gamma-sitosterol and 1-4-androstadiene-3-17-dione

Effects of different carbon sources on growth, membrane permeability, β-sitosterol consumption, androstadienedione and androstenedione (AD(D)) production by Mycobacterium neoaurum were investigated. The results indicated that glucose was advantageous to the growth and resulted in the adverse effects on the phytosterols consumption and AD(D) production compared to the results of propanol and isopropanol as sole carbon source. The cell wall widths of 9.76 by propanol and 8.00 nm by isopropanol were 38.3 and 49.4 % thinner than that of 15.82 nm by glucose, respectively. The partition coefficient of the cell grown in propanol and isopropanol was 18.1 and 22.2, which were 7.23- and 9.09-fold higher than that of the cell grown in glucose.

Topics: Androstadienes; Androstenedione; Carbon; Cell Membrane Permeability; Cell Wall; Hydrophobic and Hydrophilic Interactions; Lipids; Mycobacterium; Sitosterols

The use of a biocompatible water-immiscible organic phase as a substrate and product pool has been acknowledged as an effective tool to overcome the low volumetric productivity of aqueous bioconversion systems involving hydrophobic compounds. The growing environmental and public health awareness is nevertheless leading to restrictions in the use of organic solvents in industrial processes, in order to render these more environmentally friendly. Different approaches are hence being assessed for the design of alternative bioconversion media, involving the use of supercritical fluids, ionic liquids and natural oils and liquid polymers, among others. In this work, the use of liquid polymers as key components in the bioconversion media for a multi-step microbial bioconversion was assessed. The model system used was the selective cleavage of the side-chain of beta-sitosterol by free resting cells of Mycobacterium sp. NRRL B-3805, a well established industrial multi-enzymatic process involving the use of nine catabolic enzymes in a fourteen-step metabolic pathway. High product yields were obtained when silicone B oil was used as substrate carrier/product pool, both in single oil and in oil:buffer two liquid phase system.

Topics: Androstadienes; Buffers; Mycobacterium; Polymers; Sitosterols; Solubility; Time Factors

Mycobacterium sp. VKM Ac-1815D and its derivatives with altered resistance to antibacterial agents were able to produce androst-4-ene-3,17-dione (AD) as a major product from sitosterol. In this study, those strains were subjected to subsequent mutagenization by chemical agents and UV irradiation in combination with sitosterol selection pressure. The mutant Mycobacterium sp. 2-4 M was selected, being capable of producing 9alpha-hydroxyandrost-4-ene-3,17-dione (9-OH-AD) as a major product from sitosterol, with a 50% molar yield. Along with 9-OH-AD, both AD and 9alpha-hydroxylated metabolites with a partially degraded side-chain were formed from sitosterol by the mutant strain. The strain was unable to degrade 9-OH-AD, but degraded androsta-1,4-diene-3,17-dione (ADD), thus indicating a deficiency in steroid 1(2)-dehydrogenase and the presence of 9alpha-hydroxylase activity.

Topics: Androstadienes; Androstenedione; Biotransformation; Molecular Structure; Mutagenesis; Mycobacterium; Oxidoreductases; Selection, Genetic; Sitosterols

Fermentation of (+)-androsta-1,4-diene-3,17-dione ([structure: see text]) with Cephalosporium aphidicola for 8 days yielded oxidative and reductive metabolites, androst-4-ene-3,17-dione ([structure: see text]), 17beta-hydroxyandrosta-1,4-diene-3-one ([structure: see text]), 11alpha-hydroxyandrosta-1,4-diene-3,17-dione ([structure: see text]), 11alpha-hydroxyandrost-4-ene-3,17-dione ([structure: see text]), 11alpha,17beta-dihydroxyandrost-4-ene-3-one ([structure: see text]) and 11alpha,17beta-dihydroxyandrosta-1,4-diene-3-one ([structure: see text]). The fermentation of [structure: see text] with Fusarium lini also yielded metabolites [structure: see text]. The structures of these metabolites were elucidated on the basis of spectroscopic techniques.

Topics: Acremonium; Androstadienes; Cholesterol; Fermentation; Fusarium; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Sitosterols; Spectrophotometry, Infrared; Spectroscopy, Fourier Transform Infrared; Stereoisomerism

Mycobacterium vaccae exposed to compounds which are known to disorganise the cell wall composition and architecture (protamine, glycine) showed increased specific activity in beta-sitosterol biotransformation to androstene derivatives, intennediates in the production of most medical steroids. GC/MS analysis of free lipid fatty acids revealed higher content of unsaturated compounds, mainly C16:1 and C18:1 in protamine- and glycine-treated cells than that in control cells, which seems to change the permeability features of the cell wall barrier, facilitating hydrophobic beta-sitosterol diffusion.

Topics: Androstadienes; Androstenedione; Biotransformation; Cell Membrane Permeability; Cell Wall; Fatty Acids; Glycine; Mycobacterium; Protamines; Sitosterols

In this work, phytosterol-biotransforming strains were selected from Mycobacterium sp., using a high concentration of beta-sitosterol. The selection was made by culturing the strains in a medium enriched with 14 g beta-sitosterol/l as the unique source of carbon. During 2 months, the bacterial cultures were transferred successively. The extraction of the biotransformation products was made with methanol and ethyl acetate. The qualitative and quantitative analysis was made by means of thin-layer chromatography, gas-liquid chromatography (GLC) and GLC-mass spectrometry. Under these conditions, it was observed that after seven transfers, the strains MYcobacterium sp. MB-3683 and the Mycobacterium fortuitum B-11045 increased their biotransformation capacity from 20% to 64% and from 34% to 55%, respectively. The products in the highest proportion identified for each trial were androstenedione and androstadienedione. The results suggest that the high substrate concentration could be a selective mechanism to obtain strains more efficient in the biotransformation of beta-sitosterol into steroidal bases.

Topics: Androstadienes; Androstenedione; Chromatography, Thin Layer; Gas Chromatography-Mass Spectrometry; Mycobacterium; Nuclear Magnetic Resonance, Biomolecular; Sitosterols

Plasmid-harbouring, sterol-decomposing organism Arthrobacter oxydans 317 was treated with sodium dodecylsulphate to obtain a plasmid-cured strain A. oxydans 317 A1 incapable of utilizing 4-androstene-3,17-dione (AD). The strain 317 A1 was unable to degrade beta-sitosterol side chain completely to form AD but could carry out partial degradation as shown by the accumulation of 3-oxochol-4-en-24-oic acid as a major metabolite and 27-norcholest-4-en-3,24-dione as a minor metabolite. The strain could form 1,4-androstadiene-3,17-dione (ADD) from 3-oxo-23,24-bisnorchol-1,4-dien-22- oic acid (BNC) to a limited extent. The existence of metabolic blocks in the conversion of 3-oxochol-4-en-24-oic acid to 3-oxo-23,24-bis-norchol-4-en-22-oic acid and further conversion to AD by the plasmid-cured strain 317 A1 was suggested. Neither the formation of ADD from AD nor the conversion of AD and ADD to 9 alpha-hydroxy derivatives leading to steroid ring opening could be done by the plasmid-cured strain but the 17 beta-reduction of AD and ADD and 1(2)-reduction of ADD were not affected by the absence of the plasmid. It was proposed that plasmid determines 1(2)-dehydrogenation and 9 alpha-hydroxylation of steroid ring structure in this organism.

Topics: Androstadienes; Androstenedione; Arthrobacter; Biodegradation, Environmental; Cholestenones; Plasmids; Sitosterols; Species Specificity

Transformation of sitosterol to androsta-1, 4-diene-3, 17-dione was studied with Mycobacterium cells entrapped in various polymeric matrices. Of the three supports viz. alginate, carageenan, agarose and polyacrylamide, studied, the polyacrylamide immobilized cells showed optimum catalytic stability and reusability.

Topics: Androstadienes; Biotransformation; Kinetics; Mycobacterium; Sitosterols