Biological CO2 fixation is so far the most effective means for CO2 reduction at scale and accounts for most of the CO2 fixed on Earth. Through this process, carbon is fixed in cellular components and biomass during organismal growth. To uncouple CO2 fixation from growth and cellular regulation, cell-free CO2 fixation systems represent an alternative approach since the rate can be independently manipulated. Here we designed an oxygen-insensitive, self-replenishing CO2 fixation system with opto-sensing. The system comprises a synthetic reductive glyoxylate and pyruvate synthesis (rGPS) cycle and the malyl-CoA-glycerate (MCG) pathway to produce acetyl-coenzyme A (CoA), pyruvate and malate from CO2, which are also intermediates in the cycle. We solved various problems associated with the in vitro system, and implemented opto-sensing modules to control the regeneration of cofactors. We accomplished sustained operation for 6 hours with a CO2-fixing rate comparable to or greater than typical CO2 fixation rates of photosynthetic or lithoautotrophic organisms.
This work was supported by Sustainability Science Research Program from Academia Sinica (grant nos. AS-SS-109-07 and AS-SS-110-03). Dr. Paul Lin from the Institute of Biological Chemistry in Academia Sinica shares the co-first authorship in this study. Dr. James Liao from Institute of Biological Chemistry in Academia Sinica is the corresponding author in this study. Additional collaborator includes Dr. Chi Chen from Research Center for Applied Sciences in Academia Sinica.
This study has recently been published in Nature Catalysis. Article title: “A cell-free self-replenishing CO2-fixing system”
Article link: https://www.nature.com/articles/s41929-022-00746-x
Authors: Luo S, Lin PP, Nieh LY, Liao GB, Tang PW, Chen C, Liao JC*
Updated : 2022.03.07