Progesterone transformation as a biochemical aid in classification of the genusEmericella

A total of 65 isolates representing 13Emericella taxa (5 isolates of each of 12 species and 1 variety) had the ability to transform progesterone into 11α-hydroxyprogesterone. A systematic variation could be observed between the different testedEmericella taxa with respect to the transformation products. The isolates were divided according to the transformation types into six groups: (1) progesterone was hydroxylated into 6β-hydroxyprogesterone, 11α-hydroxyprogesterone and 6β, 11α-dihydroxyprogesterone— found inEmericella acristata andE. dentata; (2) E. aurantio-brunna andE. parvathecia hydroxylated progesterone into 11α-hydroxyprogesterone, 17α-hydroxyprogesterone and 11α,17α-dihydroxyprogesterone; (3)E. nidulans andE. quadrilineata formed the same three products as members of group (2) and form epicortisol; (4)E. nidulans var.lata, E. bicolor andE. variecolor transformed progesterone into a mixture of mono- di-and trihydroxy products; (5)E. striata andE. 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 andE. 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 theEmericella taxa.