ammonia is the chief excretory product in fishes. however, non-availability of enough of water in the habitat, may lead to the formation of urea, in fishes. in the present study, the possible role of urea formation to avoid the toxicity of ammonia under water-restricted condition was tested in channa gachua. circulatory urea and ammonia were estimated in the blood of the fishes and glutamate de...

The collecting duct is the primary site of urinary ammonia secretion; the current study determines whether apical ammonia transport in the mouse inner medullary collecting duct cell (mIMCD-3) occurs via nonionic diffusion or a transporter-mediated process and, if the latter, presents the characteristics of this apical ammonia transport. We used confluent cells on permeable support membranes and...

Pathways of ammonia assimilation into glutamic acid were investigated in ammonia-grown and N2-fixing Clostridium kluyverii and Clostridium butyricum by measuring the specific activities of glutamate dehydrogenase, glutamine synthetase, and glutamate synthase. C. kluyverii had NADPH-glutamate dehydrogenase with a Km of 12.0 mM for NH4+. The glutamate dehydrogenase pathway played an important rol...

This study examines the use of a moving bed biofilm reactor (MBBR) as a tertiary treatment step for ammonia removal in high temperature (35-45°C) effluents, and quantifies different phenotypes of ammonia and nitrite oxidizing bacteria responsible for nitrification at elevated temperatures. Bench scale reactors operating at 35 and 40°C were able to successfully remove greater than 90% of the inf...

Effects of chemical and physical preservation of blood on changes in ammonia concentration during storage were studied with samples containing init ial concentrations of .143, .316, .771, .816, and 1.308 mg ammonia-N per 100 ml blood. A saturated solution of mercuric chloride was added to the blood in amounts of 3.33, 5.00, 6.66, 8.33 or 10.00%. Deionized water was added to control samples in t...

The effect of ammonia exposure and substrate temperature on the reaction of ammonia with GaAs(lOO)-c(8 x 2) has been studied using temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), and high resolution electron energy loss spectroscopy (HREELS). TPD data indicate that thermal decomposition of ammonia occurs at moderate temperatures (250 K). Above 250 K, recombinati...

The phytopathogenic fungus Colletotrichum gloeosporioides produces one pectate lyase (PL) that is a key virulence factor in disease development. During growth of C. gloeosporioides, Colletotrichum acutatum, and Colletotrichum coccodes in acidified yeast extract medium, the fungus secreted ammonia and increased the medium pH. Ammonia accumulation and the consequent pH change increased as a funct...

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, ...

The interaction between ammonia and the benzene radical cation has been investigated by gas-phase studies of mass selected ion clusters {C(6)H(6)-(NH(3))(n=0-8)}(+) via tandem quadrupole mass spectrometry and through calculations. Experiments show a special stability for the cluster ion that contains four ammonias: {C(6)H(6)(NH(3))(4)}(+). Calculations provide evidence that the first ammonia fo...

Experimental data were applied for the modelling optimal cowshed temperature environment in laboratory test bench by a mass-flow method. The principal factor affecting exponent growth of ammonia emission was increasing air and manure surface temperature. With the manure temperature increasing from 4°C to 30°C, growth in the ammonia emission grew fourfold, that is, from 102 to 430 mg m(-2)h(-1)....