Light-Driven C₄ Biosynthesis from CO₂ and H₂O via Engineered Photocatalyst-Microbial Consortia

The development of sustainable technologies for converting CO₂ into value-added chemicals using solar energy remains a critical challenge. We presented a biohybrid system integrating Z-scheme photocatalysts with engineered microbial consortia for light-driven succinic acid production from CO₂ and H₂O without sacrificial agents. The system combined Escherichia coli biofilms expressing formate dehydrogenase for photoelectrochemical CO₂ reduction to formate with adaptively evolved Vibrio natriegens for formate upgrading to succinic acid. This configuration achieved 0.06 mM succinic acid in 6 h with an apparent quantum yield of 0.154%. The biofilms maintained conformal contact with photocatalysts through four operational cycles, while V. natriegens viability increased by 11% owing to the formate provided by the biohybrid sheet. Further, isotopic tracing revealed approximately 20% carbon incorporation from CO₂. This work establishes a sustainable platform for solar-driven multicarbon synthesis through rational integration of photocatalysis and synthetic microbial consortia.