title: A bioelectrochemical approach to characterize extracellular electron transfer by Synechocystis sp. PCC6803.
abstract: Biophotovoltaic devices employ photosynthetic organisms at the anode of a microbial fuel cell to generate electrical power. Although a range of cyanobacteria and algae have been shown to generate photocurrent in devices of a multitude of architectures, mechanistic understanding of extracellular electron transfer by phototrophs remains minimal. Here we describe a mediatorless bioelectrochemical device to measure the electrogenic output of a planktonically grown cyanobacterium, Synechocystis sp. PCC6803. Light dependent production of current is measured, and its magnitude is shown to scale with microbial cell concentration and light intensity. Bioelectrochemical characterization of a Synechocystis mutant lacking Photosystem II demonstrates conclusively that production of the majority of photocurrent requires a functional water splitting aparatus and electrons are likely ultimately derived from water. This shows the potential of the device to rapidly and quantitatively characterize photocurrent production by genetically modified strains, an approach that can be used in future studies to delineate the mechanisms of cyanobacterial extracellular electron transport.
authors.affiliation: Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America.
authors.forename: Angelo
authors.initials: A
authors.lastname: Cereda
authors.affiliation: Ocean and Earth Sciences, University of Southampton, Southampton, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: Hitchcock
authors.affiliation: School of Chemistry, The University of Glasgow, Glasgow, United Kingdom.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Symes
authors.affiliation: School of Chemistry, The University of Glasgow, Glasgow, United Kingdom.
authors.forename: Leroy
authors.initials: L
authors.lastname: Cronin
authors.affiliation: Ocean and Earth Sciences, University of Southampton, Southampton, United Kingdom.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Bibby
authors.affiliation: Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America.
authors.forename: Anne K
authors.initials: AK
authors.lastname: Jones
mesh_terms: D004563:Electrochemistry; D004579:Electron Transport; D005110:Extracellular Space / Q000378:metabolism*; D010084:Oxidation-Reduction; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D046939:Synechocystis / Q000378:metabolism*
chemical_list: D045332:Photosystem II Protein Complex