State Key Lab of Regional and Urban Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Environ Pollut. 2011 Jul;159(7):1886-95. doi: 10.1016/j.envpol.2011.03.035. Epub 2011 Apr 16.
Toxicity of pyrene on the denitrifiers was studied by spiking an agricultural soil with pyrene to a series of concentrations (0-500 mg kg(-1)) followed by dose-response and dynamic incubation experiments. Results showed a positive correlation between potential denitrification activity and copy numbers of denitrifying functional genes (nirK, nirS and nosZ), and were both negatively correlated with pyrene concentrations. Based on the comparison of EC(50) values, denitrifiers harboring nirK, nirS or nosZ gene were more sensitive than denitrification activity, and denitrifiers harboring nirS gene were more sensitive than that harboring nirK or nosZ genes. Seven days after spiking with EC(50) concentration of pyrene, denitrifiers diversity decreased and community composition changed in comparison with the control. Phylogenetic analyses of three genes showed that the addition of pyrene increased the proportion of Bradyrhizobiaceae, Rhodospirillales, Burkholderiales and Pseudomonadales. Some species belonging to these groups were reported to be able to degrade PAHs.
采用添加芘的方式研究了芘对反硝化菌的毒性，将芘添加到一系列浓度（0-500mg/kg）的农业土壤中，随后进行剂量反应和动态培养实验。结果表明，潜在反硝化活性与反硝化功能基因（nirK、nirS 和 nosZ）的拷贝数之间呈正相关，且与芘浓度均呈负相关。基于 EC50 值的比较，携带 nirK、nirS 或 nosZ 基因的反硝化菌比反硝化活性更敏感，而携带 nirS 基因的反硝化菌比携带 nirK 或 nosZ 基因的反硝化菌更敏感。在添加 EC50 浓度的芘 7 天后，与对照相比，反硝化菌的多样性减少，群落组成发生变化。对三个基因的系统发育分析表明，添加芘增加了慢生根瘤菌科、红螺菌目、伯克霍尔德氏菌目和假单胞菌目的比例。属于这些组的一些物种被报道能够降解 PAHs。
