酵母蔗糖酶的提取工艺.doc

酵母蔗糖酶的提取工艺
摘要
蔗糖酶是一种水解酶, 广泛存在于动物、植物、微生物等各种生物体内。它可以不可逆的催化蔗糖水解为D-葡萄糖和D-果糖,为微生物的生长提供碳源和能源。
[1]采用甲苯自溶法、冻融法、SDS抽提法3种方法从酵母中提取蔗糖酶,冻融法和SDS
抽提法的提取效率远高于传统的甲苯自溶法。其中冻融法的效率最高(纯化倍数比活力与总活力),加之其操作简便,更适合于酵母蔗糖酶大规模的制备提取。
比较了乙醇分级沉淀、硫酸铵分级沉淀对于冻融法得到的粗提物的沉淀效果,结果表明:50%(w/w)乙醇分级沉淀效果较好(比活力与总活力),乙醇分级沉淀所得蔗糖酶经DEAE-Sepharose 离子交换层析纯化后,制得高纯度的酵母蔗糖酶(比活力与总活力)。,,%。
蔗糖酶的酶促动力学性质表明,,最适温度为50℃,,。
关键词:酵母;蔗糖酶;提取;纯化
Study on Purification of Invertase from Yeast Abstract
Sucrase is widespread in prokaryotes and eukaryotes .Sucrase catalyzes
the irreversible hydrolysis of sucrose into glucose and mainfroms of carbon and energy supplies in anism growth and development.
This paper used three methods to extract invertase from yeast,which included in this manuscript, three different extraction method breaking cells by adding methylbenzene,frost grinding,and adding SDS for extracting invertase from yeast were the purified invertase was obtained by precipitatation with 50% ethyl alcohol、sequential ammonium sulpate precipitation and DEAE-Sepharose lon-exchange purified sucrase was characterized by SDS- results showed all three methods had both advantages and invertase extracted by adding SDS and frost grinding had much more total activity than that of extracted by adding highest total invertase activity was found in the forst grinding,and it was a convent and economical method mercial production of invertase from yeast.
The results of our study were followed:
1、Purification of invertase from yeast
The specific activity was ,purification fold was activity recovery of sucrase was %.
2、Properties of sucrase
The ic characters of the enzyme have been optimum PH and optimum temperature for the enzyme are and 50℃.Km is 21mmol/Land Vmax is .
Key words : yeast;in