摘 要：以微生物降解为基础的生物修复技术是消除环境中亚硝酸盐的有效办法。本课题从河边污泥中分离得到一株亚硝酸盐降解菌，并对该菌进行了形态学和分子鉴定，确定该菌为真菌，属于Daldinia属，命名为 Daldinia sp. HYTC-TB2。另外还对该菌株的亚硝酸盐耐受性、培养基中的亚硝酸盐的降解率以及菌体粗蛋白的酶活进行了测试。结果表明，在固体平板上该菌对亚硝酸钠的耐受性达30 g·L-1；在发酵培养基中，培养6 d亚硝酸盐降解率达到100%；其粗提取胞内酶活性达到5.6 U·mg-1总蛋白。表明该菌株对亚硝酸盐具有较强的降解效果。70573

毕业论文关键词：真菌，亚硝酸盐降解，亚硝酸盐还原酶

Abstract：Bioremediation based on microbial degradation is an effective way to eliminate nitrite in the environment. A nitrite degrading bacterium was isolated from the sludge of the river, and the strain was identified by morphology and molecular identification, which was fungus, belonged to Daldinia, and named as Daldinia sp. HYTC-TB2. The nitrite tolerance, degradation rate of nitrite in culture medium and enzyme activity of crude protein of the fungus were tested. The results show that the nitrite tolerance was 30 g/L, the nitrite degradation rate reached 100% after 6 d′s fermentation,  the crude intracellular enzyme activity reached 5.6 U·mg-1 total protein. All of the tests above indicated that the strain can degrade the nitrite efficiently.

Keywords：Fungi, nitrite degradation, nitrite reductase

目录

1  前言 3

1.1  亚硝酸盐的产生 3

1.2  亚硝酸盐的作用 3

1.3  亚硝酸盐的危害 3

1.4  降解亚硝酸盐的研究进展 4

2  试验材料与方法 5

2.1  试验材料 5

2.1.1  试验菌种 5

2.1.2  培养基 5

2.1.3  试验试剂及配制 5

2.1.4  试验仪器及设备 6

2.2  试验方法 6

2.2.1  菌株的分离筛选 6

2.2.2  菌株的形态学鉴定 6

2.2.3  Daldinia sp. HYTC-TB2在平板上对亚硝酸钠的耐受性测试 7

2.2.4  液体培养基中亚硝酸钠的降解率测试 7

2.2.5  亚硝酸盐还原酶活的测定 7

3  试验结果与分析 8

3.1  Daldinia sp. HYTC-TB2对亚硝酸钠的耐受性 8

3.2  Daldinia sp. HYTC-TB2对亚硝酸钠的降解率 8

3.2.1  亚硝酸钠的标准曲线 8

3.2.2  Daldinia sp. HYTC-TB2的降解率 9

3.3  亚硝酸还原酶活性 9

结  论 11

参 考 文 献 12

致  谢 14

1  前言

亚硝酸盐，一类无机化合物的总称。主要指亚硝酸钠，亚硝酸钠为白色至淡黄色粉末或颗粒状，味微咸，易溶于水[1]。