Li Hui, Jiang Yuji, Wang Shanli, Chen Lijun, Wen Xiaocui, Huang Minxue, Cheng Xiaocui, Cheng Zhongliang, Tao Liang
School of Computer Science, South China Normal University, Guangzhou, 510631, PR China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China.
J Hazard Mater. 2020 Feb 15;384:121295. doi: 10.1016/j.jhazmat.2019.121295. Epub 2019 Sep 25.
Soil microorganisms play a crucial role in the bioremediation of pentachlorophenol (PCP)-contaminated soils. However, whether and how soil bacterial networks with keystone taxa affect PCP dechlorination is not well understood. The present study investigated the effects of citrate on soil bacterial networks mediating PCP dechlorination by direct and indirect transformation in iron-rich upland and paddy soils. The rates of PCP dechlorination and Fe(II) generation were accelerated by citrate addition, particularly in the paddy soils. Network analysis revealed that the topological properties of bacterial networks were changed by citrate addition; more modules and keystone taxa were significantly correlated with PCP dechlorination and Fe(II) generation in the networks. Random forest modeling indicated that Clostridiales was the most important bacterial order; it was significantly involved in both the direct and indirect pathways of PCP dechlorination. Citrate addition had less influence on the balance between the direct and indirect pathways of PCP dechlorination in the upland soils, whereas it enhanced biological PCP dechlorination more directly and efficiently in the paddy soils. Our results suggested that land-use type and citrate addition play a critical role in controlling the biogeochemical mechanisms of PCP dechlorination.
土壤微生物在五氯苯酚（PCP）污染土壤的生物修复中起着关键作用。然而，具有关键类群的土壤细菌网络是否以及如何影响PCP脱氯尚不清楚。本研究通过直接和间接转化，研究了柠檬酸盐对富铁旱地和水稻土中介导PCP脱氯的土壤细菌网络的影响。添加柠檬酸盐可加速PCP脱氯和Fe（II）生成的速率，尤其是在水稻土中。网络分析表明，添加柠檬酸盐会改变细菌网络的拓扑性质；网络中更多的模块和关键类群与PCP脱氯和Fe（II）生成显著相关。随机森林建模表明，梭菌目是最重要的细菌目；它显著参与了PCP脱氯的直接和间接途径。添加柠檬酸盐对旱地土壤中PCP脱氯直接和间接途径之间的平衡影响较小，而在水稻土中，它更直接、有效地增强了生物PCP脱氯。我们的结果表明，土地利用类型和柠檬酸盐添加在控制PCP脱氯的生物地球化学机制中起着关键作用。
