title: Distinct compositions of free-living, particle-associated and benthic communities of the Roseobacter group in the North Sea.
abstract: The Roseobacter group is one of the predominant lineages in the marine environment. While most investigations focus on pelagic roseobacters, the distribution and metabolic potential of benthic representatives is less understood. In this study, the diversity of the Roseobacter group was characterized in sediment and water samples along the German/Scandinavian North Sea coast by 16S rRNA gene analysis and cultivation-based methods. Molecular analysis indicated an increasing diversity between communities of the Roseobacter group from the sea surface to the seafloor and revealed distinct compositions of free-living and attached fractions. Culture media containing dimethyl sulfide (DMS), dimethyl sulfonium propionate (DMSP) or dimethyl sulfoxide (DMSO) stimulated growth of roseobacters showing highest most probable numbers (MPN) in DMSO-containing dilutions of surface sediments (2.1 × 10(7) roseobacters cm(-3)). Twenty roseobacters (12 from sediments) were isolated from DMSP- and DMS-containing cultures. Sequences of the isolates represented 0.04% of all Bacteria and 4.7% of all roseobacters in the pyrosequencing dataset from sediments. Growth experiments with the isolate Shimia sp. SK013 indicated that benthic roseobacters are able to switch between aerobic and anaerobic utilization of organic sulfur compounds. This response to changing redox conditions might be an adaptation to specific environmental conditions on particles and in sediments.
authors.affiliation: Carl-von-Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres, Carl-von-Ossietzky Straße 9-11, D-26129 Oldenburg, Germany.
authors.forename: Saranya
authors.initials: S
authors.lastname: Kanukollu
authors.affiliation: Georg-August-Universität Göttingen, Genomische und Angewandte Mikrobiologie, Institut für Mikrobiologie und Genetik, Grisebachstr. 8, D-37077 Göttingen, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Wemheuer
authors.affiliation: Carl-von-Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres, Carl-von-Ossietzky Straße 9-11, D-26129 Oldenburg, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Herber
authors.affiliation: Carl-von-Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres, Carl-von-Ossietzky Straße 9-11, D-26129 Oldenburg, Germany.
authors.forename: Sara
authors.initials: S
authors.lastname: Billerbeck
authors.affiliation: Carl-von-Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres, Carl-von-Ossietzky Straße 9-11, D-26129 Oldenburg, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Lucas
authors.affiliation: Georg-August-Universität Göttingen, Genomische und Angewandte Mikrobiologie, Institut für Mikrobiologie und Genetik, Grisebachstr. 8, D-37077 Göttingen, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Daniel
authors.affiliation: Carl-von-Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres, Carl-von-Ossietzky Straße 9-11, D-26129 Oldenburg, Germany.
authors.forename: Meinhard
authors.initials: M
authors.lastname: Simon
authors.affiliation: Carl-von-Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres, Carl-von-Ossietzky Straße 9-11, D-26129 Oldenburg, Germany.
authors.forename: Heribert
authors.initials: H
authors.lastname: Cypionka
authors.affiliation: Carl-von-Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres, Carl-von-Ossietzky Straße 9-11, D-26129 Oldenburg, Germany engelen@icbm.de.
authors.forename: Bert
authors.initials: B
authors.lastname: Engelen
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004121:Dimethyl Sulfoxide / Q000378:metabolism*; D009659:North Sea; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D041904:Roseobacter / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013440:Sulfides / Q000378:metabolism*; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013440:Sulfides; C004784:dimethyl sulfide; D004121:Dimethyl Sulfoxide
keywords: DGGE; MPN; Shimia sp; enrichment cultures; organic sulfur compounds; pyrosequencing