离子液体-水双相体系中Gibberella intermedia C1双羟化去氢表雄酮(DHEA)

Dihydroxylation of dehydroepiandro sterone (DHEA) by Gibberella intermedia C1 in an ionic liquid-water biphasic system

摘要:

【目的】考察离子液体-水双相体系中赤霉菌(Gibberella intermedia C1)双羟化甾体类底物去氢表雄酮(DHEA)生成三羟基雄甾烯酮(7α,15α-diOH-DHEA)的生物转化过程。【方法】比较5种不同种类的离子液体([Hmim][PF6]、[Bmim][PF6]、[Bmim][BF4]、[Bmim][NTF2]、[Emim][EtSO4])对底物转化率和产物得率的影响。优化该双相体系中离子液体的浓度、底物的投料浓度及投料时间等。【结果】选择[Emim][EtSO4]作为构建该体系的离子液体。摇瓶中最适双相体系转化条件为：菌体生长12 h后，向转化培养基中加入0.8% (体积比)的[Emim][EtSO4]，同时投加6 g/L底物DHEA。在5 L发酵罐上，当转化至60 h时，产物浓度高达5.03±0.21 g/L，7α,15α-diOH-DHEA产物摩尔得率达到最高75.5%。【结论】确定了离子液体-水双相转化体系的最适转化条件，并在5 L发酵罐中进行了实验，为该体系的工业化应用奠定了基础。

Abstract:

[Objective] This paper studied the biotransformation of the catalytic substrate dehydroepiandrosterone (DHEA) generated 7α,15α-diOH-DHEA by Gibberella intermedia C1 in the ionic liquid-water biphasic system. [Methods] The comparison of substrate conversion rates and product yields in five different ILs/water two-phase systems was carried out. And then, the optimization of bioconversion process in ionic liquid-water biphasic system was investigated to establish a suitable biphasic system with G. intermedia C1. [Results] The optimal conversion condition in ionic liquid-water biphasic system was as follows: 6 g/L DHEA and [Emim][EtSO4] (VILs:Vwater =0.8) were simultaneously added after 12 h fermentation of G. intermedia C1. In addition, the amplification experiments were carried out in 5 L fermentor. At 60 h fermentation of G. intermedia C1, the concentration of 7α,15α-diOH-DHEA increased to 5.03±0.21 g/L and the product molar yield reached 75.5%. [Conclusion] The optimal conversion condition in ionic liquid-water biphasic system was determined and the amplification experiments were carried out on the 5 L fermentor, which laid a solid foundation for industrial application further.