Abstract: Androstenedione is an important intermediate in the production of steroid medicine. Its C9 hydroxylation product, 9-hydroxyandrostenedione, is also a precursor of many important steroid medicines and has important clinical medicinal value. Therefore, the production of 9-hydroxyandrostenedione by microbial transformation has important economic value. In this study, the svu005 gene of Streptomyces Virginia IBL14 was fused with pET28a plasmid and introduced into Escherichia coli BL21(DE3). The expression of CYP105D1 protein was induced by optimized self-induction medium, and various substrates, including androstenedione, were used for microbial transformation. The results showed that the constructed recombinant plasmid pET28a-svu005 was successfully expressed in E. coli. The production of self-induced active protein was 0.0916 nmol/L in ZYM medium, which was significantly higher than that of traditional IPTG induction method (0.0367 nmol/L). The expressed product CYP105D1 protein has the function of biotransforming androstenedione to 9-hydroxyandrostenedione. This study has opened up a new way for the synthesis of 9-hydroxyandrostenedione by microbial transformation and has a good prospect of industrial application.

Key words: font-size:medium, ">9-hydroxyandrostenedione； microbial transformation； CYP105D1； self-induction