Europe needs a sustainable chemical industry which will only be realized by new breakthrough technologies. Industrial biotechnology is established in chemical manufacturing, offering more efficient, more specific, safer and less energy demanding production, but is held back by the limited number of enzyme classes in industrial use. This project opens up an important new enzyme class of tungsten-containing enzymes (W-enzymes) which catalyse amazing chemical reactions involving challenging low redox potential reduction reactions, but are currently impossible to obtain economically and on scale to match industrial needs. We need to produce W-enzymes using an industrial workhorse micro-organism such as E. coli. Yet, we discovered that W-cofactor biosynthesis is the bottleneck preventing successful production of W-enzymes in E. coli. We can solve this challenge by using cutting-edge computational enzyme design approaches we recently developed, to create a completely new W-cofactor biosynthesis pathway for E. coli. The W-BioCat strains developed in this project will enable expression of new W-enzymes from genetic databases, and facilitate production of new engineered W-enzymes. The catalytic potential of these new W-enzymes will be established and implemented in new processes. Exciting new reaction scope in biocatalytic CO2 reduction to valuable chemicals and Birch reduction of aromatic compounds will be explored, alongside the already-established and broadly applicable carboxylic acid reductions. W-BioCat will be the breakthrough to make W-enzymes accessible for industry. As a proof of concept, a hydrogen-driven process to convert plant-derived oleic acid to the emollient ester oleyl oleate will be created. Oleyl oleate is used in many cosmetic products used daily by millions of people. This process will be demonstrated in multi-gram yield in scalable, industrially-relevant hydrogenation reactors, together with market research to address a pathway to commercialisation.