Dynamics of auto- and heterotrophic picoplankton and associated viruses in Lake Geneva - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Accéder directement au contenu
Article Dans Une Revue Hydrology and Earth System Sciences Année : 2014

Dynamics of auto- and heterotrophic picoplankton and associated viruses in Lake Geneva

Résumé

Microbial dynamics have rarely been investigated in Lake Geneva, known as the largest lake in western Europe. From a 5-month survey, we report dynamic patterns of free-living virus, bacteria and small phytoplankton abundances in response to a variety of environmental parameters. For the first time, we fractionated the primary production to separate the contribution of different size-related biological compartments and measured both bacterial and viral production in addition to experiments conducted to quantify the virus-induced bacterial mortality. We observed marked seasonal and vertical variations in picocyanobacteria, bacteria and virus abundances and production. The contribution of picoplankton and nanoplankton production to the total primary production was high (reaching up to 76% of total primary production) in November and the spring-summer transition period, respectively. The impact of viral lysis on both bacteria and picocyanobacteria was significantly higher than grazing activities. Virus-induced picocyanobacterial mortality reached up to 66% of cell removal compared to virus induced (heterotrophic) bacterial mortality, which reached a maximum of 34% in July. Statistical analyzes revealed that temperature and top-down control by viruses are among important factors regulating the picocyanobacterial dynamics in this lake. More generally speaking, our results add to the growing evidence and accepted view nowadays that viruses are an important actor of freshwater microbial dynamics and more globally of the functioning of the microbial food webs.
Fichier principal
Vignette du fichier
2014_Parvathi_Hydrology and Earth System Sciences_1.pdf (942.58 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-02632569 , version 1 (27-05-2020)

Licence

Paternité

Identifiants

Citer

Ammini Parvathi, Xu Zhong, A. S. Pradeep Ram, Stéphan Jacquet. Dynamics of auto- and heterotrophic picoplankton and associated viruses in Lake Geneva. Hydrology and Earth System Sciences, 2014, 18 (3), pp.1073 - 1087. ⟨10.5194/hess-18-1073-2014⟩. ⟨hal-02632569⟩
43 Consultations
63 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More