Fixing carbon dioxide in situ during ethanol production by formate dehydrogenase

Concerns regarding the increasing carbon dioxide (CO 2 ) concentration has aroused global interest in renewable fuels and conversion of CO 2 into chemicals. This study provides a sustainable strategy for fixing CO 2 in situ during the production of ethanol in a single cell expressing formate dehydrogenase (FDH) without the addition of a cofactor. Glucose was converted to ethanol, with the main by-product CO 2 fixed to formate, increasing the yield of ethanol and glucose fermentation efficiency in the recombinant Saccharomyces cerevisiae-fdh . Higher concentrations of glucose and amount of ScFDH1 yielded more formate, confirming the feasibility of CO 2 fixation. Significantly, the glucose consumption rate and ethanol yield increased by 30% and 13% after the overexpression of ScFDH1, respectively. Finally, the increase in CO 2 concentration with the addition of zeolite imidazole framework-8 (ZIF-8) further demonstrated the CO 2 fixation in situ , increasing the production of formate 2.1 times. Due to ZIF-8, up to 60.67 mg L −1 formate was produced. Our findings establish a green, economical, and sustainable alternative for CO 2 conversion in situ , contributing to the ethanol yield by ScFDH1 without extra energy input and cofactor supply. This synergistic strategy has significance for both the energy and environmental crises.