纤维素降解菌的筛选分析研究 环境工程专业

纤维素降解菌的筛选及特性研究

摘要

生物堆肥是大部分养殖场固废资源化利用的主要手段，具有投资小、效益高、有机固体废弃物重复资源化利用效率高等优点，但堆肥过程中也存在一些缺陷，如发酵周期长、有臭味、纤维素木质素分解不彻底等。牛粪中含有大量未能消化的纤维素和半纤维素，它们是影响堆肥腐熟进程、决定其堆肥产品质量的关键因素。因此，在牛粪堆肥发酵中选择添加合适的堆肥发酵菌剂和高效纤维素降解菌剂，是解决畜禽粪便堆肥周期长，降解率低等问题的有效途径。本研究采用富集培养及纯培养法从牛粪中将纤维素降解细菌进行分离并分析其降解特性，以期获得一些高效纤维素降解菌。采用水解圈法和3，5-二硝基水杨酸（DNS）法进行菌株筛选与酶学特性研究，结合形态学方法对其初步鉴定，分子生物学方法对其鉴定其种属，共得到降解效果良好的菌株3株，分别命名为DH01、DH02、DC02，其中DH01为枯草芽孢杆菌，其纤维素酶活性最高；DH02为苏云金芽孢杆菌，纤维素酶活性次之；DC02为贝莱斯芽孢杆菌，纤维素酶活性低于前两者。三种菌株均能不同程度分解纤维素，因此，可为牛粪堆肥发酵提供菌种思路，具有重要应用价值。

关键词：纤维素降解菌，纤维素酶，分离，酶学特性

Abstract

Biological composting is the main method for the utilization of solid waste resources in most farms. It has the advantages of low investment, high efficiency, and high efficiency in the reuse of organic solid waste. However, there are also some shortcomings in the composting process, such as long fermentation cycles and Odor, incomplete decomposition of cellulose and lignin, etc. Cow manure contains a large amount of undigested cellulose and hemicellulose, which are the key factors that affect the maturity of compost and determine the quality of the compost product. Therefore, selecting and adding appropriate composting fermentation inoculants and high-efficiency cellulose degrading inoculants in the cattle manure composting fermentation is an effective way to solve the problems of long composting cycle of livestock and poultry manure and low degradation rate. In this study, enrichment culture and pure culture methods were used to isolate cellulose-degrading bacteria from cow manure and analyze their degradation characteristics, in order to obtain some high-efficiency cellulose-degrading bacteria. Using hydrolysis circle method and 3,5-dinitrosalicylic acid (DNS) method for strain screening and enzymatic characteristics research, combined with morphological methods for preliminary identification, molecular biological methods to identify its species, a total of Three strains with good degradation effects were named DH01, DH02, and DC02. Among them, DH01 is Bacillus subtilis with the highest cellulase activity; DH02 is Bacillus thuringiensis, followed by cellulase activity; DC02 is Bacillus velezs Bacillus,

cellulase activity is lower than the former two. The three strains can decompose cellulose to different degrees, so they can provide strain ideas for cattle manure composting and fermentation, which has important application value.

Key words: cellulolytic bacteria，Cellulase，isolation，enzymatic properties

目录

1. 引言 (1)

2. 材料与方法 (2)

2.1 试验材料 (2)

2.1.1样品来源 (2)

2.1.2培养基 (2)

2.1.3供试溶液 (2)

2.1.4供试仪器 (2)

2.2 试验方法 (3)

2.2.1纤维素降解菌的富集 (3)

2.2.2纤维素降解菌的初筛 (3)

2.2.3纤维素降解菌的复筛及酶活测定 ............................................................ 错误!未定义书签。

2.2.4纤维素降解菌的滤纸条崩解实验 (3)

2.2.5纤维素降解菌的生物学鉴定 (4)

3. 数据与分析 (4)

3.1 纤维素降解菌的富集、分离与纯化 (4)

3.2 纤维素降解菌的初筛 (5)

3.3 滤纸崩解实验 (5)

3.4 维素降解菌的鉴定 (5)

3.4.1 菌株形态学鉴定 (6)

3.4.2 纤维素降解菌的分子生物学鉴定 (6)

3.5 纤维素降解菌的酶活测定 (7)

3.5.1 标准曲线的制作 (7)

3.5.2 酶活的测定 (8)

4. 结论与展望 (9)

4.1 结论 (9)

4.1.1 实验结果 (9)

4.1.2 讨论 (9)

4.2 展望 (9)

参考文献 (12)

谢辞....................................................................................................................................... 错误!未定义书签。