Characterization of the thermophilic anode-respiring Thermincola ferriacetica

Thermincola ferriacetica, a thermophilic, Gram-positive bacterium was recently shown to transfer electrons from oxidation of acetate to an anode. We are conducting a comprehensive characterization of T. ferriacetica strain Z-0001. This strain was grown at 55°C on graphite rods poised at 0 V vs. SHE, in a single-chamber microbial electrolysis cell, and fed with 25 mM phosphate buffer medium containing 20 mM acetate. These conditions resulted in current densities up to 3.5 A m ^-2. The first derivatives of cyclic voltammetry scans revealed a catalytic wave with a midpoint potential of -0.152 V vs. SHE, similar to the Nernst-Monod E _KA for Geobacter sulfurreducens. We will next determine the effect of temperature and buffer concentration on current densities and characterize the substrate range for this strain. The development of thermophilic microbial electrochemical cells may provide an opportunity for recovering energy while treating high temperature wastewaters, such as those from food processing industries.