Anabaena sp. CA fails to synthesize heterocysts and nitrogenase when grown with KNO3 as the nitrogen source. By contrast, both heterocysts and proheterocysts are synthesized in NH4Cl-containing media to a level nearly commensurate with cells grown in the absence of combined nitrogen. The growth rate of the organism in NH4Cl-containing media was similar to that obtained with KNO3 as the nitrogen...

Ammonia volatilization from poultry litter often causes high levels of atmospheric ammonia in poultry houses, which is detrimental to both farm workers and birds. Ammonia emissions from houses also aggravate environmental problems, such as acid rain, and result in a loss of fertilizer nitrogen. The objectives of this study were to determine the effect of litter amendments on ammonia volatilizat...

for the conversion of dinitrogen into ammonia, by demonstrating that ammonia is directly obtained from the nitrido species. The reactivity of the transitionmetal–nitrido complexes described in their papers shows a real advance towards developing a ‘post-Haber–Bosch process’: a synthetic method for the catalytic formation of ammonia from molecular dinitrogen under mild reaction conditions. These...

1 ABSTRACT Atmospheric deposition is important to nutrient loadings to coastal estuaries. Atmospheric emissions of nitrogen travel hundreds of kilometers as they are removed via atmospheric deposition. Long-range transport from outside the Neuse/Pamlico system in North Carolina is an important contributor to the total (wet + dry) deposition of nitrogen to the watershed, estuary and Sound. We ne...

UNLABELLED Ammonia emissions were quantified for the laboratory-scale composting of three typical organic wastes with medium nitrogen content: organic fraction of municipal solid wastes, raw sludge and anaerobically digested sludge; and the composting of two wastes with high nitrogen content: animal by-products from slaughterhouses and partially hydrolysed hair from the leather industry. All th...

WHEN the collection of faeces during a metabolic experiment extends over a considerable period of time, difficulties arise in the determination of the total nitrogen and sulphur contents. Sampling of the wet composite specimen is generally unsatisfactory and ordinary methods of drying on a steam-bath result in a considerable loss of both nitrogen (as ammonia) and sulphur (mainly as sulphide). I...

TiO2-based nanofibers were synthesized using a sol-gel method and electrospinning technique. The as-spun composite fibers were heat-treated at different temperatures (500°C, 550°C, 600°C, and 650°C) and atmospheres (ammonia and nitrogen) for 4 h. The fibers had diameters of 50 to 200 nm and mainly featured anatase and rutile phases. The anatase phase decreased and the rutile phase increased wit...

Five crucian carp, Carassius auratus langsdorfiicarps had been reared in a closed water recirculating system. The system was equipped with the compact bioreactor using the plate gels capable of both nitrification and denitrification in a single unit. Ammonia and nitrite concentrations in the rearing water had been maintained below 0.05 mg-N/L, and nitrate concentration also controlled between 2...

Many of the current greenhouse based intensive marine shrimp production systems have used photoautotrophic algae systems to control inorganic nitrogen accumulation. A second strategy of nitrogen control used in some indoor intensive recirculating production systems is using large fixed-film bioreactors. This option utilizes chemosynthetic autotrophic bacteria, Ammonia Oxidizing Bacteria (AOB) a...

The effect of nitrogen and sulfur nutrition on sulfate permease and O-acetylserine sulfhydrylase was studied in tobacco cells.Sulfate transport rates increased 10-fold in cells transferred to sulfur-deficient B-5 medium. The addition of either sulfate or l-cysteine reduced transport 95 and 80%, respectively. The pools of sulfate, cysteine, glutathione, and methionine declined in sulfur-starved ...