Temporal factors and habitats drive the variation of microbial distributions and co-occurrence patterns in the Pearl River Estuary.

Background: Estuaries are dynamic and complicated aquatic ecosystems, where both abiotic and biotic factors heavily vary across seasons and among habitats. However, the distributions and co-occurrence patterns of microorganisms in estuarine ecosystems are still little known. Here, the microeukaryotic and prokaryotic communities in the Pearl River Estuary (PRE) in southern China across different sampling time and habitat types were investigated using amplicon sequencing.

Results: Results showed that both the distribution and co-occurrence patterns of microeukaryotes and prokaryotes were driven by sampling time and habitat types. The sampling time showed stronger impact on distribution patterns and co-occurrence patterns of microeukaryotes than those of prokaryotes, whereas habitat types showed stronger influence on prokaryotes than on microeukaryotes. Additionally, the deterministic processes played a more important role in structuring microeukaryotic community structures and networks than those of prokaryotic counterparts in PRE. And the species interactions of prokaryotic communities were more stable than those of microeukaryotic counterparts.

Conclusions: Our study sheds light on the importance of sampling time and habitat types in maintaining microbial diversities, and showed that prokaryotes and microeukaryotes may have different strategies when responding to the environmental changes in estuarine ecosystems.