This study assessed the conductivity of a Geobacter-enriched biofilm anode along with biofilm activity in a microbial electrochemical cell (MxC) equipped with two gold anodes (25 mM acetate medium), as different proton gradients were built throughout the biofilm. There was no pH gradient across the biofilm anode at 100 mM phosphate buffer (current density 2.38 A/m2) and biofilm conductivity (Kbio) was as high as 0.87 mS/cm. In comparison, an inner biofilm became acidic at 2.5 mM phosphate buffer in which approximately 80 μm of the inner biofilm anode was metabolically inactive. At this low phosphate buffer, Kbio significantly decreased by 0.27 mS/cm, together with declined current density of 0.64 A/m2. This work demonstrates that biofilm conductivity depends on metabolic activity of Geobacter in the conductive biofilm anode. The decreased Kbio at acidic environment implies the presence of multiple conduction-EET pathways in the biofilm anode.

This dataset is associated with the following publication: Dhar, B., J. Sim, H. Ryu, H. Ren, J. Santodomingo, J. Chae, and H. Lee. Microbial Activity Influences Electrical Conductivity of Biofilm Anode. WATER RESEARCH. Elsevier Science Ltd, New York, NY, USA, 127: 230-238, (2017).