紫外诱变黑曲霉微生物转化甘草皂苷

Biotransformation of Glycyrrhizic acid by UV mutated Aspergillus niger

甘草皂苷是甘草的主要药效成分。但由于其结构上的特点,在机体中的运输和药效发挥上受到一定限制。微生物转化方法可以定向脱去一个单葡萄糖醛酸基以改变分子的极性,转化后的产物单葡萄糖醛酸基甘草皂苷元可以更好地为机体所利用。本文对微生物转化甘草皂苷所用黑曲霉进行了改性研究,通过紫外诱变使黑曲霉产生变异。从致死率曲线中选取黑曲霉变异几率最大的时间范围,再进行初筛、复筛和发酵,最后选出对甘草皂苷转化较高的变异菌株。实验筛选出的变异黑曲霉菌株对甘草皂苷的转化率为原始菌株的6.5倍。

Glycyrrhizic acid（GL）is the main component of liquorice root and has obvious pharmaceutical functions. However,its physiological function and transport ability in biosmass was limited due to its structural characteristic. The molecular structure of GL can be changed by cleaving one of molecular glucuronide through biological transformation method resulting in the improved polarity. Moreover,the transformed product monoglucurony-glycyrrhetinic acid has more pharmacological function as well. In this paper,the ability of biotransformation glycyrrhizin by Aspergillus niger were improved by UV mutation. The mutation time of parent Aspergillus niger strain was optimized by the fatality curve. Then after screening,re-screening and fermentation,the mutated Aspergillus niger which has more bioactivity to transform the glycyrrhizic acid were selected. The transformation of glycyrrhizic acid was 6.5 times more than the parent Aspergillus niger.