Abstract：In order to solve the shortage of dioscin used in the synthesis of steroid drugs, the production of androst-4-ene-3,17-dione (AD) and other intermediates using phytosterols as the substrate has drawn great attention in recent years. The main problem of sterols conversion in side-chain cleavage of sterols by microbial fermentation is its strong hydrophobic character, which leads to poor contact between substrate and enzymes and thus results in low conversion rate and the fermentation time was delayed. In this study, 6 kinds of organic solvents and 8 kinds of cyclodextrin and their derivatives were used to enhance the dissolution of sterols in side-chain cleavage of sterols by Mycobacterium sp. MB 3863, and the preferences of different substrates on solubilizer were investigated. The results showed that phytosterols (mixture sterols) was one of the most suitable substrates in producing AD, and different substrates showed no preferences for given solubilizer to some extent. When organic solvents were used as solubilizer, ethanol and acetone were found to be the most ideal. As for cyclodextrin and its derivatives, the methyl-β-cyclodextrin was the best candidate; when the concentration of phytosterols was increased to 15 g/L, the molar yield of AD could still be over 60% at optimized feeding time and molar ratio of methyl-β-cyclodextrin to phytosterols (2:1).
Xu Yangguang,Fan Yamin,Luo Lan et al. Study on Substrate and Solubilizer in Side-Chain Cleavage of Sterols by Mycobacterium sp. MB 3863[J]. 化学反应工程与工艺, 2015, 31(5): 423-429.
