Spatial And Temporal Distribution Of Sediment Microorganisms In The Inlet And Their Response To Environmental Changes

Microorganisms are an important part of lake ecology and play an important role in lake elemental cycling and water purification.The physical and chemical properties of lakes are easily influenced by incoming rivers,and microorganisms are very responsive to environmental changes,leading to their heterogeneity in time and space.Therefore,in order to achieve a more scientific grasp of lake ecological change patterns,it is necessary to carry out research on the environmental change response of microbial communities.In this study,we used high-throughput sequencing and bioinformatics methods to study the microbial response to environmental change in three different periods of Chaohu Lake（dry water,flat water,and abundant water）in the inlet of Nanfei River,Pai River,and Hangbu River in terms of spatial and temporal heterogeneity of the environment,composition and structure of microbial communities,correlation between microbial diversity and environmental factors,drivers of microbial communities,and microbial co-linear networks.The response to environmental changes was studied in order to provide a theoretical basis for the construction of a complete lake ecology system.The main results are as follows:（1）There were significant differences in the spatial and temporal distribution of environmental factors in the water bodies and sediments of different inlets,and the contents of dissolved oxygen,ammonia nitrogen,total nitrogen,total phosphorus and chemical oxygen demand in the water bodies of the inlets showed some spatial and temporal differences,generally showing that the inlet of the Nanfei River>the inlet of the Pai River>the inlet of the Hangbu River,and the dry water period>the flat water period>the rich water period;the contents of p H,total nitrogen and total phosphorus in the sediments showed some spatial and temporal differences.The sediment pollution evaluation results show that the sediment pollution in the lake mouth is more serious in nitrogen and light in phosphorus.（2）There are significant differences in microbial diversity and community structure in the inlet at different periods,and the dominant microorganisms at the inlet phylum level are Proteobacteria,Acidobacteriota,Chloroflexi and Bacteroidota at different periods,and their relative abundance varies with different periods.The relative abundance of the dominant microorganisms at the family level varied among different periods,with Enterobacteriaceae and Xanthobacteraceae as the dominant microorganisms in the dry season,Flavobacteriaceae as the dominant microorganisms in the level season,and Spirochaetaceae,BS as the dominant microorganisms in the wet season.Spirochaetaceae,BSV26,Pedosphaeraceae and Thermoanaerobaculaceae.The microbial community composition was the most diverse in the level season,and the microorganisms in the dry season had high alpha diversity.For microbial community composition and structure,the most important driver was the water column NH₄⁺-N content in the dry season,the most important driver was TP and water column COD content in the sediment in the level season,and the most important driver was the water column TN content in the wet season.The network structure of the microbial community was more complex in the wet season,and the effects of environmental factors on the microbial network structure varied in different periods.Finally,the predicted microbial function results pointed out that the abundance of microbial carbon and nitrogen cycle function was higher in the river inlet during the level season.（3）There were significant differences in the microbial diversity and community structure of the different inlets,and the relative abundance of the phylum Aspergillus in the different inlets was greater than 30%,which was the most abundant phylum in the inlet.The dominant microorganisms were Sphingomonadaceae,Vicinamibacteraceae,Nitrospiraceae,Geothermobacteraceae and Flavobacteriaceae in the Nanfei River inlet,Rhodanobacteraceae in the Pai River inlet,and Enterobacteriaceae and Chavobacteriaceae in the Hangbu River inlet.Enterobacteriaceae and Chitinophagaceae;the Pai River inlet has a microbial co mmunity with high alpha diversity.For microbial community composition and structure,the most important drivers were water column TN and sediment TP content in the Nanfei River inlet,the most important drivers were water column temperature and TN content in the Pai River inlet,and the second most important drivers were water column COD and sediment p H content in the Hangbu River inlet,and the most important drivers were water column temperature and the second most important drivers were water column NH₄⁺-N and TN content in the Hangbu River inlet.The next most important drivers were NH₄⁺-N and TN content.The dominant microorganisms in different inlets were strongly correlated with the driving factors.The microbial ecological co-linear network indicates that Hangbu River has a complex microbial network structure and reveals the influence of environmental differences between different inlets on the microbial network structure.Finally,microbial function predictions indicated that the abundance of microbial functions in different inlets differed,with higher abundance of functions related to nitrogen conversion in the Nanfei inlet,higher abundance of functions related to dark oxidation in the Pai River inlet,and higher abundance of functions related to carbon conversion and animal-related pathogens in the Hangbu River inlet.Figure[24]table[18]reference[111]...