title: Variations in spatial and temporal distribution of Archaea in the North Sea in relation to environmental variables.
abstract: The spatial and temporal distribution of pelagic Archaea was studied in the southern North Sea by rRNA hybridization, sequencing and quantification of 16S rRNA gene and membrane lipid analyses and related to physical, chemical and biological parameters to determine the factors influencing archaeal biogeography. A clear temporal variability was observed, with marine Crenarchaeota (Group I.1a) being relatively more abundant in winter and Euryarchaeota dominating the archaeal assemblage in spring and summer. Spatial differences in the lateral distribution of Crenarchaeota were also evident. In fact, their abundance was positively correlated with the copy number of the gene encoding the alpha subunit of crenarchaeotal ammonia monooxygenase (amoA) and with concentrations of ammonia, nitrate, nitrite and phosphorus. This suggests that most Crenarchaeota in the North Sea are nitrifiers and that their distribution is determined by nutrient concentrations. However, Crenarchaeota were not abundant when larger phytoplankton (>3 microm) dominated the algal population. It is hypothesized that together with nutrient concentration, phytoplankton biomass and community structure can predict crenarchaeotal abundance in the southern North Sea. Euryarchaeotal abundance was positively correlated with chlorophyll a concentrations, but not with phytoplankton community structure. Whether this is related to the potential of Euryarchaeota to perform aerobic anoxygenic phototrophy remains to be shown, but the conspicuous seasonal distribution pattern of Crenarchaeota and Euryarchaeota suggests that they occupy a different ecological niche.
authors.affiliation: Department of Marine Biogeochemistry and Toxicology, Royal Netherlands Institute for Sea Research (NIOZ), Texel, The Netherlands. herfortl@ebs.ogi.edu
authors.forename: Lydie
authors.initials: L
authors.lastname: Herfort
authors.forename: Stefan
authors.initials: S
authors.lastname: Schouten
authors.forename: Ben
authors.initials: B
authors.lastname: Abbas
authors.forename: Marcel J W
authors.initials: MJ
authors.lastname: Veldhuis
authors.forename: Marco J L
authors.initials: MJ
authors.lastname: Coolen
authors.forename: Cornelia
authors.initials: C
authors.lastname: Wuchter
authors.forename: Jan P
authors.initials: JP
authors.lastname: Boon
authors.forename: Gerhard J
authors.initials: GJ
authors.lastname: Herndl
authors.forename: Jaap S
authors.initials: JS
authors.lastname: Sinninghe Damsté
mesh_terms: D019615:Crenarchaeota / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D019641:DNA, Archaeal / Q000032:analysis; D017753:Ecosystem; D019605:Euryarchaeota / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D020459:Genes, rRNA; D008563:Membrane Lipids / Q000032:analysis; D008969:Molecular Sequence Data; D009573:Nitrites / Q000378:metabolism; D009659:North Sea; D009693:Nucleic Acid Hybridization; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D012623:Seawater / Q000737:chemistry* / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D019641:DNA, Archaeal; D008563:Membrane Lipids; D009573:Nitrites; D012336:RNA, Ribosomal, 16S; D010088:Oxidoreductases; C045582:ammonia monooxygenase