Data/hora: 16/06/2024 16:54:02

Provedor de dados: | 5
País: | France

Título:

Cycles biogéochimiques du Fer et du Soufre dans les systèmes hydrothermaux en contexte sédimentaire du Bassin de Guaymas : traçages isotopiques et interactions micro-organismes/minéraux

Iron and sulfur biogeochemical cycles in sedimentary hydrothermal systems context (Guaymas Basin) : isotopic tracing and interaction microorganism-mineral

Autores: | Callac, Nolwenn.
Data: | 2013-07-09
Ano: | 2013
Palavras-chave: | Interactions procaryotes-biotopes; Cycle du fer; Cycle du soufre; Thermophiles; Cultures en bioréacteurs; Cultures en fioles; Module de colonisation in situ; Isotopie du fer; Isotopie du soufre; Systèmes hydrothermaux du Bassin de Guaymas; Prokaryote-biotope interactions; Iron cycle; Sulfur cycle; Thermophilic micro-organisms; Cultures in bioreactors; Cultures in batch; In situ colonization module; Iron isotope; Sulfur isotope; Hydrothermal systems of Guaymas Basin.
Resumo: | Active hydrothermal chimney and sediments of the Guaymas Basin (Mexico) host various microbial communities with different metabolisms, including those involved in biogeochemical cycles of sulfur and iron. It is established that, in these dynamic ecosystems, microbial activity depends on the availability of substrates in their environment and that prokaryotes could, in return locally affect the composition of the hydrothermal fluid and mineralogical composition of the chimney or sediment, by mediating the dissolution and / or precipitation of some mineral phases. In order to study these prokaryotes-biotope interactions, and establish links between the structure, the activity and the isotopic signatures of microbial communities with the physico-chemical characteristics of hydrothermal systems of Guaymas Basin, a multidisciplinary approach based on the implementation of microbiology, geochemistry and isotope technics was performed using enrichment cultures in bioreactors and the study of the colonization of basaltic substrates. This work led to: 1) characterize the diversity of microorganisms in different hydrothermal compartments (chimney and sediments) of the Guaymas Basin using both cultural and molecular approaches; 2) to decrypt the functioning of sulfur and iron biogeochemical cycles, by highlighting the occurrence, at high temperature and anaerobic condition, of sulfur-reducing, sulfate-reducing, sulfur-oxidizing and also iron-reducing and iron-oxidizing prokaryotes ; and 3) to better understand the prokaryote-mineral-fluid interactions by pointing out the role of microorganisms in environmental condition changes, mineral precipitation and their direct or indirect role in iron and sulfur isotope fractionation. Thus these studies have demonstrated the importance of the cross-interactions between the different hydrothermal components: microbial communities, fluids (hydrothermal fluid, sediment pore water, sea water) and mineral structures.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00498/60953/64356.pdf

https://archimer.ifremer.fr/doc/00498/60953/

Editor: | Université de Bretagne occidentale
Formato: | application/pdf

Fonte:

info:eu-repo/semantics/openAccess

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