Electron transfer processes between microbes and electrodes in bioelectrochemical reactors

Over a century ago, researchers observed that certain microorganisms generate electrical current. This led to the discovery of dozens, if not hundreds of electroactive microbes able to produce and/or consume electrical current. In recent decades, electroactive microbes have been explored as biocatalysts in bioelectrochemical systems at laboratory scales. Today, we are on the precipice of deploying these systems at industrial scales for bio-commodity production, energy generation, bioremediation, and more. However, challenges remain before this is feasible. Among these are the electron transfer rates between microbes and electrodes, product yields, and bioreactor design, all of which affect economic feasibility and scalability. Therefore, it is important to take stock of where we are now with respect to microbe–electrode interactions in bioelectrochemical systems and assess future directions. This chapter explores the current state of knowledge regarding topics related to electron transfer processes in bioelectrochemical systems while providing perspectives about the future of these technologies.