Abstract Innovative biohydroxylation catalysts for the preparation of drug metabolites were developed from scratch. A set of bacterial and fungal sequences of putative and already known bifunctional P450 enzymes was identified by protein sequence alignments, expressed in Escherichia coli and characterised. Notably, a fungal self-sufficient cytochrome P450 (CYP) from Aspergillus fumigatus turned out to be especially stable during catalyst ...