HR: 11:20h
AN: B52A-05    [Abstracts]
TI: Anaerobic Biodegradation of Pristane by Nitrate Reducing Bacteria
AU: * Dawson, K S
EM: kdawson@geosc.psu.edu
AF: Pennsylvania State University, Department of Geosciences, University Park, PA 16802, United States
AU: Freeman, K H
EM: kate@essc.psu.edu
AF: Pennsylvania State University, Department of Geosciences, University Park, PA 16802, United States
AU: Macalady, J L
EM: jmacalad@geosc.psu.edu
AF: Pennsylvania State University, Department of Geosciences, University Park, PA 16802, United States
AB: In recent sediments, microbial biodegradation provides a control on the long-term preservation of organic matter, through the preferential loss of certain biomolecules and the alteration and concentration of other more recalcitrant molecules. Biodegradation of hydrocarbons derived from membrane lipids, has been demonstrated by both aerobic and strictly anaerobic culturing experiments. The isoprenoid pristane, once considered stable under anaerobic conditions, is in fact degraded by a denitrifying microcosm (BREGNARD et al., 1997) and a methanogenic, sulphate-reducing enrichment culture (GROSSI, 2000). We recently demonstrated pristane biodegradation and accompanying loss of nitrate by an activated sludge isolate. The measured nitrate consumption accounts for a 7.1 +/- 0.4 mg loss of pristane, 4.74% of the initial substrate, in 181 days, assuming pristane conversion to CO₂. We have characterized the microorganisms active in the biodegradation process, through the creation of a 16S rDNA clone library, as well as fluorescence in situ hybridization (FISH). Experiments are in progress to enrich cultures of sulfate reducing bacteria that utilize pristane as a sole carbon source and to characterize reaction mechanisms in pristane-oxidizing pathways.
DE: 0400 BIOGEOSCIENCES
DE: 0404 Anoxic and hypoxic environments (4802, 4834)
DE: 0432 Contaminant and organic biogeochemistry (0792)
DE: 0448 Geomicrobiology
SC: Biogeosciences [B]
MN: 2007 Fall Meeting