Members of candidate divisions OP11, OD1 and SR1 are widespread along the water column of the meromictic Lake Pavin (France)

An autotrophic, hydrogenotrophic methanogen, designated strain 17A1T, was isolated from the profundal sediment of the meromictic Lake Pavin, France. The cells of the novel strain, which were non-motile, Gram-staining-negative rods that measured 2–15 µm in length and 0.2–0.4 µm in width, grew as filaments. Strain 17A1T grew in a mineral medium and its growth was stimulated by the addition of yeast extract, vitamins, acetate or rumen fluid. Penicillin, vancomycin and kanamycin reduced growth but did not completely inhibit it. Growth occurred at 14–41 °C (optimum 30 °C), at pH 5.0–8.5 (optimum pH 6.5) and with 0–0.4 M NaCl (optimum 0.1 M). The novel strain utilized H2/CO2 and methanol/H2 as substrates but not formate, acetate, methylamine/H2, isobutanol or 2-propanol. Its genomic DNA G+C content was 37.0 mol%. In phylogenetic analyses based on 16S rRNA gene sequences, strain 17A1T appeared to be a member of the genus Methanobacterium , with Methanobacterium beijingense 8-2T (96.3 % sequence similarity) identified as the most closely related established species. Based on phenotypic and phylogenetic data, strain 17A1T represents a novel species of methanogen within the genus Methanobacterium , for which the name Methanobacterium lacus sp. nov. is proposed. The type strain is 17A1T ( = DSM 24406T = JCM 17760T).

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Caractéristiques du microphytobenthos d'un lac volcanique. Characterization of the Microphytobenthos in a Volcanic Meromictic Lake (Lake Pavin, France). II. Productivity and Relationships

Internationale Revue der gesamten Hydrobiologie und Hydrographie ◽

10.1002/iroh.19800650608 ◽

1980 ◽

Vol 65 (6) ◽

pp. 849-869 ◽

Cited By ~ 3

Author(s):

Jean-Claude Romagoux

Keyword(s):

Meromictic Lake ◽

Lake Pavin

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Bacterial diversity in the water column of meromictic Lake Cadagno and evidence for seasonal dynamics

PLoS ONE ◽

10.1371/journal.pone.0209743 ◽

2018 ◽

Vol 13 (12) ◽

pp. e0209743 ◽

Cited By ~ 4

Author(s):

Francesco Danza ◽

Damiana Ravasi ◽

Nicola Storelli ◽

Samuele Roman ◽

Samuel Lüdin ◽

...

Keyword(s):

Water Column ◽

Bacterial Diversity ◽

Seasonal Dynamics ◽

Meromictic Lake

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Methanotrophy under Versatile Conditions in the Water Column of the Ferruginous Meromictic Lake La Cruz (Spain)

Frontiers in Microbiology ◽

10.3389/fmicb.2016.01762 ◽

2016 ◽

Vol 7 ◽

Cited By ~ 19

Author(s):

Kirsten Oswald ◽

Corinne Jegge ◽

Jana Tischer ◽

Jasmine Berg ◽

Andreas Brand ◽

...

Keyword(s):

Water Column ◽

Meromictic Lake

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Biomineralization of iron-phosphates in the water column of Lake Pavin (Massif Central, France)

Geochimica et Cosmochimica Acta ◽

10.1016/j.gca.2013.10.037 ◽

2014 ◽

Vol 126 ◽

pp. 78-96 ◽

Cited By ~ 74

Author(s):

Julie Cosmidis ◽

Karim Benzerara ◽

Guillaume Morin ◽

Vincent Busigny ◽

Oanez Lebeau ◽

...

Keyword(s):

Water Column ◽

Massif Central ◽

Iron Phosphates ◽

Lake Pavin

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Biogeochemical Niche of Magnetotactic Cocci Capable of Sequestering Large Polyphosphate Inclusions in the Anoxic Layer of the Lake Pavin Water Column

Frontiers in Microbiology ◽

10.3389/fmicb.2021.789134 ◽

2022 ◽

Vol 12 ◽

Author(s):

Cécile C. Bidaud ◽

Caroline L. Monteil ◽

Nicolas Menguy ◽

Vincent Busigny ◽

Didier Jézéquel ◽

...

Keyword(s):

Water Column ◽

Light And Electron Microscopy ◽

Environmental Parameters ◽

Aqueous System ◽

Calcium Carbonates ◽

Chemical Gradients ◽

Anoxic Layer ◽

Geochemical Analyses ◽

Lake Pavin ◽

Biogeochemical Niche

Magnetotactic bacteria (MTB) are microorganisms thriving mostly at oxic–anoxic boundaries of aquatic habitats. MTB are efficient in biomineralising or sequestering diverse elements intracellularly, which makes them potentially important actors in biogeochemical cycles. Lake Pavin is a unique aqueous system populated by a wide diversity of MTB with two communities harbouring the capability to sequester not only iron under the form of magnetosomes but also phosphorus and magnesium under the form of polyphosphates, or calcium carbonates, respectively. MTB thrive in the water column of Lake Pavin over a few metres along strong redox and chemical gradients representing a series of different microenvironments. In this study, we investigate the relative abundance and the vertical stratification of the diverse populations of MTB in relation to environmental parameters, by using a new method coupling a precise sampling for geochemical analyses, MTB morphotype description, and in situ measurement of the physicochemical parameters. We assess the ultrastructure of MTB as a function of depth using light and electron microscopy. We evidence the biogeochemical niche of magnetotactic cocci, capable of sequestering large PolyP inclusions below the oxic–anoxic transition zone. Our results suggest a tight link between the S and P metabolisms of these bacteria and pave the way to better understand the implication of MTB for the P cycle in stratified environmental conditions.

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