title: Manganese and iron as structuring parameters of microbial communities in Arctic marine sediments from the Baffin Bay.
abstract: The Arctic Baffin Bay between Canada and Greenland is sea ice-covered during the majority of the year, restricting primary production to the summer months. Sediments receive low amounts of mostly terrestrial- and less marine-derived organic matter. To study microbial communities constrained by physicochemical conditions changing with distance from land and ocean depth, we applied high-throughput 16S rRNA gene sequencing and compared sequence diversity with biogeochemical parameters in 40 different sediment samples. Samples originated from seven cores down to 470 cm below seafloor along a shelf-to-basin transect. Bacterial diversity decreased faster with depth in basin than in shelf sediments, suggesting higher organic matter content sustained diversity into greater depths. All samples were dominated by Betaproteobacteria (mostly order Burkholderiales), which were especially abundant in basin sediments with low organic carbon and high Mn and Fe pore water concentrations. Strong statistical correlations between concentrations of reduced Mn and/or Fe and the relative abundances of Betaproteobacteria suggest that this group is involved in metal reduction in Baffin Bay sediments. Dehalococcoidia (phylum Chloroflexi) were abundant in all samples, especially in shelf sediments with high organic content. This study indicates that Mn and/or Fe play important roles structuring microbial communities in Arctic sediments poor in organic matter.
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany.
authors.forename: Camelia
authors.initials: C
authors.lastname: Algora
authors.affiliation: Istituto di Chimica Agraria ed Ambientale, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Vasileiadis
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Wasmund
authors.affiliation: Istituto di Chimica Agraria ed Ambientale, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Trevisan
authors.affiliation: Department of Resource Geochemistry, Germany Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655 Hannover; Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Krüger
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Puglisi
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany lorenz.adrian@ufz.de.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Adrian
mesh_terms: D001105:Archaea / Q000235:genetics / Q000302:isolation & purification; D001110:Arctic Regions; D001483:Base Sequence; D061006:Bays; D020562:Betaproteobacteria / Q000235:genetics* / Q000302:isolation & purification; D044822:Biodiversity; D002170:Canada; D041862:Chloroflexi / Q000235:genetics* / Q000302:isolation & purification; D019015:Geologic Sediments / Q000382:microbiology*; D006116:Greenland; D007501:Iron / Q000378:metabolism*; D008345:Manganese / Q000378:metabolism*; D059013:Microbial Consortia / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D012336:RNA, Ribosomal, 16S; D008345:Manganese; D007501:Iron
keywords: Baffin Bay; Betaproteobacteria; Burkholderiales; Chloroflexi; Dehalococcoidia; Illumina sequencing; marine subsurface; microbial diversity