narK mutants of Escherichia coli produce wild-type levels of nitrate reductase but, unlike the wild-type strain, do not accumulate nitrite when grown anaerobically on a glucose-nitrate medium. Comparison of the rates of nitrate and nitrite metabolism in cultures growing anaerobically on glucose-nitrate medium revealed that a narK mutant reduced nitrate at a rate only slightly slower than that i...

The aim of this study was to investigate the histological characteristics following a 2-year nitrate-rich diet in miniature pigs with parotid atrophy. Using averages collected data from three time points at 6, 12, and 24 months following the induction of parotid gland atrophy, salivary nitrate levels of the nitrate-diet parotid-atrophied group (17.3 ± 3.9 ng/µl) were close to those of the contr...

Factors affecting nitrate reduction by leaf discs of cotton (Gossypium hirsutum L.) were investigated. When incubated in 30 mm nitrate, discs reduced nitrate much more slowly under air or O(2) than under N(2). Inhibition by O(2) did not occur at nitrate levels of 100 mm or greater. Treatment with arsenate had little effect under N(2) but stimulated nitrate reduction under air. Similarly, ammoni...

Nitrate and nitrite can be organic or inorganic chemicals depending on their chemical structures. This profile pertains to inorganic nitrate and nitrite, specifically the nitrate anion and the nitrite anion. Nitrate and nitrite occur naturally in the environment as part of the nitrogen cycle, and are produced both endogenously and exogenously. Ammonia-oxidizing bacteria convert ammonia into nit...

Nitrate is an inhibitor of sulfate-reducing bacteria (SRB). In petroleum production sites, amendments of nitrate and nitrite are used to prevent SRB production of sulfide that causes souring of oil wells. A better understanding of nitrate stress responses in the model SRB, Desulfovibrio vulgaris Hildenborough and Desulfovibrio alaskensis G20, will strengthen predictions of environmental outcome...

The observation that exposure of the leaf canopy to increasing concentrations of CO(2) (100-400 mul/l) decreases the influx of nitrate to the leaf blades, but not to the roots or stalks (largely leaf sheaths), was reconfirmed using (15)NO(3) (-). Decreases in leaf nitrate supply were associated with decreases in induction of nitrate reductase, thus supporting the view that the influx of nitrate...

Nitrate is an essential nutrient for plants, and crops depend on its availability for growth and development, but its presence in agricultural soils is far from stable. In order to overcome nitrate fluctuations in soil, plants have developed adaptive mechanisms allowing them to grow despite changes in external nitrate availability. Nitrate can act as both nutrient and signal, regulating global ...

Nitrate reductase, the first enzyme in nitrate assimilation, is located at the crossroad of two energy-consuming pathways: nitrate assimilation and carbon fixation. Light, which regulates the expression of many higher-plant carbon fixation genes, also regulates nitrate reductase gene expression. Located in the cytosol, nitrate reductase obtains its reductant not from photosynthesis but from car...