Tang Lei, Bao Zhongkang, Zhao Xuqiang, Wang Xinbo, Gao Yanzheng, Lu Chao, Ling Wanting
Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
National Agricultural Experiment Station for Agricultural Environment, Luhe, Ministry of Agriculture, China.
J Hazard Mater. 2023 Sep 15;458:131903. doi: 10.1016/j.jhazmat.2023.131903. Epub 2023 Jun 20.
Wild PAH-contaminated sites struggle to provide continuous and stable monitoring, resulting in the potential risks of contaminated soil utilization could not be evaluated effectively. This work provided a 9-months laboratory simulation which was close to the natural ecological process. These results believed that PAH-degrading bacteria (PDB) preferred to degrade organic extracted PAH (PAH_OS) and fresh bound-PAH (79.36-99.97%). The formation and migration efficiency of PAH binding with HA humic acid (HA) (PAH_HA) was lower than that of PAH binding with fulvic acid (FA) and humin (HM) (PAH_FA and PAH_HM), leading to PAH_HA had more persistent retention and influenced bacterial communities in shallow soils. Besides, phylum Proteobacteria gradually dominated the bacterial community and decreased 12.05-20.48% diversity at all depths during the biological self-purification process. Although the effect of this process enhanced the abundance of 28 genes 16 s rRNA and three PAH-degrading genes (PDGs) by 5.91-2047.34 times (phe, nahAc and nidA), the top 30 genera maintained their ecological characteristics. This study provided insights into the important influencing factor and mechanism of the biological self-purification processes and discerned the linkages between bacterial communities and environmental variables in the vertical profile, which is important to the isolation and application of PDB and ecological risk assessment.
受多环芳烃（PAH）污染的野外场地难以提供持续稳定的监测，导致无法有效评估污染土壤利用的潜在风险。本研究进行了为期9个月的实验室模拟，该模拟接近自然生态过程。研究结果表明，PAH降解菌（PDB）更倾向于降解有机提取态PAH（PAH_OS）和新鲜结合态PAH（79.36 - 99.97%）。PAH与腐殖酸（HA）结合形成的PAH_HA的形成和迁移效率低于PAH与富里酸（FA）和胡敏素（HM）结合形成的PAH_FA和PAH_HM，导致PAH_HA具有更强的持久性保留，并影响浅层土壤中的细菌群落。此外，在生物自净过程中，变形菌门在各深度的细菌群落中逐渐占据主导地位，多样性降低了12.05 - 20.48%。尽管这一过程使28个16 s rRNA基因和3个PAH降解基因（PDGs）（phe、nahAc和nidA）的丰度提高了5.91 - 2047.34倍，但排名前30的属保持了它们的生态特征。本研究深入探讨了生物自净过程的重要影响因素和机制，识别了垂直剖面中细菌群落与环境变量之间的联系，这对于PDB的分离与应用以及生态风险评估具有重要意义。
