The effect of pH on Marinobacter hydrocarbonoclasticus denitrification pathway and nitrous oxide reductase.
J Biol Inorg Chem
; 25(7): 927-940, 2020 10.
Article
en En
| MEDLINE
| ID: mdl-32851479
ABSTRACT
Increasing atmospheric concentration of N2O has been a concern, as it is a potent greenhouse gas and promotes ozone layer destruction. In the N-cycle, release of N2O is boosted upon a drop of pH in the environment. Here, Marinobacter hydrocarbonoclasticus was grown in batch mode in the presence of nitrate, to study the effect of pH in the denitrification pathway by gene expression profiling, quantification of nitrate and nitrite, and evaluating the ability of whole cells to reduce NO and N2O. At pH 6.5, accumulation of nitrite in the medium occurs and the cells were unable to reduce N2O. In addition, the biochemical properties of N2O reductase isolated from cells grown at pH 6.5, 7.5 and 8.5 were compared for the first time. The amount of this enzyme at acidic pH was lower than that at pH 7.5 and 8.5, pinpointing to a post-transcriptional regulation, though pH did not affect gene expression of N2O reductase accessory genes. N2O reductase isolated from cells grown at pH 6.5 has its catalytic center mainly as CuZ(4Cu1S), while that from cells grown at pH 7.5 or 8.5 has it as CuZ(4Cu2S). This study evidences that an in vivo secondary level of regulation is required to maintain N2O reductase in an active state.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oxidorreductasas
/
Marinobacter
/
Desnitrificación
Idioma:
En
Revista:
J Biol Inorg Chem
Asunto de la revista:
BIOQUIMICA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Portugal