초록
The use of biocatalysts to convert CO<SUB>2</SUB> into useful chemicals is a promising alternative to chemical conversion. In this study, the electro-biocatalytic conversion of CO<SUB>2</SUB> to formate was attempted with a whole cell biocatalyst. Eight species of Methylobacteria were tested for CO<SUB>2</SUB> reduction, and one of them, Methylobacterium extorquens AM1, exhibited an exceptionally higher capability to synthesize formate from CO<SUB>2</SUB> by supplying electrons with electrodes, which produced formate concentrations of up to 60mM. The oxygen stability of the biocatalyst was investigated, and the results indicated that the whole cell catalyst still exhibited CO<SUB>2</SUB> reduction activity even after being exposed to oxygen gas. From the results, we could demonstrate the electro-biocatalytic conversion of CO<SUB>2</SUB> to formate using an obligate aerobe, M. extorquens AM1, as a whole cell biocatalyst without providing extra cofactors or hydrogen gas. This electro-biocatalytic process suggests a promising approach toward feasible way of CO<SUB>2</SUB> conversion to formate.