LAUSR

Biotechnological transformation of steroids using enzyme systems of microorganisms is often the only possible method to modify the molecule in the industrial production of steroid drugs. Filamentous fungus Aspergillus nidulans has been little studied as a steroid-transforming microorganism. We studied the ability of the A. nidulans VKPM F-1069 strain to transform progesterone (PG) for the first time. This strain converts PG into 3 main products: 11α-hydroxy-PG, 11α-acetoxy-PG and 6β,11α-dihydroxy-PG. It has been established that in the first stage, the hydroxylation of PG occurs into C11α position, then the formed 11α-hydroxy-PG is modified into 11α-acetoxy-PG and 6β,11α-dihydroxy-PG. It was found that changes in the composition of the growth medium, aeration and the duration of the mycelium cultivation do not affect the qualitative composition of PG transformation products, but their ratios have changed. Under conditions of limited aeration, the direction of secondary modification of 11α-hydroxy-PG is shifted towards the formation of 11α-acetoxy-PG.