Ammonia (NH3) is a key commodity chemical of vital importance for fertilizers. It is made on an industrial scale via the Haber Bosch process, which requires significant infrastructure to be in place such that ammonia is generally made in large, centralized facilities. If ammonia could be produced under less demanding conditions, then there would be the potential for smaller devices to be used t...

Changes in the fractions of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria in two laboratory-scale reactors were investigated using 16S rRNA probe hybridizations. The reactors were operated in intermittent aeration mode and different aeration cycles to treat anaerobically digested swine wastewater with ammonia concentrations up to 175 mg NH(3)-N/L. High ammonia removals (>98.8%) were...

The GATA family proteins Gln3p and Gat1p mediate nitrogen catabolite repression (NCR)-sensitive transcription in Saccharomyces cerevisiae. When cells are cultured with a good nitrogen source (glutamine, ammonia), Gln3p and Gat1p are restricted to the cytoplasm, whereas with a poor nitrogen source (proline), they localize to the nucleus, bind to the GATA sequences of NCR-sensitive gene promoters...

According to current concepts, renal ammonia synthesis may be attributed to the renal extraction and catabolism of certain plasma amino acids. In 1943, Van Slyke and associates demonstrated in the dog that the amide nitrogen of glutamine was removed from arterial plasma in quantities sufficient to account for approximately 60 per cent of the urinary ammonia excreted during metabolic acidosis (1...

Nitrification, the microbial oxidation of ammonia to nitrite and nitrate, occurs in a wide variety of environments and plays a central role in the global nitrogen cycle. Catalyzed by the enzyme ammonia monooxygenase, the ability to oxidize ammonia was previously thought to be restricted to a few groups within the beta- and gamma-Proteobacteria. However, recent metagenomic studies have revealed ...

The contribution of ammonia-oxidizing bacteria and archaea (AOB and AOA, respectively) to the net oxidation of ammonia varies greatly between terrestrial environments. To better understand, predict and possibly manage terrestrial nitrogen turnover, we need to develop a conceptual understanding of ammonia oxidation as a function of environmental conditions including the ecophysiology of associat...

-l. Nitrogen and cation excretion/storage in 23 cockroach species representing I l subfamilies have been examined. Measurements of externally excreted ammonia nitrogen, uric acid nitrogen, total nitrogen, potassium and sodium were made. Values of total body nitrogen, body urate nitrogen, and body potassium and sodium are also reported. 2. A significant correlation was found between body nitroge...

conclusions based on nitrification and denitrification data, the best condition for nitrifying/ denitrifying performance was obtained by modified-ifas. hence, the modification can be used to obtain the best activities of microbial and nitrogen removal improvement. results employing the bet, surface area (sa), total pore volume (vp), and average size of the nanostructure were 0.4026 m2/g, 3.8089...

We examined the relationship between plasma cortisol levels, hepatic glutamine synthetase (GNS) activity and the form of nitrogen excreted (e.g. urea, ammonia) in undisturbed versus confined/crowded (acutely stressed) gulf toadfish. Specifically, we tested the hypothesis that acute increases in plasma cortisol levels are required to trigger the increase in GNS activity induced by the confinemen...

This strongly alkaline chemical is widely used in industry as a feed stock for nitrogen-based chemicals such as fertilizers, plastics and explosives (ATSDR, 1990). Ammonia is also used as a refrigerant. The general public is exposed by off-gasing from cleaning solutions containing aqueous ammonia. Household ammonia solutions contain 5-10% ammonia in water while industrial strength can be up to ...