Viability and stress state of bacteria associated with primary production or zooplankton-derived suspended particulate matter in summer along a transect in Baffin Bay (Arctic Ocean)
| Type | Article | ||||||||||||
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| Date | 2021-05 | ||||||||||||
| Language | English | ||||||||||||
| Author(s) | Burot Christopher1, Amiraux Rémi1, 2, 3, Bonin Patricia1, Guasco Sophie1, Babin Marcel3, Joux Fabien4, Marie Dominique5, Vilgrain Laure6, Heipieper Hermann7, Rontani Jean-François1 | ||||||||||||
| Affiliation(s) | 1 : Aix-Marseille University, Université de Toulon, CNRS/INSU/IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France 2 : UMR 6539 Laboratoire des Sciences de l’Environnement Marin (CNRS, UBO, IRD, Ifremer) Institut Universitaire Européen de la Mer (IUEM) Plouzané, France 3 : Takuvik Joint International Laboratory, Laval University (Canada) - CNRS, Département de biologie, Université Laval, Québec, G1V 0A6, Québec, Canada 4 : Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique de Banyuls, 66650, Banyuls sur mer, France 5 : Sorbonne Université, CNRS, UMR 7144, Station Biologique de Roscoff, 29680, Roscoff, France 6 : Sorbonne Université, CNRS UMR 7093, LOV, Observatoire océanologique, Villefranche-sur-Mer, France 7 : Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research – UFZ. Permoserstr. 15, 04318, Leipzig, Germany |
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| Source | Science Of The Total Environment (0048-9697) (Elsevier BV), 2021-05 , Vol. 770 , P. 145252 (13p.) | ||||||||||||
| DOI | 10.1016/j.scitotenv.2021.145252 | ||||||||||||
| WOS© Times Cited | 3 | ||||||||||||
| Keyword(s) | Sea ice algae, Bacterial viability, Salinity stress, Cis-trans isomerase, EPS, Micro- and macro-zooplankton | ||||||||||||
| Abstract | In the framework of the GreenEdge Project (whose the general objective is to understand the dynamic of the phytoplankton spring bloom in Arctic Ocean), lipid composition and viability and stress state of bacteria were monitored in sea ice and suspended particulate matter (SPM) samples collected in 2016 along a transect from sea ice to open water in Baffin Bay (Arctic Ocean). Lipid analyses confirmed the dominance of diatoms in the bottommost layer of ice and suggested (i) the presence of a strong proportion of micro-zooplankton in SPM samples collected at the western ice covered St 403 and St 409 and (ii) a high proportion of macro-zooplankton (copepods) in SPM samples collected at the eastern ice covered St 413 and open water St 418. The use of the propidium monoazide (PMA) method allowed to show a high bacterial mortality in sea ice and in SPM material collected in shallower waters at St 409 and St 418. This mortality was attributed to the release of bactericidal free fatty acids by sympagic diatoms under the effect of light stress. A strong cis-trans isomerization of bacterial MUFAs was observed in the deeper SPM samples collected at the St 403 and St 409. It was attributed to the ingestion of bacteria stressed by salinity in brine channels of ice by sympagic bacterivorous microzooplankton (ciliates) incorporating trans fatty acids of their preys before to be released in the water column during melting. The high trans/cis ratios also observed in SPM samples collected in the shallower waters at St 413 and St 418 suggest the presence of positively or neutrally buoyant extracellular polymeric substances (EPS)-rich particles retained in sea ice and discharged (with bacteria stressed by salinity) in seawater after the initial release of algal biomass. Such EPS particles, which are generally considered as ideal vectors for bacterial horizontal distribution in the Arctic, appeared to contain a high proportion of dead and non-growing bacteria. |
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