Denitrification in Haloarchaea: from genes to climate change
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http://hdl.handle.net/10045/99175
Título: | Denitrification in Haloarchaea: from genes to climate change |
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Autor/es: | Torregrosa-Crespo, Javier |
Director de la investigación: | Martínez-Espinosa, Rosa María | Pire, Carmen |
Centro, Departamento o Servicio: | Universidad de Alicante. Departamento de Agroquímica y Bioquímica |
Palabras clave: | Haloarchaea | Climate change | Denitrification | Nitrogenous gases |
Área/s de conocimiento: | Bioquímica y Biología Molecular |
Fecha de creación: | 2019 |
Fecha de publicación: | 2019 |
Fecha de lectura: | 27-sep-2019 |
Editor: | Universidad de Alicante |
Resumen: | Haloarchaea are extremophiles, generally thriving at high temperatures and salt concentrations, thus, with limited access to oxygen. As a strategy to maintain a respiratory metabolism, many halophilic archaea are capable of denitrification. Among them are members of the genus Haloferax, which are abundant in saline/hypersaline environments. Based on the haloarchaeal genomes analysed, the genes involved in denitrification are grouped into three gene clusters (nar, nir-nor, nos) coding for denitrification enzymes NarGHI, NirK, qNor and NosZ. In case of incomplete denitrifiers, some of the genes or clusters are absent. Amon all haloarchaea analysed, three reported denitrifiers, H. mediterranei, H. denitrificans and H. volcanii were characterized with respect to their denitrification phenotype using a semi-automatic incubation system. Out of the species tested, only H. mediterranei was able to consistently reduce all available N-oxyanions to N2, while the other two released significant amounts of NO and N2 O, which affect tropospheric and stratospheric chemistries respectively. Also, H. mediterranei showed a well-orchestrated system of gene expression during denitrification, being Nar and Nos, both transcriptionally activated by hypoxia (and probably nitrate), while Nir and Nor expression require the presence of nitric oxide (and possibly nitrite) as well as Nos. The prevalence and magnitude of hypersaline ecosystems are on the rise due to climate change and anthropogenic activity. Thus, the biology of halophilic denitrifiers is inherently interesting, due to their contribution to the global nitrogen cycle, and potential application in bioremediation. |
URI: | http://hdl.handle.net/10045/99175 |
Idioma: | eng |
Tipo: | info:eu-repo/semantics/doctoralThesis |
Derechos: | Licencia Creative Commons Reconocimiento-NoComercial-SinObraDerivada 4.0 |
Aparece en las colecciones: | Tesis doctorales |
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tesis_javier_torregrosa_crespo.pdf | 4,82 MB | Adobe PDF | Abrir Vista previa | |
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