The level of glutamine synthetase activity in Agmenellum quadruplicatum strain PR-6 was dependent on the nitrogen source used for growth and on the nutritional status of the cells. During exponential growth, glutamine synthetase activity was low in cells grown on ammonia, urea, or nitrate. During the transition from nitrogen replete to nitrogen starved growth, glutamine synthetase activity bega...

Dietary protein intake is the most important factor determining milk production, milk composition, milk nitrogen efficiency, urinary nitrogen losses, urea content in milk and consequently, ammonia emissions from dairy cow manure. According to the nutrition requirements two main protein sources are available for cows: rumen degradable protein, provided to the animal through ruminally synthesized...

In ruminants excess dietary Nitrogen (N) is excreted as urea mainly through urine. Urea, the major form of urinary N is rapidly converted to ammonia after excretion. Ammonia is an important environmental pollutant that impacts the quality of human and animal life .The NRC (2001) considered ammonia emissions from concentrated animal feeding operations (CAFO) as a major air quality concern. Ammon...

Variations in the transcription of nitrogen-regulated genes and in the activities of nitrogen-regulated enzymes of the yeast Saccharomyces cerevisiae were studied by changing the carbon and nitrogen fluxes. S. cerevisiae was grown in continuous culture at various dilution rates (D) under nitrogen limitation with NH4Cl as sole nitrogen source. With an increase in D from 0.05 to 0.29 h-1, both th...

The objectives of this study were to evaluate the effects of different fertilizer types and application rates on ammonia volatilization loss and to explore nitrogen distribution and nitrogen use efficiency using the 15N isotope tracing technique in different alkaline salt-affected conditions in the Songnen Plain, Northeast China. The results showed a decreasing trend in ammonia volatilization l...

We doped graphene in situ during synthesis from methane and ammonia on copper in a low-pressure chemical vapour deposition system, and investigated the effect of the synthesis temperature and ammonia concentration on the growth. Raman and X-ray photoelectron spectroscopy was used to investigate the quality and nitrogen content of the graphene and demonstrated that decreasing the synthesis tempe...

The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm). The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Comp...

Both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) play an important role in nitrification in terrestrial environments. Most often AOA outnumber AOB, but the relative contribution of AOA and AOB to nitrification rates remains unclear. The aim of this experiment was to test the hypotheses that high nitrogen availability would favor AOB and result in high gross nitrificatio...