CAREER: Engineering crop plants to metabolize products of CO2 electrolysis to enable food production with artificial photosynthesis

Plants capture sunlight and perform photosynthesis to drive plant growth. Biological photosynthesis is very energy inefficient. Therefore, large areas are required for food cultivation. Artificial photosynthesis is more energy efficient than natural photosynthesis but has never been used for food production. This project seeks to develop an interface between plants and artificial photosynthesis systems (APS). Once the interface has been developed, plants will be engineered to grow more efficiently utilizing APS augmentation. The research will be integrated with educational and outreach activities. These will include engaging undergraduates in labs focused on CO2 electrolysis and creating and running a ‘Startup Design Competition’ to encourage students to translate research results into entrepreneurial pursuits. Artificial photosynthesis has the potential to be much more energy efficient than biological photosynthesis but has not yet been applied to food production. A hybrid inorganic–biological artificial photosynthesis system for energy-efficient food production was recently developed. In a two-step process, CO2 electrolysis converts CO2 into acetate, which serves as a carbon and energy source for food producing organisms (algae, yeast, and mushrooms) grown in the dark. Coupling this system to commercial photovoltaics gives a solar energy-to-biomass energy conversion efficiency of ~4% for the growth of algae. Crop plants cannot currently be cultivated with CO2 electrolysis effluent as their sole carbon and energy source. Many knowledge gaps exist about plant metabolism of short chain carboxylic acids, alcohols, and aldehydes found in CO2 electrolysis effluent. The goals of this project are to discover how plants metabolize products of CO2 electrolysis and to engineer plant metabolism to better use these products as heterotrophic sources of carbon and energy. To achieve these goals the project has two main objectives: (1) engineer plants with improved acetate tolerance and utilization; and (2) discover how plants tolerate and metabolize other products of CO2 electrolysis. This project is being jointly supported by the Cellular and Biochemical Engineering (CBE) Program in ENG/CBET and by the Systems and Synthetic Biology (SSB) Program in BIO/MCB. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.