Abstract:

Biosynthesis of glycyrrhetinic acid monoglucuronide (GAMG) by β-D-glucuronidase from the whole cell of Penicillium purpurogenum Li-3 in an aqueous / organic system was studied.Results showed that tert-butyl alcohol is the best organic solvent and the optimum volume ratio of aqueous to organic phase is 3 to 7.The rest optimum conditions for this biocatalysis are 1.5 g•L^-1 of substrate concentration, 45℃ of temperature, pH 5.0, 7 g•L^-1 of enzyme concentration and 120 r•min^-1 of shaking rate.Under these optimized conditions,79.12% yield of GAMG was achieved after 48 h reaction. The whole-cell enzyme has a good reusability and a high stability, which demonstrates the prospect for real application.

Key words:

生物转化, 单葡糖醛酸基甘草次酸, 水/有机溶剂体系, 产紫青霉, 全细胞, β-D-葡萄糖醛酸苷酶

摘要：

研究了产紫青霉Penicillium purpurogenum Li-3 全细胞β-D-葡萄糖醛酸苷酶在水/有机溶剂体系中催化水解甘草酸，合成单葡糖醛酸基甘草次酸（GAMG）的反应。确定了最适反应体系为水/叔丁醇（体积比为3∶7），最适反应条件为：底物甘草酸用量1.5 g•L^-1、反应温度45℃、pH值5.0、全细胞酶量7 g•L^-1、摇床转速120 r•min^-1，在此条件下反应48 h，产物GAMG产率可达79.12%，全细胞酶具有较好的稳定性和可重复使用性，显示了良好的应用前景。

关键词:

生物转化, 单葡糖醛酸基甘草次酸, 水/有机溶剂体系, 产紫青霉, 全细胞, β-D-葡萄糖醛酸苷酶