Freshwater prokaryote and virus communities can adapt to a controlled increase in salinity through changes in their structure and interactions Combe Marine auteur aut IRD Bouvier T. auteur aut IRD Pringault Olivier auteur aut IRD Rochelle Newall Emma auteur aut IRD Bouvier C. auteur aut IRD Agis M. auteur aut IRD Thu P.T. auteur aut IRD Torréton Jean-Pascal auteur aut IRD Thuoc C.V. auteur aut IRD Bettarel Yvan auteur aut IRD text journalArticle eng text/pdf born digital access Little information exists on the ecological adaptive responses of riverine microorganisms to the salinity changes that typically occur in transitional waters. This study examined the precise effects of a gradual increase in salinity (+3 units per day for 12 days) on freshwater virus and prokaryote communities collected in the Red River Delta (northern Vietnam). The abundance, activity, morphology and diversity of both communities were examined along this simulated salinity gradient (0-36). Three main successive ecological stages were observed: (1) a continuous decline in prokaryotic and viral abundance from the start of the salinization process up to salinity 12-15 together with a strong decrease in the proportion of active cells, (2) a shift in both community compositions (salinity 9-15) and (3) a marked prevalence of lysogenic over lytic cycles up to salinity 21 followed by a collapse of both types of viral infection. Finally, after salinity 21, and up to seawater salinities (i.e. 36) the prokaryotic community showed multiple signs of recovery with their abundance and function even reaching initial levels. These results suggest that most of the physiological and phylogenetic changes that occurred within the salinity range 10-20 seemed to favor the installation of osmotically adapted prokaryotes accompanied by a specific cortege of viral parasites which might both be able to survive and even proliferate in saltwater conditions. specialized virus prokaryote salinity microbial ecology estuaries lysogeny tropical aquatic ecosystems VIET NAM 036 Estuarine Coastal and Shelf Science 133 58-66 2013 0272-7714 https://www.documentation.ird.fr/hor/fdi:010061297 10.1016/j.ecss.2013.08.013 0272-7714 [F B010061297] https://www.documentation.ird.fr/hor/fdi:010061297 https://www.documentation.ird.fr/intranet/publi/2013/12/010061297.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2013-12-23 2017-08-23 fdi:010061297 fre