PMID- 24739624 OWN - NLM STAT- MEDLINE DCOM- 20150310 LR - 20240325 IS - 1751-7370 (Electronic) IS - 1751-7362 (Print) IS - 1751-7362 (Linking) VI - 8 IP - 11 DP - 2014 Nov TI - Molecular and biogeochemical evidence for methane cycling beneath the western margin of the Greenland Ice Sheet. PG - 2305-16 LID - 10.1038/ismej.2014.59 [doi] AB - Microbial processes that mineralize organic carbon and enhance solute production at the bed of polar ice sheets could be of a magnitude sufficient to affect global elemental cycles. To investigate the biogeochemistry of a polar subglacial microbial ecosystem, we analyzed water discharged during the summer of 2012 and 2013 from Russell Glacier, a land-terminating outlet glacier at the western margin of the Greenland Ice Sheet. The molecular data implied that the most abundant and active component of the subglacial microbial community at these marginal locations were bacteria within the order Methylococcales (59-100% of reverse transcribed (RT)-rRNA sequences). mRNA transcripts of the particulate methane monooxygenase (pmoA) from these taxa were also detected, confirming that methanotrophic bacteria were functional members of this subglacial ecosystem. Dissolved methane ranged between 2.7 and 83 muM in the subglacial waters analyzed, and the concentration was inversely correlated with dissolved oxygen while positively correlated with electrical conductivity. Subglacial microbial methane production was supported by delta(13)C-CH4 values between -64 per thousand and -62 per thousand together with the recovery of RT-rRNA sequences that classified within the Methanosarcinales and Methanomicrobiales. Under aerobic conditions, >98% of the methane in the subglacial water was consumed over approximately 30 days incubation at approximately 4 degrees C and rates of methane oxidation were estimated at 0.32 muM per day. Our results support the occurrence of active methane cycling beneath this region of the Greenland Ice Sheet, where microbial communities poised in oxygenated subglacial drainage channels could serve as significant methane sinks. FAU - Dieser, Markus AU - Dieser M AD - Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA. FAU - Broemsen, Erik L J E AU - Broemsen EL AUID- ORCID: 000000028256156X AD - Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA. FAU - Cameron, Karen A AU - Cameron KA AD - Applied Physics Laboratory, Polar Science Center, University of Washington, Seattle, WA, USA. FAU - King, Gary M AU - King GM AD - Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA. FAU - Achberger, Amanda AU - Achberger A AD - Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA. FAU - Choquette, Kyla AU - Choquette K AD - Applied Science Engineering and Technology Laboratory, Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage, AK, USA. FAU - Hagedorn, Birgit AU - Hagedorn B AD - Applied Science Engineering and Technology Laboratory, Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage, AK, USA. FAU - Sletten, Ron AU - Sletten R AD - Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA. FAU - Junge, Karen AU - Junge K AD - Applied Physics Laboratory, Polar Science Center, University of Washington, Seattle, WA, USA. FAU - Christner, Brent C AU - Christner BC AD - Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA. LA - eng PT - Journal Article PT - Research Support, U.S. Gov't, Non-P.H.S. DEP - 20140417 PL - England TA - ISME J JT - The ISME journal JID - 101301086 RN - 0 (RNA, Ribosomal, 16S) RN - 059QF0KO0R (Water) RN - OP0UW79H66 (Methane) SB - IM MH - Bacteria/classification/genetics/isolation & purification MH - Ecosystem MH - Greenland MH - Ice Cover/*microbiology MH - Methane/*analysis MH - RNA, Ribosomal, 16S/genetics MH - Water/chemistry MH - *Water Microbiology PMC - PMC4992074 EDAT- 2014/04/18 06:00 MHDA- 2015/03/11 06:00 PMCR- 2015/11/01 CRDT- 2014/04/18 06:00 PHST- 2013/12/26 00:00 [received] PHST- 2014/03/08 00:00 [revised] PHST- 2014/03/14 00:00 [accepted] PHST- 2014/04/18 06:00 [entrez] PHST- 2014/04/18 06:00 [pubmed] PHST- 2015/03/11 06:00 [medline] PHST- 2015/11/01 00:00 [pmc-release] AID - ismej201459 [pii] AID - 10.1038/ismej.2014.59 [doi] PST - ppublish SO - ISME J. 2014 Nov;8(11):2305-16. doi: 10.1038/ismej.2014.59. Epub 2014 Apr 17.