不同的C源对里氏木霉产纤维素酶的影响的研究

论文总字数：17081字

摘 要

近年来，随着全球气候变暖趋势日益加剧、资源能源短缺问题日显突出，纤维素酶在木质纤维资源生物炼制燃料乙醇和生物基化学品上的应用受到普遍重视。通过不同C源对里氏木霉产纤维素酶活性的影响，筛选高产纤维素酶培养基，能为实际生产中利用纤维素酶提高纤维素的利用率提供依据。本论文以1%，2%，3%，5%，8%预处理木质素的培养基，培养里氏木霉测定纤维素酶的酶活变化，以3%预处理木质素 1%葡萄糖，3%预处理木质素 2g/L乳糖、3%预处理木质素 0.5%低聚木糖为起始培养基培养里氏木霉测定纤维素酶的酶活变化。以1%，2%，3%的预处理的木质纤维素为C源时，72-96h内能能检测到纤维素酶的酶活，以3%的预处理的木质纤维素为C源时168h后酶活达到最高10.44U/ml，之后酶活开始下降。较高浓度5%，8%前期酶活较低，58h也可达到较高活性，8%活性一直较低。3%预处理木质素 1%葡萄糖的培养基酶活168h酶活到达峰值8.28U/ml ，3%预处理木质素 2g/L乳糖的培养基酶活144h到达峰值14.66U/ml，3%预处理木质素 0.5%低聚木糖的培养基酶活168h到达峰值13.54U/ml ，乳糖条件下，酶活最高。葡萄糖96h后酶活上升，乳糖，低聚木糖76h就具有较高酶活。通过实验结果可知，以不同浓度的预处理的木质纤维素为C源时，3%的浓度纤维素酶的酶活高，达10.44U/ml，以3%浓度的预处理的木质纤维素，加入不同糖为C源时，加入乳糖的纤维素酶酶活，达14.66U/ml。

关键词：里氏木霉，酶活，C源

Abstract：In recent years, with the global warming trend is rising, energy shortage is getting more prominent, cellulase enzyme in wood fiber can be used to concert to refined fuel ethanol and bio-based chemicals by using cellulase enzymes. This thesis studies the influence of different C source for cellulase production from Trichoderma reesei, therefore screening for high-yield cellulase culture medium, which can raise the utilization rate of cellulose by using cellulase enzyme. This thesis uses 1%, 1%, 2%, 5% or 8% of pretreated biomass to the basic medium and monitors change the cellulase enzyme activity over time; we also study 3% pretreated biomass with 3% glucose, 3% pretreated biomass with 3% lactose and 3% pretreated biomass with 3% oligomeric xylose as the starting medium to check the cellulase enzyme activity change over time. With 1%, 1%, 3% of the, after 72-96h cellulase enzyme activity can be detected; with 3% of the pretreated lignocellulose as C source, cellulase enzyme activity reached the highest after 168h, 10.44U/ml, and then enzyme activity began to decline. With 5% pretreated biomass, the enzyme activity can also get high after 168h fermentation, while with 8% pretreated biomass, cellulase activity is low even after 168h fermentation. The cellulase activity gets to 8.28U/ml, 14.66U/ml and 13.54U/ml after 168h in the basic medium supplemented with 3% pretreated biomass with 3% glucose, 2g/L lactose and 3% oligomeric xylose, respectively. The experimental result shows that, with different concentration of pretreated biomass, 3% pretreated biomass gives the highest cellulase activity, 10.44U/ml . When supplementing with other carbon sources, lactase gives better cellulase activity, 14.66U/ml.

Keywords：Trichoderma reesei, cellulase, enzyme activity, C source

目 录

1 前言 2

2 材料与方法 3

2.1材料与仪器 3

2.2 方法 5

2.2.1 血球计数板法定量接种Rut C-30到种子培养基 5

2.2.2 纤维素酶活力测定方法 5

2.2.3 葡萄糖标准曲线 6

2.2.4 里氏木霉产纤维素酶 6

2.2.5 产酶培养基优化 6

2.2.6 酶活的计算 6

3 结果与分析 7

3.1 葡萄糖标准曲线 7

3.2 1%预处理木质素条件下里氏木霉产纤维素酶的活性 8

3.3 2%预处理木质素条件下里氏木霉产纤维素酶的活性 9

3.4 3%预处理木质素条件下里氏木霉产纤维素酶的活性 10

3.5 5%预处理木质素条件下里氏木霉产纤维素酶的活性 11

3.6 8%预处理木质素条件下里氏木霉产纤维素酶的活性 12

3.7 3%预处理木质素 1%葡萄糖里氏木霉产纤维素酶的活性 13

3.8 3%预处理木质素 2g/L乳糖里氏木霉产纤维素酶的活性 14

3.9 3%预处理木质素 0.5%低聚木糖里氏木霉产纤维素酶的活性 15

4 分析 16

结 论 18

参 考 文 献 19

致 谢 21

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