Tracing the Biotransformation of Polycyclic Aromatic Hydrocarbons in Contaminated Soil Using Stable Isotope-Assisted Metabolomics.
Tracing the Biotransformation of Polycyclic Aromatic Hydrocarbons in Contaminated Soil Using Stable Isotope-Assisted Metabolomics.
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DOI：
10.1021/acs.estlett.7b00554
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发表时间：
2018-01
影响因子：
10.9
通讯作者：
Z. Tian;J. Vila;Miao Yu;Wanda Bodnar;M. D. Aitken
中科院分区：
文献类型：
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作者：
Z. Tian;J. Vila;Miao Yu;Wanda Bodnar;M. D. Aitken
有机污染物的生物转化可能导致形成比母体污染物毒性更大的氧化产物。然而，在复杂的环境样本中，追踪和识别这些产物及其形成的代谢途径仍然具有挑战性。我们将稳定同位素辅助代谢组学（SIAM）应用于从木材处理设施收集的多环芳烃污染土壤。将土壤样品分别加入13c均匀标记的荧光蒽、芘或苯并[a]蒽，其含量低于天然污染物，并在有氧生物刺激条件下孵育1或2周。结合高分辨率质谱法和自动化SIAM工作流程，提出了土壤中代谢物的化学结构和代谢途径。环裂解产物，包括以前未报道的中间体，如C11H10O6和C15H12O5，分别来自荧光蒽和苯并[a]蒽。二羟基化合物的硫酸盐偶联物被发现是芘和苯并[a]蒽的主要代谢物，这表明真菌在土壤中生物转化中的潜在作用。从芘中鉴定出一系列未知的含n代谢物，但其结构有待进一步研究。我们的研究结果表明，SIAM可以成功地应用于了解环境样品中有机污染物的命运，为这种复杂基质中微生物转化的新机制开辟了证据线。
Biotransformation of organic pollutants may result in the formation of oxidation products more toxic than the parent contaminants. However, to trace and identify those products, and the metabolic pathways involved in their formation, is still challenging within complex environmental samples. We applied stable isotope-assisted metabolomics (SIAM) to PAH-contaminated soil collected from a wood treatment facility. Soil samples were separately spiked with uniformly 13C-labeled fluoranthene, pyrene, or benzo[a]anthracene at a level below that of the native contaminant, and incubated for 1 or 2 weeks under aerobic biostimulated conditions. Combining high-resolution mass spectrometry and automated SIAM workflows, chemical structures of metabolites and metabolic pathways in the soil were proposed. Ring-cleavage products, including previously unreported intermediates such as C11H10O6 and C15H12O5, were detected originating from fluoranthene and benzo[a]anthracene, respectively. Sulfate conjugates of dihydroxy compounds were found as major metabolites of pyrene and benzo[a]anthracene, suggesting the potential role of fungi in their biotransformation in soils. A series of unknown N-containing metabolites were identified from pyrene, but their structural elucidation requires further investigation. Our results suggest that SIAM can be successfully applied to understand the fate of organic pollutants in environmental samples, opening lines of evidence for novel mechanisms of microbial transformation within such complex matrices.