毕业论文移动版

摘要木质素与纤维素是地球上储量最多，开发较不完善的有机可再生能源。由于当今世界环境恶化加剧，能源的逐渐减少，可再生资源的利用，渐渐地被大家所重视。香草酸（Vanillic acid）作为一种木质素单体模型化合物，广泛地存在于木质素中。同时它也是纤维素的主要成分阿魏酸降解过程中，出现的重要中间产物。虽然香草酸，作为一种高价值的化工原料，已经被普遍地运用于食物、饮料和化妆品等多个行业，可是对于其进一步降解的相关研究仍较少。本实验利用香草酸作为唯一碳源，通过富集培养的技术，从常温土壤环境中提取出了两株菌株（B1和B2）。通过实验测定，这两种菌株最适温度都是在50℃。经过对菌株的16s rDNA测序，绘制得到系统进化树表明，筛选出来的菌株与解淀粉芽孢杆菌（Bacillus amyloliquefaciens subsp. amyloliquefaciens DSM 7）的相似度为97.14%。另外，还发现这两株嗜热菌同时还能降解苯甲酸、4-羟基苯甲酸和对羟基苯甲酸等芳香族化合物。希望通过该实验，为之后的大规模，工业化降解木质素与纤维素提供一定的方向。69180

该论文有图13幅，表2个，参考文献13篇。

毕业论文关键字：香草酸  木质素  嗜热菌  生物降解

Isolation and Characterization of thermophilic vanillic acid degradation bacteria 

Abstract

Lignin and cellulose are the reserves owning the most storage on earth, but which are less developed organic renewable energy. With the environmental degradation, resource gradually reduce, people pay more and more attention to the use of renewable resources. Vanillic acid acts as a lignin polymer, which wildly exists in lignin. It is also the important intermediate at the ferulic acid degradation process, which the main components of the cellulose. Although vanillic acid, as a kind of high value of spices, has been widely used in food, beverage, cosmetics and other industries, but for the further degradation of related research is still rare. This experiment using vanillic acid as sole carbon source, through the enrichment culture technique, extracted from normal temperature soil environment out of the two strains(B1 and B2). Determination through our experiment, the optimum temperature for the two strains are 50 ℃. After 16 s rDNA sequencing of the two strains, we draw for phylogenetic tree , which showed that the two strains have the similarity of Bacillus (Bacillus amyloliquefaciens subsp. amyloliquefaciens DSM 7)at about 97.14%. In addition, we also found that the two strains of thermophilic bacteria can degrade benzoic acid, 4 - hydroxy benzoic acid and other aromatic compounds. We  hope that our experiment can provide a certain direction to a large-scale, industrialized degradation of lignin and cellulose in the future.

Key words:Vanillic acid  Lignin  thermophilic bacteria  biodegradation

目录

摘要 I

Abstract II

目录 III

引言 1

1.材料与方法 3

1.1 实验材料 3

1.2 培养基 4

1.3 实验器材 5

1.4 试验方法 5

2.结果与分析 9

2.1嗜热菌的分离 9

2.2菌株的鉴定 11

2.3菌株生理生化性质的研究 14

3.讨论与展望 16

参考文献 (责任编辑：qin)