一株异养硝化细菌的分离鉴定及其亚硝化作用研究

Studies on the Identification and Nitrosification of a Heterotrophic Nitrifier Bacterial Strain

从复合垂直流人工湿地表层基质中分离出一株硝化活性较强的异养硝化细菌H-1,进行biolog菌种鉴定,鉴定系统中没有与该菌株特性相似的数据记录。16SrDNA的序列分析结果显示,菌株H-1与产碱杆菌属(Alcaligenes)粪产碱杆菌(A.faecalis)有98%相似性,认为分离菌株H-1可能为Alcaligenes A.faecalis。通过4因素3水平的正交试验,结果显示,当温度为30℃,pH为7.5,接种量为107CFU,溶氧2.25mg·L-1时,该菌株亚硝化反应效果最佳;影响亚硝化反应效果的因素顺序为:溶氧>温度>pH>接种量;温度和溶氧影响极显著,pH和接种量影响相对不显著。

A strain of heterotrophic nitrifier, named H-1, which had higher nitrification potential ,was isolated from the surface layers of the integrated vertical flow constructed wetland. The identification result of Biolog Microbial Identification System indicated that there were no similar records as the isolated bacterial strain in the system. The phylogenetic analysis based on 16S rDNA suggested that the bacterial strain was 98% homology at the nucleotide level compared with 16S rDNA ofA lcaligenes faecalis. It was thought that bacterial strain H-1 was possibly Alcaligenes A.faecalis .Orthogonal experiments of four factors and three levels were designed to screen out the optimum nitrosification condition. The experiment results indicated that the nitrosification effect was optimal when the temperature, pH, inoculation quantities and dissolved oxygen were 30 ℃, 7.5, 107 CFU and 2.25 mg·L^-1, respectivly. Sorting Order of the factors on the nitrosification effect was dissolved oxygen〉 temperature〉pH〉 inoculation quantities; The influences of temperature and dissolved oxygen on nitrosification effect were highly significant, but the influences of pH and inoculation quantities on nitrosification effect were relatively insignificant.