[P001] Poster

12:10 PM - 1:00 PM JST(3:10 AM - 4:00 AM UTC)

[P01-023] The study of formate dehydrogenase reaction and bioconversion for turning carbon dioxide into valuable chemical feedstock

○Ruchanok Tinikul¹, Thunchanok Wilasri¹, Pratchaya Watthaisong², Panu Pimviriyakul³, Somchart Maenpuen⁴ (1. Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok (Thailand), 2. School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong (Thailand), 3. Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok (Thailand), 4. Department of Biochemistry, Faculty of Science, Burapha University, Chonburi (Thailand))

Keywords:

Formate dehydrogenase,Formaldehyde dehydrogenase,Carbon dioxide reduction,Carbon dioxide bioconversion,Biocatalysis

Formate dehydrogenase (FDH) catalyzes the single step reduction of CO₂ to formate, offering a promising route for converting greenhouse gas into valuable chemical building blocks. In this study, we characterize a metal independent FDH from Xanthobacter sp. 91 (XaFDH) and establish an enzymatic cascade for the conversion of gaseous CO₂ into formate, formaldehyde, and methanol. XaFDH exhibited a 9-fold higher catalytic efficiency for CO₂ reduction compared to FDH from Candida boidinii (CbFDH) and produced up to 2.5 folds more formate from gaseous CO₂. Notably, XaFDH demonstrated strong tolerance to acidic conditions, retaining over 80% of its activity, and showed enhanced binding affinity toward both NADH and NAD⁺. To further improve the conversion, we identified an efficient formaldehyde dehydrogenase from Pseudomonas lalkunensis (PlFaldDH), which exhibited superior activity in catalyzing the conversion of formate to formaldehyde. A multienzyme CO₂ to methanol cascade comprising XaFDH, PlFaldDH, alcohol dehydrogenase, and a phosphite dehydrogenase-based cofactor regeneration system resulted in significantly enhanced formaldehyde and methanol production, achieving a methanol yield of 3.03 ± 0.05 mM. Collectively, these findings highlight XaFDH and PlFaldDH as efficient biocatalysts for CO₂ valorization and underscore their potential for biobased chemical production.