Composition and metabolic potential of microbial communities in chemically contaminated soils: a multi-dimensional...

Microbial communities are a crucial component of soil resources and play key roles in various biogeochemical processes. However, in the process of industrialization, the operation, transformation, relocation and other activities of chemical companies inevitably subject soil microorganisms to harsh and complex chemical pressures. Additionally, single-factor biological toxicity tests are difficult to reflect the true situation of contaminated soil environments. A multi-dimensional assessment approach- integrating non-target screening via HPLC-HRMS and 16S rDNA high-throughput sequencing technology with molecular ecological network analysis- was utilized to investigate and compare the soil microbial community structure and composition across seven distinct contaminated sites in China. Additionally, we explored the interactions among microbial species and analyzed the correlations between microorganisms and environmental factors. Phthalates, biphenyls, benzene, polycyclic aromatic hydrocarbons (PAHs), anilines, and phenols were predominant in soil samples, with PAHs serving as the typical representative pollutants across seven contaminated sites. Statistical analysis revealed that Comamonas aquatica and Deltaproteobacteria showed significant positive correlations with naphthalene and benzene substituents. Aniline compounds and high-molecular-weight PAHs were primary drivers reducing soil microbial richness and community complexity. Functional prediction based on KEGG and COG indicates that soil microbiomes at different contaminated sites adapt to chemical pollution and remodel community functions through an integrated membrane transport-regulation-catabolism response, characterized by site-specific enrichment of efflux pumps, transport systems, and xenobiotic degradation pathways. This work provides valuable data and scientific support for management of emerging contaminants in chemically contaminated soil.