Light-driven CO2 utilization for chemical production in bacterium biohybrids

Abstract

Artificial photosynthetic systems provide an alternative approach for the sustainable, efficient, and versatile production of biofuels and biochemicals. However, improving the efficiency of electron transfer between semiconductor materials and microbial cells remains a challenge. In this study, an inorganic-biological photosynthetic biohybrid system (IBPHS) consisting of photocatalytic and biocatalytic modules was developed by integrating cadmium telluride quantum dots (CdTe QDs) with Escherichia coli cells. A photocatalytic module was constructed by biosynthesizing CdTe QDs to capture light and generate electrons. The biocatalytic module was built by converting photo-induced electrons to enhance NADH regeneration; thus, the NADH content in E. coli under blue light increased by 5.1-fold compared to that in darkness. Finally, IBPHS was utilized to drive CO₂ reduction pathways for versatile bioproduction such as formate and pyruvate, with CO₂ utilization rates up to 51.98 and 21.92 mg/gDCW/h, respectively, exceeding that of cyanobacteria. This study offers a promising platform for the rational design of biohybrids for efficient biomanufacturing processes with high complexity and functionality.