Herbicides that bind specifically to Photosystem II greatly increased ammonia liberation by a heterotrophic cyanobacterium incubated with methionine sulfoximine anaerobically in light. Comparison of cells incubated under argon and nitrogen indicated that about one-half of the liberated ammonia came from endogenous sources, as well as from dinitrogen fixation. Chromatography of cell extracts rev...

Rhodobacter sphaeroides only showed chemotaxis towards ammonia if grown under nitrogen-limited conditions. This chemotactic response was completely inhibited by the addition of methionine sulfoximine. There was no effect of methionine sulfoximine treatment on motility or taxis towards propionate, demonstrating that the effect is specific to ammonia taxis. It is known that methionine sulfoximine...

The reduction of ammonia-nitrogen fluxes from polluted streams entering the Tai Lake is an important task in areas with limnetic eutrophication. Biofilm technique for the polluted streams has been proposed as one effective method to reduce ammonia-nitrogen fluxes entering the Tai Lake. In this study, ammonia-nitrogen biodegradation in a created biofilm purification engineering was evaluated by ...

Fishes, in general, follow ammonotelic mode of excretion. However, certain stress factors may provoke them to excrete urea. In the present study, the possible role of ureogenesis to avoid accumulation of toxic ammonia under water-restricted condition was tested in Heteropneustes fossilis. A total of hundred fishes were collected and sacrificed. Excretory urea and ammonia were estimated in the w...

In 2004,ammonia concentration in raw water of Sitalakhya River at the eastern periphery of Dhaka was found higher than the expected rate of 4 mg/Lforecasted in feasibility studies,with a value of about 8 mg/L, which could not be removed by conventional treatment chain employed at Dhaka, hence, recentlyan ammonia removal plant has been constructed. This important background has ledto the current...

The objective of this experiment was to determine the capability of ruminant gut tissues to detoxify ammonia-N using short-term incubations of isolated cells in vitro. Ruminal epithelial cells (REC) and duodenal mucosal cells (DMC) were isolated from growing Texel-Polypay ram lambs (n = 4) fed a pelleted forage:concentrate-based diet. Immediately after isolation, primary cells were incubated fo...

Remarkably little is known about nitrogenous excretion in freshwater invertebrates. In the current study, the nitrogen excretion mechanism in the carnivorous ribbon leech, Nephelopsis obscura, was investigated. Excretion experiments showed that the ribbon leech is ammonotelic, excreting 166.0 ± 8.6 nmol·grams fresh weight (gFW)(-1)·h(-1) ammonia and 14.7 ± 1.9 nmol·gFW(-1)·h(-1) urea. Exposure ...

Iron oxide nanoparticles were synthesized by coprecipitation method using ammonia as precipitation agent. Most researchers usually add ammonia into the iron salt solution but in this work the salt solution drop wise has been added to the ammonia and the new obtained results were compared with those of other researches. Magnetic properties of nanoparticles were measured by VSM. The effect of rea...

The effects of limiting concentrations of ammonium on the metabolic activity of Nitrosomonas europaea, an obligate ammonia-oxidizing soil bacterium, were investigated. Cells were harvested during late logarithmic growth and were incubated for 24 h in growth medium containing 0, 15, or 50 mM ammonium. The changes in nitrite production and the rates of ammonia- and hydroxylamine-dependent oxygen ...