Deammonification represents a short-cut in the N-metabolism pathway and comprises 2 steps: about half the amount of ammonia is oxidised to nitrite and then residual ammonia and nitrite is anaerobically transformed to elementary nitrogen. Implementation of the pH-controlled DEMON process for deammonification of reject water in a single-sludge SBR system at the WWTP Strass (Austria) contributed e...

Klebsiella aerogenes W70 could grow aerobically with nitrate or nitrite as the sole nitrogen source. The assimilatory nitrate reductase and nitrite reductase responsible for this ability required the presence of either nitrate or nitrite as an inducer, and both enzymes were repressed by ammonia. The repression by ammonia, which required the NTR (nitrogen regulatory) system (A. Macaluso, E. A. B...

Saccharomyces cerevisiae contains two distinct l-glutamate dehydrogenases. These enzymes are affected in a reciprocal fashion by growth on ammonia or dicarboxylic amino acids as the nitrogen source. The specific activity of the nicotinamide adenine dinucleotide phosphate (NADP) (anabolic) enzyme is highest in ammonia-grown cells and is reduced in cells grown on glutamate or aspartate. Conversel...

When Azotobcter vinelandii is grown on molecular nitrogen, it utilizes ammonia without enzymatic adaptation. Furthermore, the distribution of N15 in amino acids derived from cell hydrolysates is the same whether the isotope is supplied to the organism as ammonia or as Nx. These and other findings (1, 2) provide strong evidence that ammonia is the key intermediate in nitrogen fixation by this or...

Investigations using ammonium citrate-(15)N and urea-(15)N showed that children in the acute stage of kwashiorkor and marasmus receiving a diet of adequate protein content retained a considerable percentage of the label from both compounds. Excretion of both total (15)N and urea-(15)N was subnormal and elimination was virtually completed 36 hr after administration of the isotope. During recover...

Microbial communities present in marine sediments play a central role in nitrogen biogeochemistry at local to global scales. Along the oxidation-reduction gradients present in sediment profiles, multiple nitrogen cycling processes (such as nitrification, denitrification, nitrogen fixation, and anaerobic ammonium oxidation) are active and actively coupled to one another - yet the microbial commu...

the replacement of corn silage with varying levels of ammonia gassed wheat straw on performance, digestibility, fermentation parameters, chewing activities, blood metabolites and profitability of holstein heifers have been evaluated. fifteen holstein heifer with 9-10 months of age were assigned in a completely randomized design with 3 treatment as 1) 36% corn silage, 2) 18% corn silage and 18% ...

Novel nitrogen removal technologies via nitrite pathway attract increasing interest in recent years. In this study, batch experiments were performed to investigate nitrite accumulation characteristics and shifts in nitrifying community structure at different growth environments including ammonia concentration, pH and alkalinity. It was found that nitrite accumulation ratios were maintained at a...

The phenomena that accompany the growth of aluminum nitride (AlN) by metal-organic molecular beam epitaxy with trimethylaluminum and ammonia as sources of aluminum and nitrogen, respectively, have been systematically investigated. Optimizing the growth temperature, flux ratios, and the ammonia injector temperature, we obtained an efficient growth with a rate of 500 nm/h and a low consumption of...

A submerged biofilter (SBF) with 0.1 m of filter medium was maintained without backwash at four different water temperatures (14°C, 18°C, 22°C and 26°C) in four different recirculating systems stocked with green tiger shrimp (Penaeus semisulcatus). The ammonia removal profile and nitrification performance of the SBF was evaluated at feed loading rates of 2.65 g day at 14°C, 5.52 g day at 18°C, ...