title: Short-Term Dynamics of North Sea Bacterioplankton-Dissolved Organic Matter Coherence on Molecular Level.
abstract: Remineralization and transformation of dissolved organic matter (DOM) by marine microbes shape the DOM composition and thus, have large impact on global carbon and nutrient cycling. However, information on bacterioplankton-DOM interactions on a molecular level is limited. We examined the variation of bacterial community composition (BCC) at Helgoland Roads (North Sea) in relation to variation of molecular DOM composition and various environmental parameters on short-time scales. Surface water samples were taken daily over a period of 20 days. Bacterial community and molecular DOM composition were assessed via 16S rRNA gene tag sequencing and ultrahigh resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), respectively. Environmental conditions were driven by a coastal water influx during the first half of the sampling period and the onset of a summer phytoplankton bloom toward the end of the sampling period. These phenomena led to a distinct grouping of bacterial communities and DOM composition which was particularly influenced by total dissolved nitrogen (TDN) concentration, temperature, and salinity, as revealed by distance-based linear regression analyses. Bacterioplankton-DOM interaction was demonstrated in strong correlations between specific bacterial taxa and particular DOM molecules, thus, suggesting potential specialization on particular substrates. We propose that a combination of high resolution techniques, as used in this study, may provide substantial information on substrate generalists and specialists and thus, contribute to prediction of BCC variation.
authors.affiliation: Biological Station Helgoland, Shelf Sea Systems Ecology, Alfred-Wegener-Institute Helmholtz-Center for Polar and Marine Research Helgoland, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Lucas
authors.affiliation: Research Group for Marine Geochemistry (ICBM-MPI Bridging Group), Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University Oldenburg Oldenburg, Germany.
authors.forename: Irina
authors.initials: I
authors.lastname: Koester
authors.affiliation: Biological Station Helgoland, Shelf Sea Systems Ecology, Alfred-Wegener-Institute Helmholtz-Center for Polar and Marine Research Helgoland, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Wichels
authors.affiliation: Research Group for Marine Geochemistry (ICBM-MPI Bridging Group), Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University Oldenburg Oldenburg, Germany.
authors.forename: Jutta
authors.initials: J
authors.lastname: Niggemann
authors.affiliation: Research Group for Marine Geochemistry (ICBM-MPI Bridging Group), Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University Oldenburg Oldenburg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Dittmar
authors.affiliation: Helmholtz-Zentrum Geesthacht Centre for Materials and Coastal Research, Institute of Coastal Research, Modelling for the Assessment of Coastal Systems Geesthacht, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Callies
authors.affiliation: Biological Station Helgoland, Shelf Sea Systems Ecology, Alfred-Wegener-Institute Helmholtz-Center for Polar and Marine ResearchHelgoland, Germany; Wattenmeerstation Sylt, Coastal Ecology, Alfred-Wegener-Institute Helmholtz-Center for Polar and Marine ResearchList/Sylt, Germany.
authors.forename: Karen H
authors.initials: KH
authors.lastname: Wiltshire
authors.affiliation: Biological Station Helgoland, Shelf Sea Systems Ecology, Alfred-Wegener-Institute Helmholtz-Center for Polar and Marine Research Helgoland, Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Gerdts
keywords: 16S rRNA sequencing; DOM; FT-ICR-MS; bacterioplankton community variation; short-term