摘要
为探究离子液体双相体系中蜡状芽孢杆菌(Bacillus cereus)HDZJU1-11羟基化维生素D_3的生物催化反应,比较了5种离子液体([PrMIm][PF6],[BMIm][PF6],[BMIm][NTf2],[HMIm][PF6],[OMIm][NTf2])对底物的溶解能力以及与实验菌株的生物相容性;优化了离子液体双相体系中相比(水相与离子液体相的体积比)、pH及底物浓度等条件,选择[BMIm][PF6],[BMIm][NTf2]及[OMIm][NTf2]作为构建双相体系的离子液体.对[BMIm][PF6]/水双相体系而言,菌体生长12h后进行转化,相比为4∶1,水相pH为7.5,离子液体中底物浓度为0.5mg/mL时,24h后产物25-羟基维生素D_3浓度最高达0.38mg/mL.结果表明,离子液体双相体系可成功应用于蜡状芽孢杆菌羟基化维生素D_3的转化反应,为放大实验与工业化生产提供了理论支持.
To explore the biocatalytic hydroxylation of vitamin D 3 catalyzed by Bacillus cereus HDZJU1-11 in ionic liquid biphasic systems,a comparison was conducted of the substrate solubility and biocompatibility in 5 ionic liquids([PrMIm][PF6],[PF6],[NTf2],[HMIm][PF6],and[OMIm][NTf2])and the optimization of phase ratio,pH,and substrate concentration in ionic liquid biphasic systems was performed.[PF6],[NTf2],and[OMIm][NTf2]were chosen to construct biphasic systems.In[PF 6]/water biphasic system,the optimal conversion condition is as follows:0.5 mg/mL vitamin D3 and[PF6](V water∶V IL=4∶1)are added after 12 h fermentation of Bacillus cereus,and the pH of water phase is 7.5.The concentration of 25-hydroxyvitamin D3 is increased to 0.38 mg/mL at 24 h fermentation.The optimal conversion conditions in ionic liquid biphasic systems are determined,which lays a foundation for expanding experiment and industrial applications.
作者
程兆鹏
汤丹丹
徐志南
CHENG Zhaopeng;TANG Dandan;XU Zhinan(Institute of Bioengineering,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,China)
