Distinct cyclic pattern of marine microbial community in the Jeju Island

Abstract

High-resolution 16S rRNA tag pyrosequencing was used to obtain a seasonal snapshots of the bacterial diversity and community structure at two locations in Jeju island (South Sea, Korea) over a one year period. Seasonal sampling from the water column at each site revealed highly diverse bacterial communities containing up to 1000 estimated Operational Taxonomic Units (OTUs). The Rhodobacteraceae and Flavobacteriaceae were the most abundant group and predominant members of the OTUs shared among all sampling seasons, and the most frequently recorded OTUs were members of Pelagibacter and Glaciecola, respectively. Inparticular, it was observed that Citromicrobium, a genus of the Alphaprobacteria, dominated during summer. Environmental factors significantly influenced the bacterial community structure among season, with the phosphate and nitrate concentrations contributing strongly to the spatial distribution of the Alphaproteobacteria and Coscinodiscophyceae the Gammaproteobacteria, Flavobacteria, and Actinobacteria all showed marked negative correlations with all nutrients, particularly silicon dioxide and chlorophyll-a. The results suggest that seasonal changes in environmental variables contribute to the dynamic structure of the bacterial community in the study area.er column at each site revealed highly diverse bacterial communities containing up to 1000 estimated Operational Taxonomic Units (OTUs). The Rhodobacteraceae and Flavobacteriaceae were the most abundant group and predominant members of the OTUs shared among all sampling seasons, and the most frequently recorded OTUs were members of Pelagibacter and Glaciecola, respectively. Inparticular, it was observed that Citromicrobium, a genus of the Alphaprobacteria, dominated during summer. Environmental factors significantly influenced the bacterial community structure among season, with the phosphate and nitrate concentrations contributing strongly to the spatial distribution of the Alphaproteobacteria and Coscinodiscophyceae the Gammaproteobacteria, Flavobacteria, and Actinobacteria all showed marked negative correlations with all nutrients, particularly silicon dioxide and chlorophyll-a. The results suggest that seasonal changes in environmental variables contribute to the dynamic structure of the bacterial community in the study area.