Cell-free biocatalysis coupled with photo-catalysis and electro-catalysis: Efficient CO2-to-chemical conversion

The increasing atmospheric carbon dioxide (CO2) concentration has exposed a series of crises in the earth's ecological environment. How to effectively fix and convert carbon dioxide into products with added value has attracted the attention of many researchers. Cell-free enzyme catalytic system coupled with electrical and light have been a promising attempt in the field of biological carbon fixation in recent years. In this review, the research progresses of photoenzyme catalysis, electroenzyme catalysis and photo-electroenzyme catalysis for converting carbon dioxide into chemical products in cell-free systems are systematically summarized. We focus on reviewing and comparing various coupling methods and principles of photoenzyme catalysis and electroenzyme catalysis in cell-free systems, especially the materials used in the construction of the coupling system, and analyze and point out the characteristics and possible problems of different coupling methods. Finally, we discuss the major challenges and prospects of coupling physical signals and cell-free enzymatic catalytic systems in the field of CO2 fixation, suggesting possible strategies to improve the carbon sequestration capacity of such systems.