Hydrogen-fueled CO2 reduction using oxygen-tolerant oxidoreductases

Jaehyun Cha; Hyeonseon Bak; Inchan Kwon

doi:10.3389/fbioe.2022.1078164

Hydrogen-fueled CO₂ reduction using oxygen-tolerant oxidoreductases

Front Bioeng Biotechnol. 2023 Jan 5:10:1078164. doi: 10.3389/fbioe.2022.1078164. eCollection 2022.

Authors

Jaehyun Cha¹, Hyeonseon Bak¹, Inchan Kwon^{1

2}

Affiliations

¹ School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.
² Research Center for Innovative Energy and Carbon Optimized Synthesis for Chemicals (Inn-ECOSysChem), Gwangju Institute of Science and Technology (GIST), Gwangju, South Korea.

Abstract

Hydrogen gas obtained from cheap or sustainable sources has been investigated as an alternative to fossil fuels. By using hydrogenase (H₂ase) and formate dehydrogenase (FDH), H₂ and CO₂ gases can be converted to formate, which can be conveniently stored and transported. However, developing an enzymatic process that converts H₂ and CO₂ obtained from cheap sources into formate is challenging because even a very small amount of O₂ included in the cheap sources damages most H₂ases and FDHs. In order to overcome this limitation, we investigated a pair of oxygen-tolerant H₂ase and FDH. We achieved the cascade reaction between H₂ase from Ralstonia eutropha H16 (ReSH) and FDH from Rhodobacter capsulatus (RcFDH) to convert H₂ and CO₂ to formate using in situ regeneration of NAD⁺/NADH in the presence of O₂.

Keywords: carbon dioxide; formate; formate dehydrogenase; hydrogen; hydrogenase; oxygen-tolerant.