Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
J Hazard Mater. 2023 Jul 5;453:131328. doi: 10.1016/j.jhazmat.2023.131328. Epub 2023 Mar 30.
The situ pollutant residue and microbial characteristics in contaminated environments are crucial for ecological restoration and soil utilization. This work reported the variation of polycyclic aromatic hydrocarbon (PAH) residues and the bacterial community at different depths in an aged-abandoned site. These results unveiled that over 90% of low molecular weight (LMW) and medium molecular weight (MMW), 52.84-76.88% of high molecular weight (HMW) bound-PAH (BP) residues were sequestrated in humin (HM). The stresses of PAH and soil depth enhanced the frequency of bacteria associations, especially positive associations. We enriched and cultured PAH degradation bacteria (PDB) from the sampling site mainly consisting of Pseudomonas and Acinetobacter, which were originally 0.39-0.52% abundant in the sampling site. The abundances of PDB and PAH-degradation genes (PDGs) were higher at shallower depths and increased with high PAH concentration. Simultaneously, Pearson correlation analysis and experimental verification found that the process of PAH binding with SOM limited the further increase of PDB and PDGs in PAH-contaminated sites. These findings may illustrate possible ecological risks of contaminated soils and provide guidance for the isolation and application of PDB.
污染环境中的位置污染物残留和微生物特征对于生态恢复和土壤利用至关重要。本工作报道了在一个老化废弃场地不同深度的多环芳烃（PAH）残留和细菌群落的变化。这些结果表明，超过 90%的低分子量（LMW）和中分子量（MMW）、52.84-76.88%的高分子量（HMW）结合多环芳烃（BP）残留被束缚在腐殖质（HM）中。PAH 的胁迫和土壤深度增加了细菌关联的频率，特别是正关联。我们从采样地点富集和培养了多环芳烃降解菌（PDB），主要由假单胞菌和不动杆菌组成，它们在采样地点的丰度最初为 0.39-0.52%。在较浅的深度，PDB 和多环芳烃降解基因（PDG）的丰度更高，并随着高浓度 PAH 而增加。同时，Pearson 相关分析和实验验证发现，PAH 与 SOM 的结合过程限制了污染场地中 PDB 和 PDG 的进一步增加。这些发现可能说明了污染土壤的潜在生态风险，并为 PDB 的分离和应用提供了指导。
