Role of Some Fermentative Parameters for Microbial Transformation of Progesterone to Cortexolone and/or Hydrocortisone.

Abstract

Four strains belonging to the genus Curvularia were tested for their ability to transform progesterone to cortexolone and hydrocortisone. Curvularia lunata RCMB 019002 showed the greatest bioconversion efficiency (29.64%). In a medium containing (g/l); yeast extract 4 and malt extract 20, the substrate was converted after 48h to cortexolone and cortisol. The maximum bioconversion efficiency (37. 72%) was recorded when phosphate buffer was used at pH 7.0. The transformation pattern of progesterone markedly affected by the inoculum size and culture age. The bioconversion efficiency increased (63.2 %) when the substrate concentration was 5 mg/50ml fermentation medium. The addition of the surface active agents Tween 60 and Tween 80 to the medium at concentrations of 100 µl, 50 µl, respectively increased the bioconversion efficiency (66.70 and 68.64 %, respectively). Among the tested amino acids, L-asparagine enhanced the formation of cortexolone and cortisol.