Enhancement of Butanol Production: From Biocatalysis to Bioelectrocatalysis

Butanol from renewable biomass is a promising advanced biofuel that can be used as an optimal substitute for gasoline in the transportation sectors, and therefore, large-scale industrial production of biobutanol has great importance to the development of sustainable energy. However, the low bioproductivity of butanol is a big challenge, despite great progress in metabolic engineering and bioprocessing. More importantly, butanol biosynthesis is mainly a consequence of anaerobic transformations catalyzed by specific oxidoreductases and driven by the reducing power; thus, both redox metabolism and electron transfer determine the efficiency of butanol bioconversion. In this Perspective, we highlight the significance of redox balance and electron transfer or energy conversion as a foundation to propose a strategy toward high butanol production from biocatalysis to bioelectrocatalysis. Potential challenges and future directions in the upcoming years are discussed from a bioelectrochemical perspective.