Evaluation of C19 Steroid Intermediates during Microbial Transformation of Phytosterol

Abstract

Aim: To assay for C19 steroid intermediates during biotransformation of phytosterol. Study of Design: Pretreatment and processing of wheat bran and rice bran, Sulphate-phosphate-ferric technique, phytosterol screening, fermentation process, enzymatic assay and steroid intermediate assay. Place and Duration of Study: Microbiology Unit, Department of Biological Sciences, College of Natural and Applied Sciences, Fountain University Osogbo, Osun State, Nigeria between  April, 2015 and March, 2016. Methodology: Preliminary screening of agricultural residues (wheat bran and rice bran) for presence of phytosterols was determined using Sulphate-phosphate-ferric technique. Saccharomyces cerevisiae strain was screened for its ability to transform phytosterol to steroid intermediates after fermentation process using gas chromatography-flame ionization detector (GCFID) and enzymes such as 3-ketosteroid-9-hydroxylase (Ksh) and 3-ketosteroid-1-dehydrogenase (KstD) required for transformation were also assayed through Ion exchange and gel permeation chromatography respectively. Results: Steroid intermediates such as Boldenone, Testosterone, 4-androstene-3, 17-dione (AD), Androsta-1,4-diene-3,17-dione (ADD), 9-OH-Testosterone and 9-OH-AD were obtained from crude extract after fermentation using GCFID. The result shows the ability of Saccharomyces cerevisiae to transform rice bran and wheat bran phytosterols to precursors for synthesis of steroid hormones. Conclusion: Sterol uptake takes place via the direct contact between the cells and the sterol particles, thus Saccharomyces cerevisiae ability to transform phytosterols to steroids shows its adaptive mechanism which allows microorganisms to use minimally water-soluble hydrocarbons as carbon sources.