Two-Liquid phase reactor studies of 11alpha-hydroxylation of progesterone by Aspergillus ochraceus.

The 11alpha-hydroxylation of progesterone by free cells of Aspergillus ochraceus has been examined in a reactor with an aqueous and a natural oil phase. As the proportion of oil is increased, the point of inversion from a continuous aqueous phase is affected by the cell concentration, as is the optimum ratio of the phases for conversion. High oil ratios are not productive because of poor mass transfer to the concentrated cells in the aqueous phase. The cells are stable in the presence of oleic acid for at least 24 h.