title: Preferential use of an anode as an electron acceptor by an acidophilic bacterium in the presence of oxygen.
abstract: Several anaerobic metal-reducing bacteria have been shown to be able to donate electrons directly to an electrode. This property is of great interest for microbial fuel cell development. To date, microbial fuel cell design requires avoiding O(2) diffusion from the cathodic compartment to the sensitive anodic compartment. Here, we show that Acidiphilium sp. strain 3.2 Sup 5 cells that were isolated from an extreme acidic environment are able to colonize graphite felt electrodes. These bacterial electrodes were able to produce high-density electrocatalytic currents, up to 3 A/m(2) at a poised potential of +0.15 V (compared to the value for the reference standard calomel electrode) in the absence of redox mediators, by oxidizing glucose even at saturating air concentrations and very low pHs.
authors.affiliation: Instituto de Catálisis, CSIC, c/Marie Curie 2, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Moustafa
authors.initials: M
authors.lastname: Malki
authors.forename: Antonio L
authors.initials: AL
authors.lastname: De Lacey
authors.forename: Nuria
authors.initials: N
authors.lastname: Rodríguez
authors.forename: Ricardo
authors.initials: R
authors.lastname: Amils
authors.forename: Victor M
authors.initials: VM
authors.lastname: Fernandez
mesh_terms: D041801:Acidiphilium / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D001674:Bioelectric Energy Sources; D004269:DNA, Bacterial / Q000302:isolation & purification; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004579:Electron Transport; D005290:Ferric Compounds / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006108:Graphite / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D017423:Sequence Analysis, RNA
chemical_list: D004269:DNA, Bacterial; D005290:Ferric Compounds; D012336:RNA, Ribosomal, 16S; D006108:Graphite; D005947:Glucose; D010100:Oxygen