title: Potential contribution of anammox to nitrogen loss from paddy soils in Southern China.
abstract: The anaerobic oxidation of ammonium (anammox) process has been observed in diverse terrestrial ecosystems, while the contribution of anammox to N2 production in paddy soils is not well documented. In this study, the anammox activity and the abundance and diversity of anammox bacteria were investigated to assess the anammox potential of 12 typical paddy soils collected in southern China. Anammox bacteria related to "Candidatus Brocadia" and "Candidatus Kuenenia" and two novel unidentified clusters were detected, with "Candidatus Brocadia" comprising 50% of the anammox population. The prevalence of the anammox was confirmed by the quantitative PCR results based on hydrazine synthase (hzsB) genes, which showed that the abundance ranged from 1.16 × 10(4) to 9.65 × 10(4) copies per gram of dry weight. The anammox rates measured by the isotope-pairing technique ranged from 0.27 to 5.25 nmol N per gram of soil per hour in these paddy soils, which contributed 0.6 to 15% to soil N2 production. It is estimated that a total loss of 2.50 × 10(6) Mg N per year is linked to anammox in the paddy fields in southern China, which implied that ca. 10% of the applied ammonia fertilizers is lost via the anammox process. Anammox activity was significantly correlated with the abundance of hzsB genes, soil nitrate concentration, and C/N ratio. Additionally, ammonia concentration and pH were found to be significantly correlated with the anammox bacterial structure.
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
authors.forename: Xiao-Ru
authors.initials: XR
authors.lastname: Yang
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Hu
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China University of Chinese Academy of Sciences, Beijing, China.
authors.forename: San-An
authors.initials: SA
authors.lastname: Nie
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
authors.forename: Jian-Qiang
authors.initials: JQ
authors.lastname: Su
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
authors.forename: Bo-Sen
authors.initials: BS
authors.lastname: Weng
authors.affiliation: State Key Laboratory of Environmental Aquatic Quality, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors.forename: Gui-Bing
authors.initials: GB
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
authors.forename: Huai-Ying
authors.initials: HY
authors.lastname: Yao
authors.affiliation: Institute for Genomics and Systems Biology, Argonne National Laboratory, Lemont, Illinois, USA Department of Ecology and Evolution, University of Chicago, Chicago Illinois, USA.
authors.forename: Jack A
authors.initials: JA
authors.lastname: Gilbert
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China ygzhu@iue.ac.cn.
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D058448:Biota; D002681:China; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D064751:Ammonium Compounds; D009584:Nitrogen