Bacterial community compositions and their functionalities in soils from chemical industrial parks along the Yangtze River in Hubei Province

The chemical industry is vital to modern society and is a major source of soil contamination. This study characterized soil bacterial communities and their functional potential in eight chemical industrial parks along the Yangtze River in Hubei Province, aiming to identify microbial indicators for environmental monitoring and candidates for bioremediation. The top ten bacterial phyla, dominated by Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteria , and Firmicutes , were largely consistent between surface (0–0.5 m) and subsurface (2–3 m) soils, collectively accounting for >90 % of the bacterial sequences. A key shift was the replacement of Bacteroidota by MBNT15 in the subsurface, accompanied by a significant decrease in alpha diversity with depth. Crucially, measured soil properties (pH, moisture, and heavy metals) explained <20 % of the community variation, suggesting that stochastic processes or unmeasured parameters (e.g., organic pollutants) are primary drivers. Ten surface-enriched biomarker taxa were identified; however, they exhibited low relative abundances. Functional analyses revealed distinct nitrogen, carbon, and sulfur cycling potentials between the layers. This study provides a regional baseline for industrial soil microbiomes, underscores the limited explanatory power of standard soil properties, and highlights the need to integrate contaminant-specific data to guide targeted bioremediation strategies.