Genetic basis for denitrification in Ensifer meliloti

[Background] Denitrification is defined as the dissimilatory reduction of nitrate or nitrite to nitric oxide (NO), nitrous oxide (N2O), or dinitrogen gas (N2). N2O is a powerful atmospheric greenhouse gas and cause of ozone layer depletion. Legume crops might contribute to N2O production by providin...

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Detalles Bibliográficos
Autores: Torres Porras, María Jesús, Rubia, María I., Coba de la Peña, Teodoro, Pueyo, José Javier, Bedmar, Eulogio J., Delgado Igeño, María Jesús
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/125901
Acceso en línea:http://hdl.handle.net/10261/125901
Access Level:acceso abierto
Palabra clave:Cu-containing nitrite reductase
Nitrate respiration
Nitric oxide reductase
Nitrous oxide reductase
Periplasmic nitrate reductase
Descripción
Sumario:[Background] Denitrification is defined as the dissimilatory reduction of nitrate or nitrite to nitric oxide (NO), nitrous oxide (N2O), or dinitrogen gas (N2). N2O is a powerful atmospheric greenhouse gas and cause of ozone layer depletion. Legume crops might contribute to N2O production by providing nitrogen-rich residues for decomposition or by associating with rhizobia that are able to denitrify under free-living and symbiotic conditions. However, there are limited direct empirical data concerning N2O production by endosymbiotic bacteria associated with legume crops. Analysis of the Ensifer meliloti 1021 genome sequence revealed the presence of the napEFDABC, nirK, norECBQD and nosRZDFYLX denitrification genes. It was recently reported that this bacterium is able to grow using nitrate respiration when cells are incubated with an initial O2 concentration of 2%; however, these cells were unable to use nitrate respiration when initially incubated anoxically. The involvement of the nap, nirK, nor and nos genes in E. meliloti denitrification has not been reported.