Study Of The Eubacterial Community Structure And Diversity In The Northwest Of Yellow Sea

Microbes are a critical component of marine ecosystems,play a key role in the marine biogenic elements' mineralizati and recycling ,including carbon, nitrogen, phosphorus and sulfur .But so far the investigation on bacteria in north-west of the Yellow Sea are lack of systematic and comprehensive,the means of investigation are the traditional methods, the region is too small,so the current findings can not really reflect the ecological status of bacteria in the north-west of Yellow Sea.In order to understand that how the natural and man-made factors impact the community composition, quantity changes and dominant group,such as adjacent water, human activities, the Yellow Sea cold water,that how the bacteria response to impact. In order to provide scientific basis for the study and protection of the North Yellow Sea this paper study the microbial community structure and diversity in the north-west of Yellow Sea.In this paper, the microbial community structure and diversity within waters and sediments at five stations of north-west of Yellow Sea were investigated, the samples collect from the spring, summer, autumn and winter seasons. 16S rDNA clone library analyses indicate that the bacteria are abundant in the waters and sediments, and most of them are unknown,phylogenetic analysis show that the bacteria are high similarity with uncultured microorganisms. The microbial diversity and evenness in sediments are higher than that in water , community in Sediments have higher microbial diversity,the community structure is more complex and more stable, no exist obvious seasonal variation.some bacteria in sediment and water are same ,other are significantly different. Phylogenetic analysis showed that the Proteobacteria is the dominant group both in the sediments and waters,γ-Proteobacteria andδ-Proteobacteria are dominant in the sediments,α-Proteobacteria andγ-Proteobacteria are dominant in the water.Bacterioidetes,Actinobacteria,Cyanobacteria, Verrucomicrobia are in both water and sediment,while Acidobacteria, Planctomycetes, Chloroflexi mostly exist in sediment, Firmicutes mostly exist in water. Other specific groups 'existence is closely related to their ecological functions.Although the Proteobacteria is the dominant group,and has stable proportiona in all year round, but the bacteria in sediment and water still exist obvious differences due to the geographical location and season. pollution-resistant, anaerobic micro-organisms suitable for the offshore habitats, where suffer the impact of human activities, has poor quality, while pollution-sensitive, aerobic micro-organisms suitable for far shore habitats ,where suffer smaller interference ,has good quality. Certain bacteria exist or disappeared in a particular season ,this may be associated with the seasonal variation.