The denitrifying bacterium Paracoccus denitrificans can grow aerobically or anaerobically using nitrate or nitrite as the sole nitrogen source. The biochemical pathway responsible is expressed from a gene cluster comprising a nitrate/nitrite transporter (NasA), nitrite transporter (NasH), nitrite reductase (NasB), ferredoxin (NasG) and nitrate reductase (NasC). NasB and NasG are essential for g...

Nitrate simultaneously induced NADH- and NADPH-nitrate reductase activities in rice seedlings. Chloramphenicol, other organic nitro-compounds such as o-nitroaniline and 2,4-dinitrophenol and nitrite also induced nitrate reductase in rice seedlings. The nitrate- or nitrite-induced nitrate reductase could accept electrons more efficiently from NADH than NADPH. However, when this enzyme was induce...

The production of cytotoxic nitric oxide (NO) and conversion into the neuropharmacological agent and potent greenhouse gas nitrous oxide (N₂O) is linked with anoxic nitrate catabolism by Salmonella enterica serovar Typhimurium. Salmonella can synthesize two types of nitrate reductase: a membrane-bound form (Nar) and a periplasmic form (Nap). Nitrate catabolism was studied under nitrate-rich and...

Bromphenol blue, which was reduced with dithionite, was found to support nitrate reduction catalyzed by squash NADH:nitrate reductase at a rate about 5 times greater than NADH with freshly prepared enzyme and 10 times or more with enzyme having been frozen and thawed. Kinetic analysis of bromphenol blue as a substrate for squash nitrate reductase yielded apparent K(m) values of 60 micromolar fo...

398 Nitrate and nitrite Nitrate (NO 3 ) is found naturally in the environment and is an important plant nutrient. It is present at varying concentrations in all plants and is a part of the nitrogen cycle. Nitrite (NO 2 ) is not usually present in significant concentrations except in a reducing environment, as nitrate is the more stable oxidation state. It can be formed by the microbial reductio...

background: surface water and groundwater pollution with various forms of nitrogen such as ammonium and nitrate ions is one of the main environmental risks. the major objectives of this study were to evaluate the capacity of natural zeolite (clinoptilolite) to remove no3- and nh4+ from polluted water under both batch and column conditions. methods: the laboratory batch and column experiments we...

Long-term use of most organic nitrates is limited by development of tolerance, induction of oxidative stress and endothelial dysfunction. In this issue of the BJP, Schuhmacher et al. characterized a novel class of organic nitrates with amino moieties (aminoalkyl nitrates). Aminoethyl nitrate was identified as a novel organic mononitrate with high potency but devoid of induction of mitochondrial...

Atmospheric Chemistry and Physics Discussions This discussion paper is/has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP if available. Abstract Peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN) were measured sequentially in situ by an online gas-phase chromatograph with electron capture detector at urba...

denitrification is a reduction of nitrate by heterotrophic and autotrophic bacteria that may ultimately produce molecular nitrogen (n2) through a series of intermediate nitrogen compounds.vermiculite is a hydrous phyllosilicate mineral (mg, fe+2,fe+3)3[(al,si)4o10](oh)2·4h2o with several layers for bacterial immobilization. the goal of this study was removal of nitrate from water with vermiculi...

nitrate pollutants increase the growth of algal bloom, resulting in fresh water eutrophication. the high nitrogen level in wastewater has become a growing concern, which has risen the necessity to develop efficient nitrogen removal techniques. biological denitrification, which is the reduction of oxidized nitrogen compounds like nitrate or nitrite to gaseous nitrogen compounds, is the most impo...