title: Evidence of Nitrogen Loss from Anaerobic Ammonium Oxidation Coupled with Ferric Iron Reduction in an Intertidal Wetland.
abstract: Anaerobic ammonium oxidation coupled with nitrite reduction is an important microbial pathway of nitrogen removal in intertidal wetlands. However, little is known about the role of anaerobic ammonium oxidation coupled with ferric iron reduction (termed Feammox) in intertidal nitrogen cycling. In this study, sediment slurry incubation experiments were combined with an isotope-tracing technique to examine the dynamics of Feammox and its association with tidal fluctuations in the intertidal wetland of the Yangtze Estuary. Feammox was detected in the intertidal wetland sediments, with potential rates of 0.24-0.36 mg N kg(-1) d(-1). The Feammox rates in the sediments were generally higher during spring tides than during neap tides. The tidal fluctuations affected the growth of iron-reducing bacteria and reduction of ferric iron, which mediated Feammox activity and the associated nitrogen loss from intertidal wetlands to the atmosphere. An estimated loss of 11.5-18 t N km(-2) year(-1) was linked to Feammox, accounting for approximately 3.1-4.9% of the total external inorganic nitrogen transported into the Yangtze Estuary wetland each year. Overall, the co-occurrence of ferric iron reduction and ammonium oxidation suggests that Feammox can act as an ammonium removal mechanism in intertidal wetlands.
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Hou
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Guoyu
authors.initials: G
authors.lastname: Yin
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Xianbiao
authors.initials: X
authors.lastname: Lin
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Lv
authors.initials: L
authors.lastname: Cheng
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Geographical Sciences, and ‡State Key Laboratory of Estuarine and Coastal Research, East China Normal University , 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Hu
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D002681:China; D063366:Estuaries; D019015:Geologic Sediments; D007501:Iron / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D058458:Nitrogen Cycle; D010084:Oxidation-Reduction; D053833:Wetlands
chemical_list: D064751:Ammonium Compounds; D009573:Nitrites; D007501:Iron; D009584:Nitrogen