Trophic interactions between viruses, bacteria and nanoflagellates under various nutrient conditions and simulated climate change

Année de publication



Environmental Microbiology 13 1842 1857 7


Population dynamics in the microbial food web are influenced by resource availability and predator/parasitism activities. Climatic changes, such as an increase in temperature and/or UV radiation, can also modify ecological systems in many ways. A series of enclosure experiments was conducted using natural microbial communities from a Mediterranean lagoon to assess the response of microbial communities to top‐down control [grazing by heterotrophic nanoflagellates (HNF), viral lysis] and bottom‐up control (nutrients) under various simulated climatic conditions (temperature and UV‐B radiations). Different biological assemblages were obtained by separating bacteria and viruses from HNF by size fractionation which were then incubated in whirl‐Pak bags exposed to an increase of 3°C and 20% UV‐B above the control conditions for 96 h. The assemblages were also provided with an inorganic and organic nutrient supply. The data show (i) a clear nutrient limitation of bacterial growth under all simulated climatic conditions in the absence of HNF, (ii) a great impact of HNF grazing on bacteria irrespective of the nutrient conditions and the simulated climatic conditions, (iii) a significant decrease in burst size (BS) (number of intracellular lytic viruses per bacterium) and a significant increase of VBR (virus to bacterium ratio) in the presence of HNF, and (iv) a much larger temperature effect than UV‐B radiation effect on the bacterial dynamics. These results show that top‐down factors, essentially HNF grazing, control the dynamics of the lagoon bacterioplankton assemblage and that short‐term simulated climate changes are only a secondary effect controlling microbial processes.

Type de publication
  • journal
Type de document
  • article
Classification - Inist-CNRS
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Classification - Scopus
  • 1 - Life Sciences
  • 2 - Agricultural and Biological Sciences
  • 3 - Ecology, Evolution, Behavior and Systematics
  • 2 - Immunology and Microbiology
  • 3 - Microbiology
Classification - Science Metrix
  • 1 - health sciences
  • 2 - biomedical research
  • 3 - microbiology
Classification - Clarivate Analytics (Subject Category)
  • 1 - science
  • 2 - microbiology
Termes extraits

viral; climatic; microbiology; microbiol; ecol; heterotrophic; weinbauer; trophic; phytoplankton; climatic conditions; microb; bacterioplankton; environ; nutrient; microbial; aquat; blackwell publishing; environmental microbiology; bacterial mortality; picophytoplankton; appl; vibm; aquat microb ecol; appl environ microbiol; jacquet; ecosystem; aquatic; bouvy; lysis; viral lysis; predator; pico; limnol; climatic change; freshwater; oceanogr; agellates; bettarel; bacterium; simek; fuhrman; plankton; gasol; suttle; fems; mostajir; microbial interactions; predation; trophic conditions; limnol oceanogr; vidussi; biol; oligotrophic; heterotrophic bacteria; environ microbiol; microbial communities; viral abundance; viruses bacteria picophytoplankton; viral decay; heterotrophic nanoeukaryotes; growth rates; viruses bacteria pico; climatic treatments; size fractionation; bacterial cells; microbial food; autotrophic cells; marine viruses; bacterial communities; bacteria; bacterial biomass; clearance rates; growth rate; bacterial production; incorporation rates; oating enclosures; freshw biol; total abundance; viral infection; bacterium ratio; viral particles; burst size; aquatic systems; climatic factors; climatic variables; thymidine incorporation rates; major role; climate change; total variance; bacterial parameters; water temperature; bacterial growth rates; fems microbiol ecol; ecol prog; microbial components; biological variables

Entité nommée
Entité nommée - Emplacement géographique
  • Warrington
  • Montpellier
  • San Jose
  • Clermont-Ferrand
  • USA
  • CA
  • France
  • PA
Entité nommée - Organisme
  • Society for Applied Microbiology and Blackwell
  • IPCC
  • Environmental Microbiology
  • Society for Applied Microbiology
  • Blackwell Publishing Ltd
Entité nommée - Personne
I. Domaizon; S. Jacquet; E. Le Floc; Vidussi; Marine Ecosystem; Mostajir; Blaise Pascal; Weinbauer; Boras; F. Vidussi; Eugène Bataillon; Yvan Vergne; La Rochelle; Jean Nouguier; H. Montanié; Sharon Wein; P. Torréton; A. Sabatier; T. Bouvier; Marie; Nouguier; Olympe de Gouges; Maranger
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