Real flue gas CO2 hydrogenation to formate by an enzymatic reactor using O2- and CO-tolerant hydrogenase and formate dehydrogenase

Jaehyun Cha; Jinhee Lee; Byoung Wook Jeon; Yong Hwan Kim; Inchan Kwon

doi:10.3389/fbioe.2023.1265272

Real flue gas CO₂ hydrogenation to formate by an enzymatic reactor using O₂- and CO-tolerant hydrogenase and formate dehydrogenase

Front Bioeng Biotechnol. 2023 Oct 3:11:1265272. doi: 10.3389/fbioe.2023.1265272. eCollection 2023.

Authors

Jaehyun Cha^#¹, Jinhee Lee^#², Byoung Wook Jeon^#², Yong Hwan Kim², Inchan Kwon^{1

3}

Affiliations

¹ School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.
² School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea.
³ Research Center for Innovative Energy and Carbon Optimized Synthesis for Chemicals (Inn-ECOSysChem), Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.

^# Contributed equally.

Abstract

It is challenging to capture carbon dioxide (CO₂), a major greenhouse gas in the atmosphere, due to its high chemical stability. One potential practical solution to eliminate CO₂ is to convert CO₂ into formate using hydrogen (H₂) (CO₂ hydrogenation), which can be accomplished with inexpensive hydrogen from sustainable sources. While industrial flue gas could provide an adequate source of hydrogen, a suitable catalyst is needed that can tolerate other gas components, such as carbon monoxide (CO) and oxygen (O₂), potential inhibitors. Our proposed CO₂ hydrogenation system uses the hydrogenase derived from Ralstonia eutropha H16 (ReSH) and formate dehydrogenase derived from Methylobacterium extorquens AM1 (MeFDH1). Both enzymes are tolerant to CO and O₂, which are typical inhibitors of metalloenzymes found in flue gas. We have successfully demonstrated that combining ReSH- and MeFDH1-immobilized resins can convert H₂ and CO₂ in real flue gas to formate via a nicotinamide adenine dinucleotide-dependent cascade reaction. We anticipated that this enzyme system would enable the utilization of diverse H₂ and CO₂ sources, including waste gases, biomass, and gasified plastics.

Keywords: carbon dioxide; flue gas; formate; formate dehydrogenase; hydrogen; hydrogenase.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the National Research Foundation of Korea (NRF), the Ministry of Science, and ICT (grant numbers 2021R1A5A1028138, 2020R1A5A1019631, and 2015M3D3A1A01064923).