中文摘要：

分析红壤荒草地富集液中氨氧化细菌的种群组成，选取氨氧化细菌16S rDNA特异性引物序列，利用PCR技术对从富集液中抽提的细菌总DNA进行扩增，并建立了氨氧化细菌特异性的16S rDNA文库。用酶HhaⅠ和RsaⅠ对该文库特异性片段进行了限制性酶切片断长度多态性分析（Restriction fragment lensth polymorphism，RFLP），随机挑选的35个特异性克隆片段被分成3个不同的RFLP类型，其中优势型占了所有分析克隆子的94％，另两个型各占3％。从每个RFLP类型中挑取一定的转化子进行测序，测序结果经GenBank检索，发现在该富集液体系文库中存在大量亚硝化单胞菌属（Nitrosomonas）细菌序列，由此推测红壤荒草地中存在氨氧化细菌，Nitrosomonas属细菌能在富集条件下成为优势菌。

英文摘要：

Chemolitho-autotrophic ammonia-oxidizing bacteria are responsible for the rate-limiting step of nitrification in a wide variety of environments, making them important in the global cycling of nitrogen. In order to analyze the ammonia-oxidizing bacteria population structure in red soil enrichment culture, a pair of AOB-specific primers was designed, and total microbial genomic DNA of enrichment culture was extracted by the direct method of PCR-amplification template. An AOB-specific 16S rDNA clone library was subsequently constructed. RFLP analysis of 16S rDNA was conducted using enzymes （ Hha Ⅰ and Rsa Ⅰ ） to digest 16S rDNA from the library. The randomly selected 35 cloned fragments were finally clustered into 3 different phylotypes, with the most abundant phylotype accounting for 94% of the selected 16S rDNA clones and the other two phylotypes for 3 %, respectively. Seven clones from 3 phenotypes were sequenced and the 16S rDNA sequences were compared with those from Gen- Bank. Based on the Blast analysis, a lot of Nitrosornonas-like sequences were found in this library. The result shows that there are ammonia-oxidizing bacteria in the red soil and Nitrosomortas sp. is a dominant bacterium in enrichment condition.