Synthetic biology for CO fixation.

Recycling of carbon dioxide (CO) into fuels and chemicals is a potential approach to reduce CO emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO under normal conditions. Recently great progress has been made in this research area, and dozens of CO-derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO-fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO-fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO-fixation pathways as well as energy supply patterns using the concept and tools of synthetic biology. Finally, we will discuss future prospects in biological fixation of CO.