Methane utilizing bacteria (methanotrophs) are important in both environmental and biotechnological applications, due to their ability to convert methane to multicarbon compounds. However, systems-level studies of methane metabolism have not been carried out in methanotrophs. In this work we have integrated genomic and transcriptomic information to provide an overview of central metabolic pathways for methane utilization in Methylosinus trichosporium OB3b, a model alphaproteobacterial methanotroph. Particulate methane monooxygenase, PQQ-dependent methanol dehydrogenase, the H4MPT-pathway, and NAD-dependent formate dehydrogenase are involved in methane oxidation to CO2. All genes essential for operation of the serine cycle, the ethylmalonyl-CoA (EMC) pathway, and the citric acid (TCA) cycle were expressed. PEP-pyruvate-oxaloacetate interconversions may have a function in regulation and balancing carbon between the serine cycle and the EMC pathway. A set of transaminases may contribute to carbon partitioning between the pathways. Metabolic pathways for acquisition and/or assimilation of nitrogen and iron are discussed.
Keywords: methanotrophic proteobacteria, serine cycle, ethylmalonyl-CoA pathway in methanotrophs, TCA, gene expression
Citation: Matsen JB, Yang S, Stein LY, Beck D and Kalyuzhnaya MG (2013) Global molecular analyses of methane metabolism in methanotrophic alphaproteobacterium, Methylosinus trichosporium OB3b. Part I: transcriptomic study. Front. Microbiol. 4:40. doi: 10.3389/fmicb.2013.00040
Received: 01 January 2013; Paper pending published: 28 January 2013;
Accepted: 17 February 2013; Published online: 03 April 2013.
Edited by:Amy V. Callaghan, University of Oklahoma, USA
Reviewed by:Svetlana N. Dedysh, Russian Academy of Sciences, Russia
Copyright: © 2013 Matsen, Yang, Stein, Beck and Kalyuzhnaya. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Marina G. Kalyuzhnaya, Department of Microbiology, University of Washington, Benjamin Hall IRB RM 455, 616 NE Northlake Place, Seattle, WA 98105, USA. e-mail: firstname.lastname@example.org