Comparative study on bacterial carbon sources in lake sediments: the role of methanotrophy
Steger, K.; Premke, K.; Gudasz, C.; Boschker, H.T.S.; Tranvik, L.J. (2015). Comparative study on bacterial carbon sources in lake sediments: the role of methanotrophy. Aquat. Microb. Ecol. 76: 39–47. dx.doi.org/10.3354/ame01766 In: Aquatic Microbial Ecology. Inter-Research: Oldendorf/Luhe. ISSN 0948-3055; e-ISSN 1616-1564, more |   |
| Author keywords | Benthic microbes; Boreal lakes; Methanotrophic bacteria; Phospholipid-derived fatty acid; PLFA; Stable isotopes |
| Authors | | Top | - Steger, K.
- Premke, K.
- Gudasz, C.
| - Boschker, H.T.S., more
- Tranvik, L.J.
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| Abstract | Methane-derived carbon can be important in both benthic and pelagic food webs.Either generated in the anaerobic layers of the sediment or in the anaerobic hypolimnion of stratifiedeutrophic lakes, methane is an excellent carbon source for aerobic methanotrophic bacteria.The very negative methane d13C-signal in the methanotrophic biomass provides an excellentopportunity to trace the use of methane-derived carbon in food webs. We studied carbon sourcesof benthic bacteria in a range of Swedish lakes with different inputs of terrestrial organic carbonand indigenous primary production. We analyzed the 13C:12C ratios in phospholipid-derived fattyacids, which serve as biomarkers for specific groups of Bacteria. We demonstrate that methane isan important carbon source for sediment bacteria, not only for the methanotrophic community butalso for the non-methanotrophic heterotrophic bacteria. This most likely indirect utilization of isotopicallyhighly depleted methane masks the stable isotope signatures for terrestrial input andlocal primary production in the heterotrophic bacterial community. |
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