自养硝化细菌的分离、鉴定及系统发育分析

以城市污水处理厂A2O工艺中好氧活性污泥为菌源,筛选出2株自养型硝化细菌N3和N4.转接2株菌株至液体分离培养基中培养14d,经检测,2株菌株的硝化效果均可达100%.通过形态观察、生理生化试验初步鉴定表明,这2株菌株均属于硝化杆菌属.利用PCR扩增、克隆、测序对菌株作进一步鉴定,测序结果提交GenBank进行同源性检索,并通过MEGA软件进行比对和系统发育分析.16SrDNA序列分析表明,这2株菌株与维氏硝化细菌的同源性高达98%.

Separation, Identification and Phylogenetic Analysis of Autotrophic Nitrobacteria

Two strains of autotrophic nitrobacteria N3 and N4 were isolated from aerobic activated sludge of A~2/O treatment process, transferred to liquid separation medium, and cultured for 14 days. Test results indicated that the nitrification efficiency of the two strains could reach 100%. The two strains were preliminarily identified as species of nitrobacteria on the basis of the results of morphological observation, physiological and biochemical experiments. The strains were further identified with the methods of PCR amplification, cloning and sequencing, and the sequencing results were submitted to GenBank for homology searching, combined with comparative and phylogenetic analysis through MEGA software. 16S rDNA sequence analysis showed that the two strains homology to Nitrobacter winogradskyi was as high as 98%.