title: Spatial and temporal dynamics of ammonia oxidizers in the sediments of the Gulf of Finland, Baltic Sea.
abstract: The diversity and dynamics of ammonia-oxidizing bacteria (AOB) and archaea (AOA) nitrifying communities in the sediments of the eutrophic Gulf of Finland (GoF) were investigated. Using clone libraries of ammonia monooxygenase (amoA) gene fragments and terminal restriction fragment length polymorphism (TRFLP), we found a low richness of both AOB and AOA. The AOB amoA phylogeny matched that of AOB 16S ribosomal genes from the same samples. AOA communities were characterized by strong spatial variation while AOB communities showed notable temporal patterns. At open sea sites, where transient anoxic conditions prevail, richness of both AOA and AOB was lowest and communities were dominated by organisms with gene signatures unique to the GoF. Given the importance of nitrification as a link between the fixation of nitrogen and its removal from aquatic environments, the low diversity of ammonia-oxidizing microbes across the GoF could be of relevance for ecosystem resilience in the face of rapid global environmental changes.
authors.affiliation: Department of Environmental Sciences, University of Helsinki, P.O. Box 65, 00014, Finland; Tvärminne Zoological Station, J.A. Palménin Tie 260, 10900, Hanko, Finland. Electronic address: adrien.vetterli@gmail.com.
authors.forename: Adrien
authors.initials: A
authors.lastname: Vetterli
authors.affiliation: Department of Environmental Sciences, University of Helsinki, P.O. Box 65, 00014, Finland; Tvärminne Zoological Station, J.A. Palménin Tie 260, 10900, Hanko, Finland.
authors.forename: Susanna
authors.initials: S
authors.lastname: Hietanen
authors.affiliation: Department of Environmental Sciences, University of Helsinki, P.O. Box 65, 00014, Finland; Tvärminne Zoological Station, J.A. Palménin Tie 260, 10900, Hanko, Finland.
authors.forename: Elina
authors.initials: E
authors.lastname: Leskinen
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D001105:Archaea / Q000235:genetics / Q000378:metabolism*; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001454:Baltic States; D044822:Biodiversity; D019641:DNA, Archaeal / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D019848:Gene Expression Regulation, Archaeal / Q000502:physiology; D015723:Gene Library; D019015:Geologic Sediments; D009792:Oceans and Seas; D010084:Oxidation-Reduction; D010802:Phylogeny; D019642:RNA, Archaeal / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013997:Time Factors
chemical_list: D019843:Archaeal Proteins; D019641:DNA, Archaeal; D004269:DNA, Bacterial; D019642:RNA, Archaeal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D000641:Ammonia
keywords: 16S; Ammonia oxidizers; AmoA; Nitrification; Seasonal dynamics; Sediment