Distribution Characteristics Of Ammonia-oxidizing Microorganisms And Its Correlation With Environmental Factors In Qi Xing He Wetland

Ammonia oxidation process is a central part and limiting step of the nitrogencycle. Ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB)is the two largest microorgnisms involved in ammonia oxidation process. Qi-XingRiver wetland is a typical natural northeast cold temperate zone wetland that possesstypical soil and vegetation types. It is rich in vast area and diverse types and thensupply the study sample for the distribution and ecological function of ammoniaoxidizing community. It has important ecological representative significance for thestudy of ammonia oxidizing microorganisms in black soil region of typical marshwetland of cold temperate zone in the northest China. This paper selects the AOAand AOB under different soil depths of reeds and lobular camphor in the Qi Xinghewetland which is the typical marsh wetland of cold temperate zone in the northestChina as the research object. We regard the functional gene that encode key enzymefor ammonia oxidation-ammonia single oxygenase (AMO) as the molecular markerbuilding the clone library and analyzing the datas with bioinformatics methods.Then examine the AOA and AOB vertical distribution of different vegetationenvironment and its correlation with environmental factors.The results prove that the AOA amoA gene in this area derive from a wealth ofsources, including water, soil, sediment, hot springs, reactor and so on, covers thecrenarchaeota and the new name of Archaea community-odd bacteria doorthaumarchaeote. AOB amoA gene is mainly from the soil environment and theknown genus of AOB in this paper belong to the Nitrosomonas and Nitrosospiragroups in beta-proteobacteria subclass that include mostly AOB species in freshwater and soil.The diversity of AOA, AOB amoA gene in the soil of lobular camphor is higherthan that of reed and vary with the depth of the soil increasing. The result ofquantitative PCR (RT-PCR) of amoA gene show that the AOA, AOB amoA geneabundance in the soil of reeds is higher than that of lobular camphor. It indicates thatAmmonia oxygen process in the soil of reed vegetation is more active. Overall, theabundance of AOB amoA gene is higher than that of AOA indicating that the AOB ismain actor of the ammonia oxidation process, in the level of founctional gene.The abundance of AOA amoA gene in the different depth of the soil of reedsand lobular camphor is negatively related to the NH4+-N、NO3--N and positivelyrelated to the NO2--N; the abundance of AOB amoA gene is positively related to theNO3--N、TOC,but little relevance to the NH4+-N、NO2--N。The diversity of AOA ispositively related to NH4+-N; the diversity of AOB is positively related to NO2--N. The research will provide basic datas for the distribution patterns andecological functions of ammonia-oxidizing microorganisms in the wetland andcomplete the study of global nitrogen cycle of wetlands.