Novel Electrochemically Active Bacterium Phylogenetically Related to Arcobacter butzleri , Isolated from a Microbial Fuel Cell

Abstract

ABSTRACT Exoelectrogenic bacteria are organisms that can transfer electrons to extracellular insoluble electron acceptors and have the potential to be used in devices such as microbial fuel cells (MFCs). Currently, exoelectrogens have been identified in the Alpha -, Beta -, Gamma - and Deltaproteobacteria , as well as in the Firmicutes and Acidobacteria . Here, we describe use of culture-independent methods to identify two members of the genus Arcobacter in the Epsilon p roteobacteria that are selectively enriched in an acetate-fed MFC. One of these organisms, Arcobacter butzleri strain ED-1, associates with the electrode and rapidly generates a strong electronegative potential as a pure culture when it is supplied with acetate. A mixed-community MFC in which ∼90% of the population is comprised of the two Arcobacter species generates a maximal power density of 296 mW/liter. This demonstration of exoelectrogenesis by strain ED-1 is the first time that this property has been shown for members of this genus.

Key findings

• ▸Exoelectrogenic bacteria have been identified in various bacterial groups, but not in the Epsilonproteobacteria until now.
• ▸The isolated bacterium, Arcobacter butzleri strain ED-1, exhibits strong electrochemical activity when supplied with acetate.
• ▸A mixed-community MFC with a population of ~90% Arcobacter species showed improved performance compared to a pure culture.

Keywords

Identifiers

DOI

10.1128/aem.01345-09

Journal

Applied and Environmental Microbiology

Year

2009