Efficient bioconversion of epimedin C to icariin by a glycosidase from Aspergillus nidulans
Efficient bioconversion of epimedin C to icariin by a glycosidase from Aspergillus nidulans
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通过构巢曲霉糖苷酶将淫羊藿 C 高效生物转化为淫羊藿苷
DOI：
10.1016/j.biortech.2019.121612
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发表时间：
2019-10-01
影响因子：
11.4
通讯作者：
Zhou, Jingwen
中科院分区：
文献类型：
--
作者：
Lyu, Yunbin;Zeng, Weizhu;Zhou, Jingwen
淫羊藿是一种传统的中草药，含有生物活性黄酮苷的混合物。其中淫羊藿苷的生物活性最为突出，而朝藿定C则具有较强的毒性。利用大肠杆菌表达了构巢曲霉α-L-鼠李糖苷酶（（syn）AnRhaE），以促进朝藿定C转化为淫羊藿苷。在5L的生物反应器中，通过优化的流加发酵，获得了574.5U L-1的水解酶活力。证明该酶在低于55 ℃的酸性pH范围内稳定，最适pH为4.5，最适温度为55 ℃。重组细胞在90 min内可100%转化淫羊藿苷。休眠细胞对淫羊藿粗提物中的淫羊藿甙C和2“-O-鼠李糖甙II具有选择性。本研究为淫羊藿苷的工业化生产提供了一种新颖、高效的生物催化体系。
Herba Epimedii is a traditional Chinese herbal medicine that contains a mixture of bioactive flavonoid glycosides. Among them, icariin has the most outstanding bioactive functions, while epimedin C exhibits substantial toxicity. A recombinant alpha-L-rhamnosidase ((syn)AnRhaE) from Aspergillus nidulans was expressed in Escherichia coli to promote the efficient bioconversion of epimedin C to icariin. A hydrolase activity of 574.5 U L-1 was acquired via optimized fed-batch fermentation in a 5-L bioreactor. The enzyme proved to be stable in an acidulous pH range below 55 degrees C with an optimal pH of 4.5 and optimal temperature of 55 degrees C. Epimedin C (1 g L-1) was 100% converted to icariin within 90 min using recombinant cells. The resting cells proved to be selective for epimedin C and 2 ''-O-rhamnosylicariside II in crude extracts of the epimedium plant. This work provides an original and efficient biocatalyst system that can be applied in industrialized production of icariin.