Distinct bacterial and archaeal diversities and spatial distributions in surface sediments of the Arctic Ocean

Environmental changes in the polar oceans are more pronounced than in other regions. The lack of knowledge regarding the microbial diversity, distribution and succession in the polar oceans has hampered our understanding about the effects of environmental changes on microbial ecosystems. This study investigated bacterial and archaeal diversities and spatial distributions in surface sediments of the Bering Sea and the Chukchi Sea. The results showed that bacterial alpha-diversity was higher than archaea, and these differences were due to compositional changes. beta-diversities were not significantly different for bacterial and archaeal communities. Proteobacteria and Bacteroidetes were the dominant bacterial phyla, and the subdivisions of Proteobacteria changed obviously when compared with previous results. However, different assemblages dominated archaeal communities in different regions. Bacterial and archaeal communities were mainly determined by metallic ions, and geochemical properties were the major contributors to community dissimilarities. Interactions between geographical and geochemical properties had more pronounced impacts on archaeal communities.