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Electron Transfer Mechanisms in Biofilms

EMSL Project ID


Although interactions of microorganisms with electrodes have been studied in the literature, the mechanisms of electron transfer are still poorly understood. The goal of this proposal is to investigate electron transfer mechanisms in biofilms growing on electrode surfaces acting as anodes using nuclear magnetic resonance (NMR) spectroscopy and imaging techniques (for cathodic and anodic biofilms). This research will use laboratory and field biofilms. In the laboratory we will use 1) Shewanella oneidensis (MR-1) and 2) Geobacter sulfurreducens for anodic biofilms. However, we will also use anodic and cathodic biofilms from the Palouse River. The proposed project will quantify metabolic gradients in anodic biofilms. Later, these metabolic gradients will be correlated with chemical and redox gradients measured with microelectrodes. The project will demonstrate how biochemical and electrochemical activities vary by depth of biofilms and their dependence on electrode potential and electron transfer rate.
This proposal addresses the development and implementation of NMR to microbial fuel cell research to understand electron transfer mechanism in anodic biofilms. A NMR compatible microbial fuel cell will be used to characterize metabolite concentrations (lactate, acetate, and pyruvate) and alternative electron acceptor concentration (fumarate). NMR data will be combined with the electrochemical and microsensors data produced at Washington State University to investigate electron transfer mechanisms in anodic biofilms growing on electrode surfaces.
This proposal requests NMR time needed for a funded proposal by ONR. In addition we request CryoTEM to investigate electrode-cell interactions and to determine exact locations of the cells on the electrode surfaces.

Project Details

Project type
Large-Scale EMSL Research
Start Date
End Date


Principal Investigator

Haluk Beyenal
Washington State University

Team Members

Jerome Babauta
Washington State University

Bin Cao
Nanyang Technological University

Ryan Renslow
Pacific Northwest National Laboratory

Paul Majors
Washington State University