title: Viral ecology of organic and inorganic particles in aquatic systems: avenues for further research.
abstract: Viral abundance and processes in the water column and sediments are well studied for some systems; however, we know relatively little about virus-host interactions on particles and how particles influence these interactions. Here we review virus-prokaryote interactions on inorganic and organic particles in the water column. Profiting from recent methodological progress, we show that confocal laser scanning microscopy in combination with lectin and nucleic acid staining is one of the most powerful methods to visualize the distribution of viruses and their hosts on particles such as organic aggregates. Viral abundance on suspended matter ranges from 105to 1011ml-1. The main factors controlling viral abundance are the quality, size and age of aggregates and the exposure time of viruses to aggregates. Other factors such as water residence time likely act indirectly. Overall, aggregates appear to play a role of viral scavengers or reservoirs rather than viral factories. Adsorption of viruses to organic aggregates or inorganic particles can stimulate growth of the free-living prokaryotic community, e.g. by reducing viral lysis. Such mechanisms can affect microbial diversity, food web structure and biogeochemical cycles. Viral lysis of bacterio- and phytoplankton influences the formation and fate of aggregates and can, for example, result in a higher stability of algal flocs. Thus, viruses also influence carbon export; however, it is still not clear whether they short-circuit or prime the biological pump. Throughout this review, emphasis has been placed on defining general problems and knowledge gaps in virus-particle interactions and on providing avenues for further research, particularly those linked to global change.
authors.affiliation: Microbial Ecology & Biogeochemistry Group and Université Pierre et Marie Curie-Paris6, Laboratoire d'Océanographie de Villefranche, 06234 Villefranche-sur-Mer Cedex, France; Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie de Villefranche, 06234 Villefranche-sur-Mer, France.
authors.forename: M G
authors.initials: MG
authors.lastname: Weinbauer
authors.affiliation: Institut de Recherche pour le Développement, UMR 5119 ECOLAG, Université Montpellier II, 34095 Montpellier Cedex 5, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Bettarel
authors.affiliation: Microbial Ecology & Biogeochemistry Group and Université Pierre et Marie Curie-Paris6, Laboratoire d'Océanographie de Villefranche, 06234 Villefranche-sur-Mer Cedex, France.
authors.forename: R
authors.initials: R
authors.lastname: Cattaneo
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: B
authors.initials: B
authors.lastname: Luef
authors.affiliation: Microbial Ecology & Biogeochemistry Group and Université Pierre et Marie Curie-Paris6, Laboratoire d'Océanographie de Villefranche, 06234 Villefranche-sur-Mer Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Maier
authors.affiliation: Microbial Ecology & Biogeochemistry Group and Université Pierre et Marie Curie-Paris6, Laboratoire d'Océanographie de Villefranche, 06234 Villefranche-sur-Mer Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Motegi
authors.affiliation: Departement of Freshwater Ecology, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Peduzzi
authors.affiliation: IRD, UMR 5119 ECOLAG, Noumea Center, BP A5, NC-98848 Noumea, New Caledonia.
authors.forename: X
authors.initials: X
authors.lastname: Mari
keywords: Aggregates; Bacteria; Prokaryotes; Viruses