摘要：草酸钙是一种白色粉末状晶体，不溶于水等物质。在人体中草酸和钙堆积过多时会导致形成草酸钙结石，而草酸钙结石是肾结石中最为常见的一种，约占肾结石的80%以上。土壤中微生物的种类和数量都十分的丰富，是微生物的大本营。同时，在富含腐殖质的土壤中可能会含有分解草酸钙的微生物。故在试验中选用周口公园里富含腐殖质的土壤作为分离目的菌种的土样。根据草酸钙分解菌的特点即能够分解草酸钙来设计选择培养基，从而在37摄氏度下恒温培养筛选出能够分解草酸钙的菌株。如果在选择培养基上生长的有目的菌，那培养基上会出现透明圈，同时还可以根据透明圈的大小判断此株菌的分解能力的强弱。在试验中，为了防止单一一种培养基不能分离得到目的菌，因此我选择了多种培养基进行分离。分离纯化后的菌种还不能完全确定其种属，不同菌的代谢各不相同，对各种物质的利用、酶的种类和代谢产物也不同。通过各种菌的不同生化特性可以将菌进行具体的分类鉴定，以及对分离获得菌株经酶链聚合反应扩增后测定菌株的16SrRNA基因序列，由菌序列的相似性比对进行分类。

关键词：草酸钙；草酸钙分解菌；生化特性；16SrRNA基因测序

Isolation and Characterization of Oxalotrophic Bacteria from Soils

Abstract: Calcium oxalate is a kind of white crystalline powder, insoluble in water and other substances. The excessive accumulation of oxalic acid and calcium in the human body will cause the formation of calcium oxalate stones, which is the most common form of the kidney stones and accounts for about more than 80% of the kidney stones. The type and amount of microbes in soil is very rich and the soil is the capital of the microbes. At the same time, the rich humus soil may contain microbes that can decompose calcium oxalate. Therefore, in the trail the soil rich in humus in Zhoukou Park was chosen as the soil sample to separate the purpose strain. According to the characteristic of calcium oxalate decomposing bacteria--the ability of breaking down calcium oxalate, the medium was designed and used. Thus, in 37 degrees Celsius temperature, the bacterial strain that can break down calcium oxalate can be isolated and selected. If there are the target bacteria in the chosen culture medium, the culture medium will appear transparent circle (due to the decomposition of calcium oxalate by the target bacteria). At the same time, the ability of decomposition by these strains can be judged. In the trails, in case that the target bacteria cannot be separated from a single culture medium, a variety of medium are applied. After isolation and testing, the species of the bacteria can't completely be determined. The metabolism of different bacteria is different. The use of various substances, enzymes and the kinds of metabolites are also different. Through the biochemical characteristics of the bacteria, we can get specific classification and identification of these bacteria. Finally, by polymerase chain reaction amplification of 16S rRNA gene, isolated strains were classified according to their sequence similarity.

Keyword: Calcium oxalate; Oxalotrophic bacteria; Biochemical characteristics；16S rDNA sequencing

目录

摘要 1

Abstract 1

引言 2

1.材料与方法 2

1.1实验材料 2

1.1.1实验试材 2

1.1.2主要培养基 3

1.1.3试剂 3

1.2主要仪器与设备 4

1.3主要实验方法 4

1.3.1培养基的配置 4

1.3.2样品的采集 4

1.3.3草酸钙分解菌的分离与纯化 5

1.3.4草酸钙分解菌的形态观察 5

1.3.5目的菌的革兰氏染色5

1.3.6草酸钙分解菌的特性测定 5

2.结果与分析 6

2.1草酸钙分解菌的分离与筛选 6

2.2实验结果出现的原因6

2.2.1土样.6

2.2.2培养基.7

2.2.3培养条件7