Hydrogenase-based oxidative biocatalysis without oxygen

TUM and iAMB-RWTH scientists have developed an novel oxidative biocatalytic route with NAD⁺ as an electron acceptor to produce chemicals. The current findings have been published as an Open Access paper in Nature Communications: Ammar Al-Shameri, Dominik L. Siebert, Samuel Sutiono, Lars Lauterbach, Volker Sieber, (2023) Hydrogenase-based oxidative biocatalysis without oxygen 14:2693 : https://doi.org/10.1038/s41467-023-38227-9

To date, NADH oxidase (NOX) remains the most widely applied system for NAD⁺ regeneration. However, its dependence on O₂ implies various technical challenges in terms of O₂ supply, solubility, and mass transfer. Here, we present the suitability of a NAD⁺ regeneration system in vitro based on H₂ evolution. The efficiency of the H₂-based system is demonstrated by integrating it into a multi-enzymatic cascade to produce ketoacids from sugars. The total NAD⁺ recycled using the hydrogenase system outperforms NOX in all different setups reaching up to 44,000 mol per mol enzyme. This system proves to be scalable and superior to NOX in terms of technical simplicity, flexibility, and total output. Furthermore, the system produces only green H₂ as a by-product even in the presence of O₂.