Regulation and energization of nitrate transport in a halophilic Pseudomonas stutzeri.
Biochem Biophys Res Commun
; 166(1): 424-30, 1990 Jan 15.
Article
em En
| MEDLINE
| ID: mdl-2154208
ABSTRACT
Nitrate transport and its regulation by oxygen was studied in denitrifying halophilic Pseudomonas stutzeri, strain Zobell, and a Tn-5 transposon nitrite reductase mutant of this organism. The rate of nitrate transport was found to be 130 nanomoles nitrate min-1 mg protein-1 and 150 nanomoles nitrate min-1 mg protein-1 in the wildtype and the nitrite reductase mutant respectively as compared to 26.4 nanomoles nitrate min-1 mg protein-1 in a non-halophilic Pseudomonas stutzeri. Asparagine was found to be the best energy source for nitrate uptake. The ratio of nitrate import to nitrite export was established by measuring extracellular nitrate and nitrite concentrations using HPLC/UV analysis. There was a 1.31 (NO3-/NO2-) exchange. High concentrations of nitrate during growth was found to have a negative effect on nitrite metabolism. Oxygen exerted an inhibitory effect on nitrate uptake which was reversible and more pronounced in cells grown on low concentrations of nitrate compared to cells grown at high concentrations of nitrate.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pseudomonas
/
Nitratos
Idioma:
En
Revista:
Biochem Biophys Res Commun
Ano de publicação:
1990
Tipo de documento:
Article