Research On Transformation Of Ethinyloestradiol By S. Virginiae IBL14and Biosynthesis Of Precursors Of Ergosterol In Saccharomyces Cerevisiae

Steroids exist widely in cells of people and animals as well as some microorganisms; the major function of steroids is regulation of organisms. Steroids have both positive and negative affections to people and animals. Normally, steroids can improve growth and reproductive of people and animals, but steroids released to environment can disturb endocrine system of people and animals. Streptomyces virginiae IBL14, which used in this study, can degrade steroids efficaciously, that have been proven. Ethinyloestradiol is one kind of estrogen that can disturb endocrine system of people and animals at extremely low concentration. In this study, we researched transformation and degradation of ethinyloestradiol by IBL14, in order to discover new intermediate products and construct metabolic pathway of steroids.Saccharomyces cerevisiae can produce ergosterol, IBL20is one kind of high ergosterol-producing stains that can yield80mg ergosterol per liter culture, synthesis pathway of ergosterol in Saccharomyces cerevisiaehave been reported. In this study, we expect to discover new precursors for producing of steroid medicines by deleting of genes associated with ergosterol synthesis in Saccharomyces cerevisiaehave. We deleted and cloned the erg4, which is the last one of genes in synthesis pathway of ergosterol in Saccharomyces cerevisiaehave.This study investigated that IBL14can transform and degrade ethinyloestradiol, transformation and degradation efficiency associated with the adding time of substrate, preliminary identification of products had been done. Saccharomyces cerevisiaehave haploid of erg4-defective had been selected, but this strain still can synthesis ergosterol. erg4can express in E. Coli, the expression is soluble.