title: The effect of ammonium chloride and urea application on soil bacterial communities closely related to the reductive transformation of pentachlorophenol.
abstract: Pentachlorophenol (PCP) is widely distributed in the soil, and nitrogen fertilizer is extensively used in agricultural production. However, studies on the fate of organic contaminants as affected by nitrogen fertilizer application have been rare and superficial. The present study aimed to examine the effect of ammonium chloride (NH4Cl) and urea (CO(NH2)2) application on the reductive transformation of PCP in a paddy soil. The study showed that the addition of low concentrations of NH4Cl/CO(NH2)2 enhanced the transformation of PCP, while the addition of high concentrations of NH4Cl/CO(NH2)2 had the opposite effect. The variations in the abundance of soil microbes in response to NH4Cl/CO(NH2)2 addition showed that both NH4Cl and CO(NH2)2 had inhibitory effects on the growth of dissimilatory iron-reducing bacteria (DIRB) of the genus Comamonas. In contrast, for the genus Shewanella, low concentrations of NH4Cl inhibited growth, and high concentrations of NH4Cl enhanced growth, whereas all concentrations of CO(NH2)2 showed enhancement effects. In addition, consistent patterns of variation were found between the abundances of dechlorinating bacteria in the genus Dehalobacter and PCP transformation rates under NH4Cl/CO(NH2)2 addition. In conclusion, nitrogen application produced variations in the structure of the soil microbial community, especially in the abundance of dissimilatory iron-reducing bacteria and dechlorinating bacteria, which, in turn, affected PCP dechlorination.
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, PR China.
authors.forename: Huan-Yun
authors.initials: HY
authors.lastname: Yu
authors.affiliation: Environmental Science and Engineering College, Hubei Polytechic University, Huangshi 435003, Hubei, PR China.
authors.forename: Yong-kui
authors.initials: YK
authors.lastname: Wang
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, PR China.
authors.forename: Peng-cheng
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, PR China. Electronic address: cefbli@soil.gd.cn.
authors.forename: Fang-bai
authors.initials: FB
authors.lastname: Li
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, PR China.
authors.forename: Man-jia
authors.initials: MJ
authors.lastname: Chen
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Hu
mesh_terms: D000643:Ammonium Chloride / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry; D020585:Comamonas / Q000187:drug effects; D004247:DNA / Q000032:analysis; D007501:Iron / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D010416:Pentachlorophenol / Q000032:analysis / Q000737:chemistry*; D020592:Shewanella / Q000187:drug effects; D012987:Soil; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry; D014508:Urea / Q000737:chemistry*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D000643:Ammonium Chloride; D002713:Chlorine; D014508:Urea; D004247:DNA; D010416:Pentachlorophenol; D007501:Iron; D009584:Nitrogen
keywords: Dechlorinating bacteria; Dissimilatory iron-reducing bacteria (DIRB); Nitrogen fertilizer; Pentachlorophenol (PCP); Reductive transformation