title: Comparison of Anodic Community in Microbial Fuel Cells with Iron Oxide-Reducing Community.
abstract: The group of Fe(III) oxide-reducing bacteria includes exoelectrogenic bacteria, and they possess similar properties of transferring electrons to extracellular insoluble-electron acceptors. The exoelectrogenic bacteria can use the anode in microbial fuel cells (MFCs) as the terminal electron acceptor in anaerobic acetate oxidation. In the present study, the anodic community was compared with the community using Fe(III) oxide (ferrihydrite) as the electron acceptor coupled with acetate oxidation. To precisely analyze the structures, the community was established by enrichment cultures using the same inoculum used for the MFCs. High-throughput sequencing of the 16S rRNA gene revealed considerable differences between the structure of the anodic communities and that of the Fe(III) oxide-reducing community. Geobacter species were predominantly detected (>46%) in the anodic communities. In contrast, Pseudomonas (70%) and Desulfosporosinus (16%) were predominant in the Fe(III) oxide-reducing community. These results demonstrated that Geobacter species are the most specialized among Fe(III)-reducing bacteria for electron transfer to the anode in MFCs. In addition, the present study indicates the presence of a novel lineage of bacteria in the genus Pseudomonas that highly prefers ferrihydrite as the terminal electron acceptor in acetate oxidation.
authors.affiliation: Animal Waste Management and Environment Division, NARO Institute of Livestock and Grassland Science, Tsukuba 305-0901, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokoyama
authors.affiliation: Animal Waste Management and Environment Division, NARO Institute of Livestock and Grassland Science, Tsukuba 305-0901, Japan.
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Ishida
authors.affiliation: Animal Waste Management and Environment Division, NARO Institute of Livestock and Grassland Science, Tsukuba 305-0901, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamashita
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D004566:Electrodes; D004579:Electron Transport; D005290:Ferric Compounds / Q000378:metabolism*; D045302:Geobacter / Q000235:genetics / Q000378:metabolism; D059014:High-Throughput Nucleotide Sequencing; D059013:Microbial Consortia / Q000235:genetics / Q000502:physiology*; D010084:Oxidation-Reduction; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D005290:Ferric Compounds; D012336:RNA, Ribosomal, 16S; C000499:ferric oxide; C092844:ferric oxyhydroxide
keywords: acetate oxidation; community structure; dissimilatory Fe(III) reduction; microbial fuel cell; sulfate reduction