Patent ID: 7033779

Claim:
A method for producing hydroxylated and/or acetylated steroids, comprising the steps according to which: yeast cells are cultured on a medium comprising at least one precursor of such hydroxylated and/or acetylated steroids, and then the hydroxylated and/or acetylated steroids are isolated from the medium after bioconversion, wherein said precursor is dehydroepiandrosterone (DHEA) or pregnenolone; wherein said yeast cells are Saccharomyces cerevisiae cells; wherein said yeast cells are transformed with the rat Cyp7b gene so as to express the 7α hydroxylase enzymatic activity encoded by said rat Cyp7b gene which catalyzes 7α hydroxylation of pregnenolone and DHEA; wherein said yeast cells are further modified so as to lack an acetyl coenzyme A-pregnenolone acetyltransferase (APAT) activity when compared to wild type yeast cells; and wherein the modification of the yeast cells resulting in a lack of acetyl coenzyme A-pregnenolone acetyltransferase (APAT) activity is caused by the inactivation of the Saccharomyces cerevisiae atf2 gene.