Institution: | 1. Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 China
University of Chinese Academy of Sciences, Beijing, 100049 China;2. Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 China;3. Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 China
Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, 116023 China |
Abstract: | A non-natural cofactor and formate driven system for reductive carboxylation of pyruvate is presented. A formate dehydrogenase (FDH) mutant, FDH*, that favors a non-natural redox cofactor, nicotinamide cytosine dinucleotide (NCD), for generation of a dedicated reducing equivalent at the expense of formate were acquired. By coupling FDH* and NCD-dependent malic enzyme (ME*), the successful utilization of formate is demonstrated as both CO2 source and electron donor for reductive carboxylation of pyruvate with a perfect stoichiometry between formate and malate. When 13C-isotope-labeled formate was used in in vitro trials, up to 53 % of malate had labeled carbon atom. Upon expression of FDH* and ME* in the model host E. coli, the engineered strain produced more malate in the presence of formate and NCD. This work provides an alternative and atom-economic strategy for CO2 fixation where formate is used in lieu of CO2 and offers dedicated reducing power. |