摘要
中药虎杖含有丰富的虎杖苷,利用生物转化技术将其转化为白藜芦醇是制备天然白藜芦醇的有效方法。虎杖内生真菌Aspergillus aculeatus HZ001细胞可催化虎杖苷转化为白藜芦醇,该文对该菌株产胞内β-葡萄糖苷酶的酶学性质进行研究。结果表明:该酶的最适反应温度为60℃,在低于60℃时有较好的稳定性;最适反应pH为4.8,在pH 3.6~4.0时有较好的稳定性;Fe^2+对其活力有激活作用,相对酶活力可达到120%,Ca^2+、Co^2+、Mg^2+等离子对酶活力有明显的抑制作用,其中Co^2+的抑制作用最明显;十二烷基硫酸钠、巯基乙醇、二甲基亚砜和乙二胺四乙酸(ethylene diamine tetraacetic acid,EDTA)4种抑制剂对该酶活力具有抑制作用,其中EDTA的抑制效果最为明显,相对酶活力仅有10%左右。在最适催化条件下,进行酶催化动力学分析,米氏常数K m值为2.571 mmol/L,最大反应速率V max值为0.594μmol/(mL·h)。
Polydatin is abundant in the traditional Chinese medicine Polygonum cuspidatum,and the conversion of polydatin to resveratrol by biotransformation technology is an effective method to prepare natural resveratrol products.The cells of endophytic fungus Aspergillus aculeatus HZ001,which isolated from P.cuspidatum,can catalyze polydatin to resveratrol.The enzymatic characteristics of intracellularβ-glucosidase produced by this strain were studied.The results showed that the optimum reaction temperature was 60℃,good stability was obtained below 60℃;and the optimum reaction pH was 4.8 with good stability at pH 3.6-4.0.The β-glucosidase could be activated by Fe^2+with a relative enzyme activity of 120%and significantly inhibited by Ca^2+,Co^2+,and Mg^2+.SDS,mercaptoethanol,and dimethyl sulfoxide also inhibited the enzyme activity,and the highest inhibitory rate of 90%was obtained with EDTA.Under the optimal catalytic conditions,the kinetic parameters of the enzymatic reaction were established with the K m of 2.571 mmol/L and the V max of 0.594μmol/(mL·h).
作者
于洁
徐勤茜
李子院
刘红艳
郝再彬
李海云
YU Jie;XU Qinqian;LI Ziyuan;LIU Hongyang;HAO Zaibin;LI Haiyun(College of Chemistry&Bioengineering,Guilin University of Technology,Guilin 541004,China;Guangxi Colleges and Universities Key Laboratory of Food Safety and Detection,Guilin University of Technology,Guilin 541004,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2021年第3期31-35,共5页
Food and Fermentation Industries
基金
国家自然科学基金项目(31460409)
广西自然科学基金项目(2016GXNSFAA380014)
广西科技基地和人才专项项目(桂科AD18050004)
广西壮族自治区特聘专家项目(农产品精深加工关键技术与质量安全,厅发[2018]39)。
关键词
虎杖
内生真菌
刺孢曲霉
Β-葡萄糖苷酶
酶学性质
Polygonum cuspidatum
endophytic fungus
Aspergillus aculeatus
β-glucosidase
enzymatic characteristics
