Drivers of Microbial Community Structure in Surface Sediment Aross Bohai Sea

Abstract

Background: Microbial spatial distribution has been widely investigated in sediment. However, there is poorly available information on microbial distribution patterns in sediment of Bohai Sea coastal zone. Results: Here, we investigated the bacterial community composition and diversity in riverine and marine surface sediment around and in the Bohai Sea using high-throughput sequencing. Bacterial communities mainly comprised Proteobacteria, Bacteroidetes, and Firmicutes. Salinity, dissolved oxygen, pH, and magnetic susceptibility played the main role in determining bacterial α-diversity and community composition in this region. Of the total bacterial community composition variation, environmental factors (explained 29.41% of the total microbial community composition variation) played a more important role than spatial variables (explained 3.03%) in conditioning the bacterial community composition. Meanwhile, the significantly pure spatial effect and distance-decay tendency suggested that dispersal limitation was also an influential factor in shaping the bacterial biogeographical pattern. The presence of magnetite center might shape the geographical distribution of five genera Lactococcus, Clostridium, Caulobacter, Gillisia and Sphingomonas probably by affecting their iron-related geochemical cycle.Conclusion: Our results may provide a better understanding of present-day bacterial biogeography and the correlation between microbial communities and key environmental variables in a typical coastal area. Depending on these information, coastal resources could be efficiently predicted, assessed and used.