Journal article
Metabolic associations with archaea drive shifts in hydrogen isotope fractionation in sulfate-reducing bacterial lipids in cocultures and methane seeps
Geobiology, v 13(5), pp 462-477
Sep 2015
PMID: 25923659
Abstract
Correlation between hydrogen isotope fractionation in fatty acids and carbon metabolism in pure cultures of bacteria indicates the potential of biomarker D/H analysis as a tool for diagnosing carbon substrate usage in environmental samples. However, most environments, in particular anaerobic habitats, are built from metabolic networks of micro-organisms rather than a single organism. The effect of these networks on D/H of lipids has not been explored and may complicate the interpretation of these analyses. Syntrophy represents an extreme example of metabolic interdependence. Here, we analyzed the effect of metabolic interactions on the D/H biosignatures of sulfate-reducing bacteria (SRB) using both laboratory maintained cocultures of the methanogen Methanosarcina acetivorans and the SRB Desulfococcus multivorans in addition to environmental samples harboring uncultured syntrophic consortia of anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing Deltaproteobacteria (SRB) recovered from deep-sea methane seeps. Consistent with previously reported trends, we observed a similar to 80 parts per thousand range in hydrogen isotope fractionation (epsilon(lipid-water)) for D.multivorans grown under different carbon assimilation conditions, with more D-enriched values associated with heterotrophic growth. In contrast, for cocultures of D.multivorans with M.acetivorans, we observed a reduced range of epsilon(lipid-water) values (similar to 36 parts per thousand) across substrates with shifts of up to 61 parts per thousand compared to monocultures. Sediment cores from methane seep settings in Hydrate Ridge (offshore Oregon, USA) showed similar D-enrichment in diagnostic SRB fatty acids coinciding with peaks in ANME/SRB consortia concentration suggesting that metabolic associations are connected to the observed shifts in epsilon(lipid-water) values.
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Details
- Title
- Metabolic associations with archaea drive shifts in hydrogen isotope fractionation in sulfate-reducing bacterial lipids in cocultures and methane seeps
- Creators
- K. S. Dawson (Corresponding Author) - California Institute of TechnologyM. R. Osburn - Northwestern UniversityA. L. Sessions - California Institute of TechnologyV. J. Orphan - California Institute of Technology
- Publication Details
- Geobiology, v 13(5), pp 462-477
- Publisher
- Wiley
- Number of pages
- 16
- Grant note
- NSF Graduate Fellowship; National Science Foundation (NSF) 3780 / Gordon and Betty Moore Foundation Marine Microbiology Initiative; Gordon & Betty Moore Foundation NNA09DA76A / Penn State Astrobiology Research Centre (through the NASA Astrobiology Institute) PSARC post-doctoral fellowship U.S. Department of Energy, Office of Biological and Environmental Research; United States Department of Energy (DOE) 1529120 / Division Of Earth Sciences; Directorate For Geosciences; National Science Foundation (NSF); NSF - Directorate for Geosciences (GEO)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Environmental Biogeochemistry
- Web of Science ID
- WOS:000358537300005
- Scopus ID
- 2-s2.0-84928541745
- Other Identifier
- 991022207144704721