title: Influence of fertilisation regimes on a nosZ-containing denitrifying community in a rice paddy soil.
abstract: BACKGROUND
  Denitrification is a microbial process that has received considerable attention during the past decade since it can result in losses of added nitrogen fertilisers from agricultural soils. Paddy soil has been known to have strong denitrifying activity, but the denitrifying microorganisms responsible for fertilisers in paddy soil are not well known. The objective of this study was to explore the impacts of 17-year application of inorganic and organic fertiliser (rice straw) on the abundance and composition of a nosZ-denitrifier community in paddy soil. Soil samples were collected from CK plots (no fertiliser), N (nitrogen fertiliser), NPK (nitrogen, phosphorus and potassium fertilisers) and NPK + OM (NPK plus organic matter). The nitrous oxide reductase gene (nosZ) community composition was analysed using terminal restriction fragment length polymorphism, and the abundance was determined by quantitative PCR.
  
  
  RESULTS
  Both the largest abundance of nosZ-denitrifier and the highest potential denitrifying activity (PDA) occurred in the NPK + OM treatment with about four times higher than that in the CK and two times higher than that in the N and NPK treatments (no significant difference). Denitrifying community composition differed significantly among fertilisation treatments except for the comparison between CK and N treatments. Of the measured abiotic factors, total organic carbon was significantly correlated with the observed differences in community composition and abundance (P < 0.01 by Monte Carlo permutation).
  
  
  CONCLUSIONS
  This study shows that the addition of different fertilisers affects the size and composition of the nosZ-denitrifier community in paddy soil.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Regions and Taoyuan Station of Agro-ecology Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Mapoling, ChangSha, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chen
authors.forename: Haijun
authors.initials: H
authors.lastname: Hou
authors.forename: Yan
authors.initials: Y
authors.lastname: Zheng
authors.forename: Hongling
authors.initials: H
authors.lastname: Qin
authors.forename: Yijun
authors.initials: Y
authors.lastname: Zhu
authors.forename: Jinshui
authors.initials: J
authors.lastname: Wu
authors.forename: Wenxue
authors.initials: W
authors.lastname: Wei
mesh_terms: D000383:Agriculture; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D002244:Carbon / Q000032:analysis; D058440:Denitrification / Q000235:genetics; D005308:Fertilizers; D005798:Genes, Bacterial; D009010:Monte Carlo Method; D009584:Nitrogen / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism* / Q000382:microbiology; D010088:Oxidoreductases / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D005308:Fertilizers; D012987:Soil; D002244:Carbon; D010088:Oxidoreductases; C022763:nitrous oxide reductase; D009584:Nitrogen