摘  要采集中国某地区土壤样品，用梯度稀释法、平板涂布法、平板划线法等纯培养方法相结合分离出纯种菌株，观察菌落的形态特征和菌体形态特征，用通用引物扩增分离16S rDNA，测出16SrDNA的序列。在EzTaxon Server2.1数据库中找出同源性较高的模式菌株，用MEGA 6.06生成系统发育树。测定菌株的生理生化特性。实验结果显示，菌DB革兰氏染色呈阴性，菌落特征为不透明、黄色、圆形、突起、表面光滑、湿润、致密、边缘整齐，菌体为杆状，无鞭毛；菌株DB的最适NaCl浓度为1%，最适pH为5，最适通气量为50mL。DB菌可以利用甘露醇、纤维二糖、乳糖、明胶糖、果糖、山梨醇，其中对纤维二糖的利用尤为明显，不可以利用葡萄糖、维生素B1。菌株DB的16SrDNA序列与EzTaxon Server2.1数据库中的红球菌属的菌株16SrDNA序列有最高100%的同源性，确定其为Rhodococcus jialingiae djl-6-2T； 本文通过对农药降解株的鉴定，希望了解农药降解菌的表型特征和生理生化特性，来预测农药的动态，以此减少农药对环境的负面影响。69936

该论文有图9幅，表2个，参考文献15篇。

毕业论文关键词：土壤微生物  16S rDNA  系统发育树  生理生化特性

Isolation, Identification of triazine-degrading Bacteria DB and Study on physiological and biochemical characteristics

Abstract Multipled soil samples from a region in China, then separated pure bacterial strains using the gradient dilution method, plate coating method, plate streaking method, and pure strains cultivation method. Observed the morphological characteristics of bacterial colony and thallus. Separated 16S rDNA with General primer amplification method, and sequenced it. Found out type strains of high homology in EzTaxon Server2.1, and made phylogenetic tree by MEGA 6.06. Tested physiological and biochemical characteristics of strain. Experimental results show that the strain DB is gram positive, and the colony is opaque and yellow, protuberant and round , moist and density, smooth and neat; Thallus is rhabditiform with no flagellum.The best growth condition of strain DB is as follows: 1% NaCl concentration, pH5, and 50mL ventilatory capacity. Stain DB can use mannitol, cellobiose, lactose, gelatin, sugar, fructose, sorbitol, particularly to the use of cellobiose, but it can't use glucose and vitamin B1. The 16S rDNA sequences of Strain DB have the highest homology of 100% with a strain named Rhodococcus jialingiae djl-6-2T in EzTaxon Server2.1; This article is about Isolation, Identification of triazine-degrading Bacteria DB, we want to know about phenotypic characteristics, physiological and biochemical characteristics of pesticide-degrading bacteria through research, it can be used to predict the dynamic of the pesticide, thereby reducing the negative impact of pesticides on the environment.

This paper has nine figures, two tables and fifteen references.

Key Words: soil microorganisms  16SrDNA  phylogenetic tree  physiological and biochemical characteristics

目  录

摘  要 I

Abstract II

图清单 IV

表清单 IV

1 引言 1

2 材料与方法 2

2.1 实验材料与试剂 2

2.2 实验方法 3

2.3 分析方法 4

3 结果与分析 5

3.1细菌群体形态特征和个体形态特征 5

3.2 PCR扩增产物电泳分析