摘 要:在化石能源日趋短缺与能源需求的日渐增长的矛盾形势下,以及化石能源带来的环境问题日益严重背景下,利用木质纤维原料制备燃料乙醇替代传统化石能源的技术成为当今世界的研究热点之一。纤维素酶能够有效将农作物秸秆等富含纤维素的物质水解为单糖,用于乙醇发酵,因此如何获得廉价高效的纤维素酶对我国经济和社会可持续发展具有重要的意义。本论文以里氏木霉RUT C-30为产酶菌株,研究了不同诱导剂即三种不同的糖:葡萄糖、乳糖和低聚木糖诱导产纤维素酶过程。结果表明:葡萄糖虽然是纤维素酶的抑制剂,但在发酵前期加入少量葡萄糖的可使里氏木霉快速生长而产生更多的纤维素酶;乳糖由于诱导产酶效果较好,而且因为乳糖价格低廉,常用作诱导剂使用;低聚木糖诱导效果一般,不适合做诱导剂。56788
毕业论文关键词:里氏木霉,纤维素酶,诱导剂,酶活力
Abstract:Nowdays, the storage of fossil fuels is getting fewer and fewer, but the need for fuel energy is growing, and the pullotion caused by the fossil fuels become more serious too, therefore, as an alternative to traditional fossil energy technology, the use of lignocellulosic materials for fuel ethanol become one of the world's research focus.
The cellulase can hydrolyze lignocellulosic materials, rich in cellulose, such as straw. We can convert straw into ethanol using cellulase. So how to get cheap and efficient cellulase has important significance for the sustainable development of economy and society in China. This thesis used Trichoderma reesei as the enzyme producing strains and studied the effect of different inducer on the expression of cellulase expression from T. reesei. The results show that low concentration of glucose can induce cellulase expression; high concentration of glucose have repression effect; the lactose, a cheap compound, has better cellulase inducetion, so it could be a very useful inducer; the xylo-oligosaccharides is not suitable to be a inducer.
Keywords:Trichoderma reesei, cellulase, inducer, cellulase activity
目 录
1 前言 3
1.1 研究背景 3
1.2 立题依据 3
2.1 产纤维素酶菌种和纤维素酶 4
2.1.1 纤维素酶的产生菌种 4
2.1.2 纤维素酶 4
2.2 里氏木霉产纤维素酶的诱导剂 4
3 对里氏木霉产纤维素酶的诱导剂的研究 5
3.1 材料与方法 5
3.1.1 原料 5
3.1.2 培养基 6
3.1.2.1 PDA培养基(固体,液体) 6
3.1.2.2 玉米浆种子培养基 6
3.1.2.3 发酵基本培养基 8
3.1.3 菌种制备 8
3.1.4 纤维素酶制备 9
3.1.5 试剂配制 9
3.1.5.1 柠檬酸缓冲液的配制 9
3.1.5.2 DNS试剂的配制 9
3.2.1 滤纸酶活测定 9
3.2.1.1 制备葡萄糖标准曲线