In attempt to immobilize the mycelial fungi on a new hydrophobic matrix, Aspergillus terreus mycelia were immobilized into polytetrafluoroethylen (PTFE) and used for selected conversion of progesterone to 11alpha-hydroxyprogesterone. The immobilized cells exhibited higher yields than the free cells. Different parameters that can affect the cell activity were measured. The optimum pH was 6 and the optimum temperature was 30ºC. Higher transformation activities were achieved with matrix contained 40% PTFE. No considerable loss in yield was observed with storage of the cells at 4ºC for 30 days. Utilization of the immobilized cells in repeated batch processes indicated that the cells retained about 84% of their activity after reuse for eight successive cycles.
11alpha-hydroxprogesterone; polytetrafluoroethylene; Aspergillus terreus
