Anaerobic ammonium oxidation and its contribution to nitrogen removal in China's coastal wetlands.
Over the past several decades, human activities have caused substantial enrichment of reactive nitrogen in China's coastal wetlands. Although anaerobic ammonium oxidation (anammox), the process of oxidizing ammonium into dinitrogen gas through the reduction of nitrite, is identified as an important process for removing reactive nitrogen, little is known about the dynamics of anammox and its contribution to nitrogen removal in nitrogen-enriched environments. Here, we examine potential rates of anammox and associate them with bacterial diversity and abundance across the coastal wetlands of China using molecular and isotope tracing techniques. High anammox bacterial diversity was detected in China's coastal wetlands and included Candidatus Scalindua, Kuenenia, Brocadia, and Jettenia. Potential anammox rates were more closely associated with the abundance of anammox bacteria than to their diversity. Among all measured environmental variables, temperature was a key environmental factor, causing a latitudinal distribution of the anammox bacterial community composition, biodiversity and activity along the coastal wetlands of China. Based on nitrogen isotope tracing experiments, anammox was estimated to account for approximately 3.8-10.7% of the total reactive nitrogen removal in the study area. Combined with denitrification, anammox can remove 20.7% of the total external terrigenous inorganic nitrogen annually transported into China's coastal wetland ecosystems.
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
Lijun
L
Hou
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.|College of Geographical Sciences, East China Normal University, Shanghai 200241, China.
Yanling
Y
Zheng
College of Geographical Sciences, East China Normal University, Shanghai 200241, China.
Min
M
Liu
College of Geographical Sciences, East China Normal University, Shanghai 200241, China.
Xiaofei
X
Li
College of Geographical Sciences, East China Normal University, Shanghai 200241, China.
Xianbiao
X
Lin
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.|College of Geographical Sciences, East China Normal University, Shanghai 200241, China.
Guoyu
G
Yin
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
Juan
J
Gao
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
Fengyu
F
Deng
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
Fei
F
Chen
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
Xiaofen
X
Jiang
D064751:Ammonium Compounds / Q000737:chemistry*; D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D002681:China; D009584:Nitrogen / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D053833:Wetlands
D064751:Ammonium Compounds; D009584:Nitrogen