Microbiological sterol conversions: utilization of selected mutants.

Microbiological conversion of drugs and natural products, including sterols and steroids, is an important component of the commercial preparation of these agents. We have developed methodology which allows for the production and selection of mutant organisms capable of specific desirable transformations. This methodology is based upon mutation of wild-type strains which are capable of completely degrading certain sterols and selection of the mutants blocked at the desired conversion. This procedure should be equally useful for many if not all drug classes.