Progesterone transformations by three species ofHumicola

Five isolates belonging to three species of the genusHumicola were tested in this study for their ability to transform progesterone. An oxidative splitting of the side chain of progesterone with the formation of androst-4-ene-3,17-dione, testosterone and testololactone was achieved by all isolates tested ofH. fuscoatra andH. grisea. H. hyalothermophila transformed progesterone to 11α-, 11β-, 17α- and 21-hydroxyprogesterone and a dihydroxyl product (11α, 17α-dihydroxyprogesterone) with the addition of two trihydroxyl products,viz. cortisol and epicortisol. Qualitative and quantitative analysis of the different products obtained when a selective isolate of each species acted on progesterone were conducted. The chromatographic resolution of the mixture products obtained when the selective isolate of each ofH. fuscoatra andH. grisea had acted individually on 1 g progesterone revealed the presence of 25 and 20% unchanged progesterone, 20 and 22% androst-4-ene-3,17-dione, 25 and 23% testosterone and 30 and 35% testololactone, respectively. Seventy-four % of progesterone were bioconverted byH. hyalothermophila into 21-hydroxyprogesterone (6%), 17α-hydroxyprogesterone (5%), 11α-hydroxyprogesterone (11%), 11β-hydroxyprogesterone (12%), 11α,17α-dihydroxyprogesterone (5%), cortisol (21%) and epicortisol (13%). This is the first record of conversion of progesterone to both cortisol and epicortisol byH. hyalothermophila.