Cholesterol side-chain cleavage by immobilized cells of Rhodococcus equi DSM 89-133.

Side-chain cleavage of sterol and extracellular cholesterol oxidase activity were investigated using viable cells of R. equi DSM 89-133 immobilized in polyacrylamide gel. In batch culture, immobilized cells were active in side-chain cleavage of cholesterol for more than 30 days. Free or immobilized cells were incapable of side-chain cleavage in the absence of 2,2' dipyridyl; cholesterol oxidase was, however, produced in both the cases. Maximal activity of the immobilized cells was 60 to 70% of the free cells.