Whole-genome analyses and metabolic modification of Mycobacterium sp. LY-1 to enhance yield of 9α-OH-AD

Abstract

With the increasing application of steroid drugs as therapeutics, the demand for steroid drugs is increasing. In recent years, biological synthesis has become the standard approach to produce steroid intermediates, while this method still faces some problems such as unclear metabolic pathway and low yield. Mycobacterium sp. LY-1 can convert phytosterols into 9α-hydroxyandrost-4-ene-3,17-dione (9α-OH-AD) which is a key intermediate for the synthesis of steroid drugs with long effective time and significant pharmacological activity. In this work, the whole-genome sequence of the Mycobacterium sp. LY-1 was analyzed, and the side-chain degradation pathway of phytosterols in Mycobacterium sp. LY-1 was proposed. Meanwhile, the related key enzymes of phytosterol metabolism were identified through qRT-PCR. Through overexpressing the key enzymes including KshA2, KshB, and HsdB, the yield of 9α-OH-AD increased by 12.7% compared to that of the control. Furthermore, by optimizing the medium and culture conditions, the yield of 9α-OH-AD reached 50.4%. The maximum yield was 30.7% higher than that of the original strain. The results are of significance for the industrial production of 9α-OH-AD using metabolic engineering methods.

Keywords

Mycobacterium sp. LY-1 / Phytosterols / 9α-Hydroxyandrost-4-ene-3,17-dione / Biotransformation

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Funding

The National Key R & D Program of China(No. 2019YFA0905300); Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(No. TSBICIP-KJGG-001-14); The National Natural Science Foundation of China(No. 22078126); Fundamental Research Funds for the Central Universities(JUSRP221025); Qing Lan Project in Jiangsu Province