Response Of Bacterial Community Structure And Environmental Factors In Dali-Nor Lake During The Freezing Season

In order to revealed the structural feature and relationship with envirnamental factors and the influence of dominant bacteria group on lake water environment with bacterioplankton and attached bacteria.This study chooses the ice age,collected surface water under the ice.Using comprehensive nutrition index method to evaluate the lake eutrophic state,Illumina Miseq generation sequencing 2 to test the bacterioplankton and attached bacteria.In this study,we know the diversity,community composition and spatial distribution of bacteria,determined the influence of different environmental factors on the bacterial community,analyzed the effect mechanism of dominant bacteria on entrophication lake.Finally,we find the extremophiles in the lake.The specific research results are as follows:The surface water under the ice was in a state of alkalization,and the oxygen content is not sufficient.Lake's nutritional status index is between 77.24 and 89.63,the lake is already in a serious state of rich nutrition.The bacterioplankton are more abundant than the attached bacteria.Cyanobacteria was the dominant species.accounting for 30.2%.the next bacteria was Actinobacteria,accounting for 18.5%,and then Proteobacteria(17.3%)?Bacteroidetes(11.8%)?Verrucomicrobia(10.2%)?Planctomycetes(8.3%).And the lake had 3.2% of alkaliphiles and 4.4% of psyhrophile.Redundancy analysis method is used to analyze the relationship between bacterial community and environmental factors.Most significant environmental factor affect the bacterioplankton was total dissolved solid?ice thickness?total nitrogen?chlorophyll?total phosphorus and dissolved total phosphorus.The most significant environmental factor affect the attached bacteria was total nitrogen?nitrate nitrogen?total dissolved nitrogen?dissolved organic phosphorus and nitrate nitrogen.The ten dominant bacteria accounting for 55.92% of the total bacteria number.There are three dominant species from Actinobacteria.two dominant species from Cyanobacteria.two dominant species from Proteobacteria.The Verrucom-icrobia ? Bacteroidete and Planctomycetes each one.the dominant species in all ten contains 48 OTU.The OTU820?OTU763?OTU635 in Cyanobacteria,OTU386 in norank LD29,OTU1254 and OTU116 in norank Nitriliruptoraceae,OTU1386 in Pseudomonas have obvious promoting effect to the lake eutrophication.OTU417 in norank CKO6-06-Mud-mas4b-21 inhibits eutrophication.