论文总字数：19856字

摘 要

银耳胞外多糖是银耳菌发酵的主要产物，本研究从鲜银耳中分离得到银耳菌种，经液体深层发酵后离心收集发酵液，利用醇沉法获得银耳胞外粗多糖（WSK），提取率为3%。经检测，其中含有两种不同分子量的多糖组分，命名为银耳多糖TFP1和银耳多糖TFP2，GPC法测定其分子量分别为 228 kDa 和1302 kDa。采用DEAE离子交换柱对粗多糖进行分离纯化，经硫酸苯酚法和液相色谱技术检测洗脱液组分发现，TFP1主要集中于0.3 mol/L NaCl洗脱液中，得率为0.79 g/g，纯度为90.5%。TPF2则在0.7mol/L NaCl洗脱液中，得率为 0.12 g/g，纯度为85.5%。

经纯化得到的TFP1纯度为 90.5%。在此基础上，对TFP1进行吸湿性、保湿性和流变学性质实验中发现，TFP1的吸湿保湿效果均优于银耳胞外粗多糖，5mg/ml TFP1溶液表现出剪切变稀特性，零剪切速率粘度为0.25 Pa·s。

关键词：银耳发酵 胞外多糖 分离纯化 性质

The Separation and Purification and Property Analysis of Extracellular Polysaccharides from Tremella Fuciformis

Abstract

Tremella fuciformis extracellular polysaccharide is the main product of Tremella fuciformis fermentation. In this study, Tremella fuciformis strains were isolated from fresh Tremella fuciformis. The fermentation broth was centrifuged after submerged fermentation. The crude Tremella fuciformis extracellular polysaccharide（WSK）was obtained by alcohol precipitation. The extraction rate was 3%.It was found that it contained two polysaccharide components with different molecular weights, named tremella polysaccharide TFP1 and tremella polysaccharide TFP2, and their molecular weights were determined by GPC method as 228 kDa and 1302 kDa, respectively.The crude polysaccharides were separated and purified by DEAE ion exchange column, and the eluent components were detected by phenol sulfate method and liquid chromatography. It was found that TFP1 was mainly concentrated in 0.3 mol/L NaCl elution solution, and the yield was 0.79 g/g, the purity was 90.5%;TPF2 was obtained in 0.7mol/LNaCl elution solution, with a yield of 0.12 g/g and a purity of 85.5%.

The purity of TFP1 obtained by purification was 90.5%.On this basis, experiments on the hygroscopic, moisturizing and rheological properties of TFP1 showed that the hygroscopic and moisturizing effect of TFP1 was superior to that of the extracellular polysaccharide of tremella. The 5mg/ml TFP solution showed the shear thinning property, and the zero shear rate viscosity was 0.25 Pa·s.

Keywords: Tremella Fermentation；Extracellular Polysaccharide；Eeparation and Purification；Characte

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1概述 1

1.2银耳胞外多糖的提取和分离工艺应用 1

1.2.1银耳胞外多糖的发酵现状 1

1.2.2银耳胞外多糖的提取工艺现状 2

1.2.3银耳胞外多糖的分离纯化工艺现状 4

1.2.4分子量与银耳胞外多糖生物活性关系的研究现状 5

第二章 材料与方法 7

2.1实验仪器及试剂 7

2.1.1原料 7

2.1.2试剂 7

2.1.3设备与仪器 8

2.2银耳胞外多糖的制备 9

2.2.1银耳菌的平板培养 9

2.2.2银耳菌的一级培养 9

2.2.3银耳菌的二级培养 9

2.2.4发酵液的分离 10

2.3离子交换柱(DEAE)分离不同分子量的银耳胞外多糖 10

2.3.1预处理和装柱 10

2.3.2柱的平衡 10

2.3.3加样 10

2.3.4洗脱 11

2.3.5洗脱液处理 11

2.4银耳胞外多糖的测定 11

2.4.1残糖测定 11

2.4.2总糖测定 11

2.5银耳胞外多糖的液相图谱及分子量测定 12

2.5.1标准曲线的绘制 12

2.5.2纯度鉴定和分子量测定 12

2.6银耳胞外多糖的性质研究 12

2.6.1吸湿性研究 12

2.6.2保湿性研究 13

2.6.3流变性研究 13

2.7糖醛酸测定 13

第三章 结果与讨论 14

3.1银耳胞外多糖的制备 14

3.2离子交换柱纯化银耳胞外多糖 16

3.3银耳胞外多糖的液相图谱及分子量测定 17

3.4银耳胞外多糖的性质研究 19

3.4.1吸湿性 19

3.4.2保湿性 20

3.4.3流变性 21

第四章 结论与展望 22

参考文献 23

致 谢 26

第一章 绪论

1.1概述

银耳，隶属于隶属真菌门，担子菌纲，银耳目，银耳科，银耳属 ^[1]。银耳种类很多，据目前所知在全球约有60种，一般都腐生在阔叶林或者针叶林原木之上，还有极少部分银耳能够以土壤或者各种真菌为生^[2]。野生银耳绝大部分生长在亚热带地区，主要分布在我国四川、重庆、贵州三省。^[3]。

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