Building efficient biocathodes with Acidithiobacillus ferrooxidans for the high current generation

Ganesan Sathiyanarayanan (1) , Nicolas Chabert (1, 2) , Joris Tulumello (1, 2) , Wafa Achouak (1)

1 LEMIRE - Laboratoire d'Ecologie Microbienne de la Rhizosphère et d'Environnements Extrêmes
2 Biointrant

The development of biocathodes is highly fascinating in microbial electrochemical technologies research. In this study, iron-oxidizing bacterium Acidithiobacillus ferrooxidans-based biocathodes were developed under the con-stant polarization of the electrochemical reactors at -0.2 V vs. Ag/AgCl with a pH of 2. On the 15th day of the 21-day batch experiment, A. ferrooxidans-based biocathode produced a maximum current density of-38.61 +/- 13.16 A m(-2) when the reactors were supplemented with 125 mM Fe2+ ions as an electron donor and 9 mM citrate as an iron chelator to buffer the iron-rich medium. Oxidation of Fe2+ to Fe3+ by A. ferrooxidans and its electrochemical regeneration at the cathode were mainly responsible for the high current generation. Furthermore, in the presence of iron, A. ferrooxidans develop a multi-layer biofilm on the cathode surface, which could potentially perform an indirect electron transfer mechanism.

Keywords: Biocathode; Acidithiobacillus ferrooxidans; Biofilm; Current density; Indirect electron transfer

Domains: Vegetal Biology

Ganesan Sathiyanarayanan, Nicolas Chabert, Joris Tulumello, Wafa Achouak. Building efficient biocathodes with Acidithiobacillus ferrooxidans for the high current generation. Journal of Power Sources, 2021, 514, pp.230586. ⟨10.1016/j.jpowsour.2021.230586⟩. ⟨cea-03534674⟩