| As the primary producers and decomposers,microorganisms are the main factors for maintaining the steady state in water.Compared with animals and plants,it is more active and more widely distributed.It can decompose pollutants in water and sediments,and promote the restoration of water.Therefore,it plays an indispensable role in the restoration of the water but it is also susceptible to environmental and other factors.When the environmental structure changes,it will also affect the changes in the characteristics of the microbial community.This article aims to study the changes in the ecological environment of the lake and the microbial community structure and diversity of during ecological restoration of the Daye Lake,before and after the breakwater between the Daye Lake and the Yourse Lake.By constructing a 16 S r RNA gene cloning library,we analyzed the changes of microbial community structure and diversity in water and sediments,combined with the physical and chemical properties of the water body,and explored the effects of related water environmental factors on microbial community structure and diversity,providing basic data for protection and ecological restoration for the lake.The main results are as follows:(1)Microbial community richness and diversity: The water microbial richness of the samples collected in May 2018 was significantly higher than that of the samples collected in May 2019,but there was no significant difference from the samples collected in September 2019.The microbial diversity and richness of sediment samples were higher than that of water at the same time point.Species richness varied greatly in water and sediment at different sampling times,but there was no significant difference in microbial diversity.(2)Microbial community structure during ecological restoration of the Daye Lake: We collected samples from three sites in the Daye Lake and analyzed the microbial community structure in water and sediments.The results showed that 15 dominant bacteriophytes(accounting for more than 1%)were found in Daye Lake.Among them,there were 8 dominant bacteria in the water and 12 dominant bacteria in the sediment.There were large differences in the water at different time points and small differences in the sediment.It was found that bacteroidetes and Dependentiae were significantly different in the main phylum,while proteobacteria,Sphemonas and Patescibacteria were significantly different in the sediment.There is a great difference between the water body and the sediment,and Nitrospira are higher in the sediments than in water bodies.(3)Microbial community structure characteristics of the Yourse Lake after the break of the embankment: a total of 55 bacterial phylas were detected at 3 points of the Yourse Lake,mainly contains 15 dominant bacterial phylas,including 8 dominant bacterial phylas in the water and 13 dominant phylums in sediments.And there are significant differences in the microbial community between water bodies and sediments.Cyanobacteria,Actinomycetes,Proteobacteria,and Bacteroides are higher than sediments in the water,and Campylobacter,Acidobacteria,Nitrospira,and Patescibacteria are higher in the sediment.Based on the fact that before and after breaking the dike and dike in Colored Lake,the vast majority of species of the water body and the ground mud were significantly different to some extent,it was found that the bottom mud was Dependentiae with significant differences,while the sediment did not have significant differences.(4)Relationship between microbial community structure and environmental factors: The relationship between microbes and environmental factors is complex.Studies on the Daye Lake and the Yourse Lake have shown that the microbial community structure of lakes is susceptible to environmental factors.Among the factors detected,the microbial population in Daye Lake is dominated by the total dissolved solids and so on.Total nitrogen,salinity and pH were the main influencing factors in the Yourse Lake. |
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