School of Biological Sciences, Flinders University of South Australia, Sturt Road, Bedford Park, Adelaide, GPO Box 2100, Adelaide, SA 5001, Australia.
J Environ Manage. 2012 Nov 15;110:69-76. doi: 10.1016/j.jenvman.2012.05.022. Epub 2012 Jun 26.
Environmental contamination by TNT (2,4,6 trinitrotoluene), historically used in civilian industries and the military as an explosive is of great concern due to its toxicity. Scientific studies have however shown that TNT is susceptible to microbial transformation. The aim of this study was to assess the potential of a previously bioremediated hydrocarbon contaminated soil (PBR) to increase TNT degradation rates. This was investigated by adding TNT chips to PBR and uncontaminated soils (PNC) in laboratory based studies (up to 16 weeks). Residual TNT chip analysis showed greater TNT degradation in PBR soils (70%) and significantly higher metabolic rates (4.5 fold increase in cumulative CO(2) levels) than in PNC soils (30%). Molecular analysis (PCR-DGGE-cluster analysis) showed substantial shifts in soil microbial communities associated with TNT contamination between day 0 and week 4 especially in PBR soils. Bacterial communities appeared to be more sensitive to TNT contamination than fungal communities in both soils. Quantitative PCR analysis showed ~3 fold increase in the abundance of nitroreductase genes (pnrA) in PBR soils with a gradual reduction in community evenness (Pareto-Lorenz curves) in contrast to PNC soils. These results suggest that microbial response to TNT contamination was dependent on the history of soil use. The results also confirm that the microbial potential of waste soils such as PBR soil (usually disposed of via landfill) can be successfully used for accelerated TNT chip degradation. This promotes sustainable re-use of waste soils extending the life span of landfill sites.
由于 TNT（2,4,6-三硝基甲苯）的毒性，其对环境的污染引起了极大的关注。然而，科学研究表明 TNT 易被微生物转化。本研究旨在评估先前用于生物修复烃污染土壤（PBR）提高 TNT 降解率的潜力。通过在实验室研究中向 PBR 和未污染土壤（PNC）中添加 TNT 芯片（长达 16 周）来研究这一点。残留 TNT 芯片分析表明，PBR 土壤中的 TNT 降解率更高（70%），且累积 CO2 水平的代谢率显著更高（增加了 4.5 倍），而 PNC 土壤中的降解率为 30%。分子分析（PCR-DGGE-聚类分析）表明，TNT 污染后土壤微生物群落发生了实质性变化，特别是在 PBR 土壤中，从第 0 天到第 4 周。与 PNC 土壤相比，细菌群落似乎比真菌群落对 TNT 污染更为敏感。定量 PCR 分析表明，PBR 土壤中硝基还原酶基因（pnrA）的丰度增加了约 3 倍，而群落均匀度（Pareto-Lorenz 曲线）逐渐降低。这些结果表明，微生物对 TNT 污染的反应取决于土壤使用的历史。结果还证实，像 PBR 土壤这样的废物土壤（通常通过垃圾填埋场处理）的微生物潜力可成功用于加速 TNT 芯片降解。这促进了废物土壤的可持续再利用，延长了垃圾填埋场的使用寿命。
