Cathodic biofilms – A prerequisite for microbial electrosynthesis

Abstract

Cathodic biofilms have an important role in CO2 bio-reduction to carboxylic acids and biofuels in microbial electrosynthesis (MES) cells. However, robust and resilient electroactive biofilms for an efficient CO2 conversion are difficult to achieve. In this review, the fundamentals of cathodic biofilm formation, including energy conservation, electron transfer and development of catalytic biofilms, are presented. In addition, strategies for improving cathodic biofilm formation, such as the selection of electrode and carrier materials, cell design and operational conditions, are described. The knowledge gaps are individuated, and possible solutions are proposed to achieve stable and productive biofilms in MES cathode

I.V. and M.K. acknowledge the funding from Academy of Finland (grant numbers 316657, 319910, 346046, and 329227). P.D. acknowledges the funding from Science Foundation Ireland (SFI) Pathfinder Award on “Hybrid Bio-Solar Reactors for wastewater treatment and CO2 recycling” (award nr. 19/FIP/ZE/7572PF). S.P. is a Serra Hunter Fellow (UdG-AG-575) and acknowledges the funding from the ICREA Academia award and the Spanish Ministry of Science and Innovation (RTI2018-098360-B-I00 and PLEC2021-007802). LEQUIA has been recognized as a consolidated research group by the Catalan Government (2017-SGR-1552)