Screening strains for directed biosynthesis of β-D-mono-glucuronide-glycyrrhizin and kinetics of enzyme production
Screening strains for directed biosynthesis of β-D-mono-glucuronide-glycyrrhizin and kinetics of enzyme production
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DOI：
10.1016/j.molcatb.2006.06.016
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发表时间：
2006-12-04
影响因子：
--
通讯作者：
Wang, Xiaoyan
中科院分区：
文献类型：
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作者：
Feng, Shijiang;Li, Chun;Wang, Xiaoyan
其中一种真菌暂定名为青霉菌。Li-3直接生物合成β-D-单葡萄糖醛酸甘草酸(GANG)。该菌株以甘草甜素为诱导物，以唯一碳源为碳源，能表达底物专一性较高的胞内酶--β-D-葡萄糖苷酸酶。而甘草酸在青霉菌发酵过程中直接被酶降解为甘草酸。Li-3高产。结果表明，该反应的摩尔转化率高达88.45%。对该菌株产β-D-葡萄糖醛酸酶动力学的研究表明，该菌株的生长和产酶是部分耦合的。目的酶在表达过程中存在碳分解抑制，因此只有甘草甜素是最好的碳源和激发子。结果表明，表面活性剂(吐温80，0.12%)能显著提高产酶能力。在初始pH为4.8，培养温度为32℃的条件下，最大酶活为181.53 U m l(-1)。(C)2006爱思唯尔B.V.保留所有权利。
One fungus, tentatively named Penicillium sp. Li-3, was screened to biosynthesize beta-D-mono-glucuronide-glycyrrhizin (GANG), directly. Using glycyrrhizin as elicitor and the sole carbon source, this strain was capable of expressing beta-D-glucuronidase, one intracellular enzyme with high substrate specificity. And glycyrrhizin was hydrolyzed directly into GAMG by enzyme from Penicillium sp. Li-3 with high production. It was found that the mol conversion ratio of this reaction was up to 88.45%. Research about kinetics Of beta-D-glucuronidase production showed that the cell growth and enzyme production of this strain was partial coupled. During the expressing of target enzyme, carbon catabolite repression existed, so only glycyrrhizin was the best carbon source as well as the elicitor. It was found that the surfactant (Tween 80 0.12%) could improve the ability of enzyme production markedly. Under the condition of initial pH 4.8 of the medium and 32 degrees C of the culture temperature, the maximum enzyme activity of 181.53 U ml(-1) was obtained. (c) 2006 Elsevier B.V. All rights reserved.