Consulta: creatorFacets:"Byrne, Nathalie"
Registros recuperados: 4
Data/hora: 09/06/2024 13:38:01

Etude de la diversité métabolique des micro-organismes des sources hydrothermales
Provedor de dados: 5
Autores: Byrne, Nathalie.
Since the discovery of oceanic hydrothermal vents, microbial diversity of this extreme environment was studied using both cultivation and molecular approaches. In this study the microbial diversity of active chimney from both TAG and Lucky Strike sites (Mid Atlantic Ridge) was investigated using both molecular survey and continuous enrichment culture in a bioreactor. To reproduce as close as possible environmental conditions the cultures were performed in oligotrophic conditions, in the presence of hydrogen and carbondioxide in the gas sweeping mix or using in situ sampled fluid/sea water mix as culture medium. The effect of environmental changes such as temperature and the absence or presence of sulphur was also investigated. Archaeal and Bacterial...
Tipo: Text
Palavras-chave: Culture; Molecular diversity; Metabolism; Hydrothermal vents; Microorganisms; Microbiology; Culture; Diversité moléculaire; Métabolisme; Sources hydrothermales; Micro organismes; Microbiologie.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-7295.pdf

Presence and activity of anaerobic ammonium-oxidizing bacteria at deep-sea hydrothermal vents
Provedor de dados: 5
Autores: Byrne, Nathalie; Strous, Marc; Crepeau, Valentin; Kartal, Boran; Birrien, Jean-louis; Schmid, Markus; Lesongeur, Francoise; Schouten, Stefan; Jaeschke, Andrea; Jetten, Mike; Prieur, Daniel; Godfroy, Anne.
Recent studies indicate that ammonia is an important electron donor for the oxidation of fixed nitrogen, both in the marine water column and sediments. This process, known as anammox, has so far only been observed in a large range of temperature habitats. The present study investigated the role of anammox in hydrothermal settings. During three oceanographic expeditions to the Mid-Atlantic Ridge, hydrothermal samples were collected from five vent sites, at depths ranging from 750 to 3650m from cold to hot habitats. Evidence for the occurrence of anammox in these particular habitats was demonstrated by concurrent surveys, including the amplification of 16S rRNA gene sequences related to known anammox bacteria, ladderanes lipids analysis and measurement of a...
Tipo: Text
Palavras-chave: Hydrothermal vent; Ladderanes; 16S rRNA; Activity; Micro organisms; Anammox.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6921.pdf

Export of deep-sea hydrothermal particles, indigenous thermophilic microorganisms and larvae to the surrounding Ocean
Provedor de dados: 5
Autores: Lesongeur, Francoise; Briand, Patrick; Godfroy, Anne; Crassous, Philippe; Byrne, Nathalie; Khripounoff, Alexis.
To assess the production and the export of particulate and biological material in deep-sea hydrothermal vents, four moorings with sediment traps and current meters were deployed for 24 days in the Azores Triple Junction (ATJ) region. They were deployed along an axis starting at the base of a hydrothermal vent chimney and ending 1000 m away. The particles sampled at the base of the chimney were characterized by high concentrations in total sulfur (16%) and iron (4%). The particle composition changed drastically with distance from the vent: the sulfur concentration decreased with an increase in clay components. Thermophilic microorganisms were successfully enriched from all the particle samples. Cultured strains were closely related to hydrothermal species,...
Tipo: Text
Palavras-chave: Deep-sea hydrothermal vents; Particle flux; Hydrothermal microorganisms; Larvae; Regional index: North Atlantic; Mid-Atlantic Ridge; Azores Triple Junction.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00230/34111/33046.pdf

Effect of variation of environmental conditions on the microbial communities of deep-sea vent chimneys, cultured in a bioreactor
Provedor de dados: 5
Autores: Byrne, Nathalie; Lesongeur, Francoise; Bienvenu, Nadege; Geslin, Claire; Alain, Karine; Prieur, Daniel; Godfroy, Anne.
Both cultivation and molecular techniques were used to investigate the microbial diversity and dynamic of a deep-sea vent chimney. The enrichment cultures performed in a gas-lift bioreactor were inoculated with a black smoker chimney sample collected on TAG site on the mid-Atlantic ridge. To mimic as close as possible environmental conditions, the cultures were performed in oligotrophic medium with nitrogen, hydrogen and carbon dioxide (N-2/H-2/CO2) gas sweeping. Also, the temperature was first settled at a temperature of 85A degrees C and colloidal sulphur was added. Then, the temperature was lowered to 60A degrees C and sulphur was omitted. Archaeal and bacterial diversity was studied in both culture and natural samples. Through 16S rRNA gene sequences...
Tipo: Text
Palavras-chave: 16S rRNA genes; Oligotrophic condition; Environmental condition; Bioreactor; Continuous enrichment culture; Microbial diversity; Deep sea hydrothermal vent.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6920.pdf