title: Endospores of thermophilic bacteria as tracers of microbial dispersal by ocean currents.
abstract: Microbial biogeography is influenced by the combined effects of passive dispersal and environmental selection, but the contribution of either factor can be difficult to discern. As thermophilic bacteria cannot grow in the cold seabed, their inactive spores are not subject to environmental selection. We therefore conducted a global experimental survey using thermophilic endospores that are passively deposited by sedimentation to the cold seafloor as tracers to study the effect of dispersal by ocean currents on the biogeography of marine microorganisms. Our analysis of 81 different marine sediments from around the world identified 146 species-level 16S rRNA phylotypes of endospore-forming, thermophilic Firmicutes. Phylotypes showed various patterns of spatial distribution in the world oceans and were dispersal-limited to different degrees. Co-occurrence of several phylotypes in locations separated by great distances (west of Svalbard, the Baltic Sea and the Gulf of California) demonstrated a widespread but not ubiquitous distribution. In contrast, Arctic regions with water masses that are relatively isolated from global ocean circulation (Baffin Bay and east of Svalbard) were characterized by low phylotype richness and different compositions of phylotypes. The observed distribution pattern of thermophilic endospores in marine sediments suggests that the impact of passive dispersal on marine microbial biogeography is controlled by the connectivity of local water masses to ocean circulation.
authors.affiliation: 1] Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Faculty of Life Sciences, University of Vienna, Vienna, Austria [2] Austrian Polar Research Institute, Vienna, Austria.
authors.forename: Albert Leopold
authors.initials: AL
authors.lastname: Müller
authors.affiliation: 1] Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark [2] School of Civil Engineering and Geosciences, Newcastle University, Newcastle Upon Tyne, UK.
authors.forename: Júlia Rosa
authors.initials: JR
authors.lastname: de Rezende
authors.affiliation: School of Civil Engineering and Geosciences, Newcastle University, Newcastle Upon Tyne, UK.
authors.forename: Casey R J
authors.initials: CR
authors.lastname: Hubert
authors.affiliation: Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Kasper Urup
authors.initials: KU
authors.lastname: Kjeldsen
authors.affiliation: Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
authors.forename: Ilias
authors.initials: I
authors.lastname: Lagkouvardos
authors.affiliation: Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
authors.forename: David
authors.identifier: 000000028997608X
authors.initials: D
authors.lastname: Berry
authors.affiliation: Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Bo Barker
authors.initials: BB
authors.lastname: Jørgensen
authors.affiliation: 1] Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Faculty of Life Sciences, University of Vienna, Vienna, Austria [2] Austrian Polar Research Institute, Vienna, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Loy
mesh_terms: D001110:Arctic Regions; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D019015:Geologic Sediments / Q000382:microbiology; D009792:Oceans and Seas; D010802:Phylogeny; D058974:Phylogeography; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D013171:Spores, Bacterial / Q000235:genetics; D013696:Temperature; D014872:Water Movements
chemical_list: D012336:RNA, Ribosomal, 16S