HR: 0800h
AN: B11C-0620    [Abstracts]
TI: Electrochemical Performance and Microbial Characterization of Thermophilic Microbial Fuel Cells
AU: * Wrighton, K C
EM: kwrighton@berkeley.edu
AF: Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, United States
AU: Agbo, P
EM: pagbo@berkeley.edu
AF: Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, United States
AU: Brodie, E L
EM: elbrodie@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Weber, K A
EM: kweber@nature.berkeley.edu
AF: Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, United States
AU: DeSantis, T Z
EM: tdesantis@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Anderson, G L
EM: glanderson@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, United States
AU: Coates, J D
EM: jcoates@nature.berkeley.edu
AF: Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, United States
AB: Significant research effort is currently focused on microbial fuel cells (MFC) as a source of renewable energy. To date, most of these efforts have concentrated on MFCs operating at mesophilic temperatures. However, many previous studies have reported on the superiority of thermophilic conditions in anaerobic digestion and demonstrated a net gain in energy yield, in terms of methane, relative to the increased energy requirements of operation. Because of this, our recent studies on MFCs focused on investigating the operation and microbiology associated with thermophilic MFCs operating at 55°C. Over 100-day operation, these MFCs were highly stable and achieved a maximum power density of 24mW/m2 and a columbic efficiency of 89 percent with acetate as the sole electron donor. In order to characterize the microbial community involved in thermophilic electricity generation, DNA and RNA were isolated from the electrode and PhyloChip analyses performed. Exploring the changes in the microbial community over time in electricity producing MFC revealed an increase in relative abundance of populations belonging to the Firmicutes, Chloroflexi, and alpha Proteobacteria by at least one order of magnitude. In contrast, these populations decreased in the open circuit and no electron donor amended controls. In order to better characterize the active microbial populations, we enriched and isolated a novel organism, strain JR, from samples collected from an operating MFC. Based on 16S rRNA sequence analysis strain JR was a member of the family Peptococcaceae, within the Phylum Firmicutes, clustering with Thermincola ferriacetica (98 percent similarity). Phenotypic characterization revealed that strain JR was capable of thermophilic dissimilatory reduction of insoluble electron acceptors such as amorphous Fe(III); as well as reduction of the model quinone 2,6-anthraquinone disulfonate. Thermincola strain JR was also capable of producing current by coupling acetate oxidation to anodic electron transfer. This represents the first organism isolated from a thermophilic microbial fuel cell and also the first representative of this genus capable of anodic electron transfer. The results of this study indicate the potential advantages for thermophilic MFCs and the novel microbiology associated with their operation.
DE: 0410 Biodiversity
DE: 0448 Geomicrobiology
DE: 0456 Life in extreme environments
DE: 0463 Microbe/mineral interactions
DE: 0465 Microbiology: ecology, physiology and genomics (4840)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting