甲壳素酶的初步研究

论文编号:SW152  论文字数:11277,页数:26

摘 要：甲壳素是一种极其有前途和极其重要的天然高分子可再生的物质，是不造成环境污染的新型高分子材料。近年来甲壳素酶在生物防治、医药等领域的研究与开发引起了国内外普遍关注。甲壳素酶主要产生于微生物，其降解产物应用极其广泛。本研究主要是采用固体平板分离纯化及初筛甲壳素酶产生菌株，同时利用液体发酵进行复筛，结果得到一株甲壳素酶高产芽孢杆菌，编号为菌株2-3，产甲壳素酶活能力最强，达284U/ml。并对甲壳素酶的部分酶学性质进行研究，按照实验的酶活力测定方法，得出甲壳素酶的最适底物为胶体甲壳素，最适pH为6.5，最适催化反应温度为60℃，反应温度较高有利于甲壳素酶解反应的进行。此外，通过盐析实验，得到甲壳素酶的最佳(NH4)2SO4盐析浓度是70%饱和度。
关键词：甲壳素；甲壳素酶；酶活；酶学性质

Abstract：Chitin is a very prosperous and important natural macromolecule. It is also a reproducible new macromolecule material and has no pollution to environment. Chitinase was paid attention in the research and development of biological control and medicine in recent years. Chitinase is mainly produced by microbe, whose degradation   products have a wide application. The purpose of this study is purification and rapid screening of chitinase producing strains by solid plate color reaction. At the same time, it screens the high-yield strain which producing chitinase through liquid fermentation. The results showed that it screened a Bacillus strain of high yield of producing chitinase, strain 2-3 produced the enzyme activity as high as 284U/ml. And we have researched on some enzymatic characteristics of chitinase. In accordance with the experimental determination of enzyme activity, the optimum substrate of chitinase was colloidal chitin, the optimum pH was 6.5 and the optimum temperature was 60℃,higher temperature was promoting the hydrolysis reaction of chitin. In addition, by salting-out experiments, the best salting-out concentration of chitinase was 70% of (NH4)2SO4   saturation.
Keywords：Chitin;Chitinase; Enzyme activity; Enzymatic characteristics

目  录
中文摘要 I
英文摘要 II
目录 III
1. 绪论 1
 1.1  甲壳素和壳聚糖的性质 1
 1.2 微生物甲壳素酶的研究进展 2
 1.3 酶的分离纯化 6
2. 实验部分 8
 2.1 实验材料 8
 2.2 实验方法 9
3. 结果与讨论 12
 3.1 N-乙酰氨基葡萄糖标准曲线的制作 12
 3.2 平板分离筛选及摇瓶复筛  13
 3.3 甲壳素酶高产菌株的特征 13
 3.4 甲壳素酶的性质 14
 3.5 最佳盐析浓度的确定 17
4．总结与展望 18
致谢 19
参考文献 20
附录A 21

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