[Steroid transformation with immobilized microorganisms. III. Degradation of the side chain of cholesterol derivatives with immobilized Mycobaterium phlei and M. smegmatis cells].

The cholesterol derivatives 3,3-ethylendioxycholest-5-en I and 4-cholesten-3-(O-carboxymethyl)oxime II were transformed into the corresponding androstenedione derivatives by selective cleavage of the sterol side chain with immobilized preparations of Mycobacterium phlei IMET SG 1026 and M. smegmatis IMET H 124. The influence of three immobilization methods on fermentation activity and stability was investigated. The immobilized cells of M. phlei IMET SG 1026 were found to be suitable to transform the structure modified sterol II in a periodic process over a long period into the androstenedione in a yield of 50--70%. Immobilized cells of M. phlei have higher transformation stability in comparison with free intact cells.