title: Contribution of different dispersal sources to the metabolic response of lake bacterioplankton following a salinity change.
abstract: Dispersal can modify how bacterial community composition (BCC) changes in response to environmental perturbations, yet knowledge about the functional consequences of dispersal is limited. Here we hypothesized that changes in bacterial community production in response to a salinity disturbance depend on the possibility to recruit cells from different dispersal sources. To investigate this, we conducted an in situ mesocosm experiment where bacterial communities of an oligotrophic lake were exposed to different salinities (0, 18, 36 psu) for 2 weeks and subjected to dispersal of cells originating from sediments, air (mesocosms open to air deposition), both or none. BCC was determined using 454 pyrosequencing of the 16S rRNA gene and bacterial production was measured by3H leucine uptake. Bacterial production differed significantly among salinity treatments and dispersal treatments, being highest at high salinity. These changes were associated with changes in BCC and it was found that the identity of the main functional contributors differed at different salinities. Our results further showed that after a salinity perturbation, the response of bacterial communities depended on the recruitment of taxa, including marine representatives (e.g., Alphaproteobacteria Loktanella, Erythrobacter and the Gammaproteobacterium Rheiheimera) from dispersal sources, in which atmospheric deposition appeared to play a major role.
authors.affiliation: Department of Ecology and Genetics/Limnology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18 D, 75236, Uppsala, Sweden.|Environment and Climate Change Canada - Canada Centre for Inland Waters, Watershed Hydrology and Ecology Research Division-Water Science and Technology, Burlington, ON L7S 1A1, Canada.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Comte
authors.affiliation: Department of Ecology and Genetics/Limnology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18 D, 75236, Uppsala, Sweden.
authors.forename: Silke
authors.initials: S
authors.lastname: Langenheder
authors.affiliation: Department of Ecology and Genetics/Limnology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18 D, 75236, Uppsala, Sweden.|Biological Oceanography, Leibniz Institute for Baltic Sea Research, 18119 Rostock Warnemünde (IOW), Seestraße 15, Germany.
authors.forename: Mercè
authors.initials: M
authors.lastname: Berga
authors.affiliation: Department of Ecology and Genetics/Limnology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18 D, 75236, Uppsala, Sweden.
authors.forename: Eva S
authors.initials: ES
authors.lastname: Lindström
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017753:Ecosystem; D060106:Lakes / Q000737:chemistry / Q000382:microbiology*; D010933:Plankton / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D054712:Salinity
chemical_list: D012336:RNA, Ribosomal, 16S