“…Later, Ambrus et al [11] tested 312 fungal strains and found that only a limited number of them hydroxylated norethisterone. With Aspergillus flaous, hydroxylation, as well as hydrogenation of ring A of 17aethynylestradiol, was observed by Schubert et al [12]. In our work, the bioconversion of 17a-ethynyl steroids was effected with lla-hydroxylase of established activity from R. nigricans, induced with progesterone under standard conditions.…”