Microbial electrochemical platform for the production of renewable fuels and chemicals

The electrochemical conversion of CO2 and organic waste can combine renewable surplus electricity storage, CO2 utilization, and organic waste management. This review emphasizes the microbial electrochemical platform that merges electrochemical conversion and microbial conversion for the production of fuels and chemicals. In addition, this review examines methods to overcome limitations by the design of advanced reactor concepts, bioconversion with metabolic engineering, multiple-step catalysis, and anodic electro-oxidation reactions, among others. An in-depth discussion of trends is presented, including the interfacing of the classic carboxylate, syngas, and sugar platforms with microbial electrochemical technology. A critical assessment of microbial electrochemical biogas upgrading is also provided. Criticisms and perspectives related to electrobiorefineries and electro-fermentation for organic waste valorization are critically reviewed. The microbial electrochemical platform for the production of renewable fuels and chemicals is a recent application; thus, a number of concerns have yet to be resolved. Among the aspects to address are the increase in carbon fixation rate, production of highly valuable chemicals, response of physiological metabolism, and long-term assessment of scaled-up bioreactors. Insights into these factors may further increase the economic efficiency and sustainability of the technology.