Conversion of corticosteroid hormones by immobilized cells of Flavobacterium dehydrogenans, Curvularia lunata and Arthrobacter simplex on ceramic carriers

Different possibilities for converting pregnenolone triacetate to prednisolone using immobilized preparations of Flavobacterium dehydrogenans, Curvularia lunata and Arthrobacter simpelex in a fixed-bed loop reactor were investigated. The effects of the carrier, substrate concentration, pH and temperature on the rate of the substrate conversion were studied also. The biotransformations were performed with a continuous or semicontinuous substrate supply. A convenient pathway for the formation of prednisolone is proposed on the basis of the results obtained.