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

摘要

[目的]考察离子液体-水双相体系中赤霉菌(Gibberella intermediaC l)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6g/L底物DHEA.在5L发酵罐上,当转化至60 h时,产物浓度高达5.03±0.21 g/L,7cc,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5L发酵罐中进行了实验,为该体系的工业化应用奠定了基础.%[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 C 1.[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.