biostudies-literatureUnknown7(1)Lim GDespite the increasing demand for efficient and sustainable chemical processes, the development of scalable systems using biocatalysis for fine chemical production remains a significant challenge. We have developed a scalable flow system using immobilized enzymes to facilitate flavin-dependent biocatalysis, targeting as a proof-of-concept asymmetric alkene reduction. The system integrates a flavin-dependent Old Yellow Enzyme (OYE) and a soluble hydrogenase to enable H<sub>2</sub>-driven regeneration of the OYE cofactor FMNH<sub>2</sub>. Molecular hydrogen was produced by water electrolysis using a proton exchange membrane (PEM) electrolyzer and introduced into the flow system via a designed gas membrane addition module at a high diffusion rate. The flow system shows remarkable stability anCommunications chemistry200https://www.ebi.ac.uk/biostudies/studies/S-EPMC11380674biostudies-literatureH<sub>2</sub>-driven biocatalysis for flavin-dependent ene-reduction in a continuous closed-loop flow system utilizing H<sub>2</sub> from water electrolysis.PMC11380674Paul CECordero PRFMulks FFLauterbach LLim GCalabrese DWolder ARother DfalseH<sub>2</sub>-driven biocatalysis for flavin-dependent ene-reduction in a continuous closed-loop flow system utilizing H<sub>2</sub> from water electrolysis.Despite the increasing demand for efficient and sustainable chemical processes, the development of scalable systems using biocatalysis for fine chemical production remains a significant challenge. We have developed a scalable flow system using immobilized enzymes to facilitate flavin-dependent biocatalysis, targeting as a proof-of-concept asymmetric alkene reduction. The system integrates a flavin-dependent Old Yellow Enzyme (OYE) and a soluble hydrogenase to enable H<sub>2</sub>-driven regeneration of the OYE cofactor FMNH<sub>2</sub>. Molecular hydrogen was produced by water electrolysis using a proton exchange membrane (PEM) electrolyzer and introduced into the flow system via a designed gas membrane addition module at a high diffusion rate. The flow system shows remarkable stability an2024-01-01T00:00:00Z2024 Sep2025-04-18T21:42:10.994Z2025-02-19T02:33:59.804ZS-EPMC113806743924461810.1038/s42004-024-01288-y