abstract |
The invention relates to a microbial method of in vitro transformation of a steroid into its corresponding 11 alpha -hydroxy analogue using oxygen and a microorganism selected from Aspergillus ochraceus, Aspergillus niger, Rhizopus stolonifer, Rhizopus nigricans, Rhizopus arrhizus, and strains of Pestelotia, characterized in that a steroid having a purity of less than 97 % is used. |