|
|
| ammonium |
|
| CHEBI:28938 |
|
| An onium cation obtained by protonation of ammonia. |
|
This entity has been manually annotated by the ChEBI Team.
|
|
|
CHEBI:22534, CHEBI:49783, CHEBI:7435
|
|
| No supplier information found for this compound. |
|
|
Molfile
XML
SDF
|
|
|
more structures >>
|
|
call loadScript javascripts\jsmol\core\package.js call loadScript javascripts\jsmol\core\core.z.js -- required by ClazzNode call loadScript javascripts\jsmol\J\awtjs2d\WebOutputChannel.js Jmol JavaScript applet jmolApplet0_object__191046741225925__ initializing getValue debug = null getValue logLevel = null getValue allowjavascript = null AppletRegistry.checkIn(jmolApplet0_object__191046741225925__) call loadScript javascripts\jsmol\core\corestate.z.js viewerOptions: { "name":"jmolApplet0_object","applet":true,"documentBase":"https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:22534","platform":"J.awtjs2d.Platform","fullName":"jmolApplet0_object__191046741225925__","display":"jmolApplet0_canvas2d","signedApplet":"true","appletReadyCallback":"Jmol._readyCallback","statusListener":"[J.appletjs.Jmol.MyStatusListener object]","codeBase":"https://www.ebi.ac.uk/chebi/javascripts/jsmol/","syncId":"191046741225925","bgcolor":"#000" } (C) 2012 Jmol Development Jmol Version: 13.2.7 $Date: 2013-10-01 11:35:15 -0500 (Tue, 01 Oct 2013) $ java.vendor: j2s java.version: 0.0 os.name: j2s Access: ALL memory: 0.0/0.0 processors available: 1 useCommandThread: false appletId:jmolApplet0_object (signed) starting HoverWatcher_1 getValue emulate = null defaults = "Jmol" getValue boxbgcolor = null getValue bgcolor = #000 backgroundColor = "#000" getValue ANIMFRAMECallback = null getValue APPLETREADYCallback = Jmol._readyCallback APPLETREADYCallback = "Jmol._readyCallback" getValue ATOMMOVEDCallback = null getValue CLICKCallback = null getValue ECHOCallback = null getValue ERRORCallback = null getValue EVALCallback = null getValue HOVERCallback = null getValue LOADSTRUCTCallback = null getValue MEASURECallback = null getValue MESSAGECallback = null getValue MINIMIZATIONCallback = null getValue PICKCallback = null getValue RESIZECallback = null getValue SCRIPTCallback = null getValue SYNCCallback = null getValue STRUCTUREMODIFIEDCallback = null getValue doTranslate = null language=en_US getValue popupMenu = null getValue script = null Jmol applet jmolApplet0_object__191046741225925__ ready call loadScript javascripts\jsmol\core\corescript.z.js call loadScript javascripts\jsmol\J\script\FileLoadThread.js starting QueueThread0_2 script 1 started starting HoverWatcher_3 starting HoverWatcher_4 The Resolver thinks Mol Marvin 11010600403D starting HoverWatcher_5 Time for openFile( Marvin 11010600403D 5 4 0 0 0 0 999 V2000 1.0382 -0.2865 -0.2454 H 0 0 0 0 0 0 0 0 0 0 0 0 0.0861 0.9651 0.3137 H 0 0 0 0 0 0 0 0 0 0 0 0 -0.2618 -0.6077 0.7506 H 0 0 0 0 0 0 0 0 0 0 0 0 0.0861 -0.0077 -0.0000 N 0 3 0 0 0 0 0 0 0 0 0 0 -0.5182 -0.1016 -0.8190 H 0 0 0 0 0 0 0 0 0 0 0 0 4 1 1 0 0 0 0 4 2 1 0 0 0 0 4 3 1 0 0 0 0 4 5 1 0 0 0 0 M CHG 1 4 1 M END): 15 ms reading 5 atoms ModelSet: haveSymmetry:false haveUnitcells:false haveFractionalCoord:false 1 model in this collection. Use getProperty "modelInfo" or getProperty "auxiliaryInfo" to inspect them. Default Van der Waals type for model set to Babel 5 atoms created ModelSet: not autobonding; use forceAutobond=true to force automatic bond creation Script completed Jmol script terminated
|
| Ammonium is a modified form of ammonia that has an extra hydrogen atom. It is a positively charged (cationic) molecular ion with the chemical formula NH+4 or [NH4]+. It is formed by the addition of a proton (a hydrogen nucleus) to ammonia (NH3). Ammonium is also a general name for positively charged (protonated) substituted amines and quaternary ammonium cations ([NR4]+), where one or more hydrogen atoms are replaced by organic or other groups (indicated by R). Not only is ammonium a source of nitrogen and a key metabolite for many living organisms, but it is an integral part of the global nitrogen cycle. As such, human impact in recent years could have an effect on the biological communities that depend on it.
|
|
Read full article at Wikipedia
|
| QGZKDVFQNNGYKY-UHFFFAOYSA-O |
|
|
Saccharomyces cerevisiae
(NCBI:txid4932)
|
Source: yeast.sf.net
See:
PubMed
|
|
Escherichia coli
(NCBI:txid562)
|
See:
PubMed
|
|
Homo sapiens
(NCBI:txid9606)
|
See:
DOI
|
|
Escherichia coli metabolite
Any bacterial metabolite produced during a metabolic reaction in Escherichia coli.
Saccharomyces cerevisiae metabolite
Any fungal metabolite produced during a metabolic reaction in Baker's yeast (Saccharomyces cerevisiae ).
human metabolite
Any mammalian metabolite produced during a metabolic reaction in humans (Homo sapiens).
cofactor
An organic molecule or ion (usually a metal ion) that is required by an enzyme for its activity. It may be attached either loosely (coenzyme) or tightly (prosthetic group).
|
|
View more via ChEBI Ontology
|
[NH4]+
|
MolBase
|
|
ammonium
|
ChEBI
|
|
ammonium cation
|
ChemIDplus
|
|
ammonium ion
|
PDBeChem
|
|
Ammonium(1+)
|
ChemIDplus
|
|
NH4+
|
KEGG COMPOUND
|
|
NH4+
|
IUPAC
|
|
NH4+
|
UniProt
|
|
929
|
MolBase
|
|
Ammonium
|
Wikipedia
|
|
AMMONIUM
|
MetaCyc
|
|
C01342
|
KEGG COMPOUND
|
|
NH4
|
PDBeChem
|
| View more database links |
|
14798-03-9
|
CAS Registry Number
|
ChemIDplus
|
|
14798-03-9
|
CAS Registry Number
|
NIST Chemistry WebBook
|
|
16093784
|
Reaxys Registry Number
|
Reaxys
|
|
84
|
Gmelin Registry Number
|
Gmelin
|
Boopathy R, Karthikeyan S, Mandal AB, Sekaran G (2013)
Adsorption of ammonium ion by coconut shell-activated carbon from aqueous solution: kinetic, isotherm, and thermodynamic studies.
Environmental science and pollution research international 20, 533-542 [PubMed:22562341]
[show Abstract]
Ammonium ions are one of the most encountered nitrogen species in polluted water bodies. High level of ammonium ion in aqueous solution imparts unpleasant taste and odor problems, which can interfere with the life of aquatics and human population when discharged. Many chemical methods are developed and being used for removal of ammonium ion from aqueous solution. Among various techniques, adsorption was found to be the most feasible and environmentally friendly with the use of natural-activated adsorbents. Hence, in this study, coconut shell-activated carbon (CSAC) was prepared and used for the removal of ammonium ion by adsorption techniques. Ammonium chloride (analytical grade) was purchased from Merck Chemicals for adsorption studies. The CSAC was used to adsorb ammonium ions under stirring at 100 rpm, using orbital shaker in batch experiments. The concentration of ammonium ion was estimated by ammonia distillate, using a Buchi distillation unit. The influence of process parameters such as pH, temperature, and contact time was studied for adsorption of ammonium ion, and kinetic, isotherm models were validated to understand the mechanism of adsorption of ammonium ion by CSAC. Thermodynamic properties such as ∆G, ∆H, and ∆S were determined for the ammonium adsorption, using van't Hoff equation. Further, the adsorption of ammonium ion was confirmed through instrumental analyses such as SEM, XRD, and FTIR. The optimum conditions for the effective adsorption of ammonium ion onto CSAC were found to be pH 9.0, temperature 283 K, and contact time 120 min. The experimental data was best followed by pseudosecond order equation, and the adsorption isotherm model obeyed the Freundlich isotherm. This explains the ammonium ion adsorption onto CSAC which was a multilayer adsorption with intraparticle diffusion. Negative enthalpy confirmed that this adsorption process was exothermic. The instrumental analyses confirmed the adsorption of ammonium ion onto CSAC. | Shih TH, Horng JL, Liu ST, Hwang PP, Lin LY (2012)
Rhcg1 and NHE3b are involved in ammonium-dependent sodium uptake by zebrafish larvae acclimated to low-sodium water.
American journal of physiology. Regulatory, integrative and comparative physiology 302, R84-93 [PubMed:21993530]
[show Abstract]
To investigate whether Na(+) uptake by zebrafish is dependent on NH4(+) excretion, a scanning ion-selective electrode technique was applied to measure Na(+) and NH4(+) gradients at the yolk-sac surface of zebrafish larvae. Low-Na(+) acclimation induced an inward Na(+) gradient (uptake), and a combination of low Na(+) and high NH4(+) induced a larger inward Na(+) gradient. When measuring the ionic gradients, raising the external NH4(+) level (5 mM) blocked NH4(+) excretion and Na(+) uptake; in contrast, raising the external Na(+) level (10 mM) simultaneously enhanced Na(+) uptake and NH4(+) excretion. The addition of MOPS buffer (5 mM), which is known to block NH4(+) excretion, also suppressed Na(+) uptake. These results showed that Na(+) uptake and NH4(+) excretion by larval skin are associated when ambient Na(+) level is low. Knockdown of Rhcg1 translation with morpholino-oligonucleotides decreased both NH4(+) excretion and Na(+) uptake by the skin and Na(+) content of whole larvae. Knockdown of nhe3b translation or inhibitor (5-ethylisopropyl amiloride) treatment also decreased both the NH4(+) excretion and Na(+) uptake. This study provides loss-of-function evidence for the involvement of Rhcg1 and NHE3b in the ammonium-dependent Na(+) uptake mechanism in zebrafish larvae subjected to low-Na(+) water. | Kosaki Y, Takano K, Citterio D, Suzuki K, Shiratori S (2012)
Quartz crystal microbalance sensor using ionophore for ammonium ion detection.
Journal of nanoscience and nanotechnology 12, 563-567 [PubMed:22524020]
[show Abstract]
Ionophore-based quartz crystal microbalance (QCM) ammonium ion sensors with a detection limit for ammonium ion concentrations as low as 2.2 microM were fabricated. Ionophores are molecules, which selectively bind a particular ion. In this study, one of the known ionophores for ammonium, nonactin, was used to detect ammonium ions for environmental in-situ monitoring of aquarium water for the first time. To fabricate the sensing films, poly(vinyl chloride) was used as the matrix for the immobilization of nonactin. Furthermore, the anionic additive, tetrakis (4-chlorophenyl) borate potassium salt and the plasticizer dioctyl sebacate were used to enhance the sensor properties. The sensor allowed detecting ammonium ions not only in static solution, but also in flowing water. The sensor showed a nearly linear response with the increase of the ammonium ion concentration. The QCM resonance frequency increased with the increase of ammonium ion concentration, suggesting a decreasing weight of the sensing film. The detailed response mechanism could not be verified yet. However, from the results obtained when using a different plasticizer, nitrophenyl octyl ether, it is considered that this effect is caused by the release of water molecules. Consequently, the newly fabricated sensor detects ammonium ions by discharge of water. It shows high selectivity over potassium and sodium ions. We conclude that the newly fabricated sensor can be applied for detecting ammonium ions in aquarium water, since it allows measuring low ammonium ion concentrations. This sensor will be usable for water quality monitoring and controlling. | Wang S, Orabi EA, Baday S, Bernèche S, Lamoureux G (2012)
Ammonium transporters achieve charge transfer by fragmenting their substrate.
Journal of the American Chemical Society 134, 10419-10427 [PubMed:22631217]
[show Abstract]
Proteins of the Amt/MEP family facilitate ammonium transport across the membranes of plants, fungi, and bacteria and are essential for growth in nitrogen-poor environments. Some are known to facilitate the diffusion of the neutral NH(3), while others, notably in plants, transport the positively charged NH(4)(+). On the basis of the structural data for AmtB from Escherichia coli , we illustrate the mechanism by which proteins from the Amt family can sustain electrogenic transport. Free energy calculations show that NH(4)(+) is stable in the AmtB pore, reaching a binding site from which it can spontaneously transfer a proton to a pore-lining histidine residue (His168). The substrate diffuses down the pore in the form of NH(3), while the excess proton is cotransported through a highly conserved hydrogen-bonded His168-His318 pair. This constitutes a novel permeation mechanism that confers to the histidine dyad an essential mechanistic role that was so far unknown. | Ribeiro JA, Silva F, Pereira CM (2012)
Electrochemical sensing of ammonium ion at the water/1,6-dichlorohexane interface.
Talanta 88, 54-60 [PubMed:22265469]
[show Abstract]
In this work, ion transfer and facilitated ion transfer of ammonium ion by a lipophilic cyclodextrin is investigated at the water/1,6-dichlorohexane micro-interface, using electrochemical approaches (cyclic voltammetry, differential pulse voltammetry and square wave voltammetry). The association constant has been obtained for the complex between ammonium ion and the cyclodextrin. Experimental conditions for the analytical determination of ammonium ion were established and a detection limit of 0.12 μM was obtained. The amperometric sensor gave a current response proportional to the ammonium ion concentration in the range from 4.2 to 66 μM. | Hernández-Mena L, Saldarriaga-Noreña H, Carbajal-Romero P, Cosío-Ramírez R, Esquivel-Hernández B (2010)
Ionic species associated with PM2.5 in the City of Guadalajara, México during 2007.
Environmental monitoring and assessment 161, 281-293 [PubMed:19199063]
[show Abstract]
Atmospheric aerosol particles were collected from January to December 2007 at two sites in the City of Guadalajara. The first site (Centro) is located in the downtown, which is characterized by high vehicular traffic, and the second site (Miravalle) is in the southern part of the city, characterized by emissions from high industrial and vehicular activity. Sulfates, nitrates, and ammonium were the most abundant ions at both sites. Similar concentrations of sulfates, nitrates, and ammonium were observed throughout the year at Centro while only sulfates and nitrates were similar at Miravalle. From the balance of anions and cations at the two sites, Centro was determined to have acidic particles, while at Miravalle, the particles were alkaline. Based on the analysis of the ammonium/sulfate molar ratios, it was determined that in Centro, there was not enough ammonium to neutralize the sulfate, while at Miravalle, ammonium practically neutralized all sulfate. | Nimmervoll B, Svoboda N, Sacha B, Kerschbaum HH (2009)
Sustained elevation of cyclic guanosine monophosphate induces apoptosis in microglia.
Brain research bulletin 80, 428-432 [PubMed:19682559]
[show Abstract]
Cyclic nucleotides mediate transient as well as plastic cellular responses. The most ultimate response is cell death. In the present study, we propose that an increase of intracellular cyclic guanosine monophosphate (cGMP) for at least 1h promotes cell death in the murine microglial cell line, BV-2 cells, as well as in primary murine microglia. Cells were exposed to ammonium, the guanylyl cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), and to the membrane-permeable cGMP analogue, 8-Bromo-cGMP (8-Br-cGMP), respectively. Cell death was estimated using DAPI labelling and annexin-V labelling of exposed phosphatidylserine, and cGMP level was quantified by an immunoassay. Ammonium not only increased the number of apoptotic cells but also promoted a moderate increase in intracellular cGMP. Addition of ODQ suppressed ammonium-induced apoptosis. Furthermore, we found that 8-Br-cGMP significantly increased the number of BV-2 cells and primary microglia, respectively, containing nuclei with condensed chromatin accumulated at the nuclear periphery. Similarly, cells exposed to 8-Br-cGMP showed significantly more cells with exposed phosphatidylserine compared to control cells. Thus, according to the nuclear structure as well as to changes in the plasma membrane, chronic elevation of cGMP induces apoptosis in microglia. | Halse ME, Callaghan PT, Feland BC, Wasylishen RE (2009)
Quantitative analysis of Earth's field NMR spectra of strongly-coupled heteronuclear systems.
Journal of magnetic resonance (San Diego, Calif. : 1997) 200, 88-94 [PubMed:19596600]
[show Abstract]
In the Earth's magnetic field, it is possible to observe spin systems consisting of unlike spins that exhibit strongly coupled second-order NMR spectra. Such spectra result when the J-coupling between two unlike spins is of the same order of magnitude as the difference in their Larmor precession frequencies. Although the analysis of second-order spectra involving only spin-(1/2) nuclei has been discussed since the early days of NMR spectroscopy, NMR spectra involving spin-(1/2) nuclei and quadrupolar (I>(1/2)) nuclei have rarely been treated. Two examples are presented here, the tetrahydroborate anion, BH4-, and the ammonium cation, NH4+. For the tetrahydroborate anion, (1)J((11)B,(1)H)=80.9Hz, and in an Earth's field of 53.3microT, nu((1)H)=2269Hz and nu((11)B)=728Hz. The (1)H NMR spectra exhibit features that both first- and second-order perturbation theory are unable to reproduce. On the other hand, second-order perturbation theory adequately describes (1)H NMR spectra of the ammonium anion, (14)NH4+, where (1)J((14)N,(1)H)=52.75Hz when nu((1)H)=2269Hz and nu((14)N)=164Hz. Contrary to an early report, we find that the (1)H NMR spectra are independent of the sign of (1)J((14)N,(1)H). Exact analysis of two-spin systems consisting of quadrupolar nuclei and spin-(1/2) nuclei are also discussed. | Hamersley MR, Woebken D, Boehrer B, Schultze M, Lavik G, Kuypers MM (2009)
Water column anammox and denitrification in a temperate permanently stratified lake (Lake Rassnitzer, Germany).
Systematic and applied microbiology 32, 571-582 [PubMed:19716251]
[show Abstract]
We studied microbial N(2) production via anammox and denitrification in the anoxic water column of a restored mining pit lake in Germany over an annual cycle. We obtained high-resolution hydrochemical profiles using a continuous pumping sampler. Lake Rassnitzer is permanently stratified at ca. 29m depth, entraining anoxic water below a saline density gradient. Mixed-layer nitrate concentrations averaged ca. 200 micromol L(-1), but decreased to zero in the anoxic bottom waters. In contrast, ammonium was <5 micromol L(-1) in the mixed layer but increased in the anoxic waters to ca. 600 micromol L(-1) near the sediments. In January and October, (15)N tracer measurements detected anammox activity (maximum 504 nmol N(2)L(-1)d(-1) in (15)NH(4)(+)-amended incubations), but no denitrification. In contrast, in May, N(2) production was dominated by denitrification (maximum 74 nmol N(2)L(-1)d(-1)). Anammox activity in May was significantly lower than in October, as characterized by anammox rates (maximum 6 vs. 16 nmol N(2)L(-1)d(-1) in incubations with (15)NO(3)(-)), as well as relative and absolute anammox bacterial cell abundances (0.56% vs. 0.98% of all bacteria, and 2.7x10(4) vs. 5.2x10(4)anammox cells mL(-1), respectively) (quantified by catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) with anammox bacteria-specific probes). Anammox bacterial diversity was investigated with anammox bacteria-specific 16S rRNA gene clone libraries. The majority of anammox bacterial sequences were related to the widespread Candidatus Scalindua sorokinii/brodae cluster. However, we also found sequences related to Candidatus S. wagneri and Candidatus Brocadia fulgida, which suggests a high anammox bacterial diversity in this lake comparable with estuarine sediments. | van der Star WR, van de Graaf MJ, Kartal B, Picioreanu C, Jetten MS, van Loosdrecht MC (2008)
Response of anaerobic ammonium-oxidizing bacteria to hydroxylamine.
Applied and environmental microbiology 74, 4417-4426 [PubMed:18515490]
[show Abstract]
Anaerobic ammonium oxidation is a recent addition to the microbial nitrogen cycle, and its metabolic pathway, including the production and conversion of its intermediate hydrazine, is not well understood. Therefore, the effect of hydroxylamine addition on the hydrazine metabolism of anaerobic ammonium-oxidizing (anammox) bacteria was studied both experimentally and by mathematical modeling. It was observed that hydroxylamine was disproportionated biologically in the absence of nitrite into dinitrogen gas and ammonium. Little hydrazine accumulated during this process; however, rapid hydrazine production was observed when nearly all hydroxylamine was consumed. A mechanistic model is proposed in which hydrazine is suggested to be continuously produced from ammonium and hydroxylamine (possibly via nitric oxide) and subsequently oxidized to N(2). The electron acceptor for hydrazine oxidation is hydroxylamine, which is reduced to ammonium. A decrease in the hydroxylamine reduction rate, therefore, leads to a decrease in the hydrazine oxidation rate, resulting in the observed hydrazine accumulation. The proposed mechanism was verified by a mathematical model which could explain and predict most of the experimental data. | Provent P, Kickler N, Barbier EL, Bergerot A, Farion R, Goury S, Marcaggi P, Segebarth C, Coles JA (2007)
The ammonium-induced increase in rat brain lactate concentration is rapid and reversible and is compatible with trafficking and signaling roles for ammonium.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 27, 1830-1840 [PubMed:17392693]
[show Abstract]
The glutamate-glutamine shuttle requires a flux of fixed N from neurons to astrocytes. The suggestion that some or all of this N is ammonium has received support from reports that ammonium (as NH(4)(+)) rapidly enters astrocytes. Ammonium might also help control astrocyte energy metabolism by increasing lactate production. If ammonium has these functions, then its effect on brain metabolism must be rapid and reversible. To make a minimal test of this requirement, we have followed the time courses of the changes induced by a 4 min venous infusion of 1 mol/L NH(4)Cl, 2.5 mmol/kg body weight, in rat. Extracellular [NH(4)(+)] in cortex, monitored with ion-selective microelectrodes, reached a peak of approximately 0.7 mmol/L 1.65 mins after the end of the infusion, then recovered. Brain metabolites were monitored non-invasively every 4 mins by (1)H magnetic resonance spectroscopy. Lactate peak area during the 3.2 min acquisition starting at the end of the infusion was 1.84+/-0.24 times baseline (+/-s.e.m., P=0.009, n=9). Lactate increased until 13.2+/-2.1 mins after the end of the infusion and recovered halfway to baseline by 31.2 mins. Glutamate decreased by at least 7.1% (P=0.0026). Infusion of NaCl caused no change in lactate signal. Cerebral blood flow, measured by arterial magnetization labeling, more than doubled, suggesting that the lactate increase was not caused by hypoxia. At least three consecutive ammonium-induced increases in lactate signal could be evoked. The results are compatible with an intercellular trafficking/signaling function for ammonium. | Hinton TG, Kaplan DI, Knox AS, Coughlin DP, Nascimento RV, Watson SI, Fletcher DE, Koot BJ (2006)
Use of illite clay for in situ remediation of 137Cs-contaminated water bodies: field demonstration of reduced biological uptake.
Environmental science & technology 40, 4500-4505 [PubMed:16903292]
[show Abstract]
We hypothesized that adding micaceous minerals to 137Cs-contaminated aquatic systems would serve as an effective in situ remediation technique by sequestering the contaminant and reducing its bioavailability. Results from several laboratory studies are presented from which an effective amendment material was chosen for a replicated field study. The field study was conducted over a 2-year period and incorporated 16 3.3-m diameter column-plots (limnocorrals) that were randomly placed in a 137Cs-contaminated pond. The limnocorrals received three rates of amendment treatments to their water surfaces. The amendment material was a commercially available mineral with high sorption (Kd > 9000 L kg(-1)) and low desorption (<20%) characteristics for cesium, even in the presence of high concentrations of the competing cation, NH4+. In the treated limnocorrals, 137Cs concentrations were reduced some 25-30-fold in the water, 4-5-fold in aquatic plants, and 2-3-fold in fish. The addition of the amendment did not adversely affect water chemistry, although increased turbidity and subsequent siltation did alter the aquatic macroinvertebrate insect community. This in situ technology provides a valuable, less-environmentally intrusive alternative to costly ex situ technologies that require the contaminated sediment to be excavated prior to treatment, or excavated and disposed of elsewhere. | Effros RM, Biller J, Foss B, Hoagland K, Dunning MB, Castillo D, Bosbous M, Sun F, Shaker R (2003)
A simple method for estimating respiratory solute dilution in exhaled breath condensates.
American journal of respiratory and critical care medicine 168, 1500-1505 [PubMed:14512268]
[show Abstract]
Exhaled breath condensates have been widely used to detect inflammatory mediators in the fluid that covers airway surfaces of patients with inflammatory lung disorders. This approach is much less invasive than bronchoalveolar lavage, but respiratory droplets are markedly diluted by large and variable amounts of water vapor. We estimated the dilution of respiratory droplets by comparing concentrations of nonvolatile, reference indicators (total nonvolatile cations, urea or conductivity) in 18 normal subjects with normal plasma concentrations by assuming similar concentrations in the respiratory fluid and plasma. The volatile cation, NH4+ (most of which is delivered as NH3 gas from the mouth), represented 93 +/- 3% (SEM) of the condensate cations. More than 99% of the NH4+ was removed by lyophilization, making it possible to use conductivity to estimate total nonvolatile ionic concentrations and facilitating analysis of urea. Conductivity was significantly correlated with electrolyte and urea concentrations. Estimates of dilution based on total cations, conductivity, and urea were not significantly different (cations: 20,472 +/- 2,516; conductivity: 21,019 +/- 2,427; and urea: 18,818 +/- 2,402). These observations suggest that the conductivity of lyophilized samples can be used as an inexpensive, simple, and reliable method for estimating dilution of nonvolatile, hydrophilic mediators in condensates. | Sas L, Rengel Z, Tang C (2002)
The effect of nitrogen nutrition on cluster root formation and proton extrusion by Lupinus albus.
Annals of botany 89, 435-442 [PubMed:12096804]
[show Abstract]
Nitrogen nutrition can influence cluster root formation in many wild species, but the effect of N form on cluster root formation and root exudation by white lupin is not known. In a solution culture study, we examined the effect of N nutrition (ammonium, nitrate, both or N2 fixation) on cluster root formation and H+ extrusion by white lupin plants under deficient and adequate P supply. The number of cluster roots increased greatly when plants were supplied with I microM P compared with 50 microM P, the increase being 7.8-fold for plants treated with (NH4)2SO4, 3-fold for plants treated with KNO3 and NH4NO3, and 2-4-fold for N2-fixing plants. Under P deficiency. NH4+-N supply resulted in production of a greater number and biomass of cluster roots than other N sources. Dry weight of cluster roots was 30 % higher than that of non-cluster roots in P-deficient plants treated with (NH4)2SO4 and NH4NO3. In plants treated with sufficient P (50 microM), the weight of non-cluster roots was approx. 90 % greater than that of cluster roots. Both total (micromol per plant h(-1)) and specific (micromol g(-1) root d. wt h(-1)) H+ extrusions were greatest from roots of plants supplied with (NH4)2SO4, followed by those supplied with NH4NO3 and N2 fixation, whereas plants receiving KNO3 had negative net H+ extrusion between the third and fifth week of growth (indicating uptake of protons or release of OH- ions). The rate of proton extrusion by NH4+-N-fed plants was similar under P-deficient and P-sufficient conditions. In contrast, proton exudation by N2-fixing plants and KNO3-treated plants was ten-fold greater under P deficiency than under P sufficiency. In comparison with P deficiency, plants treated with 50 microM P had a significantly higher concentration of P in roots, shoots and youngest expanded leaves (YEL). Compared with the N2 fixation and KNO3 treatments, total N concentration was highest in roots, shoots and YEL of plants supplied with (NH4)2SO4 and NH4NO3, regardless of P supply. Under P deficiency, K concentrations in roots decreased at all N supplies, especially in plants treated with (NH4)2SO4 and NH4NO3, which coincided with the greatest H+ extrusion at these P and N supplies. In conclusion, NH4-N nutrition stimulated cluster root formation and H+ extrusion by roots of P-deficient white lupin. | Flores-Cotera LB, Martín R, Sánchez S (2001)
Citrate, a possible precursor of astaxanthin in Phaffia rhodozyma: influence of varying levels of ammonium, phosphate and citrate in a chemically defined medium.
Applied microbiology and biotechnology 55, 341-347 [PubMed:11341317]
[show Abstract]
The influence of ammonium, phosphate and citrate on astaxanthin production by the yeast Phaffia rhodozyma was investigated. The astaxanthin content in cells and the final astaxanthin concentration increased upon reduction of ammonium from 61 mM to 12.9 mM (from 140 microg/g to 230 microg/g and 1.2 microg/ml to 2.3 microg/ml, respectively). Similarly, both the astaxanthin content and astaxanthin concentration increased by reducing phosphate from 4.8 mM to 0.65 mM (160 microg/g to 215 microg/g and 1.7 microg/ml to 2.4 microg/ml, respectively). Low concentrations of ammonium or phosphate also increased the fatty acid content in cells. By analogy with lipid synthesis in other oleaginous yeasts, an examination of the data for varying nitrogen and phosphate levels suggested that citrate could be the source of carbon for fatty acids and carotenoid synthesis. Supporting this possibility was the fact that supplementation of citrate in the medium at levels of 28 mM or higher notably increased the final pigment concentration and pigment content in cells. Increased carotenoid synthesis at low ammonium or phosphate levels, and stimulation by citrate were both paralleled by decreased protein synthesis. This suggested that restriction of protein synthesis could play an important role in carotenoid synthesis by P. rhodozyma. | Yoneyama K, Takeuchi Y, Yokota T (2001)
Production of clover broomrape seed germination stimulants by red clover root requires nitrate but is inhibited by phosphate and ammonium.
Physiologia plantarum 112, 25-30 [PubMed:11319011]
[show Abstract]
The effect of nutrients (nitrate, ammonium, urea, phosphate and potassium) on the production and/or exudation of germination stimulants for clover broomrape (Orobanche minor Sm.), a root holoparasite, by its host red clover (Trifolium pratense L.) was examined using hydroponically grown material. Potassium (K2SO4) concentrations up to 100 mg l-1 (based on K) did not affect the production of germination stimulants by red clover while, in contrast, phosphate (NaH2PO4) was highly inhibitory even at concentrations as low as 1 mg l-1 (based on P). Nitrate (NaNO3) markedly promoted stimulant production in a dose-dependent manner from 2 to 50 mg l-1 (based on N). Ammonium [(NH4)2SO4] had no effect at 2 mg l-1 (based on N) but was inhibitory at higher concentrations. Ammonium is known to be a seed germination inhibitor of root parasites, indicating that ammonium has a dual inhibitory action. Urea had no effect at 2 mg l-1 (based on N) but was promotive at higher concentrations. These results provide a basis for the inhibitory effects of nitrogen fertilizer on infection by root parasitic weeds, broomrapes and witchweeds, and explain why these parasites prevail in areas where there is lower phosphorus availability in soils. | Tuovinen OH, Panda FA, Tsuchiya HM (1979)
Nitrogen requirement of iron-oxidizing thiobacilli for acidic ferric sulfate regeneration.
Applied and environmental microbiology 37, 954-958 [PubMed:16345391]
[show Abstract]
Ammonium was shown to be a limiting nutrient for iron oxidation in cultures of Thiobacillus ferrooxidans. In addition, one strain was also able to assimilate nitrate, but not nitrite, for growth and coupled iron oxidation. Some amino acids (0.5 mM) were tested as a source of nitrogen; none clearly stimulated bacterial activity and inhibition was commonly encountered. Complex nitrogenous compounds were inhibitory at high concentrations (0.1 to 0.5%, wt/vol) and, at low concentrations, some clearly stimulated the bacterial iron oxidation in ammonium-limited cultures. Enhancement of iron oxidation by these compounds was also observed in ammonium-unlimited cultures, suggesting their possible role in providing trace nutrients and possibly carbon for the bacteria. | FERDMAN DL, SILAKOVA AI (1951)
[Ammonium, glutamine and glutamic acid in the skeletal muscles in hypoxemia].
Doklady Akademii nauk SSSR 80, 657-659 [PubMed:14879753] |
|
