ENZYMIC OXIDATION AND REDUCTION OF CORTISOL WITH BACILLUS CEREUS

Abstract

The enzymatic transformation of cortisol with Bacillus cereus was examined in the presence of some redox agents and enzyme inhibitors. At the early phases of fermentation, the enzymic 1, 2-dehydrogenation reaction of cortisol was highly accelerated in the presence of oxidized glutathione. Thereafter, the enzymic reduction of the 20-keto group of cortisol and prednisolone was noticeably enhanced. In the presence of reduced glutathione, prednisolone was quantitatively converted to the 20β-hydroxy derivative. The bioconversion of cortisol to prednisolone, 20β-hydroxycortisol, and 20β-hydroxyprednisolone was also activated in the presence of azide and cyanide. With iodoacetate, the 1, 2-dehydrogenation reaction was promoted while the 20-keto reduction was markedly repressed.Pretreatment of the bacterial cells with various C19 and C21 steroids as well as with cholesterol affected the transformation pattern in different manners. The 1, 2-dehydrogenation reaction of cortisol was considerably induced when the cells were pretreated with Δ1-dehydroprogesterone, Δ1, 4-androstadienedione, and Δ1-dehydrotestosterone.