导　　师： 明镇寰

学科专业： G1007

授予学位： 硕士

作　　者： ;

机构地区： 浙江大学

摘　　要： 由硝化细菌催化氨氮氧化的硝化作用是氮循环的关键步骤,也是现代污水处理厂生物处理氨氮废水的重要环节.自然状况下的化能无机自养硝化细菌具有生长速率低、生物量小和对环境因子敏感等生理特点,为了快速获得大量硝化细菌用于炼油化工废水中氨氮化合物的高效去除,我们在实验室里通过富集培养条件优化,直接对活性污泥中的硝化细菌进行富集培养研究.将氨氧化为亚硝酸盐的氨氧化细菌是硝化菌群的重要组成部分,它的种类随生境差异而有所不同.氨氧化细菌的氨单加氧酶（amo）催化氨氧化生成羟胺是硝化反应的第一步,也是最为重要的步骤.amoa基因是编码氨单加氧酶活性多肽位点基因,我们通过引物筛选合成了对氨氧化细菌amoa基因特异结合的引物序列,利用pcr技术对活性污泥中的amoa基因片段进行特异扩增,得到的dna片段大约为490bp. Nitrification, performed oxidation of ammonia to nitrate by nitrifying bacteria is a key process in the cycling of nitrogen and an impotent component of modern wastewater treatment. Chemolithoautotrophic nitrifying bacteria have many unfavorable physiological characteristics, namely, slow growth, small biomass and susceptible to environmental factors. To remove high ammonia-nitrogen concentration in wastewater from refineries, we directly enriched nitrifying bacteria of activated sludge via optimizing enrichment conditions /(temperature > pHU NH4+-N concentration/). The results showed that the number of nitrifying bacteria after 6 weeks enrichment increased 32.8 times and nitrification rate improved 2.76 times than that before enrichment. Ammonia-oxidizing bacteria which oxidize ammonia to nitrite is a key group of nitrifying bacteria. The population of ammonia-oxidizing bacteria is variable with the different environment. The gene of amoA in ammonia-oxidizing encodes the active-site polypeptide of ammonia monooxygenase which catalyzes the oxidation of ammonia to hydroxylamine. We designed a pair of primers special for the amoA gene by comparing the known amoA gene sequences and used PCR to amplify the amoA gene fragments. The results showed about 490bp DNA fragments were amplified.. Because the amplified products is specific to the P -subclass of the Proteobacteria , the amplification of the amoA gene may be a powerful molecular tools for detecting and analyzing ammonia-oxidizing communities in environment.

关 键 词： 硝化细菌 富集培养 基因 扩增

分 类 号： [Q939.1]

领　　域： [生物学]