[Microbiologic transformation of microcrystalline cortisone acetate into prednisone].

The process of transformation of microcystalline acetate cortisone by two mycobacteria (Mycobacterium album and Mycobacterium globiforme) has been studied. Optimal conditions for the process have been established: amount of biomass of both cultures, concentration of the initial substrate and required concentration of the surfactant--antifoamsilane. The anzymic activity of the cultures reaches maximum if the following three requirements are met: utilization of cells separated from the medium, substrate in the microcrystalline state and surfactant of the antifoamsilane type.