Assessing the shaping factors for archaeal and bacterial communities in tidal wetland soils contaminated with polycyclic aromatic hydrocarbons

The environment and biome of coastal ecosystems are challenged by diverse human disturbances including soil pollution. Both archaea and bacteria are the main players in the biogeochemical cycling of coastal ecosystems, but their interactions with soil factors are far from being elucidated. In the tidal flats of Hangzhou Bay China, 16 soil physiochemical properties were discerned, including the major organic pollutants of polycyclic aromatic hydrocarbons (PAHs). Soil salinity, dissolved organic carbon, and PAHs varied between tidal soils and exhibited differential impacts on microbial communities. Particularly, soil salinity interacted with the beta diversity of both bacterial and archaeal communities. In comparison, soil dissolved organic carbon exhibited immense impacts on bacterial alpha diversity, beta diversity, and individual taxa but not on archaeal ones. Moreover, soil PAHs exhibited an average concentration of 463.21μg/kg in the tidal soils and were significantly correlated with bacterial alpha diversity and two bacterial genera of Algoriphagus and Candidatus Pelagibacter Additionally, archaeal and bacterial communities exhibited a strong correlation, suggesting a role of inter-kingdom interactions in shaping the microbiomes in tidal soils. Overall, our results indicated the differential impacts of soil factors on archaeal and bacterial communities. In the context of increasing human disturbance in coastal ecosystems, our findings are valuable for comprehending the determinants that influence microbial community assembly.