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T. Sime-Ngando et al. (eds.), Lake Pavin, DOI 10.1007/978-3-319-39961-4_14
Lake Pavin: A Pioneer Site for Ecological
Studies of Freshwater VirusesTélesphore Sime-Ngando , Yvan Bettarel ,
Jonathan Colombet , Stéphanie Palesse ,
Angia Sriram Pradeep Ram , Marie Charpin ,
and Christian AmblardAbstract
Since the discovery, 2–3 decades ago, that viruses of microbes are abundant in marine eco-
systems, aquatic viral ecology has grown increasingly to reach the status of a full scientifi c
discipline in environmental sciences. A dedicated society, the International Society for
Viruses of Microorganisms (ISVM) ( http://www.isvm.org/ ), was recently launched.
Increasing studies in aquatic viral ecology are a source of novel knowledge related to the
biodiversity, the functioning of ecosystems and the evolution of the cellular world. This is
because viruses are perhaps the most diverse, abundant, and ubiquitous biological entities
in the world’s aquatic ecosystems. They exhibit various lifestyles that intimately depend on
living cell metabolism, and are ultimately replicated by members of all three domains of life
( Bacteria , Eukarya , Archaea ). This establishes viruses as microbial killers and manipula-
tors in the hydrosphere. Lake Pavin is one of the pioneer sites where original ecological data
were fi rst provided on the qualitative, quantitative and functional signifi cance of both lytic
and temperate viruses of prokaryotes in temperate freshwater lakes, taking into account
both seasonal and depth-related variability in the water column and in the sediments. These
data were acquired by means of original protocols we developed. In addition to these pro-
tocols, we herein provide a synthesis of Lake Pavin studies on viral ecology, focusing on:
(i) spatio-temporal dynamics of the diversity of viral communities, (ii) the signifi cance of
seasonal and depth-related variations of viral abundance and lytic and lysogenic activities,
and (iii) the relative importance of lytic viruses and grazers for bacterial mortality and the
biogeochemical implications for the food web dynamics. Unexpected and novel putative
viruses were discovered in the deep-aged, dark, and permanently anoxic monimolimnic
waters and sediments of Lake Pavin, highlighting the possible endemicity of these habitats.
Some of these original viruses resembled dsDNA viruses of hyperthermophilic and
hyperhalophilic Archaea. Unusual types of spherical and cubic virus-like particles (VLPs)
were also observed for the fi rst time. Infected prokaryotic cells were detected in deep sedi-T. Sime-Ngando (*) • J. Colombet • S. Palesse • A. S. P. Ram
M. Charpin • C. Amblard
LMGE, Laboratoire Microorganismes: Génome et Environnement ,
UMR CNRS 6023 , Université Clermont-Auvergne, Université
Blaise Pascal, BP 80026 , 63171 Aubière Cedex , France
e-mail: [email protected]
Y. Bettarel
LMGE, Laboratoire Microorganismes: Génome et Environnement ,
UMR CNRS 6023 , Université Clermont-Auvergne, Université
Blaise Pascal, BP 80026 , 63171 Aubière Cedex , France
Institut de Recherche pour le Développement (IRD) ,
MARBEC Marine Biodiversity, Exploitation & Conservation
UMR IRD (n° 248) , Ifremer , Univ. Montpellier,
CNRS (n° 9190) , Montpellier , France