Structural and δ13C Analyses of Bacterial Phospholipids in Marine Sediments Beneath the Ross Ice Sheet, Antarctica
Abstract
Bacterial biomass estimates were calculated using phospholipid fatty acid (PLFA) concentrations and by Acridine Orange direct cell counts (AODC) for marine sediments ranging from 0-155cm below sea floor of the Ross Sea, Antarctica. Both biomass estimates were then compared to evaluate the accuracy of each method. Structural and δ13C analysis of the PLFAs will also be determined to identify changes in the microbial composition with sediment depth. δ13C values of PLFAs will reflect the δ13C of the source carbon, as well as the isotopic fractionation associated with carbon assimilation and lipid synthetic pathways. Therefore, δ13CPLFA values will be compared to the pore water chemistry (eg. SO42-, HS- and NH4+ and δ13C values of sedimentary organic matter and porewater HCO3-, to infer the changes in microbial metabolic pathways with sediment depth.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.B51C0392C
- Keywords:
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- 0424 Biosignatures and proxies;
- 0428 Carbon cycling (4806);
- 0448 Geomicrobiology;
- 0456 Life in extreme environments