Biocatalysis is increasingly adopted in the chemical industry due to its sustainability advantages, such as biodegradable catalysts, high selectivity, and operation under mild conditions.^[1] In particular, the precise control enzymes exert over reaction outcomes makes them ideally suited for the synthesis of active pharmaceutical ingredients (APIs). In this talk, I will present our integrated approach to developing new enzymatic and microbial tools for the synthesis of pharmaceutical building blocks.

We explore the catalytic potential of Rieske non-heme iron oxygenases (ROs)—an underexploited enzyme family known for their regio- and stereoselective C–H functionalization capabilities. To harness their potential, several challenges related to their multi-component nature, cofactor dependence, and susceptibility to reactive oxygen species must be addressed. By advancing our understanding of key determinants of catalytic efficiency—such as electron transfer, stability, and uncoupling—we have optimized both in vivo^[1] and in vitro^[2] RO systems. We are also exploring hybrid RO systems^[3] and redox partner fusion proteins^[4] to enhance catalytic activity, opening new avenues for late-stage functionalization in drug synthesis.

In parallel, we focus on the discovery, characterization, and engineering of nitrogen–nitrogen bond-forming enzymes (NNzymes), which utilize various metallo-cofactors and reaction types to catalyze N–N couplings, forming unique bioactive molecules.^[5] A particular focus lies on piperazate synthases (PZSs) involved in the biosynthesis of rare nitrogen-containing heterocycles.^[6] These enzymes offer a biocatalytic route to L-piperazate—a pharmacophore found in several bioactive compounds—highlighting the potential of pathway-inspired enzyme engineering. We expand the scope of characterized PZSs through genome mining and reveal promiscuous activities leading to functionalized hydrazine derivatives[6] and other nitrogen heterocycles of pharmaceutical relevance.^[7]

Complementing these enzyme-focused efforts, we have developed synthetic biology tools for Cupriavidus necator,^[8,9] a versatile and robust chemolithoautotrophic bacterium with high potential for C1-based biomanufacturing. By improving its genetic tractability, we demonstrate how C. necator can be transformed into an efficient platform for whole-cell biocatalysis in pharmaceutical applications.^[10]

Together, these efforts underscore how combining enzyme discovery and engineering with strain development of non-model bacteria can significantly expand the biocatalytic toolbox for more sustainable and efficient pharmaceutical synthesis.