Efficient heterologous expression of formate dehydrogenase and preliminary determination of the potential for conversion of carbon dioxide to formate

Formate dehydrogenase (FDH, EC 1.17.1.9) belongs to the class of d-2‑hydroxy acid dehydrogenases and is widely found in bacteria, archaea, yeast, fungi, plants and vertebrates. In recent years, the inverse reduction reaction of carbon dioxide to formate catalyzed by FDH has attracted widespread interest. However, the low catalytic activity has greatly limited its industrial application. In this work, three novel FDHs including FmFDH, KsFDH and SsFDH, were discovered. SsFDH showed relatively high catalytic activity toward CO2 conversion. The enzymological properties of the enzymes were characterized, and the catalytic mechanism of reducing CO2 to formate was investigated using bioinformatic and computational biochemical tools. The results of this work provide new insights into the function, structure and application of FDH in reducing CO2 to formate.