HR: 14:15h
AN: B23C-03    [Abstracts]
TI: The plume fringe concept - Biodegradation of organic contaminants in subsurface ecosystems
AU: * Meckenstock, R U
EM: rainer.meckenstock@gsf.de
AF: GSF Institute of Groundwater Ecology, Ingolst�dter Landstr. 1, Neuherberg, 85764 Germany
AU: Griebler, C
EM: christian.griebler@gsf.de
AF: GSF Institute of Groundwater Ecology, Ingolst�dter Landstr. 1, Neuherberg, 85764 Germany
AU: Anneser, B
EM: bettina.anneser@gsf.de
AF: GSF Institute of Groundwater Ecology, Ingolst�dter Landstr. 1, Neuherberg, 85764 Germany
AU: Winderl, C
EM: christian.winderl@gsf.de
AF: GSF Institute of Groundwater Ecology, Ingolst�dter Landstr. 1, Neuherberg, 85764 Germany
AU: Bauer, R
EM: robert.bauer@gsf.de
AF: GSF Institute of Groundwater Ecology, Ingolst�dter Landstr. 1, Neuherberg, 85764 Germany
AU: L�ders, T
EM: tillmann.lueders@gsf.de
AF: GSF Institute of Groundwater Ecology, Ingolst�dter Landstr. 1, Neuherberg, 85764 Germany
AU: Kellermann, C
EM: claudia.kellermann@gsf.de
AF: GSF Institute of Groundwater Ecology, Ingolst�dter Landstr. 1, Neuherberg, 85764 Germany
AU: Selesi, D
EM: drazenka.selesi@gsf.de
AF: GSF Institute of Groundwater Ecology, Ingolst�dter Landstr. 1, Neuherberg, 85764 Germany
AB: The biodegradation of organic pollutants in groundwater systems may be limited by the depletion of essential nutrients or the low number of degraders. However, the main problem seems to be the insufficient mixing of e-donors and e-acceptors. Main degradation activities in contaminant plumes are therefore located at their fringes. In order to investigate the ecology of pollutant-degrading microbes, experiments are carried out (1) in 2D-aquifer model systems and (2) sediment cores were drilled at a former gasworks site and a novel high-resolution multilevel sampling well was installed. (1) To assess the importance of individual abiotic (e.g. mixing, toxicity, nutrients) and biotic (e.g. cell distribution and activity, redox tolerance) parameters for biodegradation under well controlled lab conditions, contaminant plumes are generated in 2D-model systems and subsequently inoculated with aerobic and/or anaerobic bacterial strains to investigate biodegradation in a spatially resolved manner. (2) To recognize limitations of biodegradation in a PAH-contaminated aquifer, sediment cores were taken and, at the same site, a high-resolution multilevel well was installed for frequent groundwater sampling with varying spatial resolution (from cm to m range). In both systems, degradation of contaminants is followed by vertically resolved concentration measurements, compound-specific stable isotope (D/H, 13C/12C) analysis and the identification of signature metabolites. Physical-chemical gradients are resolved by means of microsensors and geochemical sediment and water analysis. The spatial distribution of microbial biomass, individual groups of microbes and the presence of functional genes coding for potential degradation activities are investigated using molecular tools. First results of the work, which is embedded in two current projects, will be discussed.
DE: 0409 Bioavailability: chemical speciation and complexation
DE: 0418 Bioremediation
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0448 Geomicrobiology
DE: 0465 Microbiology: ecology, physiology and genomics (4840)
SC: Biogeosciences [B]
MN: Fall Meeting 2005