Progesterone transformation as a biochemical aid in classification of the genus Emericella.

A total of 65 isolates representing 13 Emericella taxa (5 isolates of each of 12 species and 1 variety) had the ability to transform progesterone into 11 alpha-hydroxyprogesterone. A systematic variation could be observed between the different tested Emericella taxa with respect to the transformation products. The isolates were divided according to the transformation types into six groups: (1) progesterone was hydroxylated into 6 beta-hydroxyprogesterone, 11 alpha-hydroxyprogesterone and 6 beta,11 alpha-dihydroxyprogesterone--found in Emericella acristata and E. dentata; (2) E. aurantio-brunna and E. parvathecia hydroxylated progesterone into 11 alpha-hydroxyprogesterone, 17 alpha-hydroxyprogesterone and 11 alpha,17 alpha-dihydroxyprogesterone; (3) E. nidulans and E. quadrilineata formed the same three products as members of group (2) and form epicortisol; (4) E. nidulans var. lata, E. bicolor and E. variecolor transformed progesterone into a mixture of mono-, di- and trihydroxy products; (5) E. striata and E. sublata exhibited an oxidative splitting of the progesterone side chain in position C-17 and hydroxylated progesterone into mono- and dihydroxy products; (6) E. rugulosa and E. unguis had the ability to degrade progesterone side-chain and to hydroxylate it into mono-, di- and trihydroxy products. This biochemical differentiation may supplement the morphological and other biochemical criteria used in the classification of the Emericella taxa.