PROGESTERONE TRANSFORMATION AS A DIAGNOSTIC FEATURE IN THE CLASSIFICATION OF THE ASPERGILLUS-NIGER GROUP

Fifty-five isolates of nine species and two species varieties (5 isola tes each) of the Aspergillus niger group were tested for progesterone transformation. Generally, all isolates of the different species trans formed progesterone to 21-hydroxyprogesterone. In addition, the isolat es of seven species have the capacity to hydroxylate progesterone to 1 1 alpha-hydroxyprogesterone. A systematic variation could be observed between the tested species of the Aspergillus niger group with respect to the transformation reactions of progesterone. Comparative biotrans formation results showed that essential differences exist between the species of this group, where the different isolates of individual spec ies always produce one or more identical products. This biochemical di fferentiation may supplement the morphological criteria used in the cl assification of this group of fungi.