title: Effect of pyrene on denitrification activity and abundance and composition of denitrifying community in an agricultural soil.
abstract: 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.
authors.affiliation: State Key Lab of Regional and Urban Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Guang-Xia
authors.initials: GX
authors.lastname: Guo
authors.forename: Huan
authors.initials: H
authors.lastname: Deng
authors.forename: Min
authors.initials: M
authors.lastname: Qiao
authors.forename: Yu-Jing
authors.initials: YJ
authors.lastname: Mu
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
mesh_terms: D000383:Agriculture; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D044822:Biodiversity; D058440:Denitrification / Q000187:drug effects*; D008969:Molecular Sequence Data; D009572:Nitrite Reductases / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011721:Pyrenes / Q000494:pharmacology*; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D011721:Pyrenes; D009572:Nitrite Reductases