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PubMed1998

[Presence of nitrogen compounds in well water].

INTRODUCTION: Nitrogen compounds in drinking waters have been related to groundwater contamination and inadequate sanitary conditions. Nitrite and nitrate are etiologic agents of methemoglobinemia. In acid solution, nitrous acid formed from nitrite can react with secondary amines to form carcinogenic nitrosamines. The survey of ammoniacal and albuminoid nitrogen, nitrite and nitrate in groundwater supplies as regards the extent of the contamination they cause and discussion of the drinking water regulation regarding nitrogen compounds. MATERIAL AND METHOD: Samples collected predominantly in the Metropolitan Region of S. Paulo City was analysed for nitrogen compounds using colorimetric methods: N-NH3 and N-albuminoid by the Nessler method, nitrite by diazoted sulfanilamide with N-(1-naphthyl)-ethylenediamine, and nitrate by reaction with phenoldisuplhonic acid. RESULTS: Federal and S. Paulo State drinking water regulations, respectively, Portaria 36/90 and Decreto n degree 12.486, were applied to interpret the results obtained. Of the 607 samples analysed. 15% of them had at least one of the concentrations of nitrogen compounds exceeding the maximum contaminant level (MCL) of the S. Paulo State Regulation. Otherwise, as regards the Federal Regulation, only 4% of the samples exceeded the MCL requirement for nitrate. CONCLUSION: In federal drinking water regulation only MCL for nitrate is reported. Otherwise, S. Paulo State regulation requirements report MCLs for all the compounds that have been analysed in this work. The observed results showed that concentrations of ammonia and albuminoid nitrogen, and nitrite, as well as nitrate, gave rise to water of inadequate quality, further they may have adverse effects on human health. The inclusion of nitrogen compounds other than nitrate in federal regulation is recommended.

Ammonia↗
PubMed2006

Biodegradability of nitrogenous compounds under anaerobic conditions and its estimation.

The anaerobic biodegradability of 23 nitrogenous compounds, including nitrogenous heterocyclic compounds and aliphatic amines, was tested and assessed in integration. These nitrogenous compounds were classified into readily, partially, and poorly biodegradable compounds after calculation of their integrated assessment indices (IAIs), Rules for anaerobic biodegradation of these compounds were also drawn. Stepwise regression and backpropagation artificial neural network (BP-ANN) methods were applied to establish quantitative structure-biodegradability relationships (QSBRs) based on the assessment results. In QSBR models, three molecular structure descriptors-second-order molecular connectivity index (2chi(V3)chi(v)p), and energy of the highest occupied molecular orbital (EHOMO)--were included. After analysis of the sensitivity of variables in QSBR models, it was found that the key molecular structure descriptor affecting anaerobic biodegradability of nitrogenous compounds is EHOMO, which is directly proportional to the anaerobic biodegradability of nitrogenous compounds.

Anaerobiosis↗
PubMed2004

[Study on distribution of nitrogen compounds in catalytic diesel oil by gas chromatography-atomic emission detector].

The method for the separation and determination of nitrogen compounds in a typical catalytic diesel oil by gas chromatography-atomic emission detector (GC-AED) was established. Seventy-three nitrogen compounds (including aniline, alkyl anilines, quinoline, indole, alkyl indole, carbazole, alkyl carbazole) in the catalytic diesel oil were qualified based on the retention times of some pure nitrogen compounds and the retention indices of nitrogen compounds. Effects of pressures of various reagent gases on peak area of main nitrogen compounds in diesel oil were examined as well. The pressures of reagent gases were optimized. Retention indices of different nitrogen compounds under temperature programmed condition were calculated. Reproducibilities of peak areas of main nitrogen compounds in the catalytic diesel oil were no more than 8.0%. The detection limit for nitrogen was 1.0 mg/L under specific conditions. The linear range was 2.0 - 600 mg/L for each nitrogen compound and correlation coefficient was greater than 0.998. The method can be successfully applied in the determination of nitrogen compounds in different catalytic diesel oils.

Aniline Compounds↗
PubMed1985

Renal excretion of nitrogenous compounds in vertebrates.

The renal excretion of nitrogenous compounds plays an important role not only in the elimination of nitrogen end-products but also in regulating the acid-base and osmotic balance of body fluids. The major nitrogenous compounds excreted by the vertebrate kidney are ammonia, urea and uric acid. The present review addresses the renal excretion of these compounds and, in addition, the amino acid taurine. The functions of excretion; the mechanisms of excretion including renal metabolism, renal handling (secretion, reabsorption, and filtration), and transepithelial transport processes; and the factors regulating these mechanisms are discussed. Renal nitrogen excretion among the vertebrate classes from fish to mammals is compared.

Ammonia↗
PubMedDate not supplied

Secretion of nitrogenous compounds in the small intestine of pigs.

Secretion of nitrogenous compounds in the small intestine of pigs. Acta Physiol. Pol., 1979, 30 (2): 319--326. The study was performed on pigs weighting 50 to 75 kg with temporarily isolated loops of one of the three parts of the small intestine: proximal, middle and terminal. For measurement of intestinal secretion the isolated loops were perfused with N-free solutions and the effluent was collected and analyzed. On a protein diet, under conditions of an isotonic osmotic pressure of the solution, secretion of nitrogen compounds in the upper part was twice that in the lower part of the small intestine, 0.97 against 0.48 g N/m/24 h. A hypertonic pressure increased secretion of N into the intestinal lumen. On a protein-free diet secretion of nitrogen compounds was markedly decreased. Soluble N amounted to about 90% of total N and alpha-amino-N to 50 to 79% of soluble N. Free amino acids made up about 65% and protein 33% of the total alpha-amino-N. There was a large proportion of threonine, 6.0--6.3%, and lysine, 8.0--8.7% in the total amino acids secreted into the intestine.

Animals↗
PubMed2005

[Effects of different nitrogenous compounds on growth and nodulation of Abrus cantoniensis].

OBJECTIVE: The research aimed at the effects of different nitrogenous compounds on growth and nodulation of Abrus cantoniensis. METHOD: After the seedlings of the herb were inoculated with rhizobia in potted culture, they were supplied with nutrition solutions which contained the three nitrogenous compounds, KNO3, NH4NO3, (NH4)2SO4 of different nitrogen concentration. The growth and nodulation of seedlings was determined after 70 days. RESULT: Different nitrogenous compounds were able to enhance the vegetable growth of seedlings variously. The effect of (NH4)2SO4 and NH4NO3 on growth was better than that of KNO3. Seedlings nodulation was obviously inhibited by these nitrogenous compounds. Their inhibitory effects ranked NH4NO3 > (NH4)2SO4 > KNO3. The treatments of KNO3 and the lower concentration treatments of NH4NO3 and (NH4)2 SO4 didn't inhibit the nodulation of seedlings, but the higher concentration treatment of NH4NO3 and (NH4)2SO4 severely inhibited nodulation or even made a no formation of nodule. CONCLUSION: The results showed that ammonium nitrogen the higher inhibitory ability to the nodulation of seedlings of A. cantoniensis than nitrate nitrogen. Therefore, the application of ammonium nitrogen fertilizer should be controlled in culture of the herb, which is in favor of increasing the function of biological nitrogen fixation and the quality of the medicinal materials of A. cantoniensis.

Abrus↗
PubMed2006

Nitrogen compounds in the apoplastic sap of sugarcane stem: some implications in the association with endophytes.

Several nitrogen compounds were identified and quantified in the apoplastic and symplastic sap of sugarcane stems. The sap of stems was composed mainly of soluble sugars, which constituted 95% of the total organic compounds detected. Sap also contained nitrogen compounds, with amino acids (50-70% of N) and proteins (20-30% of N), being the main nitrogenous substances, as well as inorganic forms as ammonium, nitrite and nitrate, in low concentrations (<20% of N). Serine, proline, alanine and aspartic acid together represented around 60% of the amino acids of the sap of both field grown and high nitrogen fertilized plants, and non-nitrogen fertilized plants inoculated with Gluconacetobacter diazotrophicus. The total amino acid content of apoplastic sap was six to nine times lower in non-nitrogen fertilized plants than in fertilized ones. The possible roles of these substances to regulate endophytic associations with sugarcane are also discussed.

Gluconacetobacter↗
PubMed1976

Electrochemical properties of polycyclic compounds studied by the polarographic method in anhydrous systems. III. Polarographic reduction potentials of carcinogenic nitrogen compounds in dimethylsulfoxide.

The polarographic reduction of a series carcinogenic and noncarcinogenic polycyclic nitrogen compounds in anhydrous dimethylsulfoxide containing tetrabuthylammonium perchlorate as supporting electrolyte has been studied. The obtained results were compared with the number or with the position of nitrogen atoms in the molecules and with their carcinogenic activity. The values of half-waves potentials generally confirmed the mechanism proposed for the reduction of aromatic polycyclic carcinogenic hydrocarbons based on the polarographic experiments in dimethylsulfoxide. Agreement of the obtained results with the data reported by polarographic study in anhydrous dimethylformamide indicates, that the polarographic behavior of polycyclic nitrogen compounds in dimethylsulfoxide is very similar.

Acridines↗
PubMed1975

Electrochemical properties of polycyclic compounds studied by the polarographic method in anhydrous systems. II. Polarographic study of carcinogenic nitrogen compounds in dimethylformamide and comparison of half-wave potentials with quantum-chemical calculations of molecular orbitals.

Reduction of half-wave potentials and the mechanism of reduction of 20 polycyclic nitrogen compounds were studied on a dropping-mercury electrode in anhydrous dimethylformamide using tetrabuthylammonium perchlorate as the supporting electrolyte. The measured values of the reducing half-wave potentials of the polycyclic aza-compounds were compared in view of their carcinogenic activity with parental carcinogenic polycyclic hydrocarbons. Electrochemical measurements have confirmed that the size of the shift in reducing potentials towards the more positive values and the decline of the carcinogenic activity generally depend on the number and position of the nitrogen atoms in the molecule of the polycyclic nitrogen compound under study. At the same time, the experimental electrochemical measurements were matched with the results of the quantum-chemical calculations of the molecular orbitals and this showed a good agreement to exist between the values of reducing half-wave potentials obtained by experimental measurement and by calculation.

Aza Compounds↗
PubMed2003

Utilization of Folin-Ciocalteu phenol reagent for the detection of certain nitrogen compounds.

To determine in more detail the reaction of Folin-Ciocalteu phenol reagent with nitrogen compounds, a number of hydroxylamine-related compounds and a large number of guanidine-containing compounds were tested. In general, guanidine compounds did not react strongly unless they were hydroxyamino or hydrazino derivatives. The non-hydroxyamino paralytic shellfish poison saxitoxin, however, reacted to a significant extent. This may be due to the presence of a five-membered ring structure and its analogy to 2-aminopurines, which react strongly. A number of simpler amines were also tested. Tertiary aliphatic amines, but not primary, secondary, or quaternary amines, reacted strongly with the reagent. Primary, secondary, and tertiary aromatic amines all reacted strongly with the reagent. Reactivity was extended to pyrroles and indole derivatives but not to imidazole and benzimidazole derivatives. Defining the reactivity of Folin-Ciocalteau phenol reagent with nitrogen compounds extends the usefulness of the reagent for the detection and determination of certain nitrogen compounds in basic extracts by colorimetric means and by thin-layer chromatography.

Amides↗
PubMed1997

Novel principles in the microbial conversion of nitrogen compounds.

Some aspects of inorganic nitrogen conversion by microorganisms like N2O emission and hydroxylamine metabolism studied by Beijerinck and Kluyver, founders of the Delft School of Microbiology, are still actual today. In the Kluyver Laboratory for Biotechnology, microbial conversion of nitrogen compounds is still a central research theme. In recent years a range of new microbial processes and process technological applications have been studied. This paper gives a review of these developments including, aerobic denitrification, anaerobic ammonium oxidation, heterotrophic nitrification, and formation of intermediates (NO2-, NO, N2O), as well as the way these processes are controlled at the genetic and enzyme level.

Aerobiosis↗
PubMed1993

[Nitrogen compounds and their role in the contamination of the environment].

Nitrogen compounds occur in excess in the air, water, soil and food, which unfavourably affects human's health, causing a number of diseases. Toxic effect of nitrates and nitrites ought to be mentioned here in the first place. Nitrates and nitrites cause intoxications, specially of infants and of children, manifesting themselves by methemoglobinemia, anaemia and decreased content of vitamin A in the liver. Besides, nitrates and nitrites participate in the formation of strong nitrogen carcinogenic compounds, which may lead to stomach cancer. Due to big harmfulness of nitrogen compounds one should strive after lowering, minimizing their presence in the environment.

Anemia↗
PubMed1962

Nitrogenous compounds in germination and postgerminative development of Bacillus megaterium spores.

Levinson, Hillel S. (Quartermaster Research and Engineering Center, Natick, Mass.) and Mildred T. Hyatt. Nitrogenous compounds in germination and postgerminative development of Bacillus megaterium spores. J. Bacteriol. 83:1224-1230. 1962.-Of the 48 inorganic and organic nitrogenous compounds tested, only l-alanine, glucosamine, and N-acetylglucosamine promote germination of unheated spores of Bacillus megaterium. Heated spores also germinate in nitrate, nitrite, l-cysteine, dl-isoleucine, l-leucine, dl-methionine, dl-norleucine, l-proline and l-valine.A source of nitrogen is required for postgerminative development, but nitrogenous compounds which effect germination do not necessarily support postgerminative development. Nitrogenous compounds which support postgerminative development include (NH(4))(2)SO(4), nitrates, d-alanine, l-alanine, l-arginine, l-asparagine, l-aspartic and l-glutamic acids, glutamine, l-proline, adenine, adenosine, and guanosine. Oxygen consumption rates during postgerminative development are different with different nitrogen sources, and these rates, in general, reflect the extent of postgerminative development. Utilization of amino and ammonium nitrogen during postgerminative development was followed, and the concentration requirements were determined (ca 10 mm for at least one cell division of 5 x 10(8) spores). Inhibitor studies on postgerminative development are included.

Alanine↗