Methane-Consuming Archaea Revealed by Directly Coupled Isotopic and Phylogenetic Analysis
Abstract
Microorganisms living in anoxic marine sediments consume more than 80% of the methane produced in the world's oceans. In addition to single-species aggregates, consortia of metabolically interdependent bacteria and archaea are found in methane-rich sediments. A combination of fluorescence in situ hybridization and secondary ion mass spectrometry shows that cells belonging to one specific archaeal group associated with the Methanosarcinales were all highly depleted in ^(13)C (to values of –96‰). This depletion indicates assimilation of isotopically light methane into specific archaeal cells. Additional microbial species apparently use other carbon sources, as indicated by significantly higher ^(13)C/^(12)C ratios in their cell carbon. Our results demonstrate the feasibility of simultaneous determination of the identity and the metabolic activity of naturally occurring microorganisms.
Additional Information
© 2001 American Association for the Advancement of Science. Received 4 April 2001; accepted 5 June 2001. We thank C. Paull (MBARI) and W. Ussler (MBARI) for graciously supplying the δ^(13)C of CH_4 data used in this study and M. Harrison (UCLA) for support during the development of this new ion microprobe application. We would also like to thank K. Buck (MBARI), S. Goffredi (MBARI), and the crew of the R/V Western Flyer and ROV Tiburon for their invaluable assistance with this research and C. Coath (UCLA), W. Bach (WHOI), K. Freeman (PSU), P. Girguis (MBARI), O. Beja (MBARI), for stimulating discussions and helpful advice during this project. Funding for this project was provided by the David and Lucile Packard Foundation, the Penn State Astrobiology Research Center and the University of California, Los Angeles, Center for Astrobiology, NASA National Astrobiology Institute. The UCLA ion microprobe is partially supported by a grant from the National Science Foundation Instrumentation and Facilities Program.Additional details
- Eprint ID
- 37841
- Resolver ID
- CaltechAUTHORS:20130410-080805831
- David and Lucile Packard Foundation
- Penn State Astrobiology Research Center (PSARC)
- UCLA Center for Astrobiology
- NASA
- NSF
- Created
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2013-04-15Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences