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T. Sime-Ngando et al. (eds.), Lake Pavin, DOI 10.1007/978-3-319-39961-4_16
Anaerobic Microbial Communities
and Processes Involved in the Methane
Cycle in Freshwater Lakes-a Focus
on Lake PavinAnne-Catherine Lehours, Guillaume Borrel,
Nicole Morel- Desrosiers, Corinne Bardot, Vincent Grossi,
Benoit Keraval, Eléonore Attard, Jean-Pierre Morel,
Christian Amblard, and Gerard FontyAbstract
The atmospheric concentration of methane (CH 4 ), a major greenhouse gas, is mainly con-
trolled by the activities of CH 4 -producing (methanogens) and CH 4 -consuming (methano-
trophs) microorganisms. Freshwater lakes are identified as one of the main CH 4 sources, as
it is estimated that they contribute to 6–16 % of natural CH 4 emissions. It is therefore critical
to better understand the biogeochemical cycling of CH 4 in these ecosystems.
In this vein, the Lake Pavin provides a useful microbial ecosystem to investigate CH 4
cycle in freshwater systems. Despite a significant production of CH 4 in the deep anoxic
water column and sediment, the amounts of CH 4 emitted by Lake Pavin to the atmosphere
are several orders of magnitude lower than those of temperate lakes suggesting intense
consumption activities of this gas.
This chapter focuses on CH 4 cycle, but as methanogenesis and anaerobic methanotrophy
build competitive and cooperative relationships with a number of bacterial metabolic
groups, we also address bacterial processes that are tightly coupled with CH 4 cycle (e.g.,
ferric iron reduction). Three main sections constitute this chapter:- A presentation of CH 4 cycle, including methanogenesis and methanotrophy, in freshwa-
ter systems and particularly in Lake Pavin, - The relationships between CH 4 cycle and some other biogeochemical processes in Lake
Pavin (ferric iron reduction, sulfate reduction and fermentation), including a brief over-
view of anaerobic microbial metabolisms, - Sections on methodologies enabling to access informations on the anaerobic metabo-
lisms (e.g., biomarkers, isotopes, microcalorimetry, nucleic acid molecular markers,
magnetoFISH).
A.-C. Lehours (*) • G. Borrel • N. Morel-Desrosiers • C. Bardot
B. Keraval • J.-P. Morel • G. Fonty
LMGE, Laboratoire « Microorganismes: Génome &
Environnement », UMR CNRS 6023, Université Clermont-
Auvergne, Université Blaise Pascal,
24 avenue des Landais, BP 80026, 63171 Aubière, France
V. Grossi
LGLTPE, Laboratoire de « Géologie de Lyon, Terre, Planètes,
Environnement », UMR CNRS 5276, Université Claude Bernard,
Lyon1, Campus de la Doua, bât. GEODE, 2, rue Raphaël Dubois,
69622 Villeurbanne, France
16
E. Attard
LMGE, Laboratoire « Microorganismes: Génome &
Environnement », UMR CNRS 6023, Université Blaise Pascal,
24, avenue des Landais, 63171 Aubière Cedex Clermont-Ferrand,
France
Equipe Environnement et Microbiologie, UMR CNRS-IPREM
5254, Université de Pau et des Pays de l’Adour,
BP 1155, 64013 Pau Cedex Pau, France
C. Amblard
LMGE, Laboratoire Microorganismes: Génome et Environnement,
UMR CNRS 6023, Université Clermont-Auvergne, Université
Blaise Pascal, BP 80026, 63171 Aubière Cedex, France