摘 要:自然界中分布最广、贮藏最多的就是纤维,具有广阔的应用前景。纤维素酶可以降解自然界的纤维素生成葡萄糖等可溶性的糖。如今纤维素酶已广泛应用在食品、饲料、纺织等多种行业的应用。本文以产纤维素酶效果最好的里氏木霉为研究对象,采用液体培养基进行振荡培养,探索里氏木霉产纤维素酶的最适pH和温度。研究表明,3%秸秆作为碳源,温度在27℃,pH5的时候,里氏木霉产纤维素酶的效果最好,最高酶活达到0.24U,是理想的条件。36℃ pH6的时候最大的酶活仅为0.11U。在24℃时,各pH下的酶活增长缓慢,不利于酶活增长。62471
毕业论文关键词: 纤维素酶,里氏木霉,温度,pH
Abstract: Fibre, the most widely distributed and stored material in nature, has a broad application prospect. Cellulase can hydrolyze cellulose to produce glucose and other soluble sugar. Now cellulase has been used in the food, feed, agriculture and other industries. This thesis, using Trichoderma reesei as the cellulase production strain, tried to find the optimal pH and temperature for cellulase production by T. reesei in liquid medium with shaking. The results show that, with 3% of straw as carbon source, 27 ℃ and pH5, gives the highest cellulase activity, with the highest enzyme activity reach 0.24 U. Too high temperature has a great influence on the production of cellulase by T. reesei to produce cellulase enzyme activity. At 36 ℃, pH6 gives the highest cellulase activity of about 0.11U. At 24 ℃, the cellulase activity grows slowly at all the pH tested, therefore it isn’t suitable for cellulase production.
Keywords:Cellulase; Trichoderma reesei; Temperature; pH
1 前言 6
1.1 里氏木霉 6
1.1.1 里氏木霉的结构 6
1.1.2 里氏木霉的功能 6
1.1.3 里氏木霉的特性 7
1.2 纤维素酶 7
1.2.1 纤维素酶的特性 7
1.3 里氏木霉产纤维素酶的应用 7
2 材料与方法 8
2.1 材料 8
2.2 试剂配制 8
2.3 培养基 8
2.4 实验步骤 8
2.4.1 菌种培养 8
2.4.2 接种发酵 9
2.4.3 滤纸酶活测定 9
2.4.3.1 葡萄糖标准曲线 9
2.4.3.2 测滤纸酶活 9
2.4.4 酶活计算方法 9
3 结果与分析 10
3.1 葡萄糖标准曲线 10
3.2 结果分析与讨论 11
3.2.1 24℃不同pH条件里氏木霉产纤维素酶影响 11
3.2.2 27℃不同pH条件里氏木霉产纤维素酶影响 11
3.2.3 30℃不同pH条件里氏木霉产纤维素酶影响 12
3.2.4 33℃不同pH条件里氏木霉产纤维素酶影响