title: Spatial Abundance, Diversity, and Activity of Ammonia-Oxidizing Bacteria in Coastal Sediments of the Liaohe Estuary.
abstract: Ammonia-oxidizing bacteria (AOB) play an important role in nitrification in estuaries. The aim of this study was to examine the spatial abundance, diversity, and activity of AOB in coastal sediments of the Liaohe Estuary using quantitative PCR, high-throughput sequencing of the amoA gene coding the ammonia monooxygenase enzyme active subunit, and sediment slurry incubation experiments. AOB abundance ranged from 8.54 × 104to 5.85 × 106copies g-1of wet sediment weight and exhibited an increasing trend from the Liaohe Estuary to the open coastal zone. Potential nitrification rates (PNRs) ranged from 0.1 to 336.8 nmol N g-1day-1along the estuary to the coastal zone. Log AOB abundance and PNRs were significantly positively correlated. AOB richness decreased from the estuary to the coastal zone. High-throughput sequencing analysis indicated that the majority of amoA gene sequences fell within the Nitrosomonas and Nitrosomonas-like clade, and only a few sequences were clustered within the Nitrosospira clade. This finding indicates that the Nitrosomonas-related lineage may be more adaptable to the specific conditions in this estuary than the Nitrosospira lineage. Sites with high nitrification rates were located in the southern open region and were dominated by the Nitrosomonas-like lineage, whereas the Nitrosospira lineage was found primarily in the northern estuary mouth sites with low nitrification rates. Thus, nitrification potentials in Liaohe estuarine sediments in the southern open region were greater than those in the northern estuary mouth, and the Nitrosomonas-related lineage might play a more important role than the Nitrosospira lineage in nitrification in this estuary.
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.|College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023, China.
authors.forename: Yongkai
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China. jffan@nmemc.org.cn.
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Fan
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Su
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Ming
authors.affiliation: College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.|College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.|College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023, China.
authors.forename: Fengyun
authors.initials: F
authors.lastname: Ji
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.|College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023, China.
authors.forename: Limei
authors.initials: L
authors.lastname: Guo
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023, China.
authors.forename: Shuaijun
authors.initials: S
authors.lastname: Zan
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.|College of Fisheries and Life Science, Dalian Ocean University, Dalian, 116023, China.
authors.forename: Bochao
authors.initials: B
authors.lastname: Li
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Guo
authors.affiliation: Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, 42 Linghe Street, Dalian, 116023, China.
authors.forename: Daoming
authors.initials: D
authors.lastname: Guan
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D044822:Biodiversity; D002681:China; D063366:Estuaries; D005798:Genes, Bacterial; D005843:Geography; D019015:Geologic Sediments / Q000382:microbiology*; D010084:Oxidation-Reduction; D010802:Phylogeny; D062206:Spatial Analysis
chemical_list: D000641:Ammonia