Li Xiaofei, Hou Lijun, Liu Min, Zheng Yanling, Li Ye, Lin Xianbiao
College of Geographical Sciences, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China.
Appl Microbiol Biotechnol. 2015 Apr;99(8):3639-49. doi: 10.1007/s00253-014-6299-x. Epub 2014 Dec 18.
Understanding the impact of polycyclic aromatic hydrocarbons (PAHs) on soil environments is of increasingly important concern. Therefore, the microbial degradation of PAHs in soils has drawn considerable attention, but little is known about the PAH degradation genes in urban soils. In this study, we examined the diversity and abundance of the PAH degradation bacteria and evaluated whether the specific bacteria can reflect PAH contents in the soils from urban roadsides directly receiving traffic emission. The results of phylogenetic analysis indicated that low PAH degradation bacterial diversity occurred in the urban roadside soils, only including Mycobacterium sp., Terrabacter sp., and one novel cluster. The community composition diversity of PAH degradation bacteria did not show a significant difference across the sampling sites. The abundance of PAH degradation genes ranged from 5.70 × 10(6) to 6.44 × 10(7) gene copies g(-1) dry soil, with an average abundance of 1.43 × 10(7) gene copies g(-1) dry soil, and their spatial variations were related significantly to PAH contents in the soils. The Mycobacterium sp. was the most widely detected and estimated to occupy 65.9-100 % of the total PAH degradation bacteria at most of the soil samples, implying that the Mycobacterium sp. might play a primary role in degrading PAHs in the contaminated urban soil environments.
了解多环芳烃（PAHs）对土壤环境的影响日益受到关注。因此，土壤中多环芳烃的微生物降解已引起相当大的关注，但对于城市土壤中的多环芳烃降解基因却知之甚少。在本研究中，我们检测了多环芳烃降解细菌的多样性和丰度，并评估了特定细菌是否能够直接反映来自直接受交通排放影响的城市路边土壤中的多环芳烃含量。系统发育分析结果表明，城市路边土壤中多环芳烃降解细菌的多样性较低，仅包括分枝杆菌属、地杆菌属和一个新的类群。多环芳烃降解细菌的群落组成多样性在各采样点之间未显示出显著差异。多环芳烃降解基因的丰度范围为5.70×10⁶至6.44×10⁷基因拷贝 g⁻¹干土，平均丰度为1.43×10⁷基因拷贝 g⁻¹干土，其空间变化与土壤中的多环芳烃含量显著相关。分枝杆菌属是检测到最广泛的，估计在大多数土壤样品中占总多环芳烃降解细菌的65.9 - 100%，这意味着分枝杆菌属可能在污染的城市土壤环境中多环芳烃的降解中起主要作用。
