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

Area of Science:

• Biotechnology
• Photocatalysis
• Synthetic Biology

Background:

• Sustainable conversion of carbon dioxide (CO2) into value-added chemicals using solar energy is a significant challenge.
• Existing methods often require sacrificial agents or lack efficiency in solar-driven synthesis.

Purpose of the Study:

• To develop a sustainable biohybrid system for light-driven succinic acid production from CO2 and water.
• To integrate Z-scheme photocatalysts with engineered microbial consortia for efficient carbon fixation and chemical synthesis.

Main Methods:

• A biohybrid system combining Escherichia coli biofilms for photoelectrochemical CO2 reduction to formate and Vibrio natriegens for formate upgrading to succinic acid was constructed.
• The system utilized Z-scheme photocatalysts and engineered microbial consortia without sacrificial agents.
• Adaptive evolution was employed for V. natriegens to enhance formate utilization.

Main Results:

• The biohybrid system produced 0.06 mM succinic acid in 6 hours with an apparent quantum yield of 0.154%.
• Biofilms maintained stable contact with photocatalysts over four cycles, and V. natriegens viability increased by 11%.
• Isotopic tracing confirmed approximately 20% carbon incorporation from CO2 into the synthesized product.

Conclusions:

• This work establishes a sustainable platform for solar-driven multicarbon synthesis.
• The rational integration of photocatalysis and synthetic microbial consortia offers a promising approach for CO2 valorization.
• The developed system demonstrates efficient and sustainable production of succinic acid from CO2 using renewable energy.