Screening of mycelial fungi for 7α- and 7β-hydroxylase activity towards dehydroepiandrosterone

Abstract

In total, 481 fungal strains were screened for the ability to carry out 7(a/b)-hydroxylation of dehydroepiandrosterone (DHEA, 3b-hydroxy-5-androsten-17-one). Representatives of 31 genera of 15 families and 9 orders of ascomycetes, 17 genera of 9 families and 2 orders of zygomycetes, 2 genera of two families and 2 orders of basidiomycetes, and 14 genera of mitosporic fungi expressed 7(a/b)-hydroxylase activity. The majority of strains were able to introduce a hydroxyl group to position 7a. Active strains selectively producing 3b,7a-dihydroxy-5-androsten-17-one were found among Actinomucor, Backusella, Benjaminiella, Epicoccum, Fusarium, Phycomyces and Trichothecium, with the highest yield of 1.25 and 1.9 g L (1 from 2 and 5 g L (1 DHEA, respectively, reached with F. oxysporum. Representatives of Acremonium, Bipolaris, Conidiobolus and Curvularia formed 3b,7b-dihydroxy-5-androsten-17-one as a major product from DHEA. The structures of the major steroid products were confirmed by thin-layer chromatography (TLC), gas chromatography (GC), mass spectra (MS), and 1 H-NMR analyses.

Genotyping of HCV-Egyptian infected cases, and response to treatment

“…Among 482 strains of different taxonomy filamentous fungi tested, mainly Fusarium, Gibberella and Trichothecium representatives catalysed 7␣ -hydroxylation of DHEA (Lobastova et al, 2007;Lobastova et al, 2009), while the strains of Acremonium, Bipolaris, Curvularia expressed 7␤ -hydroxylating activity. Quality control studies has been achieved, as double blind studies were conducted in both Egypt and France .and proved to have 96% correlation, which proves absence of contamination -(No false positive cases).…”

Hydroxylation of 3α- and 3β-hydroxy steroids in position 7 by a fungus of Gibberella zeae VKM F-2600

“…3␣-hydroxy-5␤-cholan-24-oic acid, litocholic acid, LCA). Among 482 strains of different taxonomy filamentous fungi tested, mainly Fusarium, Gibberella and Trichothecium representatives catalysed 7␣ -hydroxylation of DHEA (Lobastova et al, 2007;Lobastova et al, 2009), while the strains of Acremonium, Bipolaris, Curvularia expressed 7␤ -hydroxylating activity.When using LCA as an only substrate, the same strains of Fusarium, Gibberella, Bipolaris and Curvularia genera demonstrated 7␤-hydroxylase activity, thus forming ursodeoxycholic acid (3␣,7␤-dihydroxy-5␤-cholan-24-oic acid, USDA) as a major bioconversion product from LCA. No hydroxylating activity towards LCA was observed for the fungi of Trichothecium and Acremonium tested.…”

“…3␣-hydroxy-5␤-cholan-24-oic acid, litocholic acid, LCA). Among 482 strains of different taxonomy filamentous fungi tested, mainly Fusarium, Gibberella and Trichothecium representatives catalysed 7␣ -hydroxylation of DHEA (Lobastova et al, 2007;Lobastova et al, 2009), while the strains of Acremonium, Bipolaris, Curvularia expressed 7␤ -hydroxylating activity.…”

The microbial formation of lactones from dehydroepiandrosterone

“…Pregnenolone converted via DHEA to 3␤-hydroxy-17а-oxo-D-homo-androst-5-en-17-one and via progesterone to testololactone Kolek et al, 2008, Kolek et al, 2009 A strain of Spicaria sp. was selected among the filamentous fungi at their testing for the ability to carry out hydroxylation of DHEA in positions 7␣ and 7␤ Lobastova et al, 2007. The strain is capable of converting DHEA forming 7␣-and 7␤-hydroxydehydroepiandrosterone (7␣-OН-DHEA and 7␤-OН-DHEA), 3␤,7␣-dihydroxy-17а-oxo-D-homo-androst-5-en-17-one and 3␤,7␤-dihydroxy-17а-oxo-D-homo-androst-5-en-17one.…”