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Mawaddah, Aida, Roto Roto e Adhitasari Suratman. "PENGARUH PENAMBAHAN UREA TERHADAP PENINGKATAN PENCEMARAN NITRIT DAN NITRAT DALAM TANAH (Influence of Addition of Urea to Increased Pollution of Nitrite and Nitrate in The Soil)". Jurnal Manusia dan Lingkungan 23, n. 3 (27 febbraio 2017): 360. http://dx.doi.org/10.22146/jml.22473.
Testo completoAbstract (sommario):
ABSTRAKNitrat dan nitrit merupakan sumber nitrogen bagi tanaman. Nitrogen sangat diperlukan tanaman untuk pertumbuhan dan perkembangan. Bentuk-bentuk nitrogen di lingkungan mengalami transformasi sebagai bagian dari siklus nitrogen seperti nitrifikasi dan denitrifikasi. Apabila kadar nitrogen dalam tanah rendah, maka urea digunakan sebagai sumber nitrogen. Perubahan urea menjadi nitrit atau nitrat pada beberapa sampel tanah perlu diketahui. Kadar nitrit dan nitrat yang tinggi dapat meningkatkan pencemaran di dalam tanah. Sampel tanah yang digunakan dalam penelitian ini adalah tanah pasir, tanah sawah, tanah pupuk kompos dan tanah pupuk kandang. Analisis nitrit dan nitrat dilakukan dengan menggunakan pereaksi asam p-amino benzoat (PABA) yang dikopling dengan N-naftiletilendiamin (NEDA) dan reduktor spongy cadmium. Sebelum digunakan untuk analisis nitrit dan nitrat, metode divalidasi terlebih dahulu. Hasil validasi metode analisis nitrit dan nitrat dengan pereaksi PABA/NEDA menunjukkan persentase perolehan kembali masing-masing antara 87,15–100,8% untuk nitrit dan 88,16–105,7% untuk nitrat. Setelah ditambah urea sebesar 0,66 g.kg-1 ke dalam tanah, konsentrasi nitrit dan nitrat pada semua sampel tanah mengalami peningkatan. Dari penelitian ini diketahui bahwa peningkatan kadar nitrit dan nitrat setelah ditambahkan urea sangat dipengaruhi oleh kondisi tanah. ABSTRACTNitrate and nitrite were sources of nitrogen for plants. Nitrogen is indispensable for the growth and development of plants. The forms of nitrogen in the environment undergoes a transformation as part of the nitrogen cycle like nitrification and denitrification. If nitrogen level in the soil is low, urea is used as a source of nitrogen. Changes of urea into nitrite or nitrate in some of soil samples need to be known. The levels of nitrite and nitrate are high can increase pollution in the soil. Some of soil samples which is used in this research were sandy soil, paddy soil, compost soil and manure soil. Analysis of nitrite and nitrate were conducted by using a reagent p-amino benzoic acid (PABA) / N-napthylethylenediamine (NEDA) and spongy cadmium as reductor. Before being used for the analysis of nitrite and nitrate, this method was validated first. The results of validation of nitrite and nitrate analysis method by using a reagents PABA / NEDA showed the percent recovery were respectively 87.15-100.8% for nitrite and 88.16-105.7% for nitrate. After the addition of 0.66 g.kg-1 urea into the soil, nitrite and nitrate concentration in all soil sample has increased. Based on this research was known that the increased levels of nitrite and nitrate after the addition of urea was influenced by soil condition.
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Bernardo, Patrícia, Luís Patarata, Jose M. Lorenzo e Maria João Fraqueza. "Nitrate Is Nitrate: The Status Quo of Using Nitrate through Vegetable Extracts in Meat Products". Foods 10, n. 12 (5 dicembre 2021): 3019. http://dx.doi.org/10.3390/foods10123019.
Testo completoAbstract (sommario):
Nitrate and nitrites are used to give the characteristic color to cured meat products and to preserve them. According to the scientific knowledge available at the moment, these compounds are approved as food additives based on a detailed ponderation between the potential risks and benefits. The controversy over nitrites has increased with the release of an IARC Monograph suggesting an association between colorectal cancer and dietary nitrite in processed meats. The trend in “clean label” products reinforced the concern of consumers about nitrates and nitrites in meat products. This review aims to explain the role of nitrates and nitrites used in meat products. The potential chemical hazards and health risks linked to the consumption of cured meat products are described. Different strategies aiming to replace synthetic nitrate and nitrite and obtain green-label meat products are summarized, discussing their impact on various potential hazards. In the light of the present knowledge, the use or not of nitrite is highly dependent on the ponderation of two main risks—the eventual formation of nitrosamines or the eventual out-growth of severe pathogens. It is evident that synthetic nitrite and nitrate alternatives must be researched, but always considering the equilibrium that is the safety of a meat product.
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KATSOULOS (Π. Δ. ΚΑΤΣΟΥΛΟΣ), P. D., N. PANOUSIS (Ν. ΠΑΝΟΥΣΗΣ) e H. KARATZIAS (Χ. ΚΑΡΑΤΖΙΑΣ). "Nitrate poisoning in ruminants". Journal of the Hellenic Veterinary Medical Society 55, n. 3 (6 dicembre 2017): 226. http://dx.doi.org/10.12681/jhvms.15098.
Testo completoAbstract (sommario):
This paper describes the nitrate - nitrite poisoning of ruminants. This disease is caused by the ingestion of large amount of nitrate salts, which are reduced in the rumen to nitrite ions. Nitrites, after their absorption, cause the formation of methemoglobin and, in turn, respiratory and circulatory distress. The aim of the treatment is to reduce the percentage of methemoglobin in blood and to stop the continuing production of nitrite ions in the rumen. For the prevention of the disease, avoidance of feedstuff rich in nitrates and improvement of the water quality, are suggested.
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Fogarasi, Erzsébet, Ibolya Fülöp, Emanuela Marcu e Mircea Dumitru Croitoru. "Presence of Nitrate and Nitrite in Well Water in Mureș County". Acta Medica Marisiensis 62, n. 1 (1 marzo 2016): 78–81. http://dx.doi.org/10.1515/amma-2015-0063.
Testo completoAbstract (sommario):
AbstractObjective: One of the most important sources of nitrite and nitrate anions, besides vegetables and meat products, is the drinking water. Presence of nitrite and nitrate in the water in higher concentrations than those set by EFSA (0.5 mg/l nitrite, 50 mg/l nitrate), may have toxicological significance. A quantitative determination of these ions in samples collected from several pleases from Mureș County was made. Methods: Ninety-seven well water samples were tested from 12 different places from Mureș County. We used a simple HPLC-UV ion pair method for the determination of nitrite and nitrate concentrations. Sensitivity of the method enables the quantification for concentrations far below the MCL value. Results: The highest amounts of nitrate and nitrite were measured in Sangeorgiu de Mureș and Cristești. Concentrations of nitrite and nitrate were exceeded in 4.12% and respectively 44.32% of the samples. Conclusions: The high amounts of nitrites and nitrates existing in well water go beyond the expected extent. This pollution can become a health risk since this water is used in human nutrition especially in child nourishment.
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Yulianti, Wina, Ima Kusumanti e Nurul Jannah. "Determination of Nitrite and Nitrate Level in Wastewater Discharge from Smoked Fish Industry". JURNAL SAINS NATURAL 12, n. 1 (27 gennaio 2022): 17. http://dx.doi.org/10.31938/jsn.v12i1.323.
Testo completoAbstract (sommario):
This research aimed to determine nitrite and nitrate contamination in wastewater discharge from the smoked fish industry around the fishpond area in Penatarsewu village, Sidoarjo East Java. Samples were taken from ten locations along The Alo River from September to November 2020. Nitrate and nitrite levels were determined by the Standard Method for Examination of Water and Wastewater 4500-NO2-B dan 4500-NO3-B. Nitrite formed a reddishpurple azo dye produced by coupling diazotized sulfanilamide with N-(1-naphthyl)-ethylene-diamine dihydrochloride after a visible spectrophotometer measured the complexes nitrite at wavelength 543 nm. Meanwhile, the Nitrate level was determined by ultraviolet spectrophotometer at a wavelength of 220 nm. The standard nitrite calibration curve was shown by the line equation y= 3,30361x-0,0028 and a determination coefficient of 0.9999. Whereas the standard nitrate was showed by the line equation y=0,2507x + 0,0067 and a determination coefficient 0,9996. The level of nitrate and nitrite in the sample ranged from 0.05-0.93mg / L 1,2-1,6 mg / L. According to a quality standard threshold value for nitrite and nitrate-based on the Government Regulation of the Republic of Indonesia (PPRI) No.82 2001 is 0,06mg/L and 10 mg/L, therefore it can be concluded that some samples are above the threshold value for nitrite level.Keywords: Alo River, nitate, nitrite, smoked fish, spectrophotometerPenentuan Kadar Nitrit dan Nitrat Pembuangan Limbah Cair Industri Ikan AsapABSTRAKPenelitian bertujuan untuk menentukan tingkat kontaminasi nitrat dan nitrit pada limbah industri ikan asap di sekitar kawasan tambak ikan asap di Desa Penatarsewu, Sidoardjo, Jawa Timur. Sampel diambil dari 10 titik di areal sekitar tambak sepanjang badan Sungai Alo pada bulan September sampai November 2020. Penentuan kadar nitrat dan nitrit mengacu pada Standard Methods for the Examination Water and Wastewater 4500-NO2-B dan 4500-NO3-B. Nitrit membentuk kompleks ungu kemerahan yang dihasilkan dari kopling sulfanilamida dengan N-(1-naptil)-etilena-diamina dihidroklorida kemudian kadarnya ditentukan dengan spektrofotometer sinar tampak pada panjang gelombang 543 nm. Kadar nitrat ditentukan menggunakan spektrofotometer ultraviolet pada panjang gelombang 220 nm. Hasil pengukuran standar nitrit menghasilkan persamaan garis y=3,30361x-0,0028 dengan koefesien determinasi 0,999 dan standar nitrat menghasilkan persamaan garis y=0,2507x+0,0067 dengan koefesien determinasi 0,9996. Kadar nitrit dan nitrat secara berturut-turut berkisar antara 0,05-0,93 mg/L dan 1,2-1,6 mg/L. Berdasarkan nilai ambang batas baku mutu nitrit dan nitrat berdasarkan Peraturan Pemerintah Republik Indonesia (PPRI) No.82 tahun 2001 adalah 0,06 mg/L dan 10 mg/L, maka dapat disimpulkan bahwa beberapa sampel mengandung kadar nitrit di atas ambang batas.Kata kunci : ikan asap, nitrat, nitrit, Sungai Alo, spektrofotometer
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McMullen, Sarah E., John A. Casanova, Lois K. Gross e Frank J. Schenck. "Ion Chromatographic Determination of Nitrate and Nitrite in Vegetable and Fruit Baby Foods". Journal of AOAC INTERNATIONAL 88, n. 6 (1 settembre 2005): 1793–96. http://dx.doi.org/10.1093/jaoac/88.6.1793.
Testo completoAbstract (sommario):
Abstract An ion chromatographic method was developed for the determination of nitrate and nitrite in vegetable and fruit baby foods. The introduction of nitrate or nitrite to food may be natural or artificial as a preservative. Because of the higher pH found in babies' stomachs, nitrate can act as a reservoir for the production of nitrite by nitrate-reducing bacteria that can be harbored in the intestinal tract. This problem does not exist in adults because of the lower pH of the adult stomach. Exposure to nitrite by infants can result in methemoglobinemia (blue baby syndrome). There are also indications that carcinogenic nitrosamines can be formed from nitrates at the higher pH. These gastric conditions disappear at approximately 6 months of age. In this method, nitrate and nitrite were separated on a hydroxide-selective anion exchange column using online electrolytically generated high-purity hydroxide eluant and detected using suppressed conductivity detection. Average recoveries of spiked nitrite residue ranged from 91 to 104% and spiked nitrate residue ranged from 87 to 104%. This method and the AOAC Official Method yield comparable results for samples containing incurred nitrate residue. In addition, this method eliminates the hazardous waste associated with the use of cadmium found in the AOAC Official Method.
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Drysdale, G. D., H. C. Kasan e F. Bux. "Assessment of denitrification by the ordinary heterotrophic organisms in an NDBEPR activated sludge sytem". Water Science and Technology 43, n. 1 (1 gennaio 2001): 147–54. http://dx.doi.org/10.2166/wst.2001.0036.
Testo completoAbstract (sommario):
The purpose of this study was to isolate and characterise the ordinary heterotrophic organisms (OHOs) present in a NDBEPR system in order to gain a better understanding of the organisms involved in denitrification as well as a more holistic and accurate evaluation of the OHO fraction attributable to denitrification in such a system. Heterotrophic bacteria were isolated from the pre- and secondary anoxic zones of the Darvill NDBEPR process and characterised according to their ability to reduce nitrates and/or nitrites under anoxic conditions. Results showed that the OHO fraction is more complex than currently accepted and, with respect to denitrification, can be more accurately subdivided into five functional groups, four of which interactively contribute to denitrification occurring in the system and one group that are non-denitrifying. These groups were defined as true denitrifiers (bacteria capable of both nitrate and nitrite reduction), incomplete denitrifiers (bacteria that reduced nitrates to nitrites with no further reduction of the nitrites produced), incomplete-nitrite reducers (bacteria capable of both nitrate and nitrite reduction, however, exhibiting severe inhibition of nitrite reduction by nitrates), exclusive nitrite reducers (bacteria only capable of reducing nitrites) and non-denitrifiers (bacteria not capable of nitrate or nitrite reduction).
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Gutyj, B., K. Leskiv, A. Shcherbatyy, V. Pritsak, V. Fedorovych, O. Fedorovych e V. Rusyn. "The influence of Metisevit on biochemical and morphological indicators of blood of piglets under nitrate loading". Regulatory Mechanisms in Biosystems 8, n. 3 (29 luglio 2017): 427–32. http://dx.doi.org/10.15421/021767.
Testo completoAbstract (sommario):
The article presents the results of research on the influence of the developed complex preparation Metisevit on the dynamics of morphological and biochemical blood indicators of piglets under nitrate loading. The research established that sodium nitrate intoxication causes disbalance of the physiological level of hematological indicators of the tested animals’ organisms. This was indicated by the manifestations of subclinical chronic nitrate-nitrite toxicosis: the increase in the level of nitrates, nitrites and methemoglobin in the blood. After prolonged feeding of the piglets with sodium nitrate at a dose of 0.3 g nitrate ion/kg, the concentration of nitrates and nitrites in the blood serum reached its maximum on the 60th day of the experiment. Also, the number of leukocytes and erythrocytes in the blood increased, and the activity of aspartate- and alanineaminotransferase in the blood serum increased. We rank the extent of liver intoxication with nitrates according to intensity of aminotransferase in the blood serum of the tested piglets. The normalization of morphological and biochemical indicators of blood of piglets under nitrate-nitrite intoxication requires usage of a preparation which contains vitamins, zeolites and antioxidants. If the fodder contains high doses of nitrates, 1.0 mg/kg dose of Metisevit is added to the fodder for preventing subclinical nitrate-nitrite toxicosis. Metisevit contains the following agents: phenozan acid, methionine, zeolite, selenium, vitamins E and C. The research conducted proved the feasibility of using Metisevit for preventing chronic nitrate-nitrite toxicosis in piglets. This preparation caused a decrease in the concentration of nitrates, nitrites and in the level of methemoglobin in the blood of piglets. Usage of Metisevit on piglets showed normalization of the number of erythrocytes and hemoglobin in the blood on the 10th day, and normalization of ASAT and ALAT on 30th and 90th days. The mechanism of Metisevit activity is connected with the direct contribution of its elements to the inhibition of the processes of absorbing metabolites which cause a toxic effect on the cell membranes of an animal’s organism. The absorbing activity of zeolite leads to decrease in concentration of agents which can be substrates for processes of peroxidation of lipids in the alimentary canal, and also to elimination of toxic pro-oxidant metabolites from the blood. This process occurs through osmosis and diffusion of these elements in the capillaries of microvilli of the small intestine and through their further fixation on sorbent granules.
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Carlsson, S., M. Govoni, N. P. Wiklund, E. Weitzberg e J. O. Lundberg. "In Vitro Evaluation of a New Treatment for Urinary Tract Infections Caused by Nitrate-Reducing Bacteria". Antimicrobial Agents and Chemotherapy 47, n. 12 (dicembre 2003): 3713–18. http://dx.doi.org/10.1128/aac.47.12.3713-3718.2003.
Testo completoAbstract (sommario):
ABSTRACT Dietary and endogenous nitrates are excreted in urine, and during infection with nitrate-reducing bacteria they are reduced to nitrite. At a low pH nitrite is converted to a variety of nitrogen oxides that are toxic to bacteria. We hypothesized that acidification of nitrite-rich infected urine would result in the killing of the nitrate-reducing bacteria. An Escherichia coli control strain and a mutant lacking nitrate reductase activity were preincubated in urine supplemented with sodium nitrate (0 to 10 mM) at pH 7.0. Then, the nitrite-containing bacterial culture was transferred (and diluted 1/10) to slightly acidic urine (pH 5 and 5.5) containing ascorbic acid (10 mM) and growth was monitored. The control strain produced nitrite in amounts related to the amount of nitrate added. This strain was killed when the culture was transferred to acidic urine. In contrast, the mutant that did not produce nitrite retained full viability. When control bacteria were grown in acidic urine with nitrate and ascorbic acid present from the start of the experiment, no inhibition of growth was noted. The MICs and minimal bactericidal concentrations of sodium nitrite-ascorbic acid in acidic urine were comparable to those of conventional antibiotics. Preincubation of nitrate-reducing E. coli in nitrate-rich urine leads to the accumulation of nitrite. Subsequent acidification of the urine results in generation of nitrogen oxides that are bactericidal. Killing, however, requires a sequential procedure in which the bacteria are first allowed to grow in a nitrate-rich neutral environment, later followed by acidification. We speculate that ingestion of nitrate followed some hours later by acidification of urine could be a new therapeutic strategy for the treatment of urinary tract infections.
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Jones, Trevor. "Nitrate/nitrite". In Practice 15, n. 3 (maggio 1993): 146–47. http://dx.doi.org/10.1136/inpract.15.3.146.
Testo completo
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Luetic, Sanja, Zlatka Knezovic, Katarina Jurcic, Zrinka Majic, Ksenija Tripkovic e Davorka Sutlovic. "Leafy Vegetable Nitrite and Nitrate Content: Potential Health Effects". Foods 12, n. 8 (15 aprile 2023): 1655. http://dx.doi.org/10.3390/foods12081655.
Testo completoAbstract (sommario):
The aim of this research was to determine the concentrations of nitrates and nitrites in different types of vegetables that are commonly represented in the diet of the inhabitants of Split and Dalmatian County. Therefore, using the method of random selection, there were 96 samples of different vegetables. The determination of the nitrate and nitrite concentrations was carried out by high-pressure liquid chromatography (HPLC) with a diode array detector (DAD). The nitrate concentrations in the range 2.1–4526.3 mg kg−1 were found in 92.7% of the analyzed samples. The highest nitrate values were found in rucola (Eruca sativa L.) followed by Swiss chard (Beta vulgaris L.). In 36.5% of the leafy vegetables intended for consumption without prior heat treatment, nitrite was found in the range of 3.3–537.9 mg kg−1. The high levels of nitrite in the vegetables intended for fresh consumption and the high nitrate values in Swiss chard indicate the need to establish maximum nitrite limits in vegetables, as well as the broadening of legal nitrate limits to wide varieties of vegetables.
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Said Abasse, Kassim, Eno E. Essien, Muhammad Abbas, Xiaojin Yu, Weihua Xie, Jinfang Sun, Laboni Akter e Andre Cote. "Association between Dietary Nitrate, Nitrite Intake, and Site-Specific Cancer Risk: A Systematic Review and Meta-Analysis". Nutrients 14, n. 3 (4 febbraio 2022): 666. http://dx.doi.org/10.3390/nu14030666.
Testo completoAbstract (sommario):
Background: People consume nitrates, nitrites, nitrosamines, and NOCs compounds primarily through processed food. Many studies have yielded inconclusive results regarding the association between cancer and dietary intakes of nitrates and nitrites. This study aimed to quantify these associations across the reported literature thus far. Methods: We performed a systematic review following PRISMA and MOOSE guidelines. A literature search was performed using Web of Science, Embase, PubMed, the Cochrane library, and google scholar up to January 2020. STATA version 12.0 was used to conduct meta-regression and a two-stage meta-analysis. Results: A total of 41 articles with 13 different cancer sites were used for analysis. Of these 13 cancer types/sites, meta-regression analysis showed that bladder and stomach cancer risk was greater, and that pancreatic cancer risk was lower with increasing nitrite intakes. Kidney and bladder cancer risk were both lower with increasing nitrate intakes. When comparing highest to lowest (reference) categories of intake, meta-analysis of studies showed that high nitrate intake was associated with an increased risk of thyroid cancer (OR = 1.40, 95% CI: 1.02, 1.77). When pooling all intake categories and comparing against the lowest (reference) category, higher nitrite intake was associated with an increased risk of glioma (OR = 1.12, 95% CI: 1.03, 1.22). No other associations between cancer risk and dietary intakes of nitrates or nitrites were observed. Conclusion: This study showed varied associations between site-specific cancer risks and dietary intakes of nitrate and nitrite. Glioma, bladder, and stomach cancer risks were higher and pancreatic cancer risk was lower with higher nitrite intakes, and thyroid cancer risk was higher and kidney cancer risk lower with higher nitrate intakes. These data suggest type- and site-specific effects of cancer risk, including protective effects, from dietary intakes of nitrate and nitrite.
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LIN, KUEN-SONG, NI-BIN CHANG e TIEN-DENG CHUANG. "DECONTAMINATION OF NITRATES AND NITRITES IN WASTEWATER BY ZERO-VALENT IRON NANOPARTICLES". Nano 03, n. 04 (agosto 2008): 291–95. http://dx.doi.org/10.1142/s1793292008001283.
Testo completoAbstract (sommario):
The chemical reduction of nitrate or nitrite species by zero-valent iron nanoparticle (ZVIN) in aqueous solution and related reaction kinetics or mechanisms using fine structure characterization were investigated. Experimentally, ZVIN of this study was prepared by borohydride reduction method at room temperature. The morphology of as-synthesized ZVIN shows that the nearly ball and ultrafine particles ranged of 20–50 nm were observed with FE-SEM analysis. The kinetic model of nitrites or nitrates reductive reaction by ZVIN is proposed as a pseudo-first-order kinetic equation. The nitrite and nitrate removal efficiencies using ZVIN were found 65–83% and 51–68%, respectively, based on three different initial concentrations. By using XRD patterns, the quantitative relationship between nitrite and Fe(III) or Fe(II) becomes similar to the one between nitrate and Fe(III) in the ZVIN study. The possible reason is linked with a faster nitrite reduction by ZVIN. In fact, the occurrence of the relative faster nitrite reductive reaction suggested that the passivation of the ZVIN have a significant contribution to iron corrosion. The XANES spectra show that the nitrites or nitrates reduce to N 2 while oxidizing the ZVIN to Fe 2 O 3 or Fe 3 O 4 electrochemically. It is also very clear that decontamination of nitrate or nitrite species in groundwater via the in-situ remediation with a ZVIN permeable reactive barrier would be environmentally attractive.
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Muhaemin, Moh, Dewi Alfya Rahmadita, Joko Suwiryono e Henky Mayaguezz. "Variabilitas Konsentrasi dan Sebaran N-anorganik (Amonia, Nitrit, dan Nitrat) Terlarut di Perairan Kalianda dan Perairan Anyer-Panimbang". Journal of Marine Research 12, n. 4 (8 ottobre 2023): 237–45. http://dx.doi.org/10.14710/jmr.v12i4.38566.
Testo completoAbstract (sommario):
N-anorganik yang berdekatan dengan hatchery atau tambak, permukiman warga, dan muara sungai diduga bersebaran berbeda di perairan teluk dan perairan selat. Penelitian bertujuan untuk menganalisis sebaran horizontal, tingkat kesesuaiannya terhadap baku mutu, serta menganalisis konektivitas antara konsentrasi amonia, nitrit, dan nitrat dengan parameter fisika dan kimia non nitrogen di perairan Kalianda (perairan Teluk) dan perairan Anyer-Panimbang (menghadap Selat Sunda). Penelitian dilaksanakan di perairan Kalianda dan perairan Anyer-Panimbang pada bulan September dan Oktober 2022. Konsentrasi amonia, nitrit, dan nitrat tersebut dianalisis, dibuat sebaran horizontalnya, serta dianalisis konektivitas antar variabelnya dengan Principal Component Analysis (PCA). Hasil penelitian menunjukkan bahwa sebaran horizontal konsentrasi amonia yang cenderung tinggi didominasi oleh lokasi muara sungai di perairan Kalianda, sebaran horizontal konsentrasi nitrit yang cenderung tinggi didominasi oleh lokasi yang berdekatan dengan hatchery atau tambak di perairan Kalianda dan perairan Anyer-Panimbang, dan sebaran horizontal konsentrasi nitrat yang cenderung tinggi didominasi oleh lokasi dekat permukiman warga di perairan Anyer-Panimbang. Secara dominan, konsentrasi amonia dan nitrit di perairan Kalianda dan perairan Anyer-Panimbang di bawah baku mutu, kecuali konsentrasi nitrit di Pantai Sambolo pada perairan Anyer-Panimbang yang melebihi baku mutu, serta seluruh konsentrasi nitrat di perairan Kalianda dan perairan Anyer-Panimbang di atas baku mutu. Konsentrasi amonia, nitrit, dan nitrat berkorelasi positif dengan parameter suhu, namun berkorelasi negatif dengan parameter DO dan salinitas. Inorganic nitrogen potential sources such as hatcheries/ponds, residential areas, and estuaries may affect loading capacity of n-inorganic in bay and strait waters. The concentration distributions of ammonia, nitrite, and nitrate in the bay and strait waters may have different values. The study aims was to analyze the horizontal distribution and suitability of ammonia, nitrite, and nitrate concentrations with quality standard, and to analize the intercorrelation between the concentrations of ammonia, nitrite, and nitrate with non nitrogen physical and chemical parameters in Kalianda waters and Anyer-Panimbang waters. The study was carried out in specific location of Kalianda and Anyer-Panimbang waters in September and October 2022. The concentrations of ammonia, nitrite, and nitrate were analyzed for their concentration distributions and analyzed using the Principal Component Analysis (PCA) method. The results showed that the horizontal distribution of ammonia concentrations was dominated by location of estuary in Kalianda waters, the horizontal distribution of nitrite concentrations was dominated by location near hatchery or pond in Kalianda waters and Anyer-Panimbang waters, and the horizontal distribution of nitrate concentrations was dominated by location near residential area in Anyer-Panimbang waters. Most of ammonia and nitrite concentrations in Kalianda waters and Anyer-Panimbang waters were below of quality standards, except for nitrite concentration at Sambolo Beach in Anyer-Panimbang waters which exceed the quality standard, and all nitrate concentrations in Kalianda waters and Anyer-Panimbang waters above the quality standard. The intercorrelation between the concentrations of ammonia, nitrite, and nitrate were positively correlated with water temperature, but those have negative correlated with DO and salinity.
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M. Heavenlin, I. Kanitha Christy e C.Gunasekaran. "DETECTION OF NITRATE ACCUMULATION IN FORAGE CROP (SORGHUM) OF SALEM DISTRICT". EPH - International Journal of Science And Engineering 1, n. 1 (27 marzo 2015): 26–28. http://dx.doi.org/10.53555/eijse.v1i1.21.
Testo completoAbstract (sommario):
Nitrates transpire in drought conditions in poor pastures and reduce forage yields. Producers use barren or low producing grain crops as replacement forage. These forages may be toxic due to high nitrate level accumulation from water. Nitrate analysis from Panamarathupatti zone of Salem district revealed high level of prevalence and hence veterinarians and livestock owners should be aware of the prevailing nitrate contents in forage which would decline the health of livestock.
Nitrate, Sorghum forage and livestock health. Nitrates in forages do not in themselves cause the poisoning of farm animals. Instead, they are converted to nitrites in the animal, and nitrites are toxic. When the temperature is high and moisture is adequate, plants may undergo a process called photorespiration. Photorespiration produces carbon dioxide rather than assimilating carbon into energy building blocks (i.e., sugars, carbohydrates, etc.). This may cause nitrates to accumulate in cows and sheep this conversion takes place in the rumen (paunch). If forage contains too much nitrate the animals cannot complete the conversion and nitrite levels build up and the animal suffers from a type of asphyxiation.
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Ulfah, Maria, Octavia Devi Puspita Sari e Muhammad Syaipul Hayat. "Bioremediation of Nitrate and Nitrite on the Rehabilitation of Contaminated Jatibarang Landfill and the Application of Calla Lily". Jurnal Penelitian Pendidikan IPA 10, n. 7 (30 luglio 2024): 4172–78. http://dx.doi.org/10.29303/jppipa.v10i7.8095.
Testo completoAbstract (sommario):
Currently, waste processing is a problem because it is not yet optimal. The high content of nitrates and nitrites results in environmental pollution which can cause losses because it affects health and biodiversity. One effort to control environmental pollution is phytoremediation using calla lily (Zantedeschia aethiopica) to remediate nitrate and nitrite levels that do not comply with quality standards so that pollution can be minimized. This research aims to determine the effectiveness of calla lily as a phytoremediation agent for landfill leachate nitrate and nitrite. This experimental research method uses a Completely Randomized Design (CRD) which consists of three treatment levels, namely variations in calla lily biomass of 0 grams, 200 grams, and 400 grams with 3 repetitions, and measurements of nitrate and nitrite levels are carried out on day 1, day 2. 3, and 7. The results showed that the most optimal percentage reduction in leachate nitrate levels occurred in the P1 on the day 7, namely 45%, while the most optimal percentage reduction in leachate nitrite levels occurred in the P1 on the day 7, it was 53%. The final nitrate content after the research was in accordance with the quality standards of PP RI No.22 of 2021, while the leachate nitrite content after treatment still exceeded the quality standards of PP RI No.22 of 2021. Calla lily has the potential to reduce nitrate and nitrite levels due to landfill leachate pollution.
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Ngibad, Khoirul. "PENGUKURAN KADAR FLUORIDA, NITRAT, DAN NITRIT DALAM AIR SUMUR MENGGUNAKAN METODE SPEKTROFOTOMETRI UV-VIS". CHEDS: Journal of Chemistry, Education, and Science 7, n. 1 (10 giugno 2023): 51–58. http://dx.doi.org/10.30743/cheds.v7i1.6791.
Testo completoAbstract (sommario):
Fluoride is beneficial to human health but its excess or lack of water is harmful to humans as well as the environment and can cause fluorosis. On the other hand, the intake of high concentrations of nitrates and nitrites can cause methemoglobinemia. This study aims to analyze fluoride, nitrate, and nitrite levels in well water around Taman District, Sidoarjo Regency. The method used in this study was UV-Vis spectrophotometry at a wavelength of 570 nm for the measurement of fluoride levels and a wavelength of 543 nm for the measurement of nitrate and nitrite cadaver. The results showed that the well water around the Taman District of Sidoarjo Regency had fluoride, nitrate, and nitrite levels in the sample of 0.23 each; 0,73; and 0.019 mg/L (well water A) and 0.18; 0,8; and 0.042 mg/L (well water B). The fluoride, nitrate, and nitrite levels still meet the quality standard (maximum level) of chemical parameters in the environmental health quality standard for water media for sanitary hygiene purposes.
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Saputra, Alfian Dony, Haeruddin Haeruddin e Niniek Widyorini. "EFEKTIVITAS KOMBINASI MIKROORGANISME DAN TUMBUHAN AIR Lemna minor SEBAGAI BIOREMEDIATOR DALAM MEREDUKSI SENYAWA AMONIAK, NITRIT, DAN NITRAT PADA LIMBAH PENCUCIAN IKAN". Management of Aquatic Resources Journal (MAQUARES) 5, n. 3 (20 dicembre 2016): 80–90. http://dx.doi.org/10.14710/marj.v5i3.14393.
Testo completoAbstract (sommario):
ABSTRAK Limbah pencucian ikan bersumber dari kegiatan pencucian bagian luar dan dalam tubuh ikan. Limbah pencucian ikan memiliki kandungan senyawa amoniak, nitrit, dan nitrat yang tinggi sehingga kemungkinan mempunyai efek negatif bagi lingkungan. Sebagian besar industri pengolahan ikan belum melakukan pengolahan limbah cairnya dengan baik. Bioremediasi merupakan metode biologi dengan memanfaatkan mikroorganisme dan tumbuhan air Lemna minor dalam pengolahan air limbah. Penelitian ini bertujuan untuk mengetahui efektivitas dan pengaruhdari kombinasi mikroorganisme dan Lemna minor dalam mereduksi senyawa amoniak, nitrit, dan nitrat pada limbah pencucian ikan. Metode penelitian yang digunakan adalah eksperimen skala laboratorium dimana wadah percobaan berisi limbah pencucian ikan dengan volume 1 Liter. Desain penelitian yang digunakan yaitu percobaan faktorial 3 x 3 dengan 2 faktor, sehingga terdapat 9 kombinasi perlakuan M1L10, M1L50, M1L100, M5L10, M5L50, M5L100, M10L10, M10L50, dan M10L100, dimana “M” faktor konsentrasi mikroorganisme (1 mL/L, 5 mL/L, 10 mL/L), sedangkan “L” faktor bobot biomassaLemna minor (0,0255 gr/cm2, 0,1273 gr/cm2 , 0,2546 gr/cm2). Variabel utama penelitian adalah amoniak, nitrit, dan nitrat yang didukung oleh temperatur, pH, dan oksigen terlarut. Analisis data dengan menggunakan analisis efektivitas, uji two way Anova, dan uji Beda Nyata Jujur. Hasil penelitian menunjukkan bahwa nilai efektivitas berkisar antara 40,85% - 74,03% (amoniak), 42,21% - 74,10% (nitrit), dan 3,19% - 34,65% (nitrat). Pengaruh interaksi kombinasi mikroorganisme dan Lemna minor yaitu terdapat pengaruh yang nyata dan efektif dalam mereduksi senyawa amoniak, nitrit, dan nitrat pada limbah pencucian ikan. Kata Kunci: Amoniak; Bioremediasi; Lemna minor; Limbah Pencucian Ikan; Mikroorganisme; Nitrat; Nitrit ABSTRACT Fish washery waste derived from washing inner and outer part of fish body.Fish washery waste containshigh ammonia, nitrite, and nitrate which may have negative effect for the environment.Most of the fish processing industry are not doing the processing of waste water properly yet. Bioremediation is a biological method by using microorganisms and aquatic plant Lemna minor in wastewater treatment. The aims of study is to determine the effectiveness anda effect of the use of microorganism and Lemna minor combination in effort to reduce ammonia, nitrite, and nitrate compound in fish washery waste. The method used is laboratory-scale experiments where the experimental containers containing fish washery waste with a volume of 1 Liter. 3 x 3 factorial with 2 factor method design were used, so there are nine treatment combinations of M1L10, M1L50, M1L100, M5L10, M5L50, M5L100, M10L10, M10L50, and M10L100, where "M" forconcentrationof microorganisms factor (1 mL/L, 5mL/L, 10 mL/L), while the "L" for biomass weight of Lemna minorfactor (0,0255 gr/cm2, 0,1273 gr/cm2 , 0,2546 gr/cm2). The main variable of this study are ammonia, nitrite, and nitrate supported by temperature, pH, and Dissolved Oxygen. The data was analyzed using effectiveness analysis, two way Anova, and Least Signifficant Difference methode. The results show that the concentration of ammonia, nitrite, and nitrate decreased after 96 hours for all treatmentscombination. The effectiveness value, ranged between 40.85% - 74.03% (ammonia), 42.21% - 74.10% (nitrite), and 3.19% - 34.65% (nitrate). There is a signifficant influence and effective in combination of microorganisms and Lemna minor to reduce ammonia, nitrite, and nitrate compound in fish washery waste. Keywords: Ammonia; Bioremediation; Lemna minor; Fish Washery Waste; Microorganism; Nitrate;Nitrite
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Hirose, Daisuke, e Tsuyoshi Taniguchi. "Aerobic radical multifunctionalization of alkenes using tert-butyl nitrite and water". Beilstein Journal of Organic Chemistry 9 (20 agosto 2013): 1713–17. http://dx.doi.org/10.3762/bjoc.9.196.
Testo completoAbstract (sommario):
Water induces a change in the product of radical multifunctionalization reactions of aliphatic alkenes involving an sp3 C–H functionalization by an 1,5-hydrogen shift using tert-butyl nitrite and molecular oxygen. The reaction without water, reported previously, gives nitrated γ-lactols, whereas the reaction in the presence of water produces 4-hydroxy-5-nitropentyl nitrate or 4-hydroxy-3-nitropentyl nitrate derivatives.
20
Schlagenhauf, Ulrich. "On the Role of Dietary Nitrate in the Maintenance of Systemic and Oral Health". Dentistry Journal 10, n. 5 (13 maggio 2022): 84. http://dx.doi.org/10.3390/dj10050084.
Testo completoAbstract (sommario):
The assessment of the significance of nitrates ingested with food has undergone a fundamental change in recent years after many controversial discussions. While for a long time, a diet as low in nitrates as possible was advocated on the basis of epidemiological data suggesting a cancer-promoting effect of nitrate-rich diets, more recent findings show that dietary nitrate, after its conversion to nitrite by nitrate-reducing bacteria of the oral microbiota, is an indispensable alternative source for the formation of nitric oxide (NO), which comprises a key element in the physiology of a variety of central body functions such as blood pressure control, defense against invading bacteria and maintenance of a eubiotic microbiota in the gut and oral cavity. This compact narrative review aims to present the evidence supported by clinical and in vitro studies on the ambivalent nature of dietary nitrates for general and oral health and to explain how the targeted adjuvant use of nitrate-rich diets could open new opportunities for a more cause-related control of caries and periodontal disease.
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Silvi, Monica Virgiana, Sri Redjeki e Ita Riniatsih. "Kandungan Nutrien di Sedimen pada Ekosistem Padang Lamun di Teluk Awur dan Pulau Panjang, Jepara". Journal of Marine Research 11, n. 3 (25 maggio 2022): 420–28. http://dx.doi.org/10.14710/jmr.v11i3.32219.
Testo completoAbstract (sommario):
Nutrien merupakan zat hara penting di perairan untuk menyokong proses pertumbuhan dan perkembangan potensi sumberdaya dari ekosistem laut. Nutrien nitrat dan fosfat secara alami merupakan zat hara yang berasal dari perairan itu sendiri melalui proses penguraian, pelapukan, dekomposisi tumbuhan dan buangan limbah daratan (domestik, industri, pertanian, perikanan dan sisa pakan). Nitrat dan fosfat berperan sebagai faktor pembatas pertumbuhan organisme dan kesuburan perairan. Sedimen merupakan tempat penyimpanan utama bahan organik dan mampu untuk mengikat senyawa seperti nitrat dan fosfat. Penelitian ini bertujuan untuk mengetahui kandungan nitrat dan fosfat pada sedimen di Teluk Awur dan Pulau Panjang Jepara. Pengambilan sampel sedimen pada penelitian ini dilakukan dengan menggunakan sedimen core, kemudian sedimen dianalisis kandungan nitrat dan fosfat dengan metoda spektrofotometri. Hasil dari penelitin ini yaitu kandungan nitrat di Teluk Awur berkisar 0,2128–0,6383 mg/l dan fosfat 0,48-0,1362 mg/l. Kandungan nitrat di Pulau Panjang berkisar 0,4681–3,9447 mg/l dan fosfat 0,0153–0,2138 mg/l. Nutrients are important nutrients in the waters because they can support the growth and development of the potential of marine ecosystem biological resources. Natural nitrate and phosphate are nutrients that come from the waters themselves through the process of decomposition, weathering, plant decomposition, and land waste disposal (domestic, industrial, agricultural, aquaculture, and feed residues). Nitrates and phosphates can act as limiting factors for organism growth and water fertility. Sediment is the main storage place for organic matter and is able to bind compounds such as nitrates and phosphates. This study aims to determine the content of nitrate and phosphate in sediments in Teluk Awur and Pulau Panjang, Jepara. sediment sampling in this study was carried out using a sediment core, then the sediment was analyzed for nitrate and phosphate content by spectrophotometric methods. The result of this research is that the nitrate content in Teluk Awur ranges from 0.2128–0.6383 mg/l and phosphate range from 0.048–0.1362 mg/l. The nitrate content in Panjang Island ranges from 0.4681–3.9447 mg/l and phosphate 0.0153–0.2138 mg/l.
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MOTTELET, S., A. FILALI, S. GUERIN-RECHDAOUI, V. ROCHER, S. AZIMI e A. PAUSS. "Mesure en ligne des concentrations d’ions nitrites et nitrates pour l’optimisation de la dénitrification et la réduction de la production de protoxyde d’azote". Techniques Sciences Méthodes, n. 6 (22 giugno 2020): 23–32. http://dx.doi.org/10.36904/tsm/202006023.
Testo completoAbstract (sommario):
Cette étude vise à évaluer la capacité d’une sonde à rayons ultraviolets (UV) à estimer simultanément les teneurs en nitrate et nitrite en sortie d’une unité de biofiltration en postdénitrification. L’estimation de ces deux espèces est compliquée du fait de la très grande similitude de leur spectre UV et de la présence d’autres molécules absorbantes dans l’UV. Celle-ci est pourtant indispensable au développement d’algorithmes de contrôle, seuls à même de garantir un résiduel en nitrite et nitrate conforme aux exigences de la directive cadre sur l’eau. La sonde WTW Nitra Vis 705 IQ NI a été calibrée puis validée en laboratoire sur un effluent réel dans une gamme de 0 à 3,5 mgN/L en nitrite. Elle a ensuite été installée en sortie d’une unité de biofiltration de la station de Seine Centre afin d’évaluer sa capacité à prédire les dynamiques de concentrations en nitrites et nitrates. Le suivi a montré que, moyennant une calibration multipoint pour le nitrite et multilinéaire pour le nitrate, il est possible de mesurer simultanément et dynamiquement le nitrite dans la gamme 0-5 mgN/L avec une précision de 0,2 mgN/L et le nitrate dans la gamme 0-10 mgN/L avec une précision de 0,3 à 0,4 mgN/L. Les mesures en ligne de protoxyde d’azote dissous, effectuées sur site au moyen de sondes ampérométriques, montrent que la dynamique est similaire à celle du nitrite en fonction du ratio DBO/N-NO3– appliqué, et que l’on obtient une meilleure corrélation du protoxyde d’azote avec le nitrite (R2 = 0,72) comparativement à la somme nitrite + nitrate (R2 = 0,52).
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KILIÇ, Arzu, Serden BAŞAK, Kevser CIRIK, Dilek ÖZGÜN, Dilek AKMAN, Şebnem ÖZDEMİR e ÖZER ÇINAR. "İçme Sularından Nitrat Gideriminde İkincil Kirleticilerin Denitrifikasyona Etkisi / The Effect of Co-Contaminant on Denitrification Removal of Nitrate in Drinking Water". Journal of History Culture and Art Research 1, n. 4 (28 gennaio 2013): 475. http://dx.doi.org/10.7596/taksad.v1i4.83.
Testo completoAbstract (sommario):
Son yıllarda tarımda bilinçsizce kullanılan azotlu gübreler ve arıtılmadan deşarj edilen atıksular yeraltısularında nitrat kirliliğinin artmasına neden olmuştur. Geçmişteki çalışmalar birçok ülkede yeraltısuyunda nitrat konsantrasyonunun hızında artış olduğunu göstermektedir. Ülkemizde yeraltısularının ve kullanılabilir içme suyu kaynaklarının kirlilik haritası henüz çıkarılmış değildir. Yapılan bölgesel çalışmalarda ülkemizdeki kaynakların da hızlı bir şekilde kirlendiği görülmektedir. Şanlıurfa, Harran ovasında, Akdeniz kıyı bölgelerinde yapılan çalışmalarda kuyularda nitrat konsantrasyonun yükseldiği belirtilmektedir. İçme sularının nitratla kirlenmesinin yanı sıra artan su tüketimi, bilinçsiz gübreleme ve tarım ilaçlarının kullanımı içme suyu kaynaklarında nitratla birlikte ikincil kirleticilerinde ortaya çıkmasına neden olmuştur. Son zamanlarda nitratla kirlenmiş sularda arsenik, pestisit, perklorat, kromat, gibi insan sağlığı için tehlikeli ikincil kirleticilere rastlanmaktadır. Nitrat giderimi için kullanılan uygulanabilirliği zor ve pahalı yöntemlerin yanında biyolojik arıtım yöntemleri daha ekonomik ve uygulanabilir olmaları nedeniyle son yıllarda araştırmacıların ilgisini çekmektedir. Ancak ikincil kirleticiler ile kirlenmiş sularda biyolojik denitrifikasyonun etkinliği ve uygulanabilirliği üzerine sınırlı sayıda çalışma bulunmaktadır. Bu makalenin amacı içme sularından nitrat giderimi için etkili ve ucuz bir yöntem olan biyolojik denitrifikasyonun, nitrat yanında ikincil kirleticiler ile kirlenmiş yeraltısularının arıtımında kullanılabilirliğinin irdelenmesidir. The Effect of Co-Contaminant on Denitrification Removal of Nitrate in Drinking Water In recent years, nitrogenous fertilizers used in agriculture, unconscious and without treatment wastewater is discharged led to an increase in groundwater nitrate pollution. In many countries, nitrate concentration in the ground waters used as drinking water source exceeded the maximum allowable concentration of 10 mg/L NO3-N. Additionally, increased water consumption, unconscious use of fertilizers and pesticides has led to the emergence of co-contaminant in drinking water. Recently, hazardous to human health co-contaminant such as arsenic, pesticides, perchlorate, selenite, chromate, uranium are observed in the nitrate pollution drinking water. There are many processes used for the removal of nitrate. The physicalchemical technologies that can be used for nitrate removal are reverse osmosis, ion exchange and electro dialysis. Important disadvantages of these processes are their poor selectivity, high operation and maintenance costs and the generation of brine wastes after treatment. Consequently, biological treatment processes to convert nitrates to benign dinitrogen gas, could be an interesting alternative for the remediation of groundwater contaminated with nitrates. The aim of this article, effective and cheap method for the removal of nitrate from drinking water biological denitrification is to examine the usability of contaminated drinking water with co-contaminant pollutions.
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ARCHER, DOUGLAS L. "Evidence that Ingested Nitrate and Nitrite Are Beneficial to Health†". Journal of Food Protection 65, n. 5 (1 maggio 2002): 872–75. http://dx.doi.org/10.4315/0362-028x-65.5.872.
Testo completoAbstract (sommario):
The literature was reviewed to determine whether ingested nitrate or nitrite may be detrimental or beneficial to human health. Nitrate is ingested when vegetables are consumed. Nitrite, nitrate's metabolite, has a long history of use as a food additive, particularly in cured meat products. Nitrite has been a valuable antibotulinal agent in cured meats and may offer some protection from other pathogens in these products as well. Nitrite's use in food has been clouded by suspicions that nitrite could react with amines in the gastric acid and form carcinogenic nitrosamines, leading to various cancers. Nitrate's safety has also been questioned, particularly with regard to several cancers. Recently, and for related reasons, nitrite became a suspected developmental toxicant. A substantial body of epidemiological evidence and evidence from chronic feeding studies conducted by the National Toxicology Program refute the suspicions of detrimental effects. Recent studies demonstrate that nitrite, upon its ingestion and mixture with gastric acid, is a potent bacteriostatic and/or bactericidal agent and that ingested nitrate is responsible for much of the ingested nitrite. Acidified nitrite has been shown to be bactericidal for gastrointestinal, oral, and skin pathogenic bacteria. Although these are in vitro studies, the possibility is raised that nitrite, in synergy with acid in the stomach, mouth, or skin, may be an element of innate immunity.
25
TYRPENOU, A. E., E. H. GOUTA (E.H. ΓΟΥΤΑ), A. D. TSIGOURI (Α.Δ. ΤΣΙΓΟΥΡΗ) e Ch N. VLASIOTIS (Χ.Ν. ΒΛΑΣΙΩΤΗΣ). "Nitrate and nitrite residues in Greek pastirma". Journal of the Hellenic Veterinary Medical Society 51, n. 4 (31 gennaio 2018): 302. http://dx.doi.org/10.12681/jhvms.15691.
Testo completoAbstract (sommario):
In this research, for the investigation of the nitrate and nitrite content of Greek pastirma samples coming from several Greek meat processing factories were examined. Nitrate and nitrite determination was carried out following the standard methods of the International Standard Organization ISO No. 2918/751 and 3091/75.2 According to these Standard Operating Procedures-SOPs, reducing capacity of cadmium column should always has to be >90%. Because this critical point usually causes problems [never was >70%], we succeeded and validated this point by amending 3 points of the Standard Operating Procedure [SOP]. These amendments referred to the replacement of the buffer pH 9,6 of the cadmium column with the buffer pH 12,0 according to the method of Margeson et al., 1980.3 The result was that the reducing capacity of the cadmium column increased from 70% to 90-105%. Thirty pastirma samples have been tasted and the concentrations determined ranged from 0,85 to 189,65mg/kg for nitrites and from 2,66 to 639,67mg /kg for nitrates expressed as sodium nitrite. Nitrites, in 56,66% of the samples and nitrates in 83,33% of the samples were ranging in the limits foreseen by the Greek Legislation.
26
Dzakwan, Ardhatama Zafron, Hadi Endrawati e Raden Ario. "Analisis Konsentrasi Nitrat Dan Fosfat Terhadap Kelimpahan Fitoplankton Di Perairan Sengkarang Pekalongan". Journal of Marine Research 12, n. 4 (8 ottobre 2023): 571–78. http://dx.doi.org/10.14710/jmr.v12i4.35259.
Testo completoAbstract (sommario):
Peran penting nitrat dan fosfat sangat berpengaruh sekali terhadap pertumbuhan dan perkembangan biota yang ada di laut. Kedua nutrien ini sangat dibutuhkan dalam pembentukan sel jaringan pada organisme laut maupun proses fotosintesis yang terjadi pada organisme seperti fitoplankton. Salah satu parameter biologi yang erat kaitanya dengan nutrien seperti nitrat dan fosfat yaitu fitoplankton. Tingkat kelimpahan dari fitoplankton dapat dipengaruhi oleh konsentrasi nitrat fosfat yang ada di perairan tersebut. Adapun tujuan dilakukanya kajian mengenai konsentrasi nitrat dan fosfat dengan kelimpahan fitoplankton yaitu untuk mengetahui konsentrasi nitrat dan fosfat kaitanya dengan kelimpahan fitoplankton yang berada di perairan Sengkarang. Konsentrasi nitrat memiliki kisaran antara 0,001-0,118 mg/L. Stasiun 1 memiliki konsentrasi nitrat yang berkisar antara 0,022-0,118 mg/L. Stasiun 2 memiliki konsentrasi nitrat 0,001 mg/L pada semua titik. Stasiun 3 memiliki konsentrasi nitrat 0,001 mg/L pada semua titik. Konsentrasi Fosfat di perairan Sengkarang Pekalongan berkisar antara 0,002-0,005 mg/L. Stasiun 1 memiliki konsentrasi fosfat yang berkisar antara 0,003-0,005 mg/L. Stasiun 2 memiliki konsentrasi fosfat yang berkisar antara 0,002-0,004 mg/L. Stasiun 3 memiliki konsentrasi fosfat yang berkisar antara 0,002-0,004 mg/L. Kelimpahan fitoplankton dengan hasil yang terendah yaitu pada stasiun 1 sebesar 561,5349 ind/L. Kemudian hasil kelimpahan tertinggi yaitu pada stasiun 2 sebesar 2246,1394 ind/L dan pada stasiun 3 yaitu sebesar 655,1240 ind/L. Keberadaan nitrat dan fosfat di perairan Sengkarang dapat dikatakan tidak signifikan berpengaruh terhadap fitoplankton karena nilai korelasi (r) sebesar 0,403 untuk nitrat dan 0,271 untuk fosfat.The important role of nitrates and phosphates is very influential on the growth and development of biota in the sea. Both of these nutrients are needed in the formation of tissue cells in marine organisms and the photosynthesis process that occurs in organisms such as phytoplankton. One biological parameter that is closely related to nutrients such as nitrates and phosphates is phytoplankton. The level abundance of phytoplankton can be influenced by the concentration of nitrate phosphate present in these waters. The purpose of the study on the concentration of nitrate and phosphate with an abundance of phytoplankton is to determine the concentration of nitrate and phosphate associated with the abundance of phytoplankton in the water of Sengkarang. Nitrate concentration has a range between 0.001-0.118 mg/L. Station 1 has nitrate concentrations ranging from 0.022-0.118 mg/L. Station 2 had a nitrate concentration of 0.001 mg/L at all points. Station 3 had a nitrate concentration of 0.001 mg / L at all points. Phosphate concentration in the waters of Sengkarang Pekalongan ranged from 0.002-0.005 mg/L. Station 1 has a phosphate concentration that ranges from 0.003-0.005 mg/L. Station 2 has a phosphate concentration that ranges from 0.002-0.004 mg/L. Station 3 has a phosphate concentration that ranges from 0.002-0.004 mg/L. Phytoplankton abundance with the lowest yield at Station 1 of 561.5349 ind/L. Then the highest abundance results are at Station 2 of 2246.1394 ind/L and at Station 3 of 655.1240 ind / L. The presence of nitrate and phosphate in Sengkarang waters can be said to have no significant effect on phytoplankton because the correlation value (r) of 0.403 for nitrate and 0.271 for phosphate.
27
Cabrera, Elisa, Rafaela González-Montelongo, Teresa Giraldez, Diego Alvarez de la Rosa e José M. Siverio. "Molecular Components of Nitrate and Nitrite Efflux in Yeast". Eukaryotic Cell 13, n. 2 (20 dicembre 2013): 267–78. http://dx.doi.org/10.1128/ec.00268-13.
Testo completoAbstract (sommario):
ABSTRACTSome eukaryotes, such as plant and fungi, are capable of utilizing nitrate as the sole nitrogen source. Once transported into the cell, nitrate is reduced to ammonium by the consecutive action of nitrate and nitrite reductase. How nitrate assimilation is balanced with nitrate and nitrite efflux is unknown, as are the proteins involved. The nitrate assimilatory yeastHansenula polymorphawas used as a model to dissect these efflux systems. We identified the sulfite transporters Ssu1 and Ssu2 as effective nitrate exporters, Ssu2 being quantitatively more important, and we characterize the Nar1 protein as a nitrate/nitrite exporter. The use of strains lacking eitherSSU2orNAR1along with the nitrate reductase geneYNR1showed that nitrate reductase activity is not required for net nitrate uptake. Growth test experiments indicated that Ssu2 and Nar1 exporters allow yeast to cope with nitrite toxicity. We also have shown that the well-knownSaccharomyces cerevisiaesulfite efflux permease Ssu1 is also able to excrete nitrite and nitrate. These results characterize for the first time essential components of the nitrate/nitrite efflux system and their impact on net nitrate uptake and its regulation.
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Petrescu, Cristina. "SPATIAL AND TEMPORAL DISTRIBUTION OF NITRATES AND NITRITES IN THE FARMS’ WATER OF TIMIS COUNTY, ROMANIA: A CASE-STUDY". Proceedings of CBU in Medicine and Pharmacy 3 (1 dicembre 2022): 23–28. http://dx.doi.org/10.12955/pmp.v3.319.
Testo completoAbstract (sommario):
The present study aimed to investigate the spatial and temporal distribution of nitrates and nitrites in the farms’ water of Timis County. The sample for the study consisted of 4028 analysis bulletins of the nitrate and nitrite concentrations, measured in 41 farms and local water sources over two years (2016- 2242 and 2017- 1904 water samples) by the Surveillance Service, Public Health Direction, Timis. The data has been analysed with an observational case study of the spatial and temporal distribution of nitrate and nitrite concentrations in the farm water in Timis County. It has been found that the mean concentrations of nitrite and nitrate were lower than the standards, with a statistically significant difference (t=8.11, Sig.< 0.001) between the 2 years of study and with higher values recorded in 2016 than in 2017. A specific spatial distribution of the mean concentrations of these two substances was slightly high in old, polluted localities and pig farms in Timis County.
29
Smychok, T. Z., B. V. Gutyj, O. V. Kozenko, V. B. Todoriuk, T. V. Martyshuk, V. I. Kushnir, N. Yu Krempa et al. "The influence of the feed additive “Metisevit” on the activity of the antioxi-dant defense system of piglets under conditions of nitrate-nitrite load". Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 25, n. 99 (5 settembre 2023): 176–81. http://dx.doi.org/10.32718/nvlvet-a9929.
Testo completoAbstract (sommario):
The work aimed to investigate the effect of the “Metisevit” feed additive on the activity of the enzymes of the antioxidant system of the blood of piglets under conditions of nitrate-nitrite load. The research was carried out on 60-day-old piglets of the large white breed. For the experiment, 10 clinically healthy piglets were selected, from which 2 groups of five animals were formed. Piglets of the control group were fed sodium nitrate at a dose of 0.3 g NO3-/kg body weight for three months. Piglets of the research group were also fed sodium nitrate at a dose of 0.3 g NO3-/kg of body weight, together with Metisevit at a dose of 0.36 g/kg of feed for three months. The “Metisevit” feed additive was developed at the Department of Pharmacology and Toxicology of the Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnology Lviv, which contains vitamin E, selenium, and methiphene (methionine, phenarone, zeolite). Under the conditions of feeding piglets with sodium nitrate feed at a dose of 0.3 g of NO3ˉ/kg, a decrease in the activity of enzymes of the antioxidant defense system was established: superoxide dismutase by 14.8 %, catalase by 20%, glutathione peroxidase by 15.1 %. Metisevit in piglets increased the activity of the enzyme link of the antioxidant protection system, preventing the development of oxidative stress that occurs in nitrate-nitrite toxicosis. During our experiments, it was found that the introduction of Metisevit into the diet of piglets with excessive consumption of nitrates prevented the development of chronic nitrate-nitrite toxicosis. It was established that Metisevit increases the activity of enzymes – superoxide dismutase, catalase, and glutathione peroxidase. These enzymes reduce the high level of lipid peroxidation products in the body of piglets under conditions of nitrate-nitrite load.
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Gates, Andrew J., Victor M. Luque-Almagro, Alan D. Goddard, Stuart J. Ferguson, M. Dolores Roldán e David J. Richardson. "A composite biochemical system for bacterial nitrate and nitrite assimilation as exemplified by Paracoccus denitrificans". Biochemical Journal 435, n. 3 (13 aprile 2011): 743–53. http://dx.doi.org/10.1042/bj20101920.
Testo completoAbstract (sommario):
The denitrifying bacterium Paracoccus denitrificans can grow aerobically or anaerobically using nitrate or nitrite as the sole nitrogen source. The biochemical pathway responsible is expressed from a gene cluster comprising a nitrate/nitrite transporter (NasA), nitrite transporter (NasH), nitrite reductase (NasB), ferredoxin (NasG) and nitrate reductase (NasC). NasB and NasG are essential for growth with nitrate or nitrite as the nitrogen source. NADH serves as the electron donor for nitrate and nitrite reduction, but only NasB has a NADH-oxidizing domain. Nitrate and nitrite reductase activities show the same Km for NADH and can be separated by anion-exchange chromatography, but only fractions containing NasB retain the ability to oxidize NADH. This implies that NasG mediates electron flux from the NADH-oxidizing site in NasB to the sites of nitrate and nitrite reduction in NasC and NasB respectively. Delivery of extracellular nitrate to NasBGC is mediated by NasA, but both NasA and NasH contribute to nitrite uptake. The roles of NasA and NasC can be substituted during anaerobic growth by the biochemically distinct membrane-bound respiratory nitrate reductase (Nar), demonstrating functional overlap. nasG is highly conserved in nitrate/nitrite assimilation gene clusters, which is consistent with a key role for the NasG ferredoxin, as part of a phylogenetically widespread composite nitrate and nitrite reductase system.
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Moshage, H., B. Kok, J. R. Huizenga e P. L. Jansen. "Nitrite and nitrate determinations in plasma: a critical evaluation". Clinical Chemistry 41, n. 6 (1 giugno 1995): 892–96. http://dx.doi.org/10.1093/clinchem/41.6.892.
Testo completoAbstract (sommario):
Abstract Plasma nitrite and nitrate determinations are increasingly being used in clinical chemistry as markers for the activity of nitric oxide synthase and the production of nitric oxide radicals. However, a systematic evaluation of the determination of nitrite and nitrate in plasma has not been performed. In this study the recovery and stability of nitrite and nitrate in whole blood and in plasma, the relation between nitrite and nitrate concentrations in plasma, and possible sources of artifacts were investigated. The main conclusions are: (a) Recovery of nitrite and nitrate from plasma is near-quantitative (87%) and reproducible; (b) nitrite and nitrate are stable in (frozen) plasma for at least 1 year; (c) nitrite in whole blood is very rapidly (> 95% in 1 h) oxidized to nitrate, and therefore plasma nitrite determination alone is meaningless; (d) the ranges of nitrite and nitrate concentrations in plasma samples of 26 healthy persons are 1.3-13 mumol/L (mean 4.2 mumol/L) and 4.0-45.3 mumol/L (mean 19.7 mumol/L), respectively; (e) plasma nitrite and nitrate concentrations were not correlated (nitrite as % of total nitrite + nitrate varied from 3.9% to 88% in plasma samples); and (f) plasma samples should be deproteinized, and background controls for each sample should be included in the assay, to avoid measuring artifactually high nitrite and nitrate concentrations in plasma.
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Agić, Tea, Maja Rečić, Dorotea Piškor, Marina Posavec e Dubravka MArija Kreković. "Određivanje sadržaja nitrata i nitrita u mesnim proizvodima bez dodanih aditiva". Meso 25, n. 4 (14 luglio 2023): 300–309. http://dx.doi.org/10.31727/m.25.4.1.
Testo completoAbstract (sommario):
A food additive is any substance not consumed as a food ingredient but added to food for a specific purpose, for example inhibiting microorganism growth and maintaining sensory quality. Potassium and sodium nitrates and nitrites are among the most commonly used food additives in the meat industry due to their antimicrobial effect, in particular to prevent the growth of pathogenic bacteria Clostridium botulinum and its spores. Additionally, they provide specific sensory attributes, primarily the inherent pink color of meat products. Studies showed that excessive intake of nitrates and nitrites may pose a risk to human health. The object of this research was determination of nitrite and nitrate content in meat products without added additives or with those additives from natural sources. Samples were mortadella, cooked ham and bologna sausage as thermally proccessed (cured) meat products and fermented sausage. The statistical analysis of the results for mortadella, cooked ham and bologna sausage as thermally proccessed meat products showed a p-value <0.05 between recipes with added nitrite salt and new recipes. The values of the median mass concentration of sodium nitrite in the commercial recipes were from 3.50-40.50 mg/kg, whereas this value was below the limit of detection in new recipes. Also, for fermented sausage, the p-value below 0.05 between commercial recipe with nitrite and nitrate salt and new recipes confirmed the hypothesis for replacement of mentioned salts with new concepts. The value of the median mass concentration of sodium nitrate in the recipe with added nitrate salt was 268.52 mg/ kg, whereas this value was below the limit of detection in other recipes.
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Chatterjee, Amrita, Dipratn G. Khandare, Praveen Saini, Anjan Chattopadhyay, Mahesh S. Majik e Mainak Banerjee. "Amine functionalized tetraphenylethylene: a novel aggregation-induced emission based fluorescent chemodosimeter for nitrite and nitrate ions". RSC Advances 5, n. 40 (2015): 31479–84. http://dx.doi.org/10.1039/c4ra14765k.
Testo completoAbstract (sommario):
A novel AIE-based fluorescent probe for the detection of trace amounts of nitrite and nitrate ions in water has been developed, which spontaneously detects nitrites (or nitrates) by a fluorescence “turn-off” method.
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Ardhaneswari, Mutia, e Bambang Wispriyono. "Analisis Risiko Kesehatan Akibat Pajanan Senyawa Nitrat dan Nitrit Pada Air Tanah di Desa Cihambulu Subang". Jurnal Kesehatan Lingkungan Indonesia 21, n. 1 (27 ottobre 2021): 65–72. http://dx.doi.org/10.14710/jkli.21.1.65-72.
Testo completoAbstract (sommario):
Latar belakang: Penggunaan pupuk nitrogen seperti NPK dan urea pada lahan pertanian dapat menyebabkan pencemaran pada air tanah di wilayah pertanian. Pupuk nitrogen yang diaplikasikan pada tanah akan mengalami leaching terbawa air hujan masuk ke dalam tanah. Konsumsi air tanah yang mengandung nitrat dan nitrit dapat mengakibatkan dampak kesehatan seperti Blue Baby Syndrome atau Methemoglobinemia dan kanker. Penelitian ini dilakukan untuk menganalisis konsentrasi nitrat dan nitrit pada air tanah dan mengukur tingkat risiko kesehatan yang ditimbulkan dari kedua pajanan ini terhadap penduduk di Desa Cihambulu, Subang.Metode: Penelitian ini dilakukan pada bulan Februari 2021 dengan menggunakan metode Analisis Risiko Kesehatan Lingkungan. Wawancara dilakukan kepada 123 responden dari 33 unit rumah tangga untuk memperoleh informasi berat badan, laju konsumsi dan lama tinggal responden di lokasi penelitian.. Sebanyak 33 sampel air tanah diambil dari 33 unit rumah tangga yang telah dilakukan wawancara. Pengukuran tingkat risiko kesehatan dilakukan dengan menghitung nilai Risk Quotion (RQ) dari masing-masing kelompok responden anak, wanita dan pria dewasa. Hasil: Hasil analisis menunjukkan konsentrasi nitrat (NO3-N) pada air tanah berkisar antara 0,03 - 6,7 mg/L dengan rata-rata 1,38 mg/L sedangkan konsentrasi nitrit (NO2-N) pada air tanah berkisar antara 0,01 - 0,08 mg/L dengan rata-rata 0,02 mg/L. Tingkat risiko kesehatan non karsinogenik menunjukkan nilai RQ < 1 untuk 3 (tiga) kelompok responden yaitu anak, wanita dan pria dewasa.Simpulan: Seluruh sampel air tanah masih memenuhi baku mutu dalam Peraturan Menteri Kesehatan Nomor 492/Menkes/Per/IV/2010 tentang Persyaratan Kualitas Air Minum, untuk parameter nitrat dan nitrit. Tingkat risiko kesehatan non karsinogenik yang disebabkan dari kedua pajanan tersebut pada air tanah menunjukkan nilai RQ < 1 dimana kedua pajanan tersebut belum beresiko menimbukan efek merugikan bagi kesehatan. ABSTRACT Title: Health Risk Assessment of Nitrate and Nitrite in Groundwater in the Agricultural Area, Cihambulu Village, Subang,Background: The use of nitrogen fertilizers such as NPK and urea on agricultural land can cause contamination of groundwater in agricultural areas. Nitrogen fertilizer applied to the soil will be carried by rainwater into the soil. Consumption of groundwater containing nitrates and nitrites can lead to health effects such as Blue Baby Syndrome or Methemoglobinemia and cancer. This study was conducted to determine the concentration of nitrate and nitrite in groundwater and to determine the level of health risk posed by these two exposures to residents in Cihambulu Village, Subang..Method: This study was conducted in February 2021 using the method of Environmental Health Risk Assessment. Interview were conducted with 123 respondents from 33 household units to obtain information on weight, consumption rate and length of stay of respondents in the study location. A total of 33 groundwater samples were taken from 33 household units that had been interviewed.Result: The results shows that the concentration of nitrate (NO3-N) in groundwater ranged from 0.03 - 6.7 mg/L with an average of 1.38 mg/L while the concentration of nitrite (NO2-N) in groundwater ranged from 0.01 - 0.08 mg/L with an average of 0.02 mg/L. The level of non-carcinogenic health risk shows an RQ value < 1 for 3 (three) groups of respondents, namely children, women and adult men.Conclusion: All groundwater samples contain nitrate and nitrite within acceptable limits according to the requirements in the Regulation of the Minister of Health Number 492/Menkes/Per/IV/2010 concerning Requirements for Drinking Water Quality, especially nitrate and nitrite requirementrs. The level of non-carcinogenic health risk caused by this exposures to groundwater shows an RQ value < 1 where the two exposures are not at risk of causing adverse health effects.
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Wangiyana, I. Gde Adi Suryawan, e Wayan Wangiyana. "Distribusi Enzim Nitrat Reduktase pada Cabai Merah (Capsicum annum) dalam Rangka Mendukung Sistem Agroforestry Berkelanjutan". Rona Teknik Pertanian 11, n. 2 (1 ottobre 2018): 28–37. http://dx.doi.org/10.17969/rtp.v11i2.12061.
Testo completoAbstract (sommario):
Abstrak. Penelitian ini bertujuan untuk mengetahui distribusi enzim nitrat reduktase pada tanaman cabai merah (C. annum) yang dipengaruhi oleh berbagai faktor fisiologis. Percobaan ini menggunakan Rancangan Acak Lengkap dengan banyak faktor diantaranya: Faktor organ tanaman, umur tanaman, posisi daun dan pemupukan dengan nitrat. Berbagai organ tanaman cabai direndam dalam buffer fosfat pH 7,5 selama 20 menit. Setelah itu dilakukan penambahan susbtrat berupa 0,1M NaNO3 dan diinkubasi selama 60 menit. Sampel selanjutnya direndam dalam larutan Napthylediamine dan Sulfanilamide 1:1. Absorbansi sampel diukur dengan spektrofotometer pada panjang gelombang 540nm. Berdasarkan pengukuran absorbansi diperoleh hasil bahwa tanaman cabai usia dewasa memiliki aktivitas nitrat reduktse lebih tinggi dibandingkan dengan usia muda dan tua. Aktivitas nitrat reduktase pada organ daun lebih tinggi dibandingkan organ akar, batang dan buah. Sementara itu daun pada posisi pucuk memiliki aktivitas nitrat reduktase lebih tinggi dibandingkan dengan daun di posisi pangkal dan tengah. Pemupukan nitrat tidak memberikan pengaruh yang signifikan terhadap aktivitas nitrat reduktse pada tanaman cabai. Berdasarkan hal tersebut, dapat disimpulkan bahwa Capsicum annum usia dewasa memiliki aktivitas nitrat reduktase tertinggi dengan kecenderungan organ daun memiliki aktivitas nitrat reduktase terbesar dibandingkan organ lainnya terutama daun pada posisi pucuk. Penambahan susbtrat NaNO3 tidak memberikan pengaruh secara signifikan terhadap aktivitas nitrat reduktase. Distribution of Nitrate Reductase Enzymes in Red Chili (Capsicum annum) in Order to Support Sustainable Agroforestry Systems Abstract. This study aims to determine the distribution of the enzyme nitrate reductase in red chili plants (C. annum) which are influenced by various physiological factors. This experiment uses a completely randomized design with many factors including: Plant organ factors, plant age, leaf position and fertilization with nitrates. Various organs of chili plants are immersed in phosphate buffer pH 7.5 for 20 minutes. After that the addition of susbtrat in the form of 0.1 M NaNO3 and incubated for 60 minutes. The samples were then immersed in Napthylediamine and Sulfanilamide 1: 1 solutions. Sample absorbance was measured by a spectrophotometer at a wavelength of 540 nm. Based on absorbance measurements, the results showed that adult chili plants had higher nitrate reductase activity compared to young and old age. The activity of nitrate reductase in leaf organs is higher than that of root, stem and fruit organs. Meanwhile the leaves in the shoot position have higher nitrate reductase activity compared to the leaves in the base and middle positions. Nitrate fertilization did not have a significant effect on nitrate reductase activity in chili plants. Based on this, it can be concluded that the adult age Capsicum annum has the highest nitrate reductase activity with the tendency of leaf organs to have the greatest nitrate reductase activity compared to other organs, especially leaves in the shoot position. The addition of NaClO3 does not significantly influence the activity of nitrate reductase.
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Taneja, Pinky, Pawan Labhasetwar, Pranav Nagarnaik e Jeroen H. J. Ensink. "The risk of cancer as a result of elevated levels of nitrate in drinking water and vegetables in Central India". Journal of Water and Health 15, n. 4 (11 maggio 2017): 602–14. http://dx.doi.org/10.2166/wh.2017.283.
Testo completoAbstract (sommario):
The objective of the present study was to determine the effect of nitrates on the incidence of gastrointestinal (GI) cancer development. Nitrate converted to nitrite under reducing conditions of gut results in the formation of N-nitrosamines which are linked to an increased gastric cancer risk. A population of 234 individuals with 78 cases of GI cancer and 156 controls residing at urban and rural settings in Nagpur and Bhandara districts of India were studied for 2 years using a case-control study. A detailed survey of 16 predictor variables using Formhub software was carried out. Nitrate concentrations in vegetables and primary drinking water supplies were measured. The logistic regression model showed that nitrate was statistically significant in predicting increasing risk of cancer when potential confounders were kept at base level (P value of 0.001 nitrate in drinking water; 0.003 for nitrate in vegetable) at P < 0.01. Exposure to nitrate in drinking water at >45 mg/L level of nitrate was associated with a higher risk of GI cancers. Analysis suggests that nitrate concentration in drinking water was found statistically significant in predicting cancer risk with an odds ratio of 1.20.
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Stief, Peter, e Dietrich Neumann. "Nitrite formation in sediment cores from nitrate-enriched running waters". Fundamental and Applied Limnology 142, n. 2 (26 maggio 1998): 153–69. http://dx.doi.org/10.1127/archiv-hydrobiol/142/1998/153.
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Frías, José E., e Enrique Flores. "Induction of the Nitrate AssimilationnirAOperon and Protein-Protein Interactions in the Maturation of Nitrate and Nitrite Reductases in the Cyanobacterium Anabaena sp. Strain PCC 7120". Journal of Bacteriology 197, n. 14 (11 maggio 2015): 2442–52. http://dx.doi.org/10.1128/jb.00198-15.
Testo completoAbstract (sommario):
ABSTRACTNitrate is widely used as a nitrogen source by cyanobacteria, in which the nitrate assimilation structural genes frequently constitute the so-callednirAoperon. This operon contains the genes encoding nitrite reductase (nirA), a nitrate/nitrite transporter (frequently an ABC-type transporter;nrtABCD), and nitrate reductase (narB). In the model filamentous cyanobacteriumAnabaenasp. strain PCC 7120, which can fix N2in specialized cells termed heterocysts, thenirAoperon is expressed at high levels only in media containing nitrate or nitrite and lacking ammonium, a preferred nitrogen source. Here we examined the genes downstream of thenirAoperon inAnabaenaand found that a small open reading frame of unknown function,alr0613, can be cotranscribed with the operon. The next gene in the genome,alr0614(narM), showed an expression pattern similar to that of thenirAoperon, implying correlated expression ofnarMand the operon. A mutant ofnarMwith an insertion mutation failed to produce nitrate reductase activity, consistent with the idea that NarM is required for the maturation of NarB. BothnarMandnarBmutants were impaired in the nitrate-dependent induction of thenirAoperon, suggesting that nitrite is an inducer of the operon inAnabaena. It has previously been shown that the nitrite reductase protein NirA requires NirB, a protein likely involved in protein-protein interactions, to attain maximum activity. Bacterial two-hybrid analysis confirmed possible NirA-NirB and NarB-NarM interactions, suggesting that the development of both nitrite reductase and nitrate reductase activities in cyanobacteria involves physical interaction of the corresponding enzymes with their cognate partners, NirB and NarM, respectively.IMPORTANCENitrate is an important source of nitrogen for many microorganisms that is utilized through the nitrate assimilation system, which includes nitrate/nitrite membrane transporters and the nitrate and nitrite reductases. Many cyanobacteria assimilate nitrate, but regulation of the nitrate assimilation system varies in different cyanobacterial groups. In the N2-fixing, heterocyst-forming cyanobacteria, thenirAoperon, which includes the structural genes for the nitrate assimilation system, is expressed in the presence of nitrate or nitrite if ammonium is not available to the cells. Here we studied the genes required for production of an active nitrate reductase, providing information on the nitrate-dependent induction of the operon, and found evidence for possible protein-protein interactions in the maturation of nitrate reductase and nitrite reductase.
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Nerdy, Nerdy, e Effendy De Lux Putra. "Spectrophotometric Method for Determination of Nitrite and Nitrate Levels in Broccoli and Cauliflower with Different Fertilization Treatment". Oriental Journal of Chemistry 34, n. 6 (13 novembre 2018): 2983–91. http://dx.doi.org/10.13005/ojc/340639.
Testo completoAbstract (sommario):
Both broccoli and cauliflower are plants that are widely cultivated and consumed. The vegetable also contains Nitrite and Nitrite, which have a negative impact on human health because of the carcinogenic effect. Levels of Nitrite and Nitrate in vegetable are dependent on several factors, one of them is fertilization. The objective of this research is to determine the levels of Nitrite and Nitrate in broccoli and cauliflower without fertilization and with fertilization (natural and chemical). Samples were planted broccoli and cauliflower with different fertilization treatment. Determination of Nitrite and Nitrate levels were done by the colorimetric method (visible spectrophotometric) by using N-(1-Naphthyl) Ethylenediamine Dihydrochloride and Sulfanilic Acid as the dyes and measured at the maximum absorbance wavelength (540 nm) and on the operating time between 11 minutes to 18 minutes. Nitrite and Nitrate levels in various fertilization treatments of broccoli and cauliflower were different significantly. Nitrite and Nitrate levels in broccoli and cauliflower without fertilization are lower than Nitrite and Nitrate levels in broccoli and cauliflower with fertilization. Nitrite and Nitrate levels in broccoli and cauliflower with natural fertilizer fertilization are lower than Nitrite and Nitrate levels in broccoli and cauliflower with chemical fertilizer fertilization.
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Cintya, Henni, Jansen Silalahi, Effendy De Lux Putra e Rikson Siburian. "The influence of storage condition on nitrite, nitrate and vitamin C levels in vegetables". F1000Research 7 (6 dicembre 2018): 1899. http://dx.doi.org/10.12688/f1000research.16853.1.
Testo completoAbstract (sommario):
Vegetables are the main sources of nitrate and nitrite in food. The presence of nitrate and nitrite at a high level may cause a negative impact on health, because nitrite and nitrate when reduced to nitrite, may react with alkylamine to form carcinogenic nitrosamine. The influence of temperature and time of storage on nitrite, nitrate, and vitamin C contents in vegetables were investigated in this study. The vegetables were sweet mustard, bokchoy, spinach and lettuce obtained from a local market. Samples were stored at ±25oC and ±5oC. Analysis of nitrite, nitrate, and vitamin C was conducted in fresh samples, after storage for 24 and 48 hours. Nitrite was analyzed by spectrophotometry at 540 nm. Nitrate reduced into nitrite with Zn in acidic conditions and then analyzed as nitrite. Vitamin C was analyzed by titration with 2.6-dichlorophenolindophenol. During storage, nitrite and nitrate increased, while vitamin C decreased. Nitrite and nitrate content in fresh samples were 15.22 and 22.46 mg/kg (sweet mustard), 12.57 and 6.55 mg/kg (bokchoy), 20.26 and 90.60 mg/kg (spinach), 18.77 and 32.68 mg/kg (lettuce), respectively. Vitamin C content in fresh samples was 101.15 mg/100g (mustard), 92.17 mg/100g (bokchoy), 88.95 mg/100g (spinach), 40.03 mg/100g (lettuce). After storage for 48 hours at ±25oC, nitrite and nitrate increased 44.97% and 53.19% (mustard), 46.18% and 62.59% (bokchoy), 43.86% and 16.48% (spinach), and 41.05% and 47.09% (lettuce), respectively. Vitamin C decreased 67.57% (mustard), 24.68% (bokchoy), 81.25% (spinach), and 79.74% (lettuce). Storage at ±5oC, showed that nitrite and nitrate increased 27.54% and 35.08% (mustard), 13.75% and 43.51% (bokchoy), 19.59% and 10.60% (spinach), 19.85% and 25.16% (lettuce), respectively. Vitamin C decreased 30.88% (mustard), 6.05% (bokchoy), 60.92% (spinach), and 74.94% (lettuce). During storage, nitrite and nitrate increased more significantly at ±25oC than ±5oC while vitamin levels C decreased and were more effective at 25oC than 5oC.
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Wu, Qitu, e Roger Knowles. "Cellular regulation of nitrate uptake in denitrifying Flexibacter canadensis". Canadian Journal of Microbiology 40, n. 7 (1 luglio 1994): 576–82. http://dx.doi.org/10.1139/m94-092.
Testo completoAbstract (sommario):
Nitrate uptake and its regulation were investigated using an ion-specific nitrate electrode for denitrifying Flexibacter canadensis under anaerobic conditions. Glucose supported a greater rate of nitrate uptake than did glycerol, glutamate, lactose, cellobiose, or ethanol. Nitrate uptake closely approximated Michaelis–Menten kinetics; the estimated Ks(glucose) and apparent Km(nitrate) for nitrate uptake were 21 and 44 μM, respectively. Nitrate disappearance was correlated with nitrite accumulation, and nitrate had an inhibitory effect on nitrite reduction. Oxygen inhibition of nitrate uptake increased as the percent air saturation increased, and reversed readily as the percent air saturation decreased. The minimal air saturation showing inhibition of nitrate uptake was about 2–4%. Azide and cyanide completely inhibited nitrate uptake. No nitrate uptake was observed in cells grown in the presence of 1 or 5 mM tungstate (no added molybdate). When molybdate (100–200μM) was present in the medium, nitrate uptake was exhibited by organisms grown with 1 mM, but not with 5 mM, tungstate, indicating that nitrate uptake was dependent on the presence of an active nitrate reductase, and that competition between tungsten and molybdenum occurred during the formation of nitrate reductase. Nitrite production from nitrate by whole cells but not cell-free extracts was inhibited by 2,4-dinitrophenol and carbonyl cyanide m-chlorophenylhydrazone, indicating that nitrate and (or) nitrite transport depended upon the electrochemical proton gradient.Key words: denitrification, nitrate uptake, Flexibacter canadensis.
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Dung, T. T. T., D. T. Nhan e T. B. Chau. "The level of nitrate and nitrite in some fruits available in the local markets in District 7, Ho Chi Minh City, Vietnam". IOP Conference Series: Earth and Environmental Science 1349, n. 1 (1 maggio 2024): 012013. http://dx.doi.org/10.1088/1755-1315/1349/1/012013.
Testo completoAbstract (sommario):
Abstract Nitrate and nitrite are main contaminants in fruits that must be controlled due to their potential adverse health effects on humans. The objectives of this study were to analyze levels of nitrate and nitrite in some selected fruits in local markets in District 7, Ho Chi Minh City, and to determine whether estimated dietary exposure to nitrate and nitrite poses a risk to human health. Mango, banana, tomato, and cucumber were collected and tested. Nitrate levels varied widely, ranging from 89 mg/kg to 1104 mg/kg across different fruits. Mango had the highest average nitrate level (588 mg/kg), while tomato had the lowest (109 mg/kg). Nitrite levels in fruits were significantly lower than nitrate levels, ranging from 0.090 mg/kg to 2.60 mg/kg. Mango had the highest average nitrite level (0.77 mg/kg), and cucumber had the lowest (0.01 mg/kg). The nitrate and nitrite health risk quotient (RQ) was within acceptable limits, indicating that nitrate and nitrite intake from fruit consumption poses no health risk to the local population. When the endogenous process of nitrate to nitrite transformation was considered, the EDI of nitrite increased significantly compared to the original calculation, but the result remained within the acceptable limit.
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Stuehr, D. J., e M. A. Marletta. "Induction of nitrite/nitrate synthesis in murine macrophages by BCG infection, lymphokines, or interferon-gamma." Journal of Immunology 139, n. 2 (15 luglio 1987): 518–25. http://dx.doi.org/10.4049/jimmunol.139.2.518.
Testo completoAbstract (sommario):
Abstract Macrophage synthesis of nitrite and nitrate after activation by BCG infection or by treatment in vitro with both T cell-derived (lymphokines (LK) or recombinant murine interferon-gamma (IFN-gamma] and bacterial (lipopolysaccharide (LPS) and heat-killed bacillus Calmette-Guerin (hk BCG] agents was studied by using macrophages from C3H/He and C3H/HeJ mice. Spleen and peritoneal macrophages isolated from BCG-infected donors that were producing nitrate continued to synthesize nitrite and nitrate in culture. LPS treatment in vitro (25 or 50 micrograms/ml) additionally increased this nitrite/nitrate synthesis. Thioglycolate-elicited macrophages from non-infected C3H/HeJ mice treated with LK also produced nitrite/nitrate, and concurrent LPS (0.1 to 50 micrograms/ml) treatment resulted in enhanced synthesis. Recombinant IFN-gamma also stimulated nitrite/nitrate synthesis by C3H/He and CeH/HeJ macrophages as did LPS (C3H/He only) and hk BCG. When given concurrently with either LPS or hk BCG, IFN-gamma enhanced C3H/He and C3H/HeJ macrophage nitrite/nitrate synthesis over that produced by macrophages treated with either LPS or hk BCG alone. Macrophages activated in vitro exhibited a 4 to 12 hr lag time before engaging in nitrite/nitrate synthesis, which then proceeded for 36 to 42 hr at linear rates. Daily medium renewal did not alter the synthesis kinetics but increased the total amount of nitrite/nitrate produced. Nitrate and nitrite were stable under the conditions of culture and when added did not influence additional macrophage synthesis. Taken together, these results indicate that T cell lymphokines and IFN-gamma are powerful modulators of macrophage nitrite/nitrate synthesis during BCG infection and in vitro, and nitrite/nitrate synthesis appears to be common property of both primed and fully activated macrophage populations.
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Hiskey, Michael A., Melvin J. Hatch e Jimmie C. Oxley. "Nitrato Amine Nitrates: Nitrate ester explosives with reduced impact sensitivity". Propellants, Explosives, Pyrotechnics 16, n. 1 (febbraio 1991): 40–42. http://dx.doi.org/10.1002/prep.19910160110.
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Jacková, A., P. Siklenka e J. Pleva. "Transrenal passage of nitrates and nitrites in calves (short communication)". Archives Animal Breeding 42, n. 3 (10 ottobre 1999): 235–40. http://dx.doi.org/10.5194/aab-42-235-1999.
Testo completoAbstract (sommario):
Abstract. In a study with 12 calves on milk nutrition, the course of methemoglobinemia as well as ttansrenal passage of nitrates and nitrites after single per os administrations of 4 g NaNO2 per animal and 30 g KNO3 per animal in the form of water Solutions has been observed. The response of the organism of calves to per os administered doses of sodium nitrite and potassium nitrate was observed by the determination of tlie methemoglobin percentage in blood and the nitrate and nitrite content in urine before the administration ofthe respective dose and after h 1, 2, 3 and 4 after the administration. A significant elevation in the values of methemoglobin was recorded after h 2 after the administration of 4g NaNO3 per animal. The mean value of methemoglobin in blood was 18.84% of total hemoglobin. A slight decline in the values occurred as early as after h 3 after the administration. Of clinical signs, cyanosis of visible mucosae was observed. The highest nitrite and nitrate values in urine were determined after h 2 after per os administration of 4g NaNO2, With the administration of 30g KNO3 per animal, the most pronounced elevation in methemoglobinemia was observed after h 3, when the means values of methemoglobin was 11,75%. Of clinical signs, only slight cyanosis of mucosae was detectable. Maximum values of nitrates in urine of experimental calves after h 3 after the administration of 30 g KNO3 per animal, with the mean value of 29,9 mM NO3−1 clearly demonstrate a good transrenal passage of nitrates in calves on milk nutrition.
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Aichi, Makiko, Shin-Ichi Maeda, Kazuhiro Ichikawa e Tatsuo Omata. "Nitrite-Responsive Activation of the Nitrate Assimilation Operon in Cyanobacteria Plays an Essential Role in Up-Regulation of Nitrate Assimilation Activities under Nitrate-Limited Growth Conditions". Journal of Bacteriology 186, n. 10 (15 maggio 2004): 3224–29. http://dx.doi.org/10.1128/jb.186.10.3224-3229.2004.
Testo completoAbstract (sommario):
ABSTRACT NtcB of the cyanobacterium Synechococcus elongatus strain PCC 7942 is a LysR family protein that enhances expression of the nitrate assimilation operon (nirA operon) in response to the presence of nitrite, an intermediate of assimilatory nitrate reduction. Inactivation of ntcB in this cyanobacterium specifically abolishes the nitrite responsiveness of nirA operon expression, but under nitrate-replete conditions (wherein negative feedback by intracellularly generated ammonium prevails over the positive effect of nitrite) activity levels of the nitrate assimilation enzymes are marginally higher in the wild-type cells than in the mutant cells, raising the issue of whether the nitrite-promoted regulation has physiological importance. On the other hand, the strains carrying ntcB expressed much higher nitrate assimilation enzyme activities under nitrate-limited growth conditions than under nitrate-replete conditions whereas the ntcB-deficient strains showed levels of the enzyme activities lower than those seen under the nitrate-replete conditions. Although the ntcB mutant maintained a constant cell population in a nitrate-limited chemostat when grown as a single culture, it was diluted at a rate expected for nondividing cells when mixed with the wild-type cells and subjected to nitrate limitation in the chemostat culture system. These results demonstrated that the nitrite-promoted activation of the nitrate assimilation operon is essential for up-regulation of the nitrate assimilation activities under the conditions of nitrate limitation and for competitive utilization of nitrate.
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Florin, T. H. J., G. Neale e J. H. Cummings. "The effect of dietary nitrate on nitrate and nitrite excretion in man". British Journal of Nutrition 64, n. 2 (settembre 1990): 387–97. http://dx.doi.org/10.1079/bjn19900040.
Testo completoAbstract (sommario):
Dietary nitrate and nitrite may affect colonic pathophysiology. These anions influence fermentation, and nitrite has been shown to augment sodium absorption by the colon and participate in the formation ofN-nitroso compounds. There is, however, no general agreement as to how much dietary nitrate and nitrite reaches the colon. To help resolve this question, balance studies were performed on six healthy ileostomy subjects who were given diets that varied in nitrate content from 0.83 to 5.20 mmol/d. Nitrate and nitrite excretion in ileal effluent and urine were measured by anion-exchange chromatography with conductivity detection. There was no significant nitrite in the diets, urine, or ideal effluent. Dietary nitrate was largely excreted in urine (1.31–4.25 mmol/d). The urinary excretion findings indicated net synthesis of nitrate at low dietary intakes and net catabolism of nitrate at high intakes. Nitrate losses in ileal effluent were very low (0.03–0.05 mmol/d, 0.03–0.06 mmol/kg) and unrelated to intake for all the diets. It is concluded that dietary nitrate and nitrite do not enter the colon from the small intestine in amounts that would affect fermentation and mucosal metabolism in man. The possibility of significant amounts of nitrate reaching the colon via blood in normal subjects has not been excluded.
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Gomes, Tamara Maria, João Carlos Cury Saad, Raimundo Leite Cruz e Carlos Tadeu dos Santos Dias. "AVALIAÇÃO DA CONCENTRAÇÃO E DISTRIBUIÇÃO DE NITRITO, AMÔNIO E NITRATO PROVENIENTES DA URÉIA APLICADA VIA SISTEMA DE IRRIGAÇÃO POR GOTEJAMENTO". IRRIGA 3, n. 2 (12 agosto 1998): 29–35. http://dx.doi.org/10.15809/irriga.1998v3n2p29-35.
Testo completoAbstract (sommario):
AVALIAÇÃO DA CONCENTRAÇÃO E DISTRIBUIÇÃO DE NITRITO, AMÔNIO E NITRATO PROVENIENTES DA URÉIA APLICADA VIA SISTEMA DE IRRIGAÇÃO POR GOTEJAMENTO[1] Tamara Maria GomesBolsista do CNPq, Av. Independência 1592. CEP: 13416-225. Piracicaba-SP João Carlos Cury SaadRaimundo Leite CruzDepartamento de Engenharia Rural. FCA-UNESP, Cx: 237, CEP: 18.603-970, Botucatu Carlos Tadeu dos Santos DiasDepartamento de Matemática e Estatística ESALQ-USP, Cx: 09, CEP: 13418-900, Piracicaba 1 RESUMO O experimento foi conduzido na área experimental de irrigação do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas - UNESP/Câmpus de Botucatu, com o objetivo de avaliar a concentração e distribuição de amônio, nitrito e nitrato provenientes do fertilizante uréia em um sistema de irrigação localizada por gotejamento.As amostras de solução do solo foram coletadas nas profundidades de 25, 50 e 75cm em ambos os lados do gotejador (lado esquerdo e direito) com o uso de cápsulas porosas e as concentrações de amônio, nitrito e nitrato existentes foram determinadas em laboratório, utilizando um espectômetro de fluxo contínuo.A adubação via fertirrigação foi realizada com uréia nas doses de 0, 30 e 60 kg de N..ha-1 em três épocas de aplicação, com.a finalidade de estimar a concentração de nitrato, nitrito e amônio após a ultima fertirrigação. Os valores da concentração de amônio e nitrito encontrados nas amostras de solução do solo nos diferentes tratamentos, profundidades e bulbos não atingiram, na maioria das avaliações, teores utilizados como padrão (> 0,2 mg.L-1 e > 0,05mg.L-1, respectivamente). As concentrações de nitrato na solução do solo para as doses de nitrogênio avaliadas nas três profundidades (25, 50 e 75 cm) estudadas não apresentaram diferença significativa, entretanto a concentração de nitrato em relação a posição do gotejador no sentido do fluxo da água foi estatisticamente maior no lado esquerdo, em virtude da declividade do terreno.A baixa concentração de nitrato encontrada na solução do solo por aplicação de uréia, sugere a realização de outros estudos a respeito da concentração e caminhamento do nitrato no solo com o tempo. Para isso recomenda-se um tempo de espera para a coleta de amostras de solução do solo em torno de 30 a 40 dias após aplicação do fertilizante. Outro fator a ser considerado é com relação a instalação dos extratores de cápsulas porosas, que deve ser realizada pouco tempo (1 a 2 dias) antes das amostragens, evitando obstruções das mesmas. UNITERMO: amônio, nitrito, nitrato, fertirigação, gotejamento, cápsula porosa. GOMES, T. M., SAAD, J. C. C., CRUZ, R. L., DIAS, C.T. dos S. Evaluation of the concentration and distribution of nitrite, ammonium e nitrate deriving from the urea applied through trickle irrigation system 2 ABSTRACT This experiment was conducted in the experimental irrigation area of the Department of Rural Engineering of the Faculty of Agronomicae Sciences - UNESP/ Campus of Botucatu, with the objective of evaluating the concentration and distribution of ammonium, nitrite and nitrate deriving from the fertilizer urea in a trickle irrigation localized system.The samples of the soil solution were collected at depths of 25, 50 and 75 cm on both sides of the trickle (left and right side) using porous capsules and the existing concentrations of ammonium, nitrite and nitrate were determined in the laboratory, using a spectrophotometer of continuous flow.The application of fertilizer through fertigation was done with urea in the levels of 0, 30 and 60 kg of N.ha-1 in three times of application, with the aim to estimate the concentration of nitrate, nitrite and ammonium after the last fertigation.The values of the concentrations of ammonium and nitrite found in the samples of the soil solution in the different treatments, depths and bulbs did not reach, in most of the evaluations, contents utilized as standard (>0.2 mg.L-1 and >0.05 mg.L-1, respectively). The concentrations of nitrate in the soil solution for the levels of nitrogen evaluated at the three depths (25, 50 and 75 cm) studied did not show significative difference, although the concentration of nitrate in relation to the position of the trickle in the direction of the water flow was statistically higher on the left side, due to the slope of the soil.The low concentration of nitrate found in the soil solution due to urea application, suggest the accomplishment of other studies involving the concentration and nitrate movement in the soil with the time. Therefore, we recommend a waiting period for the collection of the samples of the soil solution of about 30 to 40 days after the fertilizer application. Another factor to be considered is the installation of extractor of porous capsules, that must be done shortly after (1 to 2 days) the collection of samples, avoiding obstructions in the porous capsules. KEI-WORDS: ammonium, nitrite, nitrate, fertigation, trickle irrigation system, porous capsules.[1] Parte da dissertação do primeiro autor
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Bhusal, Arjun, e Peter M. Muriana. "Isolation and Characterization of Nitrate Reducing Bacteria for Conversion of Vegetable-Derived Nitrate to ‘Natural Nitrite’". Applied Microbiology 1, n. 1 (5 marzo 2021): 11–23. http://dx.doi.org/10.3390/applmicrobiol1010002.
Testo completoAbstract (sommario):
In the US, sodium nitrate is used as a preservative and curing agent in processed meats and is therefore a regulated ingredient. Nitrate reducing bacteria (NRB) can convert vegetable nitrate into nitrite allowing green/clean label status in the US as per the USDA-FSIS definition of ‘natural nitrite’. The current ‘in-liquid’ test tube assay for detecting nitrite is not suitable for screening mixtures of bacteria nor is commercial nitrate broth suitable for growth of many Gram (+) bacteria. M17 broth was therefore used to develop M17-nitrate broth to be inclusive of Gram (+) bacteria. An ‘on-agar’ colony-screening assay was developed to detect the conversion of nitrate to nitrite on agar plates and could detect one NRB+ colony among ~300–500 colonies on a single plate. Samples that might have NRB were spread-plated on M17 agar plates, sandwiched with nitrate agar, and after incubation followed with sequential agar overlays containing the reagents used in the nitrate reduction assay; the appearance of red color zones above colonies indicated the presence of nitrite. NRB derived from various samples were confirmed for nitrate conversion and both nitrate and nitrite were quantified by C8 reversed-phase (RP) ion-pairing high performance liquid chromatography (HPLC) analysis (1 ppm limit of detection). Staphylococcus carnosus, a strain commonly used for nitrate reduction, was able to convert 1100 ppm M17-nitrate broth to 917 ppm nitrite. Staphylococcus caprae and Panteoa agglomerans, NRB isolated using the M17-nitrate agar assay, were also able to ferment the same broth to 916 ppm and 867 ppm nitrite, respectively. This is the first report of an on-agar colony screening assay for the detection and isolation of nitrite reducing bacteria allowing NRB to be readily isolated. This may allow for the identification of new bacteria that may have a more efficient process to generate nitrite, and possibly concomitant with production of additional natural antimicrobials, as vegetable nitrite becomes more widely used to prevent spore germination.
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Dorosh, L. S., T. B. Peretyatko e S. P. Gudz. "The patterns of utilization of sulfate and nitrate ions by bacteria Desulfomicrobium sp. CrR3 and Desulfovibrio desulfuricans Ya-11". Visnyk of Dnipropetrovsk University. Biology, medicine 6, n. 2 (23 giugno 2015): 156–60. http://dx.doi.org/10.15421/021528.
Testo completoAbstract (sommario):
The aim of this work was to study the patterns of utilization of sulfate and nitrate ions by bacteria Desulfomicrobium sp. CrR3 and Desulfovibrio desulfuricans Ya-11 under different cultivation conditions. Chromium-resistant sulfate-reducing bacteria Desulfomicrobium sp. CrR3 and D. desulfuricans Ya-11 were used. Bacteria were grown in Posgate C medium at 30°C in 25 ml test tubes under anaerobic conditions. To test the ability of bacteria Desulfomicrobium sp. CrR3 and D. desulfuricans Ya-11 to use various substances and ions as electron acceptors, they were incubated in potassium phosphate buffer (10 mM, pH 7) with sulfate, nitrate and nitrite ions in concentrations of 1, 5 and 10 mM. At various concentrations of sulfate ions (1, 5 and 10 mM), biomass of bacteria Desulfomicrobium sp. CrR3 and D. desulfuricans Ya-11 increased with the increase of concentration of electron acceptor, the maximum biomass was equal to 3.65 and 3.05 g/l at 10 mM of sulfate ions, respectively. With the increase of concentration of nitrate ions to 5 mM the biomass increased by 70% compared to the biomass of bacteria grown in the medium with nitrate ions at the concentration 1 mM. The maximal biomass was determined in the presence of nitrate ions at a concentration of 10 mM – 3.78 and 3.15 g/l for bacteria Desulfomicrobium sp. CrR3 and D. desulfuricans Ya-11, respectively. It is found, as a result of incubation of bacteria Desulfomicrobium sp. CrR3 and D. desulfuricans Ya-11, that by introducing sulfate ions at a concentration of 5 mM bacteria Desulfomicrobium sp. CrR3 used 98%, while D. desulfuricans Ya-11 used only 86%, and under these conditions hydrogen sulfide has been detected in the incubation mixture at the concentration of 0.8–1.0 mM. In the presence of 10 mM of sulfate ions efficiency of electron acceptors utilization was equal to 85–95% for both strains. Bacteria Desulfomicrobium sp. CrR3 intensively used nitrate ions, the efficiency of electron acceptor utilization at 10 mM was equal to 92.8%, while for D. desulfuricans Ya-11 the usage percent amounted to 73% only, and nitrite ions were not observed after three days of incubation. It is established that bacteria Desulfomicrobium sp. CrR3 and D. desulfuricans Ya-11 are capable to use sulfate and nitrate ions as electron acceptors in the process of the disimilatory sulfate and nitratre reduction. As a result of the study of patterns of nitrate utilization by Desulfomicrobium sp. CrR3 and D. desulfuricans Ya-11 it is found that bacteria use nitrate as a nitrogen source for biosynthetic processes, and as electron acceptors. Under these conditions nitrates are reduced to nitrites, and then they are turned to ammonium.