title: Quantification of effective exoelectrogens by most probable number (MPN) in a microbial fuel cell.
abstract: The objective of this work was to quantify the number of exoelectrogens in wastewater capable of producing current in a microbial fuel cell by adapting the classical most probable number (MPN) methodology using current production as end point. Inoculating a series of microbial fuel cells with various dilutions of domestic wastewater and with acetate as test substrate yielded an apparent number of exoelectrogens of 17perml. Using current as a proxy for activity the apparent exoelectrogen growth rate was 0.03h(-1). With starch or wastewater as more complex test substrates similar apparent growth rates were obtained, but the apparent MPN based numbers of exoelectrogens in wastewater were significantly lower, probably because in contrast to acetate, complex substrates require complex food chains to deliver the electrons to the electrodes. Consequently, the apparent MPN is a function of the combined probabilities of members of the food chain being present.
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Heidrich
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Curtis
authors.affiliation: School of Mathematical Sciences, University of Technology Sydney, Sydney, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Woodcock
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK. Electronic address: jan.dolfing@ncl.ac.uk.
authors.forename: Jan
authors.initials: J
authors.lastname: Dolfing
mesh_terms: D000085:Acetates / Q000737:chemistry; D058491:Bacterial Load / Q000592:standards; D001674:Bioelectric Energy Sources; D055664:Electrochemical Techniques / Q000592:standards; D004566:Electrodes; D011336:Probability; D013213:Starch / Q000737:chemistry; D018505:Waste Management / Q000379:methods / Q000592:standards; D062065:Wastewater / Q000382:microbiology*
chemical_list: D000085:Acetates; D013213:Starch; D062065:Wastewater
keywords: Inoculation; Microbial fuel cell; Most probable number; Wastewater treatment