Methane assimilation and trophic interactions with marine Methylomicrobium in deep-water coral reef sediment off the coast of Norway

• Published in: FEMS Microbiology Ecology
• Main Authors: Jensen, Sigmund, Neufeld, Josh D., Birkeland, Nils-Kare, Hovland, M. (Martin), Murrell, J. C. (J. Colin)
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Wiley-Blackwell Publishing Ltd. 2008
• Subjects: QP Physiology; QR Microbiology; Norway; Lophelia pertusa
• Online Access: http://wrap.warwick.ac.uk/29191/; https://doi.org/10.1111/j.1574-6941.2008.00575.x

Deep-water coral reefs are seafloor environments with diverse biological communities surrounded by cold permanent darkness. Sources of energy and carbon for the nourishment of these reefs are presently unclear. We investigated one aspect of the food web using DNA stable-isotope probing (DNA-SIP). Sediment from beneath a Lophelia pertusa reef off the coast of Norway was incubated until assimilation of 5 mu mol (CH4)-C-13 g(-1) wet weight occurred. Extracted DNA was separated into 'light' and 'heavy' fractions for analysis of labelling. Bacterial community fingerprinting of PCR-amplified 16S rRNA gene fragments revealed two predominant C-13-specific bands. Sequencing of these bands indicated that carbon from (CH4)-C-13 had been assimilated by a Methylomicrobium and an uncultivated member of the Gammaproteobacteria. Cloning and sequencing of 16S rRNA genes from the heavy DNA, in addition to genes encoding particulate methane monooxygenase and methanol dehydrogenase, all linked Methylomicrobium with methane metabolism. Putative cross-feeders were affiliated with Methylophaga (Gammaproteobacteria), Hyphomicrobium (Alphaproteobacteria) and previously unrecognized methylotrophs of the Gammaproteobacteria, Alphaproteobacteria, Deferribacteres and Bacteroidetes. This first marine methane SIP study provides evidence for the presence of methylotrophs that participate in sediment food webs associated with deep-water coral reefs.