SOLARSPOON · Solar-driven synthesis of proteins and lipids via photoelectrochemistry of living organisms

Biohybrid systems offer unique energy-efficient routes to harness solar energy for the fixation of CO2 and nitrogen into valuable, complex molecules. This project will integrate living photosynthetic bacteria and food-producing autotrophic bacteria into stand-alone photoelectrochemical devices tailored for the direct production of proteins and lipids from sunlight, air and water. Cyanobacteria will supply electrons via light-driven water oxidation, organic dyes will provide these electrons with sufficient energy to generate substrates that would directly feed either a culture or a consortia of food producing microorganisms in the same device. The result will be the demonstration of the first direct conversion of CO2 and N2 from air to protein- or lipid-rich food materials using solar energy, with the aim to produce a prototype that can reach 1% solar-conversion efficiency or surpass present food production processes via agriculture.Our bioengineering efforts will focus on three key innovations: (i) overcoming complex electron transfer pathway barriers at the cell-electrode interface, aided by the coupling of electrode engineering with advanced modelling of the interface; (ii) expanding the range of Solar-to-X products to two essential food groups (proteins and lipids), enabled by the formation of novel microbial consortia on redox polymer films that mitigate their conflicting microenvironment needs; and iii) device engineering that synergizes the different outputs and needs of the bio-anode and cathode whilst also facilitating easy food-product collection. The delivery of our envisioned Solar-to-Food devices will open the door to re-imagining sustainable food production for off-grid locations, kitchens in future households and spaceships. Current food industries, such as our partner Solar Foods, would be an immediate benefactor. Our envisioned solar-to-lipids production process could be a stepping stone to fuels production lines of the future.