title: Diversity, Abundance, and Distribution of nirS-Harboring Denitrifiers in Intertidal Sediments of the Yangtze Estuary.
abstract: Denitrification plays a critical role in nitrogen removal in estuarine and coastal ecosystems. In this study, the community composition, diversity, abundance, and distribution of cytochrome cd1-type nitrite reductase gene (nirS)-harboring denitrifiers in intertidal sediments of the Yangtze Estuary were analyzed using polymerase chain reaction (PCR)-based clone libraries and quantitative PCR techniques. Clone library analysis showed that the nirS-encoding bacterial biodiversity was significantly higher at the lower salinity sites than at the higher salinity sites. However, there was no significant seasonal difference in the nirS gene diversity between summer and winter. Phylogenetic analysis revealed that the nirS-harboring denitrifier communities at the study area had distinctive spatial heterogeneity along the estuary. At the lower salinity sites, the nirS-harboring bacterial community was co-dominated by clusters III and VII; while at the higher salinity sites, it was dominated by cluster I. Canonical correspondence analysis indicated that the community compositions of nirS-type denitrifiers were significantly correlated with salinity, ammonium, and nitrate. Quantitative PCR results showed that the nirS gene abundance was in the range of 1.01 × 10(6) to 9.00 × 10(7) copies per gram dry sediment, without significant seasonal variation. Among all the environmental factors, the nirS gene abundance was only significantly related to the change of salinity. These results can extend our current knowledge about the composition and dynamics of denitrification microbial community in the estuarine ecosystem.
authors.affiliation: State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Zheng
authors.forename: Lijun
authors.initials: L
authors.lastname: Hou
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Juan
authors.initials: J
authors.lastname: Gao
authors.forename: Guoyu
authors.initials: G
authors.lastname: Yin
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Li
authors.forename: Fengyu
authors.initials: F
authors.lastname: Deng
authors.forename: Xianbiao
authors.initials: X
authors.lastname: Lin
authors.forename: Xiaofen
authors.initials: X
authors.lastname: Jiang
authors.forename: Fei
authors.initials: F
authors.lastname: Chen
authors.forename: Haibo
authors.initials: H
authors.lastname: Zong
authors.forename: Junliang
authors.initials: J
authors.lastname: Zhou
mesh_terms: D064751:Ammonium Compounds / Q000032:analysis; D001483:Base Sequence; D044822:Biodiversity; D002681:China; D016000:Cluster Analysis; D058440:Denitrification; D063366:Estuaries; D015723:Gene Library; D019015:Geologic Sediments / Q000382:microbiology*; D064307:Microbiota; D008969:Molecular Sequence Data; D009566:Nitrates / Q000032:analysis; D010802:Phylogeny; D011156:Population Density; D060888:Real-Time Polymerase Chain Reaction; D054712:Salinity; D012621:Seasons; D017422:Sequence Analysis, DNA
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates