| 초록 |
The fixation of CO2 is one of the most important approaches to prevent global warming. Formic acid is considered a promising replacement for methanol in miniature fuel cells. NAD-independent FDHs have high CO2 reduction activity but show extremely high oxygen-sensitivity, making these FDHs unsuitable for industrial applications. Recently, NAD-dependent FDHs were utilized in a CO2 reduction system as an alternative to NAD-independent FDHs. Unfortunately, the CO2 reduction activity of CbFDH is too low to allow efficient CO2 conversion, which leads us to search for alternatives. In particular, the FDH from Thiobacillus sp. KNK65MA (TsFDH) exhibited the highest CO2-reducing activity and had a dramatic preference for the reduction reaction, i.e., a 52.2-fold higher ratio of CO2 reduction to formate oxidation in catalytic efficiency (kcat/KB) compared to CbFDH. TsFDH showed a 5.8-fold higher formate production rate than CbFDH(1,2). Interestingly, newly found formate dehydrogenase from methylotrophic bacteria showed the CO2 reduction activity by utilizing electrons supplied from cathode. |
