Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
Environ Pollut. 2019 Apr;247:229-237. doi: 10.1016/j.envpol.2018.12.079. Epub 2019 Jan 8.
The fate of polycyclic aromatic hydrocarbons (PAHs) determines their potential risk in soil, which may be directly affected by abiotic conditions and indirectly through the changes in decomposer communities. In comparison, the indirect effects on the fate remain largely elusive. In this study, the fate of phenanthrene and benzo[a]pyrene and the corresponding bacterial changes were investigated in three contaminated farmland soils using a C tracer method and Miseq sequencing. The results showed that most benzo[a]pyrene was consistently extractable with dichloromethane (DCM) after the 60-day incubation (60.4%-78.2%), while phenanthrene was mainly mineralized to CO during the 30-day incubation (40.4%-58.7%). Soils from Guangzhou (GZ) showed a different distribution pattern of C-PAHs exemplified by low mineralization and disparate bound residue formation. The PAH fate in the Shenyang (SY) and Nanjing (NJ) soils were similar to each other than to that in the GZ soil. The fate in the GZ soil seemed to be linked to the distinct edaphic properties, such as organic matter content, however soil microbial community could have influenced the distribution pattern of PAHs. This potential role of microorganisms was reflected by the unique changes in the copy numbers of Gram positive RHD gene, and by the distinct shifts in bacterial community composition during the incubation. A quite different shift in bacterial communities was found in the GZ microcosms which may influence PAH mineralization and non-extractable residue (NER) formation.
多环芳烃（PAHs）的命运决定了它们在土壤中的潜在风险，这可能直接受到非生物条件的影响，也可能间接受到分解者群落变化的影响。相比之下，间接影响命运的因素在很大程度上仍难以捉摸。在这项研究中，使用 C 示踪法和 Miseq 测序，研究了三种污染农田土壤中菲和苯并[a]芘的命运及其相应的细菌变化。结果表明，在 60 天的孵育后，大多数苯并[a]芘（60.4%-78.2%）一直可以用二氯甲烷（DCM）提取，而菲在 30 天的孵育中主要矿化为 CO（40.4%-58.7%）。广州（GZ）土壤的 C-PAHs 分布模式不同，表现为低矿化和不同的结合残留形成。沈阳（SY）和南京（NJ）土壤中的 PAH 命运与 GZ 土壤相似，而与 GZ 土壤不同。GZ 土壤中的命运似乎与独特的土壤特性有关，如有机质含量，但土壤微生物群落可能影响 PAHs 的分布模式。微生物的这种潜在作用反映在革兰氏阳性 RHD 基因的拷贝数的独特变化，以及在孵育过程中细菌群落组成的明显变化。在 GZ 微宇宙中发现了一个截然不同的细菌群落变化，这可能影响 PAH 的矿化和不可提取残留（NER）的形成。
