2Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
3Lomonosov Moscow State University, Faculty of Chemistry, 119991 Moscow, Russia
*To whom correspondence should be addressed.
Received August 4, 2017; Revision received September 15, 2017
The ability of the ascomycete Aspergillus niger N402 to transform exogenous progesterone was investigated. We found that this strain has steroid-hydroxylating activity and can introduce a hydroxyl group into the progesterone molecule mainly at positions C11(α) and C21 with predominant formation of 21-hydroxyprogesterone (deoxycortone). In addition, formation of 6β,11α-dihydroxyprogesterone was also observed. Studying the effects of the growth medium composition and temperature on progesterone conversion by A. niger N402 showed that the most intense accumulation of 21-hydroxyprogesterone occurred in minimal synthetic medium at 28°C. Increasing the cultivation temperature to 37°C resulted in almost complete inhibition of the hydroxylase activity in the minimal medium. In the complete medium, a similar increase in temperature inhibited 11α-hydroxylase activity and completely suppressed 6β-hydroxylase activity, but it produced no effect on 21-hydroxylating activity.
KEY WORDS: Aspergillus niger N402, progesterone, biotransformation, 21-hydroxylation, 11α-hydroxylation, deoxycortone