Bacterial community structure in different functional sea areas of Zhoushan archipelago

Abstract:

Planktonic bacteria are indispensable in marine ecosystems and play a key role in the process of marine biogeochemical cycling. [Objective] The aim of this study was to analyze the bacterial community structure in different functional sea areas of Zhoushan archipelago.[Methods] Samples were collected in surface seawater from Zhoushan Archipelago of the East China Sea in 8 typical sites representative of 8 functional zones in the summer (August) of 2016. We used high throughput sequencing to study bacterial diversity and community structure in seawater of the of Zhoushan archipelago based on the bacterial 16S rRNA gene. Flow cytometry was used to reveal the abundance of bacteria in each site. The technique of Canonical correspondence analysis was used to analyze the effects of the environmental factors on bacterial community composition.[Results] In this research, 305487 raw reads were obtained. OTU cluster analysis was performed at the 97% similarity level, and all the sequences were grouped into 1088 OTUs, including 29 phyla, 62 classes, 138 orders, 239 families, and 416 genera. The bacterial community structure of each station were different, but they all included three dominant strains of Flavobacteria, Alphaproteobacteria and Gammaproteobacteria. A canonical correspondence analysis showed that different stations and different Phyla were affected by different ecological factors, Cyanobacteria was most affected by nitrate, Parcubacteria was most affected by temperature, and phosphate had little effect on all bacteria in this study area. The prediction of the potential function of marine microflora showed that the sea areas of each site were more prominent in Amino Acid Metabolism, Carbohydrate Metabolism, Membrane Transport and so on, which provided a new direction for marine microbial research in the future.[Conclusion] High throughput sequencing analysis can accurately reveal the bacterial structure information of marine bacteria. This research provides references for the association of bacterial composition and diversity with environmental factors. The large amount of data that was obtained not only as a response of Zhoushan marine function zoning purposes of the case but also lay foundations for further bacterial community structure research in the east China sea.