Fluctuations in populations of subsurface methane oxidizers in coordination with changes in electron acceptor availability

• Published in: FEMS microbiology ecology Vol. 94; no. 7; p. 1
• Main Authors: Magnabosco, C, Timmers, A.P.H, Lau, Y.M.C, Borgonie, G, Linage-Alvarez, B, Kuloyo, O, Alleva, R, T.Kieft, L, Slater, F.G, Heerden, E. van, Lollar, B. Sherwood, Onstott, T.C
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01-07-2018
• Subjects: Microbial metabolism; Microbiological research; Oxidation-reduction reaction; South Africa
• ISSN: 0168-6496
• DOI: 10.1093/femsec/fy089

The concentrations of electron donors and acceptors in the terrestrial subsurface biosphere fuctuate due to migration and mixing of subsurface fluids, but the mechanisms and rates at which microbial communities respond to these changes are largely unknown. Subsurface microbial communities exhibit long cellular turnover times and are often considered relatively static--generating just enough ATP for cellular maintenance. Here, we investigated how subsurface populations of [CH.sub.4] oxidizers respond to changes in electron acceptor availability by monitoring the biological and geochemical composition in a 1339 m-below-land-surface (mbls) fluid-filled fracture over the course of both longer (2.5 year) and shorter (2-week) time scales. Using a combination of metagenomic, metatranscriptomic, and metaproteomic analyses, we observe that the [CH.sub.4] oxidizers within the subsurface microbial community change in coordination with electron acceptor availability over time. We then validate these findings through a series of ([.sup.13]C) -[CH.sub.4] laboratory incubation experiments, highlighting a connection between composition of subsurface [CH.sub.4] oxidizing communities and electron acceptor availability. Keywords: subsurface; metagenomics; archaea; methane oxidation