The Study On The Bacterial Community Structure And Function In Seaweed Beds Of Gouqi Island

The bacterial community structure and function is one of the research subject of microbial ecology, The microorganism from the water and sediment samples have close relation with the habitat environment and play important role in the circulation of matter and energy. By gathering the samples and sequencing the 16SrDNA sequence, the aim is to find out the community composition mode of the sediment and water samples in Gouqi seaweed beds. gather the water samples from seaweed beds and mussel culture area and investigate the community structure in different habitat. Through comparing the samples from seaweed beds in winter and the samples from the growth peak period in seaweed beds, the article discuss the similarities and differences of bacterial community and the ecological functions, so as to deepen the seaweed field ecosystem research and provide the basis.The results show that:1: The Proteobacteria is the preponderant bacteria in the sediment and water samples and occupies a large percentage in the clone library. The sediment samples all contain the Gammaproteobacteria, Alphaproteobacteria, Betaproteobacteria, Epsilonproteobacteria and Deltaproteobacteria ,the all five lineages of the proteobacteria, The water samples of seaweed beds in winter and the growth peak period contain the Gammaproteobacteria, Alphaproteobacteria, Betaproteobacteria, but Epsilonproteobacteria and Deltaproteobacteria are seldom found.2: In addition to Proteobacteria, The Firmicutes and Actinobacteria of Gram-positie organisms also plays a larger percentage in the clone library. They are detected in each sediment and water sample, the more common lineages are: Clostridium, Actinomyces, Staphylococcus, Sporichthya and so on. They mostly participated in decomposition of detritus and heterotrophic nutrient cycle in the seaweed beds of Gouqi Island.3: The bacterial community structure in the seaweed beds is different from the mussel culture area, The seaweed beds samples haves a more abundance than the mussel culture area, Different mechanism of habitat make the big difference of bacterial community structure, The environmental factors such as temperature, PH, salinity and so on also affect bacterial community structure of surface and bottom water samples.4: In the growth peak period of seaweed beds, The lineages in the seaweed beds samples are more than winter seaweed beds samples, the Frigoribacterium of the Actinobacteria, Desulfovibrio of the Deltaproteobacteria and Psedoateromonoas of the Gammaproteobacteria are first detected, not find in the winter samples.