Spatial Heterogeneity Analyais Of Bacterial And Ammonia-Oxidation Bacterial Community Structure Of Lakeside Wetland Of Wuliangsuhai Lake

Wuliangsuhai Lake has become one of the world’s most rapidly filling lakes which evolutes toward reed swampâ†'alkaline saline meadowâ†'desert soil. The aim of this study is to investigate ammonia oxidation bacterial community composition, abundance, phylogenetic relationship and diversity under different plant community which formed in the evolution process of Eutrophic Lake, and to combine with the soil physicochemical factors to discuss its impacts on ammonia oxidation bacterial community structure; and to understand soil bacterial community composition, abundance and diversity, and to combine with the soil physical and chemical factors to discuss it’s impacts on bacterial community structure.The total DNA was extracted according to the sediment soil DNA extraction method and then clone library was constructed based-on amoA gene in order to analyze ammonia oxidation bacterial community composition, abundance, phylogenetic relationship and diversity index; and high-throughput pyrosequencing was used to detect soil bacterial community based-on 16S rDNA gene in order to analyze bacterial community composition, abundance, and diversity index. Soil physicochemical properties were tested according to standard methods to analyze its effects on ammonia oxidation bacterial community and bacterial community composition. The main conclusions were obtained as bellows:Firstly, we devote to the development of independent intellectual property which established a new rapid and high-efficient DNA extraction method from sediments. The potassium dichromate solution was firstly used to treat the sediment samples, and then combined with mechanical and chemical agents to directly lyses microbial cells and DNA were dissolved in DNA extraction buffer that high-quality total microbial DNA were obtained.Secondly, the similarity of ammonia oxidation bacterial community composition significantly changed from the group similar to Nitrosomonas-like sequence to that similar to Nitrosospira-like sequence. Correlation analysis indicated that the combination of total nitrogen and total water soluble salt has the most significant effects on the whole ammonia oxidation bacterial community structure.Thirdly, Microbial diversity and the dominant populations have changed significantly and total phosphorus, total water soluble salt and ammonium are the leading environmental factors for spatial heterogeneity of bacterial community composition.Fourthly, nitrogen is an important factor in the formation of eutrophic lakes:the sequential oxidation of ammonia to nitrite or nitrate coupled with the process of sulfide oxidation process, and these processes can turn nitrogen compounds in sediments into gaseous nitrogen as final form which release into the atmosphere in order to mitigate the effects of farmland water from the Hetao irrigation district contained a lot of nitrogen into Wuliangsuhai lake on its ecosystem functions.