(307h) Interfacing Electrochemical and Biological Processes Enables Efficient Bioproducts Synthesis from Carbon Dioxide

Biological carbon fixation approaches, such as photosynthesis and microbial autotroph, could convert carbon dioxide to nutrients and commodity chemicals. However, these processes are constrained by their limited efficiency. Integrating electrochemical and biological synthetic pathways can overcome the carbon fixation barrier and convert CO₂ to diverse categories of high-value chemicals. By leveraging the high reaction rate of chemical catalysis and carbon assimilation design through synthetic biology, we have successfully used CO₂ as the sole carbon source to produce bioplastics polyhydroxyalkanoates (PHA) with significantly improved productivity and efficiency. We systematically analyzed electrochemical and biological processes and spotted the most favorable intermediates for energy/electron/mass transfer. Then, we implemented a four-tier design of the electrolyzer, catalysts, electrode-biological interface, and synthetic biology, which successfully enabled bio-compatible CO₂ electroreduction under industrial-related current density and integrated the electrochemical CO₂ reduction and the microbial conversion. The new chem-bio hybrid process has significantly overcome the individual limitations of chemical catalysis and biological conversion, achieved continuous electrotrophic CO₂ transformation, and created novel platforms for future diverse biomolecules production from CO₂ with improved carbon conversion efficiency.