Phylogenetic and Microbial Community Analysis Based on amoA Gene and 16SrDNA in Nitrosification Biofilm Reactor

In order to analyze microbial community and phylogenesis in nitrosification biofilm reactor, a partial stretch of the gene encoding the active-site polypeptide of ammonia monooxygenase (amoA) was amplified and the gene libraries were constructed. The result of gene sequences and phylogenetic analysis showed that Nitrosomonas eutropha was the predominant species in the reactor. Besides, there were also some kinds of ammonia-oxidizing microbe uncultured in the system. PCR-SSCP analysis of 16SrDNA of archaebacteria and eubacterium indicated that with the rising of ammonia oxidation rate, the structure and distribution of microbial community was influenced and the diversity of microbial communities decreased, and the decreasing of specificity in the reactor might be the key factor for the rising of ammonia oxidation rate.