title: Electrochemically active biofilms: facts and fiction. A review.
abstract: This review examines the electrochemical techniques used to study extracellular electron transfer in the electrochemically active biofilms that are used in microbial fuel cells and other bioelectrochemical systems. Electrochemically active biofilms are defined as biofilms that exchange electrons with conductive surfaces: electrodes. Following the electrochemical conventions, and recognizing that electrodes can be considered reactants in these bioelectrochemical processes, biofilms that deliver electrons to the biofilm electrode are called anodic, ie electrode-reducing, biofilms, while biofilms that accept electrons from the biofilm electrode are called cathodic, ie electrode-oxidizing, biofilms. How to grow these electrochemically active biofilms in bioelectrochemical systems is discussed and also the critical choices made in the experimental setup that affect the experimental results. The reactor configurations used in bioelectrochemical systems research are also described and the authors demonstrate how to use selected voltammetric techniques to study extracellular electron transfer in bioelectrochemical systems. Finally, some critical concerns with the proposed electron transfer mechanisms in bioelectrochemical systems are addressed together with the prospects of bioelectrochemical systems as energy-converting and energy-harvesting devices.
authors.affiliation: The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA.
authors.forename: Jerome
authors.initials: J
authors.lastname: Babauta
authors.forename: Ryan
authors.initials: R
authors.lastname: Renslow
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Lewandowski
authors.forename: Haluk
authors.initials: H
authors.lastname: Beyenal
mesh_terms: D001674:Bioelectric Energy Sources; D018441:Biofilms; D055664:Electrochemical Techniques; D004579:Electron Transport; D008956:Models, Chemical