Response Of Nitrogen Cycle Microorganism Diversity To Environmental Changes In In Cold-arid

Baotou Nanhai lake is a typical small-sized urban lake,which plays an important role in climate regulation,water conservation and urban beautification.Because it is located in the cold and dry region of high latitude,the seasonal ice age makes it diffierent.Nitrogen cycle in order to reveal the south China sea lake microbial community structure and its relationship with environmental factors,for the south China sea lake eutrophication control and provide a scientific basis for ecological protection,this study refer to the topography of the lake of the south China sea and its surrounding environment can be divided into four regions,in each area layout three representative sampling points,respectively,in June 2018,in September 2018 and January 2019 and April 2019 for sediment samples are collected,using primers specific function to test the sediment in the microbial community structure,and analyzes the physical and chemical indicators at each sample.Through the analysis of the bacterial community,the structural characteristics of the microbial community in the nitrogen cycle in Nanhai lake were identified,and the environmental factors affecting the bacterial community structure were determined by correlation analysis.The main research results are as follows:From the perspective of time range,water environmental factors changed significantly with time,and water pollution was more serious in the ice-bound period than in the non-ice-bound period.The indexes of environmental factors in sediments are affected by the changes of water environmental factors for a long time,but there is no significant change in a short time.From the perspective of spatial scope,the nutrient level of each lake can be roughly summarized as the central > lake area in the > aquatic grass area of tourism development zone,and the abundance and evenness of sample species are negatively correlated with the nutrient level.The bacterial diversity was affected by various factors such as the Yellow River rehydration,ice body condensation,plant growth and spoilage.In addition to cyanobacteria,there are also some microorganisms under the phylum firmicutes and proteobacteria.In terms of subordinate level,the nitrogen-fixing microorganisms are mainly composed of cyanobacteria,colifera,clostridium,anthracidae,red spirulina and anaerobic mucobacteria.Ammonia oxidation is mainly carried out by various microorganismsunder firmicutes and micrococcus.The subordinate levels of ammonia-oxidizating bacteria in the study area mainly include: pseudomonas,bacillus,clostridium,sarrenella,proteus,micrococcus,alkali-producing bacillus faecalis,etc.Nitrite oxidizing bacteria is mainly composed of bacterium door gate level,there are some other microorganisms,in the level are divided into 10 genera,including false nitrite bacteria genera,nitric acid bacteria genera,red aureus,pseudomonas,dung producing alkali coli,proteus,micrococcus,deputy aureus,bacillus genera,acinetobacter,etc.The level of denitrifying bacteria mainly consists of proteobacteria and some other bacteria,which are mainly divided into 11 genera at the genus level,including pseudomonas,erythrobacter,tauria,nitrogen-fixing screw,burkella,unclassified_Bacteria,unclassified_Proteobacteria and so on.As the external conditions change greatly during the freezing process and the ice body dissolution process,the environmental factors affecting the nitrogen cycle microorganisms are different in different periods.TN,NH3-N and C/N in sediments have a great influence on the bacterial community structure in sediments.Controlling these environmental factors is an important measure to improve the water quality in the ice age of nanhai lake.