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PubMed2002

Reduction of ammonia and odour emissions from pig slurry under slats using oil and foam layers.

In Europe, new legislation on environmental protection requires reductions in emissions of ammonia and odour from animal production. Animal housing is identified as one of the biggest ammonia emission sources in pig production, but abatement techniques for animal houses often require high initial cost. The aims of this study were to investigate the use of layers of oil and foam on slurry under slats. It was found that relatively low-cost, used frying oil (mainly rapeseed oil) could reduce ammonia and odour emissions by about 50% in weaner accommodation. The cost for this technique was Pound Sterling 2.60 per pig place per year. Foam showed poor ammonia abatement potential. The oil was biodegradable, so increasing methane emissions from stored pig slurry by about 60%.

Ammonia↗
PubMed2000

The chemical composition of Phyllanthus discoideus and its effect on the ruminal ammonia and volatile fatty acid concentration when fed to west African dwarf sheep.

The feeding value of Phyllanthus discoideus (also called Margaritaria discoidea) leaves was evaluated using eight two-year-old West African Dwarf sheep fed natural grass hay. Four of the animals were fistulated ruminally and used for ammonia and volatile fatty acid determination in the fluid. Dried leaves of Phyllanthus discoideus were offered at two levels (25% and 50% of DMI, diets D25% and D50%, respectively) as supplements to the basal hay diet. The CP content of the control, D25% and D50% diets were 11.5, 12.6 and 13.6%, respectively, and their digestible energy amounted to 58.2, 61.1 and 56.9%, respectively. Rumen liquor was sampled one hour before and one, three and five hours after the morning feeding. Sheep fed the control diet had a higher ruminal ammonia concentration than those fed diet D25%. Similarly, ruminal ammonia concentration was higher in sheep fed the control diet than those fed the diet D50%. Five hours after feeding the ruminal ammonia concentration was significantly lower than one hour after feeding. The VFA concentrations in rumen fluid of sheep fed the control diet was inferior to those fed diets D25% and D50%. Sheep fed diet D50% showed significantly higher VFA concentrations than those fed diet D25%. Digestibility of organic matter and digestible energy did not show any significant difference. However, a marginal increase in organic matter digestibility of 3.5% was observed in diet D25% compared with the control diet. There was no significant difference in the N-digestibility in sheep fed the control, D25% and D50% diets. Nevertheless, a marginal improvement in N-digestibility (1.5%) and N-retention (2.7%) was observed with the highest level of Phyllanthus discoideus (D50%). In conclusion, Phyllanthus discoideus appears as a particularly valuable feedstuff because it contains low levels of condensed tannins (12.8 g/kg), high CP content (156 g/kg) and a relatively high GE content (19.3 kJ/g DM). Although the improvement in N-digestibility and N-retention were only marginal the feeding of Phyllanthus discoideus could be justified under extreme shortage of feed resources during dry season. It should also be mentioned that a much more pronounced effect by supplementation with Phyllanthus discoideus could be expected when poor quality grass hay prevalent in West Africa during the dry season is fed. Phyllanthus discoideus could serve as a supplement to poor quality grass at 25% to 50% of supplementation.

Ammonia↗
PubMed2004

Ammonia and pH inhibition in anaerobic treatment of wastewaters, Part I: Experimental.

The influences of pH and ammonia on methane production in the anaerobic treatment of an acetic-propionic-butyric acid mixture in batch reactors operated at 37 degrees C were investigated. Two independent sets of experiments were carried out using seeds from two different full-scale industrial anaerobic treatment reactors. One of the seeds ("Sludge A") was obtained from an upflow anaerobic sludge-blanket (UASB) reactor treating the waste from a potato chips production plant. The second sludge seed ("Sludge B") was from an expanded granular sludge-blanket (EGSB) reactor treating a corn processing waste. Experiments were carried out at four different pH values (6.8, 7.4, 7.8, 8.4) and with six different TAN (Total Ammonia Nitrogen) values (262mg/L (control), 1000, 1500, 2000, 2500, 3000). Three vials (triple runs) were used for each pH and TAN value. The sludge seeds used in the inhibition tests were not exposed to high levels of ammonia at any stage before the tests. For each vial, cumulative methane production was monitored for a period long enough for the termination of biogas production. Although neither sludge was acclimated to ammonia, the lag-phase times were less than 2 days for Sludge A and essentially zero for Sludge B for all TAN and pH values. At certain high pH and high TAN values, however, methanogenic activity ceased within about 1-3 months; and then activity restarted and methane formation rate reached its maximum values after this period. If the experiments had not been continued following this period, this reactivation phenomenon would not have been detected.

Ammonia↗
PubMed1987

A detailed investigation of proposed gas-phase syntheses of ammonia in dense interstellar clouds.

The initial reactions in two proposed gas-phase synthesis of interstellar ammonia have been studied in detail. The rate of the slightly endothermic reaction N+(H2) --> NH+(H) under interstellar conditions has been reinvestigated under thermal and nonthermal (translational excitation) conditions based on low-temperature laboratory data. In the thermal case, the importance or lack of importance of this reaction in synthesizing ammonia is determined by how the existing laboratory data at low temperature are interpreted. In particular, it is unclear to what degree the greater rotational energy of laboratory H2 as compared with that of interstellar H2 affects the rate of reaction. In the nonthermal case, whether or not this reaction is important in synthesizing ammonia depends, in addition, upon which of two experimental investigations involving this reaction at low temperature is correct. The exothermic reaction N(H3+) --> NH2+(H) has been studied via ab initio quantum chemical methods and found to possess a large activation energy barrier. Consequently, this latter reaction does not take place appreciably in interstellar clouds and cannot be used to synthesize ammonia.

Ammonia↗
PubMed2006

The increase of breath ammonia induced by niacin ingestion quantified by selected ion flow tube mass spectrometry.

The ingestion of relatively large doses of the vitamin niacin by healthy volunteers results in a reddening of the skin, a skin 'flush'. Thus, we have carried out a study of the breath metabolites of two healthy volunteers following (i) the ingestion of 200 mg of immediate-release niacin, (ii) as (i) but preceded by the ingestion of 325 mg of aspirin that diminishes the skin 'flush', (iii) ingestion of 500 mg of slow-release niacin. On-line breath analysis was carried out using selected ion flow tube mass spectrometry, SIFT-MS. The interesting new observation is that the breath ammonia levels of both volunteers clearly increased following (i) and (ii), and an obvious skin flush did occur following (i) but not following (ii). The slow-release niacin (iii) did not result in a flush and the breath ammonia levels increased more slowly and did not reach the higher levels produced by (i) and (ii). The results of these experiments demonstrate that breath ammonia levels are dependent on the blood/plasma levels of niacin, but are not directly related to the flushing phenomenon, and that the observed increases in blood/breath ammonia levels are consistent with current knowledge of the metabolic pathways of niacin. The parallel measurements of breath isoprene are presented, which demonstrate the quality of breath analyses that can be achieved using SIFT-MS.

Administration, Oral↗
PubMed1990

The gastric juice urea and ammonia levels in patients with Campylobacter pylori.

The authors studied gastric juice ammonia and urea nitrogen levels to determine how they are altered by gastric Campylobacter pylori (CP) infection. Patients with chronic gastritis (20), peptic ulcer (24), hepatic cirrhosis (10), chronic renal failure (13), or gastric remnant (20) were included. Endoscopic biopsy specimens stained with the Warthin-Starry stain were evaluated for the presence of CP. Blood and gastric juice analysis was performed for 11 of the patients with chronic renal failure and 37 patients from the remaining groups. CP was identified in gastric biopsies from 50 of 87 (57.5%) patients, including 87.5% with peptic ulcer and 40-50% of those with chronic gastritis, cirrhosis, chronic renal failure, or gastric remnant. CP infection had no effect on blood urea nitrogen or blood ammonia levels in any group of patients. The urea nitrogen level of gastric juice was higher in patients with chronic renal failure than in other groups but was not related to CP infection. CP infection was associated with a significant increase in gastric juice ammonia levels, both in patients with chronic renal failure (23.3 mmol/L vs. 2.90 mmol/L; [P less than 0.05]) and in other groups (5.48 mmol/L vs. 1.26 mmol/L [P less than 0.0001]). The authors conclude that elevation of gastric juice ammonia level is an indicator of gastric CP infection.

Adult↗
PubMed1994

Responses of horse flies (Diptera: Tabanidae) to Jersey bullocks and canopy traps baited with ammonia, octenol, and carbon dioxide.

The attraction of females of six species of tabanids to stanchioned Jersey bullocks, unbaited canopy traps, and canopy traps baited with either octenol (1-octen-3-ol), ammonia (NH4OH), a combination of ammonia and octenol, or 5 kg of dry ice (CO2) was studied. A randomized Latin square design (treatments x sites x days) was used. Species diversity and number of flies captured in canopy traps unbaited or baited with octenol, ammonia, or the combination of octenol and ammonia did not differ significantly. Females of Tabanus americanus Forster, T. fuscicostatus Hine, and T. lineola F. were captured more frequently in CO2-baited canopy traps than on Jersey bullocks, but the reverse was observed for females of Leucotabanus annulatus (Say). The number of females of T. pallidescens Philip and T. wilsoni Pechuman collected from CO2-baited canopy traps and bullocks did not differ significantly.

Ammonia↗
PubMed1989

Plasma and brain ammonia and amino acids in rats measured after feeding 75% casein or 28% egg white.

Male rats were trained to consume their daily food intake in 3 h. When rats were fed 6% casein for 14 d and were then fed either the 6 or 75% casein diet for 1 d, the plasma and brain ammonia concentrations of rats fed 75% casein were higher (P less than 0.05) at 23 h after test meal initiation compared to those of rats fed 6% casein. When rats were fed 6% casein for 13 d and then fed the same 6% casein diet with or without an additional 15% ammonium acetate for an additional 7 d before feeding 75% casein for 1 d, the plasma ammonia concentration of each group was not different, but plasma and brain amino acid concentrations were lower in rats prefed 15% ammonium acetate before the 75% casein diet. When rats were fed 6.8% egg white for 9 d and then fed 27.9% egg white for an additional 7 d, food intake of rats fed the 27.9% egg white diet was lower (P less than 0.05, paired t-test) for 4 d compared with that during the 3-d pretest period. When rats were meal-fed the 6.8% egg white diet for 13 d and then fed either the same 6.8% egg white diet or the 27.9% egg white diet for 1 d, plasma ammonia and plasma and brain amino acid concentrations were higher at 5 h after test meal initiation (P less than 0.05) in rats fed 27.9% egg white compared to those of rats fed 6.8% egg white. At 23 h after test meal initiation, plasma ammonia, plasma amino acid and most brain amino acid concentrations were lower than they were at 5 h after test meal initiation in rats fed 27.9% egg white.

Amino Acids↗
PubMed2002

Catalysis-linked inactivation of fluoroacetate dehalogenase by ammonia: a novel approach to probe the active-site environment.

Fluoroacetate dehalogenase from Moraxella sp. B (FAc-DEX) catalyzes the hydrolytic dehalogenation of fluoroacetate and other haloacetates. Asp(105) of the enzyme acts as a nucleophile to attack the alpha-carbon of haloacetate to form an ester intermediate, which is subsequently hydrolyzed by a water molecule activated by His(272) [Liu, J.Q., Kurihara, T., Ichiyama, S., Miyagi, M., Tsunasawa, S., Kawasaki, H., Soda, K., and Esaki, N. (1998) J. Biol. Chem. 273, 30897-30902]. In this study, we found that FAc-DEX is inactivated concomitantly with defluorination of fluoroacetate by incubation with ammonia. Mass spectrometric analyses revealed that the inactivation of FAc-DEX is caused by nucleophilic attack of ammonia on the ester intermediate to convert the catalytic residue, Asp(105), into an asparagine residue. The results indicate that ammonia reaches the active site of FAc-DEX without losing its nucleophilicity. Analysis of the three-dimensional structure of the enzyme by homology modeling showed that the active site of the enzyme is mainly composed of hydrophobic and basic residues, which are considered to be essential for an ammonia molecule to retain its nucleophilicity. In a normal enzyme reaction, the hydrophobic environment is supposed to prevent hydration of the highly electronegative fluorine atom of the substrate and contribute to fluorine recognition by the enzyme. Basic residues probably play a role in counterbalancing the electronegativity of the substrate. These results demonstrate that catalysis-linked inactivation is useful for characterizing the active-site environment as well as for identifying the catalytic residue.

Amino Acid Sequence↗
PubMed2002

Structure of imidazole glycerol phosphate synthase from Thermus thermophilus HB8: open-closed conformational change and ammonia tunneling.

Imidazole glycerol phosphate synthase (IGPs) catalyzes the fifth step in the histidine biosynthetic pathway located at the branch point to de novo purine biosynthesis. IGPs is a multienzyme comprising glutaminase and synthase subunits. The glutaminase activity, which hydrolyzes glutamine to give ammonia, is coupled with substrate binding to the synthase subunit. The three-dimensional structure of the IGPs from Thermus thermophilus HB8 has been determined at 2.3 A resolution, and compared with the previously determined structures for the yeast and Thermotoga maritima enzymes. The structure of each subunit is similar to that of the corresponding domain in the yeast enzyme or subunit in the T. maritima enzyme. However, the overall structure is significantly different from the yeast and T. maritima enzymes, indicating that IGPs may change the relative orientation between the two subunits and close the glutaminase site upon glutamine binding. The putative ammonia tunnel, which carries nascent ammonia from glutaminase to the synthase site, has a closed gate comprising a cyclic salt bridge formed by four charged residues of the synthase subunit. The side chain of Lys100 in the cyclic salt bridge might change its side chain direction to form new interactions with the main chain carbonyl group of glutamine from the synthase subunit and the hydoxyl group of tyrosine from the glutaminase subunit, resulting in the opening of the gate for ammonia transfer.

Aminohydrolases↗
PubMed1997

Effect of ammonia starvation on hydroxylamine oxidoreductase activity of Nitrosomonas europaea.

A technique for detection of the activity of hydroxylamine oxidoreductase (HAO) involving denaturing SDS-polyacrylamide gels was developed. The activity of HAO of Nitrosomonas europaea was assayed using this technique, which revealed a single active band of 140 kDa. The HAO activity of other ammonia-oxidizers was also resistant to SDS, the molecular weights being identical to that of N. europaea. N. europaea cells starved of ammonia for up to 72 h retained a considerable amount of HAO, as detected on Western blot analysis, and a significant level of its activity, as found on assaying at the end of the starvation period. Only after 4 h incubation of starved N. europaea cells with 2.0 mM ammonia was some increase in the HAO level observed. The results indicate that HAO remains highly stable during ammonia starvation of N. europaea.

Ammonia↗
PubMed2005

Effects of chemically amended litter on broiler performances, atmospheric ammonia concentration, and phosphorus solubility in litter.

The effects of 6 different litter amendments on broiler performance, level of atmospheric ammonia (NH3) concentration, and soluble reactive phosphorus (SRP) in litter was determined. Through 3 experiments conducted on 2 different commercial farms, one chemical amendment was added to the litter and then was compared with a control. Broiler performance was not affected by any of the amendments except the ferrous sulfate amendment for which mortality was 25.5%. Application of aluminum chloride (AlCl3 x 6H2O) to the litter lowered atmospheric ammonia concentrations at 42 d by 97.2%, whereas ferrous sulfate (FeSO4 x 7H2O) lowered it by 90.77%. Ammonia concentrations were reduced by 86.18, 78.66, 75.52, and 69.00% by aluminum sulfate [alum or Al2(SO4)3 x 14H2O)], alum + CaCO3, aluminum chloride + CaCO3, and potassium permanganate (KMnO4), respectively, when compared with each control at 42 d. Each amendment except KMnO4 significantly reduced SRP contents. Alum and aluminum chloride were the effective compounds evaluated on the commercial farms with respect to reducing ammonia contents, phosphorus solubility, and mortality.

Air Pollution↗
PubMed2002

Effect of elevated systemic concentrations of ammonia and urea on the metabolite and ionic composition of oviductal fluid in cattle.

High dietary protein leads to elevated systemic concentrations of ammonia and urea, and these, in turn, have been associated with reduced fertility in cattle. The effect of elevating systemic concentrations of ammonia and urea on the concentrations of electrolytes and nonelectrolytes in bovine oviductal fluid were studied using estrus-synchronized, nulliparous heifers (n = 25). Heifers were randomly assigned to 1 of 3 treatments consisting of jugular vein infusion with either ammonium chloride (n = 8), urea (n = 8), or saline (n = 9). Oviducts were catheterized, and fluid was recovered over a 3-h period on either Day 2 or 8 of the estrous cycle. No difference (P > 0.05) was found in the concentrations of any electrolyte or nonelectrolyte between oviducts ipsi- or contralateral to the corpus luteum. Plasma and oviductal concentrations of urea were increased by infusion with urea (P < 0.001) and ammonium chloride (P < 0.05) but not by saline (P > 0.05). Plasma and oviductal concentrations of ammonia were elevated by infusion with ammonium chloride (P < 0.001) but not by infusion with urea or saline (P > 0.05). No effect (P > 0.05) of treatment was found on oviductal or plasma concentrations of glucose, lactate, magnesium, potassium, or sodium or on plasma concentrations of insulin or progesterone. The concentration of calcium in oviductal fluid was reduced by urea infusion and was negatively associated with systemic and oviductal concentrations of urea. Oviductal concentrations of sodium were higher on Day 8 than on Day 2 (P < 0.05). No effect of sample day was found on any of the other electrolytes or nonelectrolytes measured (P > 0.05). Elevated systemic concentrations of ammonia and urea are unlikely to reduce embryo survival through disruptions in the oviductal environment.

Ammonia↗
PubMedDate not supplied

Anhydrous ammonia injuries.

Anhydrous ammonia is a relatively common cause of chemical injuries. Most injuries are the result of accidental exposure, frequently in the course of work. Exposure to anhydrous ammonia may produce serious injury to the eyes, respiratory system, and integument. Anhydrous ammonia injuries occurring in a predominantly agricultural region are reviewed. The pathophysiology of anhydrous ammonia injury is reviewed. Therapeutic modalities are described. Guidelines to prevent or minimize injury are delineated.

Adolescent↗
PubMed1985

Morphologic effects of ammonia on primary astrocyte cultures. I. Light microscopic studies.

To evaluate the astrocytic alterations commonly seen in hepatic encephalopathy and other hyperammonemic states, primary astrocyte cultures derived from neonatal rats were exposed to varying concentrations of ammonia for one to ten days. Ammonia-treated cultures initially showed an increase in basophilia, prominent cytoplasmic processes and increased cytoplasmic granularity and vacuolization. Nucleoli were increased in size and there was an increase in nucleolar/nuclear ratio. Later, fragmentation and loss of cytoplasmic processes, formation of dense bodies and frank cellular disintegration were noted. The changes were proportional to the concentration and duration of ammonia treatment. Our studies show that ammonia is capable of directly causing morphologic alterations in astrocytes. We believe that the use of primary cultures provides a means of exploring the precise role of astrocytes in hyperammonemic states.

Ammonia↗
PubMed1999

Evaluation of ammonia and lidocaine clearance, and galactose elimination capacity of xenoperfused pig livers using a pharmacokinetic analysis.

BACKGROUND: We introduced the pharmacokinetic method into the functional evaluation of xenogeneic extracorporeal liver perfusion as an artificial liver assist device, and examined the influence of xenogeneic humoral injury on the metabolic function of xenoperfused pig livers. METHODS: Isolated pig livers were perfused with fresh porcine blood (group 1; n=5) or fresh human blood (group 2; n=5) for 9 hr. Clearance (CL) of ammonia and lidocaine, and galactose elimination capacity (Vmax) were determined at three points during the perfusion using a one-compartment pharmacokinetic model. RESULTS: Concentrations of ammonia and lidocaine decreased exponentially and those of galactose decreased linearly after a bolus injection in both groups. A one-compartment model provided satisfactory curve fittings for these test substances. No decreases of ammonia CL, lidocaine CL, or galactose Vmax were observed until 9 hr in either group. No differences were observed between the two groups with respect to these metabolic functions. In group 1, only slight interlobular edema was observed at 9 hr. In group 2, membrane attack complex was diffusely deposited at 3 hr and severe interlobular damage was histologically observed at 9 hr, although hepatocellular damage was minimal even at 9 hr. Alpha glutathione S-transferase and mitochondrial aspartate aminotransferase were comparable between the two groups. CONCLUSIONS: Pharmacokinetic analysis allowed the evaluation of ammonia CL, lidocaine CL, and galactose Vmax of the perfused pig livers. Despite xenogeneic humoral injuries, the xenoperfused livers maintained these metabolic functions at the same levels as the alloperfused livers for 9 hr.

Ammonia↗
PubMed2004

Assessment of cardiac wall motion and ejection fraction with gated PET using N-13 ammonia.

BACKGROUND: Cardiac gating is not routinely used in cardiac positron emission tomography (PET). The aim of this study was to determine the feasibility of assessing regional wall motion, ejection fraction (EF), cardiac volumes, and mass with nitrogen-13 ammonia (N-13 ammonia) at the time of PET myocardial perfusion imaging. METHODS: We studied 12 healthy volunteers (mean age, 28 +/- 8 years) and 53 patients with documented coronary artery disease (CAD) (mean age, 59 +/- 11 years). All subjects received a single administration of approximately 600 MBq (16 mCi) of N-13 ammonia intravenously. A 6-minute dynamic scan was performed for quantitative assessment of myocardial perfusion at rest, followed by a separate, 13-minute static scan acquired in the gated mode (8 equal bins). Gated data was imported into the Emory Toolbox. Wall motion was evaluated by dividing the myocardium into 9 anatomic regions graded semiquantitatively. RESULTS: Healthy volunteers had a normal EF (61 +/- 6), end systolic volume (ESV) (37 +/- 15 mL), end diastolic volume (EDV) (89 +/- 25 mL), and cardiac mass (116 +/- 18 g). In contrast, patients with CAD showed reduced EF (32 +/- 13%) and increased ESV (129 +/- 56 mL), EDV (188 +/- 68 mL), and cardiac mass (173 +/- 45 g) (P < 0.001 for each). In patients with CAD, EF measured by gated PET correlated significantly to independent measurements of EF (P < 0.001). CONCLUSIONS: Gating of cardiac perfusion images obtained after administration of N-13 ammonia is feasible and appears to be an accurate means of evaluating regional and global cardiac function. Gating can provide important additional diagnostic and prognostic information.

Adult↗
PubMed2004

Denitrification and ammonia oxidation by Nitrosomonas europaea wild-type, and NirK- and NorB-deficient mutants.

The phenotypes of three different Nitrosomonas europaea strains--wild-type, nitrite reductase (NirK)-deficient and nitric oxide reductase (NorB)-deficient strains--were characterized in chemostat cell cultures, and the effect of nitric oxide (NO) on metabolic activities was evaluated. All strains revealed similar aerobic ammonia oxidation activities, but the growth rates and yields of the knock-out mutants were significantly reduced. Dinitrogen (N2) was the main gaseous product of the wild-type, produced via its denitrification activity. The mutants were unable to reduce nitrite to N2, but excreted more hydroxylamine leading to the formation of almost equal amounts of NO, nitrous oxide (N2O) and N2 by chemical auto-oxidation and chemodenitrification of hydroxylamine. Under anoxic conditions Nsm. europaea wild-type gains energy for growth via nitrogen dioxide (NO2)-dependent ammonia oxidation or hydrogen-dependent denitrification using nitrite as electron acceptor. The mutant strains were restricted to NO and/or N2O as electron acceptor and consequently their growth rates and yields were much lower compared with the wild-type. When cells were transferred from anoxic (denitrification) to oxic conditions, the wild-type strain endogenously produced NO and recovered ammonia oxidation within 8 h. In contrast, the mutant strains remained inactive. For recovery of ammonia oxidation activity the NO concentration had to be adjusted to about 10 p.p.m. in the aeration gas.

Aerobiosis↗