy within the variable methanotroph community inhabiting these streams and that some of the variation in pmoA may reflect a suite of enzymes of different methane affinities which enables such a large range of methane concentrations to be oxidised. The latter, coupled to their high CCE, enables the methanotrophs to sustain net production throughout the year, regardless of the marked temporal and spatial changes that occur in methane.

Item Type:
Journal Article
Journal or Publication Title:
ISME Journal
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1100/1105
Subjects:
ID Code:
74620
Deposited By:
Deposited On:
13 Jul 2015 09:18
Refereed?:
Yes
Published?:
Published
Last Modified:
04 Jul 2020 02:46