[Degradation of steroids. XVI. Microbial side chain degradation of structurally modified sterols].

Different types of sterol derivatives substituted in position 3 have been investigated to be suitable substrates for microorganisms capable of degradating the side chain of sterols. Sterolesters were found to be either unattacked or hydrolyzed followed by complete degradation of the molecule. Derivatives of the alkylether - and ketal type were transformed to the corresponding C19-steroids by fermentation with strains of the genus Mycobacteria. With respect to stability, solubility and transformation rate the sterol-3-carboxymethyloxime-derivatives were shown to be most suitable.