Dissolved organic matter mediates the interactions between bacterial community and heavy metal fractionation in contaminated coal mine soils

作者：Wei Lin, Xiaolong Guo, Yili Wang, Junlin Zhao, Xiang Cheng, Yingjie Li, Chunyang Zhou · 发表于：Ecotoxicology and Environmental Safety · 年份：2025 · DOI：10.1016/j.ecoenv.2025.118237 · 被引用次数：11 · 研究领域：Coal and Its By-products、Heavy metals in environment、Mine drainage and remediation techniques

Heavy metal (HM) contamination in coal mine soils disrupts local bacterial networks, leading to prolonged soil deterioration. Dissolved organic matter (DOM), a crucial soil component, actively modulates both bacterial metabolism and HM mobilization. Despite its significance, our understanding of the complex interactions among bacterial communities, soil chemical and DOM properties, and HM fractionation remains limited. In this study, DOM and bacterial communities from three contaminated mines with varying HM levels and soil properties were analyzed using optical methods and high-throughput sequencing technique. Our results revealed pH and DOM composition, especially the ratio of recalcitrant to labile substances, as key environmental drivers of HM mobilization. Moreover, the composition of bacterial community, particularly the keystone and abundant species, exhibits pronounced site-specificity and HM-dependency. Distinct characteristic genera that are pertinent to HM tolerance/mobility were identified across three mines. Specifically, in Zibo (ZB) soils, Rhodococcus, Acinetobacter, and Pseudomonas significantly regulated the fractionation of Pb, Cu, Se, and Hg possibly via protein-like exudates releasing. In Zaozhuang (ZZ) soils, relationships were recognized between Reyranella, oxides associated Pb, and soil cation exchange capacity. Paenibacillus and Fictibacillus contributed to Se mobilization/tolerance in Linyi (LY) soils. Based on these field findings, two mechanisms wer...