Wu Yan-Yang, Wu Qun-He, Huang Shan, Ye Jia-Xin, Zhang Heng-Jun, Zhang Ren-Duo
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Huan Jing Ke Xue. 2012 Oct;33(10):3592-7.
To establish the relationship between polycyclic aromatic hydrocarbons (PAHs) and various stages of denitrification under denitrifying conditions in sediments, we examined the impact of PAHs on the vertical distribution of special denitrifying genes. In March of 2011, sediment samples were collected from three representative locations along the Pearl River. The characteristics of vertical distribution of PAHs as well as denitrifying genes in the sediment samples were analyzed. Based on these vertical characteristics, relationships between PAHs and special denitrifying genes (narG, nirS, nosZ and nrfA) were established using the multivariate method. Results of canonical correspondence analysis (CCA) showed a close correlation between high ring PAHs and dissimilatory nitrate reduction. The impact of PAHs on nosZ was the most significant, namely PAHs imposed strong inhibition on the nitrite reduction stage. Except for the nitrite reduction stage, denitrifying bacteria from other stages of denitrification acclimatized themselves to the high ring PAHs. Especially, bacteria containing nrfA may have the potential to anaerobically degrade high ring PAHs. Besides this, the special role of nirS remains to be studied further.
为了确定沉积物反硝化条件下多环芳烃（PAHs）与反硝化各个阶段之间的关系，我们研究了PAHs对特定反硝化基因垂直分布的影响。2011年3月，从珠江沿岸三个具有代表性的地点采集了沉积物样本。分析了沉积物样本中PAHs以及反硝化基因的垂直分布特征。基于这些垂直特征，采用多变量方法建立了PAHs与特定反硝化基因（narG、nirS、nosZ和nrfA）之间的关系。典范对应分析（CCA）结果表明，高环PAHs与异化硝酸盐还原之间存在密切相关性。PAHs对nosZ的影响最为显著，即PAHs对亚硝酸盐还原阶段具有强烈抑制作用。除亚硝酸盐还原阶段外，反硝化其他阶段的反硝化细菌适应了高环PAHs。特别是，含有nrfA的细菌可能具有厌氧降解高环PAHs的潜力。除此之外，nirS的特殊作用仍有待进一步研究。
