Steroid transformation with immobilized microorganisms. VI. The reverse reaction of steroid-1-dehydrogenases from...

Whole cells of Nocardia erythropolis, N. opaca and Mycobacterium phlei containing 4-en-3-oxosteroid: (acceptor)-1-en-oxidoreductase activities were immobilized by adsorption on DEAE-cellulose and silica and by entrapment in polyacrylamide gel. The obtained biocatalysts were used in an anaerobic continuous column process to transform 1,4-dien-3-oxo-steroids into 4-en-3-oxo- steroids. The half life of steroid-1(2)-reductase activity of the N. erythropolis was found to be up to 15 days. The DEAE-cellulose-adsorbed cells showed a slightly higher relative activity than free cells. The influence of substrate concentration and the action of dimethylformamide were also investigated.