Insight into Different Stages of Steroid Degradation in Thermophilic VKM Ac-666 Strain.

Steroids are abundant molecules in nature, and various microorganisms evolved to utilize steroids. Thermophilic actinobacteria play an important role in such processes. However, very few thermophiles have so far been reported capable of degrading or modifying natural sterols.

Steroid Metabolism in Thermophilic Actinobacterium VKM Ac-666.

The application of thermophilic microorganisms opens new prospects in steroid biotechnology, but little is known to date on steroid catabolism by thermophilic strains. The thermophilic strain VKM Ac-666 has been shown to convert various steroids and to fully degrade cholesterol. Cholest-4-en-3-one, cholesta-1,4-dien-3-one, 26-hydroxycholest-4-en-3-one, 3-oxo-cholest-4-en-26-oic acid, 3-oxo-cholesta-1,4-dien-26-oic acid, 26-hydroxycholesterol, 3β-hydroxy-cholest-5-en-26-oic acid were identified as intermediates in cholesterol oxidation.

Genome-Wide Transcriptome Profiling Provides Insight on Cholesterol and Lithocholate Degradation Mechanisms in VKM Ac-2033D.

Steroid microbial degradation plays a significant ecological role for biomass decomposition and removal/detoxification of steroid pollutants. In this study, the initial steps of cholesterol degradation and lithocholate bioconversion by a strain with enhanced 3-ketosteroid dehydrogenase (3-KSD) activity, VKM Ac-2033D, were studied. Biochemical, transcriptomic, and bioinformatic approaches were used.

Draft Genome Sequence of the Moderately Thermophilic Actinobacterial Steroid-Transforming Saccharopolyspora hirsuta subsp. Strain VKM Ac-666.

The draft genome sequence of the type strain subsp. VKM Ac-666 was sequenced. This moderately thermophilic actinobacterial strain of sugarcane bagasse origin is able to transform different steroid substrates.

Synthesis of 3beta-hydroxy-androsta-5,7-dien-17-one from 3beta-hydroxyandrost-5-en-17-one via microbial 7alpha-hydroxylation.

The synthesis of 3beta-hydroxy-androsta-5,7-dien-17-one from 3beta-hydroxy-androst-5-en-17-one (dehydroepiandrosterone, DHEA) via microbial 7alpha-hydroxylation has been accomplished. At the first stage, 3beta,7alpha-dihydroxy-androst-5-en-17-one was obtained in high yield (71.2%) using a strain of Gibberella zeae VKM F-2600, which was first applied for DHEA conversion.

Hydroxylation of carbazoles by Aspergillus flavus VKM F-1024.

Carbazole was metabolized by Aspergillus flavus VKM F-1024 forming few monohydroxylated products. The structure of metabolites was determined by TLC, GC, MS and (1)H NMR analyses. 3-Hydroxycarbazole was revealed as a major bioconversion product, 1-hydroxy- and 2-hydroxycarbazoles were observed as minor products.