An engineered living biofilm system for sustainable conversion of CO2 into polyhydroxyalkanoates

The release of CO 2 has challenged the worldwide environment and led to climate change. An emerging solution is to construct bio-abiotic semiartificial photocatalysis systems for the highly efficient conversion of CO 2 . However, biocompatibility and the narrow product spectrum are challenging these bio-abiotic photocatalysis systems integrating living cells and semiconductors. Living bacterial biofilms can provide a large specific surface area for photosensitizer mineralization, allowing CO 2 fixation, one-carbon product uptake, and further assimilation. Here, we report a living photosensitizer-mineralized biofilm platform with a biocompatible and stable bio-abiotic interface conducting single-enzyme to whole-cell photocatalytic applications. Such engineered photosensitizer-mineralized biofilms not only efficiently implement the regeneration of NADH but also enable the conversion of CO 2 into formate and finally into polyhydroxyalkanoates under light illumination. Thus, this work demonstrates an alternative approach to solar-to-chemical conversion. The proof of concept established in this work might be used for other sustainable photocatalytic applications.