Consulta: creatorFacets:"Lazar, Cassandre Sara"
Registros recuperados: 3
Data/hora: 09/06/2024 14:54:03

Methanogenic diversity and activity in hypersaline sediments of the centre of the Napoli mud volcano, Eastern Mediterranean Sea
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Lazar, Cassandre Sara; Parkes, R. John; Cragg, Barry A.; L Haridon, Stephane; Toffin, Laurent.
Submarine mud volcanoes are a significant source of methane to the atmosphere. The Napoli mud volcano, situated in the brine-impacted Olimpi Area of the Eastern Mediterranean Sea, emits mainly biogenic methane particularly at the centre of the mud volcano. Temperature gradients support the suggestion that Napoli is a cold mud volcano with moderate fluid flow rates. Biogeochemical and molecular genetic analyses were carried out to assess the methanogenic activity rates, pathways and diversity in the hypersaline sediments of the centre of the Napoli mud volcano. Methylotrophic methanogenesis was the only significant methanogenic pathway in the shallow sediments (0-40 cm) but was also measured throughout the sediment core, confirming that methylotrophic...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00043/15426/18003.pdf

Archaeal Populations in Hypersaline Sediments Underlying Orange Microbial Mats in the Napoli Mud Volcano
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Lazar, Cassandre Sara; L'Haridon, Stephane; Pignet, Patricia; Toffin, Laurent.
Microbial mats in marine cold seeps are known to be associated with ascending sulfide- and methane-rich fluids. Hence, they could be visible indicators of anaerobic oxidation of methane (AOM) and methane cycling processes in underlying sediments. The Napoli mud volcano is situated in the Olimpi Area that lies on saline deposits; from there, brine fluids migrate upward to the seafloor. Sediments associated with a brine pool and microbial orange mats of the Napoli mud volcano were recovered during the Medeco cruise. Based on analysis of RNA-derived sequences, the "active" archaeal community was composed of many uncultured lineages, such as rice cluster V or marine benthic group D. Function methyl coenzyme M reductase (mcrA) genes were affiliated with the...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00035/14589/12126.pdf

Diversité et activité des communautés microbiennes dans des sédiments marins associés aux émissions de fluides froids
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Lazar, Cassandre Sara.
A large portion of the greenhouse gas methane on Earth is trapped in marine sediments. However, little methane actually reaches the hydrsphere and the atmosphere, because it is efficiently consumed by anaerobic methane-oxidizing Archaea (ANME). This methane is mainly biogenic in marine sédiments, and is produced by methanogenic Archaea. Methane ascends from deep sources to the seabed, in cold seep sites of continental margins. In order to study microbial community diversity in cold seeps, and to determine geochemical factors that control these microbial communities, we compared four geochemically and geologically distinct sites. In this work, molecular tools (PCR, RT-PCR, DGGE, cloning) as well as genetic markers (16S rRNA, mcrA, dsrB) were employed, to...
Tipo: Text
Palavras-chave: Diversité moléculaire; Archaea; Méthanogène; ANME; McrA; DsrB; DGGE; Volcan de boue; Pockmark; Saumures; Fluides froids; Méthane; Mer de Norvège; Mer Méditerranée; Sédiments.; Molecular diversity; Archaea; Methanogen; ANME; McrA; DsrB; DGGE; Mud volcano; Pockmark; Brines; Cold seep; Methane; Norwegian Sea; Mediterranean Sea; Sediments.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00031/14250/11534.pdf