Spatial Patterns of Microbial Communities in Intertidal Sediments of the Yellow River Estuary, China

Estuarine ecosystems are among the most important natural ecosystems on Earth and contribute substantially to human survival and development. The Yellow River Estuary (YRE) is the second largest estuary in China. Microbial communities play an essential role in the material cycle and energy flow in estuarine ecosystems. To date, our knowledge of the spatial patterns of bacterial and archaeal communities is limited. In this study, we investigated the spatial profile of bacterial and archaeal communities and their co-occurrence patterns, functional roles, and environmental driving factors in the intertidal sediments of the YRE from June to July, 2019. The results showed that Proteobacteria, Bacteroidetes, Chloroflexi, and Planctomycetes were the dominant bacterial phyla, whereas Nanoarchaeaeota, Euryarchaeota and Thaumarchaeota were the dominant archaeal phyla in the intertidal sediments of the YRE. Diversity indices and differential abundance analyses revealed significant (p < 0.05) differences in the bacterial and archaeal communities in the intertidal sediments of the YRE. Bacterial communities demonstrated distinct correlations with heavy metals and pollutants. Six archaeal genera exhibited co-occurrence patterns with bacterial genera. Functions associated with sulfur cycles, disease, and pollution were specific to bacterial communities. This study presents a detailed outline of the spatial patterns of microbial communities in the YRE, enriching our understanding of microbial ecology, especially of bacteria and archaea.