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PubMed2004

Start up of deammonification process in one single SBR system.

A process for autotrophic nitrogen removal named aerobic/anoxic deammonification wherein NH4+ is oxidized by nearly 50% to NO2- and subsequently the ammonia is converted together with the nitrite to molecular nitrogen (N2 gas), has come to full-scale application within the last few years. In this research, sludge from a biological rotation disk located at a landfill leachate plant at Mechernich, Germany, which is capable of performing the deammonification process, was used as seed sludge for acclimating deammonification activities in laboratory scale batch-reactors. In parallel, the same tests were performed with normal activated sludge. Research results indicated that deammonification activities could be obtained from the seeded reactor and also, with limited performance, from normal activated sludge in a single SBR system after several months acclimation. It was also seen that oxygen is an important factor that influences the deammonification from both the acclimatization process and process running. Further results were approved that report an impact of nitrite as a process intermediate on the closely related process of anaerobic ammonia oxidation ("Anammox"). However, limiting concentrations on a bacteria population performing deammonification were found to be different to those reported for a pure Anammox-culture. Also the influence of another intermediate, hydrazine, was tested for speeding up the acclimating process by inducing the deammonification activities and recovering the activities of deammonification from nitrite inhibition.

Bacteria, Anaerobic↗

PubMed1990

[Evaluation of the effectiveness of an antiseptic preparation "Apolam" for the treatment of surgeon's hands].

The authors discuss the efficacy of sterilizing the surgeon's hands with apolam, a new antiseptic. This antiseptic is a surfactant referred to quaternary ammonia salts. Studies carried out in 140 volunteers have demonstrated high quality of sterilization with this antiseptic and its high activity against pathogenic and opportunistic microflora. No allergic reactions or local irritation symptoms were recorded. Reliable sterilization of surgeon's hands is achieved by mere plunging and standard treatment of the hands in 0.5 percent apolam solution for 60 sec.

Anti-Infective Agents, Local↗

PubMed1994

[Studies on quality of drinking water and causes of liver cancer in a high-incidence area].

Quality of drinking water was comprehensively studied in Fusui County of Guangxi, a high-incidence area for liver cancer. The results indicated pond water was polluted the most severely, well water the least, and river water intermediately. The chemical indicators for water pollution were levels of ammonia, nitrite, humic acid, suspended substances, chemical oxygen demand, and biological oxygen demand. Quality of drinking water was worse in high incidence area for liver cancer than that in low-incidence one. Mortality of liver cancer correlated positively with the levels of nitrite, humic acid, chemical oxygen demand, and so on. These results provided a basis for further studies on the etiology of liver cancer.

China↗

PubMed2005

Programmable gate delayed ion mobility spectrometry-mass spectrometry: a study with low concentrations of dipropylene-glycol-monomethyl-ether in air.

The concept of using a short ionisation event, in this case a pulsed corona discharge, in conjunction with programmed gate delay is described. This technique is proposed for the selective study of different ionisation processes within the reaction region of an ion mobility spectrometer. The utility of such an approach was tested in a study of the ionisation of dipropylene-glycol-monomethyl-ether (DPM); a compound commonly used to test the operation of ion mobility spectrometers. Dipropylene-glycol-monomethyl-ether at a concentration of 113 microg m(-3) in air, with a water level of 75 mg m(-3) in air, was analysed using a switchable, high resolution ion mobility spectrometer, operating in the positive mode at 40 degrees C at ambient pressure. The ion mobility spectrometer was fitted with a pulsed corona discharge ionisation source, doped with ammonia at a concentration of 1.3 mg m(-3) in the reaction region, and interfaced to a mass spectrometer. Synchronisation of the ionisation event to the operation of the shutter grids for the drift region enabled different parts of the product ion population to be injected into the drift tube, and programming the gate delays produced a map of the gate delay verses drift time response surface. Ammonium bound dipropylene-glycol-monomethyl-ether was observed, [(DPM)NH4]+ (m/z 166) as well as the ammonium bound dimer [(DPM)2NH4]+ (m/z 314), the same as those observed with a 63Ni source. Two other species were also observed, but their molecular identity was not elucidated. One of them m/z 146, also observed with 63Ni, formed ammonium bound ions [(m/z 146)NH4]+ (K0= 1.49 cm2 V(-1) s(-1)), ammonium bound dimer ions [(m/z 146)2NH4]+(K0= 1.18 cm2 V(-1) s(-1)) and a mixed cluster ion with DPM [(m/z 146)(DPM)NH4]+(K0= 1.18 cm2 V(-1) s(-1)); while the other, m/z 88 a decomposition product, formed ammonium bound monomer [(m/z 88)NH4]+(K0= 1.68 cm2 V(-1) s(-1)), dimer ions [(m/z 88)2NH4]+(K0= 1.40 cm2 V(-1) s(-1)) and a mixed cluster ion containing DPM and ammonium, [(DPM)(m/z 88)2NH4]+(K0= 1.40 cm2 V(-1) s(-1)). The assignment of responses to these ions required the additional dimensionality in the data provided from the gate delay studies. The relationships evident in the programmable gate delay data enabled these ions to be differentiated from alternative assignments of possible nitrogen clusters, formed at the interface of the mass spectrometer.

Air↗

PubMed2004

Kupffer cell-depleted rats have a diminished acute-phase response following major liver resection.

Partial hepatectomy (PH)-induced Kupffer cell (KC) activation results in a rapid release of cytokines inducing the acute-phase response (APR). This study was done to evaluate the role of Kupffer cells (KCs) in the course of the APR following PH and a consecutive endotoxin challenge. KC depletion was performed in rats by i.v. administration of 1 mL liposome-encapsulated dichloromethylene diphosohonate (Cl2MDP). Control rats received 1 mL NaCl 0.9%. Forty-eight hours later, PH was performed. At 24 h after PH, rats were randomized to receive either 1 mL NaCl 0.9% (saline) or 50 microg/kg LPS i.v. in 1 mL. Animals were sacrificed at 4 h after LPS or saline infusion. The APR was determined by measuring hepatic gene expression of alpha 2-macroglobulin, alpha 1-acid glycoprotein, and IL-6 and expression of hepatic albumin. The APR was significantly depressed in KC-depleted rats. Despite increased IL-6 mRNA synthesis in response to low-dose LPS, no enhancement of acute-phase protein synthesis (APP) was found in KC-depleted rats. Hepatic failure was most profound in KC-depleted rats, as indicated by elevated plasma levels of liver transaminases and ammonia. We conclude that after PH, KC function in the remnant liver is important for the acute-phase reaction and reduces endotoxin-induced hepatocyte damage.

Acute-Phase Proteins↗

PubMed2002

Assessment of source-based nitrogen removal alternatives in leather tanning industry wastewater.

Nitrogen is an important parameter of leather tanning wastewaters. Magnesium ammonium phosphate (MAP) precipitation is a chemical treatment alternative for ammonia removal. In this study, a detailed source-based wastewater characterisation of a bovine leather tannery was made and nitrogen speciation as well as other basic pollutant parameter values was evaluated. This evaluation has led to definition of alternatives for source-based MAP treatment. MAP precipitation experiments conducted on these alternatives have yielded over 90% ammonia removal at pH 9.5 and using stoichiometric doses. Among the alternatives tested liming-deliming and bating-washing was found to be the most advantageous providing 71% ammonia removal.

Animals↗

PubMed2004

The metabolic syndrome and uric acid nephrolithiasis: novel features of renal manifestation of insulin resistance.

BACKGROUND: Uric acid nephrolithiasis primarily results from low urinary pH, which increases the concentration of the insoluble undissociated uric acid, causing formation of both uric acid and mixed uric acid/calcium oxalate stones. These patients have recently been described as exhibiting features of insulin resistance. This study was designed to evaluate if insulin resistance is associated with excessively low urinary pH in overtly healthy volunteers (non-stone formers) and if insulin resistance may explain the excessively low urinary pH in patients with uric acid nephrolithiasis. METHODS: Fifty-five healthy volunteers (non stone-formers) with a large range of body mass index and 13 patients with recurrent uric acid nephrolithiasis underwent hyperinsulinemic euglycemic clamp, 24-hour urinary studies, and anthropometric measurements of adiposity. A subgroup of 35 non-stone formers had 2-hour timed urinary collection before and during the hyperinsulinemic phase of the clamp studies. RESULTS: For the non-stone former population, low insulin sensitivity measured as glucose disposal rate significantly correlated with low 24-hour urinary pH (r= 0. 35; P= 0.01). In addition to the previously described acidic urine pH and hypouricosuria, patients with recurrent uric acid nephrolithiasis were found to be severely insulin resistant (glucose disposal rate: uric acid stone-formers vs. normals; 4.1 +/- 1.3 vs. 6.9 +/- 2.1 mg/min/kg of lean body mass, P= 0.008). Acute hyperinsulinemia was associated with higher urinary pH (6.1 +/- 0.7 at baseline to 6.8 +/- 0.7 during hyperinsulinemia; P < 0.0001), urinary ammonia excretion (2.7 +/- 1.6 mEq/2 hr at baseline and 4.0 +/- 2.6 mEq/2 hr P= 0.002) and urinary citrate excretion (48 +/- 33 mg/2 hr at baseline and 113 +/- 68 mg/2 hr P < 0.0001). CONCLUSION: We conclude that one renal manifestation of insulin resistance may be low urinary ammonium and pH. This defect can result in increased risk of uric acid precipitation despite normouricosuria.

Acids↗

PubMed1979

Comparative uptake of fluoride from sodium fluoride, ammonium fluoride, and barium fluoride in rat teeth when predominantly administered in the pre-eruptive stage of development.

A comparative study was undertaken which focused on the systemic uptake of sodium fluoride (NaF), ammonium fluoride (NH4F), and barium fluoride (BaF2) in rat pups. Two critical achievements made this comparative study possible: (a) the demonstration of significant increases in fluoride (F) uptake-deposition in the treatment group pups relative to control group rats as a result of stomach tube feeding; and (b) the demonstration of clear-cut differences in F concentration levels between the treatment groups as a result of this stomach tube-systemic uptake. Data were reliable and significant enough to suggest that, of the 3 compounds in question, NH4F is absorbed most successfully in a systemic fashion, whereas BaF2 is the least absorbed.

Ammonia↗

PubMed2005

The fate of nitrogen in a moderately alkaline and calcareous soil amended with biosolids and urea.

The determination of nitrogen (N) based loading rates for land application of biosolids is challenging and site specific. Over loading may contribute to environmental, agricultural, or human health problems. The objective of this study was to monitor N mineralization and losses in a moderately alkaline and calcareous desert soil amended with either anaerobically digested (AN) or lime-stabilized (LS) biosolids, and irrigated with and without urea enriched water. For Experiment 1, N inputs, leaching and residuals in soil were evaluated in an open soil column system. For Experiment 2, ammonia (NH(3)) emissions were evaluated in a closed soil column system. In Experiment 1, AN and LS biosolids increased soil ON (organic N) by three and two fold, respectively. Respective net N mineralization of ON from biosolids alone was 90% and 62% without urea, and 71% and 77%, respectively with added urea. Nitrogen leaching losses and residuals in amended soil did not account for all N inputs into the soil/biosolids system. In Experiment 2, NH(3) emissions were not significantly different among treated soils with or without added urea, except LS amended soil receiving urea. Ammonia losses did not account for unaccounted N in Experiment 1. We concluded that deep placement and rapid mineralization of AN biosolids promoted anaerobic soil conditions and denitrification, in addition to the high denitrification potential of desert soil. LS biosolids showed greater potential than AN biosolids for safe and beneficial land application to desert soils regardless of biosolids placement and the inclusion of N rich irrigation water.

Biocompatible Materials↗

PubMed1986

Evidence for NH4+ switch-off regulation of nitrogenase activity by bacteria in salt marsh sediments and roots of the grass Spartina alterniflora.

The regulatory effect of NH4+ on nitrogen fixation in a Spartina alterniflora salt marsh was examined. Acetylene reduction activity (ARA) measured in situ was only partially inhibited by NH4+ in both the light and dark after 2 h. In vitro analysis of bulk sediment divided into sediment particles, live and dead roots, and rhizomes showed that microbes associated with sediment and dead roots have a great potential for anaerobic C2H2 reduction, but only if amended with a carbon source such as mannose. Only live roots had significant rates of ARA without an added carbon source. In sediment, N2-fixing mannose enrichment cultures could be distinguished from those enriched by lactate in that only the latter were rapidly inhibited by NH4+. Ammonia also inhibited ARA in dead and live roots and in surface-sterilized roots. The rate of this inhibition appeared to be too rapid to be attributed to the repression and subsequent dilution of nitrogenase. The kinetic characteristics of this inhibition and its prevention in root-associated microbes by methionine sulfoximine are consistent with the NH4+ switch-off-switch-on mechanism of nitrogenase regulation.

Acetylene↗

PubMed1978

Induction of transformation competence in Azotobacter vinelandii iron-limited cultures.

Azotobacter vinelandii strains UW (Nif+) or UW1 (Nif-) were induced to form competent cells by growing cultures in Burk medium without added iron. Competent cells were generated in either liquid or solid medium. The competent culture was highly colored by the characteristic fluorescent green pigment of A. vinelandii but all pigmented cultures were not competent. In liquid culture, competent cells required a fixed nitrogen source (ammonia, nitrate, or urea) that was also a nitrogenase repressor. Glucose, sucrose, glycerol, and mannitol (1% w/v) were excellent C-sources for competence induction while acetate (1% w/v) and beta-hydroxybutyrate (0.2% w/v) were ineffective. Cells induced in liquid culture remained competent for a 12-h period before the end of the exponential growth phase, then competence decreased rapidly upon the initiation of the stationary phase of growth.

Azotobacter↗

PubMed1993

[Neurotoxic role of glycocolle and derivatives in transurethral resection of the prostate].

72-year-old patient underwent an elective transurethral resection of the prostate (TURP) performed with a spinal anaesthesia. The irrigation solution contained glycine at a concentration of 15 g.l-1. The patient's level of consciousness deteriorated over the next 4 hours. He went in an areflexic coma with pupillary areflexia and left mydriasis. The diagnosis of TUR syndrome was substantiated by a sodium blood concentration of 98 mmol.l-1, an osmotic gap of 48 mosmol.kg-1 and blood ammonia at 415 mumol.l-1. To investigate the pathophysiological role of glycine and its metabolites, their concentrations were measured by chromatography and spectrometry in plasma and CSF 8, 24 and 48 hours postoperatively. Glycine and its metabolites (serine, alanine, glyoxylic acid and glycolic acid) accumulated during the postoperative period in both blood and CSF. The central nervous system is in direct contact with these neurotropic compounds. Glycine is an inhibitory neurotransmitter, whereas glyoxylic acid and glycolic acid are considered as to be neurotoxic.

Aged↗

PubMedDate not supplied

[Effect of the mineral-ammonia preparations MP-15 and MP-7 on nitrogen metabolism in cows].

It has been studied how MP-15 and MP-7 preparations fed on to lactating cows affect the indices of acid-base equilibrium of their blood, nitrogen metabolism, milk yield and milk quality. It is shown that feeding on MP-15 and MP-7 preparations to cows of test groups has no negative effect on the acid-base equilibrium indices, decreases the ammonia concentration by 38.5 and 54.9%, respectively, increases the glutamine content in blood by 23.5 and 29.4%, respectively, does not affect the pyruvate, glutamate, oxaloacetate concentration and alanine-transaminase activity, increases the average daily milk yields by 2.1 and 2.3 l, respectively, and does not deteriorate the composition and physicochemical indices of milk quality.

Acid-Base Equilibrium↗

PubMed2001

Struvite precipitation potential for nutrient recovery from anaerobically treated wastes.

Geochemical equilibrium speciation modeling was used to determine optimum conditions for precipitation of magnesium ammonium phosphate, or struvite, for the recovery of nutrients from anaerobically digested wastes. Despite a wide range of pH values with the potential to precipitate struvite, the optimum pH was determined to be 9.0. Bench experiments conducted on effluent from an anaerobic sequencing batch reactor (ASBR) treating swine wastes achieved a maximum of 88% ammonia removal at a pH of 9.5 with added magnesium and phosphate to achieve an ammonium: magnesium: phosphate molar ratio of 1:1.25:1. Struvite precipitation was performed on a continuous basis in a pilot-scale ASBR treating swine wastes. Through the addition of supplemental magnesium and phosphate, the ammonia concentration was reduced from 1500 mg/L as nitrogen to less than 10 mg/L. The supenatant from the struvite precipitation clarifier was recycled to the feed of the ASBR without adverse impact, simulating on-farm effluent reuse as flush water.

Agriculture↗

PubMed2005

Single-stage autotrophic nitrogen-removal process using a composite matrix immobilizing nitrifying and sulfur-denitrifying bacteria.

We developed a novel single-stage autotrophic nitrogen-removal process comprised of two composite immobilized biomass layers-one of nitrifying bacteria and one of sulfur-denitrifying bacteria and elemental sulfur-in a Fe-Ni fibrous slag matrix. Nitrification and consumption of dissolved oxygen occurred in the outer part and sulfur denitrification in the anoxic inner part of the composite matrix, thus realizing autotrophic nitrogen removal in a single reactor. The complete conversion of ammonia into N2 in a single reactor was demonstrated in both batch-mode incubation and continuous-feed operation. The spatial profiles of the ammonia-oxidizing bacteria and denitrifying bacteria were evaluated by real-time PCR, targeting their functional genes, and stratification of these two types was observed in the matrix after several months of incubation. This process does not require any specific reactor type or conditions and thus has the potential to be applied to many different wastewater treatment processes due to its simplicity in both operation and construction.

Aerobiosis↗

PubMed1984

Stimulation of germination of unactivated Bacillus cereus spores by ammonia.

Inclusion of ammonia in germinant mixtures containing L-alanine and inosine stimulated germination of unactivated Bacillus cereus spores at rates equal to those obtained using heat-activated spores without ammonia. D-Alanine had little effect on germination of heat-activated spores, but severely inhibited germination of unactivated spores in the presence of ammonia. Ammonia did not replace the requirement for either L-alanine or inosine: all three compounds were required for rapid germination. Kinetic analysis suggested that the functions of ammonia and L-alanine were more closely related than the functions of ammonia and inosine. With rate-saturating concentrations of L-alanine and inosine, germination rates showed saturation kinetics for ammonia with a Km for NH4Cl of 5 mM. Comparisons of the effects of salts, amines and pH on germination rates suggested that NH4OH rather than NH+4 was the rate-limiting form of ammonia. In comparisons of various strains of B. cereus, stimulation of germination by ammonia occurred in all cases, although spores of most soil isolates germinated more rapidly than B. cereus T spores in the absence of ammonia.

Alanine↗

PubMed2005

Improved methods for the cultivation of the chemolithoautotrophic bacterium Nitrosomonas europaea.

The chemolithoautotrophic nitrifier Nitrosomonas europaea is useful for biotechnological processes such as bioremediation of toxic chemicals, as well as playing an essential role in the global nitrogen cycle. To successfully apply this bacterium in biotechnology, large quantities of active cells need to be produced. In this paper we demonstrate improved methods for mass cultivation of N. europaea. A doubling in the final cell density to 30 mg dry wt l(-1) was achieved with a fed-batch culture technique using ammonium bicarbonate or sodium bicarbonate for pH control. The cells displayed high ammonia oxidizing activity in excess of 20 mmol g(-1) dry wt h(-1). Continuous culture under energy limited growth conditions (<0.1 mM residual ammonium) in a bench scale bioreactor using a microfiltration membrane for high cell recycle produced final culture densities greater than 350 mg dry wt l(-1). This system allowed operator controlled culturing of cells under excess substrate as well as energy limited growth conditions with a maximum ammonium oxidation potential in excess of 250 mmol g(-1) dry wt h(-1).

Bacteriological Techniques↗

PubMed2003

Anaerobic ammonium oxidation by marine and freshwater planctomycete-like bacteria.

Recently, two fresh water species, " Candidatus Brocadia anammoxidans" and " Candidatus Kuenenia stuttgartiensis", and one marine species, " Candidatus Scalindua sorokinii", of planctomycete anammox bacteria have been identified. " Candidatus Scalindua sorokinii" was discovered in the Black Sea, and contributed substantially to the loss of fixed nitrogen. All three species contain a unique organelle--the anammoxosome--in their cytoplasm. The anammoxosome contains the hydrazine/hydroxylamine oxidoreductase enzyme, and is thus the site of anammox catabolism. The anammoxosome is surrounded by a very dense membrane composed almost exclusively of linearly concatenated cyclobutane-containing lipids. These so-called 'ladderanes' are connected to the glycerol moiety via both ester and ether bonds. In natural and man-made ecosystems, anammox bacteria can cooperate with aerobic ammonium-oxidising bacteria, which protect them from harmful oxygen, and provide the necessary nitrite. The cooperation of these two groups of ammonium-oxidising bacteria is the microbial basis for a sustainable one reactor system, CANON (completely autotrophic nitrogen-removal over nitrite) to remove ammonia from high strength wastewater.

Anaerobiosis↗