Production of individual marine organic aggregates using Paramagnetic Microspheres: A new tool for examining microbial associations with aggregates

Type : ACL
Nature : Production scientifique
Au bénéfice du Laboratoire : Oui
Statut de publication : Publié
Année de publication : 2012
Auteurs (7) : MARI Xavier ROCHELLE-NEWALL Emma,j TORRÉTON J-p PRINGAULT O BETTAREL Y MOTEGI Chiaki WEINBAUER Markus,g
Revue scientifique : Limnology And Oceanography-methods
Volume : 10
Fascicule :
Pages : 155-166
DOI : 10.4319/lom.2012.10.155
URL : <go to isi>://wos:000309526700002
Abstract : We describe a new method to produce marine aggregates from natural organic material based on the sticking properties of transparent exopolymeric particles. Seawater samples were prescreened and ultrafiltered to concentrate the 30 kDa to 10 mu m size fraction. First, we produced small magnetizable aggregates by combining glass microfibers and paramagnetic 1-mu m beads with the organic matter present in the concentrated solution. The second step involved clustering the small aggregates into a single macro-aggregate, using a small ring-shaped magnet as an aggregation nucleus. Viral and bacterial densities, determined after dissolution of the newly formed aggregates with methanol, averaged 13.8 x 10(6) +/- 3.6 x 10(6) vir. agg.(-1) and 4.1 x 10(6) +/- 1.1 x10(6) bact. agg.(-1). Bacterial respiration and production measurements of single aggregates averaged 8.47 +/- 1.72 nmol O-2 agg.(-1) h(-1) and 1.54 +/- 0.45 ng C agg.(-1) h(-1), respectively. Particulate organic carbon and nitrogen content of the newly formed macro-aggregates averaged 31.92 +/- 2.67 mu g C agg.(-1) and 3.44 +/- 0.43 mu g N agg.(-1), respectively. This approach allows the concentration and isolation of the organic matter precursors that compose natural aggregates and provides a simple protocol for recombining those precursors into single newly formed macro-aggregates, which can then be easily manipulated for further investigation. This method is a new tool for investigations into the interactions between microorganisms and marine aggregates and their implications at the ecosystem level, but also into the interactions between aggregates and dissolved organic or inorganic substances.
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Commentaire : Times Cited: 0 Pringault, Olivier/A-7399-2008 0
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Citation :
Mari X, Rochelle-Newall EJ, Torréton J-P, Pringault O, Bettarel Y, Motegi C, Weinbauer MG (2012) Production of individual marine organic aggregates using Paramagnetic Microspheres: A new tool for examining microbial associations with aggregates. Limnol Oceanogr-meth 10: 155-166 | doi: 10.4319/lom.2012.10.155