Toward Solar-Powered Growth of Autotrophic Escherichia coli Using Photoelectrochemistry

Area of Science:

• Biotechnology and Synthetic Biology
• Renewable Energy Systems
• Carbon Capture and Utilization

Background:

• Microbial carbon fixation is crucial for sustainable biomanufacturing but faces challenges in integrating renewable energy.
• Efficiently converting carbon dioxide (CO2) into usable energy sources for microorganisms is a key hurdle.

Purpose of the Study:

• To develop a biohybrid system for direct solar-powered CO2-to-biomass conversion.
• To engineer autotrophic Escherichia coli (E. coli) for efficient formate utilization as an energy source.
• To create a functional platform that couples artificial photosynthesis with microbial carbon fixation.

Main Methods:

• Adaptive laboratory evolution to enhance formate consumption in E. coli.
• Development of an enzyme-modified cathode for electrochemical CO2 reduction to formate.
• Construction of a biophotoelectrochemical device using simulated sunlight.
• Integration of a semiartificial leaf with engineered E. coli.

Main Results:

• Enhanced E. coli strain demonstrated improved autotrophic growth using formate.
• Successful direct microbial growth using electrochemically generated formate from CO2.
• Demonstrated solar-driven CO2 conversion to biomass via the biohybrid system.
• The integrated platform achieved CO2 fixation and oxygen evolution, mimicking natural photosynthesis.

Conclusions:

• The developed biohybrid system offers a novel approach for carbon-neutral biomanufacturing by directly converting solar energy and CO2 into biomass.
• This work demonstrates the potential of coupling artificial photosynthesis with engineered microorganisms for sustainable production.
• The engineered E. coli and biohybrid device represent a significant step towards artificial photosynthesis and carbon-negative technologies.