title: Deciphering associations between dissolved organic molecules and bacterial communities in a pelagic marine system.
abstract: Dissolved organic matter (DOM) is the main substrate and energy source for heterotrophic bacterioplankton. To understand the interactions between DOM and the bacterial community (BC), it is important to identify the key factors on both sides in detail, chemically distinct moieties in DOM and the various bacterial taxa. Next-generation sequencing facilitates the classification of millions of reads of environmental DNA and RNA amplicons and ultrahigh-resolution mass spectrometry yields up to 10 000 DOM molecular formulae in a marine water sample. Linking this detailed biological and chemical information is a crucial first step toward a mechanistic understanding of the role of microorganisms in the marine carbon cycle. In this study, we interpreted the complex microbiological and molecular information via a novel combination of multivariate statistics. We were able to reveal distinct relationships between the key factors of organic matter cycling along a latitudinal transect across the North Sea. Total BC and DOM composition were mainly driven by mixing of distinct water masses and presumably retain their respective terrigenous imprint on similar timescales on their way through the North Sea. The active microbial community, however, was rather influenced by local events and correlated with specific DOM molecular formulae indicative of compounds that are easily degradable. These trends were most pronounced on the highest resolved level, that is, operationally defined 'species', reflecting the functional diversity of microorganisms at high taxonomic resolution.
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany.
authors.forename: Helena
authors.initials: H
authors.lastname: Osterholz
authors.affiliation: Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany.|Hanse-Wissenschaftskolleg (HWK), Delmenhorst, Germany.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Singer
authors.affiliation: Institute of Microbiology and Genetics, Georg August University Göttingen, Göttingen, Germany.
authors.forename: Bernd
authors.identifier: 0000-0002-1712-7871
authors.initials: B
authors.lastname: Wemheuer
authors.affiliation: Institute of Microbiology and Genetics, Georg August University Göttingen, Göttingen, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Daniel
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany.
authors.forename: Meinhard
authors.initials: M
authors.lastname: Simon
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany.
authors.forename: Jutta
authors.identifier: 0000-0003-1237-9233
authors.initials: J
authors.lastname: Niggemann
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Dittmar
mesh_terms: D059001:Aquatic Organisms; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D044822:Biodiversity; D002244:Carbon / Q000378:metabolism; D057486:Carbon Cycle; D004777:Environment; D005843:Geography; D052836:Heterotrophic Processes; D013058:Mass Spectrometry; D064307:Microbiota; D009659:North Sea; D009930:Organic Chemicals / Q000378:metabolism*; D010802:Phylogeny; D014871:Water Microbiology
chemical_list: D009930:Organic Chemicals; D002244:Carbon