Light-driven CO 2 sequestration in Escherichia coli to achieve theoretical yield of chemicals

CO2 sequestration engineering is an attractive strategy for achieving carbon- and energy-efficient bioproduction. However, the efficiency of heterotrophic CO2 sequestration is limited by bioproduct dependence and energy deficiency. Here, modular CO2 sequestration engineering was developed to produce target chemicals by integrating synthetic CO2 fixation and CO2 mitigation modules. A synthetic CO2 fixation pathway was designed, and then enhanced by light-driven reducing power using self-assembled cadmium sulfide nanoparticles. Next, a CO2 mitigation switch was designed, and then optimized by light-driven energy via proteorhodopsin. Finally, by integrating CO2 fixation and CO2 mitigation modules, the efficiency of CO2 sequestration was notably enhanced in Escherichia coli and the yields of l-malate and butyrate were increased to 1.48 and 0.79 mol/mol glucose, respectively, reaching theoretical yields. This CO2 sequestration system provides an efficient platform for channelling CO2 into value-added chemicals. Improving the efficiency of carbon yield in heterotrophic microorganisms is desired for biomanufacturing. Now, a product-independent and energy-efficient CO2 sequestration system that maximizes carbon conversion has been developed, as showcased by the production of chemicals reaching their theoretical yields.