Exploring the Molecular Mechanisms of Extracellular Electron Transfer for Harnessing Reducing Power in METs: Methodologies and Approaches

Abstract The development of microbial electrochemical technologies (METs) rests on the deep knowledge of the extracellular electron transfer (EET) processes performed by electroactive organisms. These organisms are responsible for energy harnessing, bioremediation, and production of added-value products in these systems. It is now well recognized that multiheme c -type cytochromes (MHCs) play key roles in the processes of EET. However, given the complexity of these proteins, the understanding of the mechanisms underlying EET processes that rule microbial electroactivity requires a multidisciplinary approach that includes various areas of research, including molecular biology, biophysics, biochemistry, spectroscopy, and electrochemistry. This chapter describes the methodologies and approaches that have been used so far to explore, at the molecular level, the electron transfer processes performed by the proteins involved in EET, mainly of the MHCs, with the aim of determining the distinct aspects required for harnessing reducing power in METs.