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Nitrogen cycling in the ocean: From genes to ecosystems and from the past to the future
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Nitrogen loss by denitrification and anammox in sediments of Daya Bay, China
P-M5-09-S Haitao Xie* , Guangzhou university Yiguo hong, Guangzhou university Presenter Email: 584415278@qq.com |
The community structure and function on nitrogen loss of denitrification and anammox in the coastal subsurface sediments remain poorly understood. In the present study, we conducted 15N-labeled incubation, qPCR and high-throughput sequencing technique to analyze the activity, abundance, and community composition of denitrifiers and anammox bacteria in sediment cores from Daya Bay. Results indicated that activities and abundances of both denitrifiers and anammox bacteria were observed even below the surface sediments with low concentration of DIN and total nitrogen (TN). In the surface, denitrifiers have significantly higher activity and abundance than those of anammox bacteria, but the relative contribution to nitrogen loss by anammox increased to more than 60% in the subsurface sediments. Phylogenetic analysis revealed that nirS-type denitrifiers were affiliated to 10 different clusters and Ca. Scalindua dominated the anammox community in the whole sediments. Furthermore, both denitrification and anammox bacterial communities in the subsurface were remarkably distinct from that in the surface. Combined results suggested that denitrification and anammox play significant roles in removing fixed nitrogen and the availability of electronic acceptor (e.g. nitrite and nitrate) strongly influenced the nitrogen loss activities in the subsurface, emphasizing its role as a sink for the buried nitrogen. |
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