Microchemical determination of organic nitrogen with nessler reagent

Morrison, George R.

doi:10.1016/0003-2697(71)90283-1

Cited by 45 publications

(21 citation statements)

References 6 publications

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“…The total nitrogen was determined with the Kjeldahl method, according to the Polish standard PN-EN 13342: 2002. The content of ammonia nitrogen was determined using the Nessler method (Morrison 1971) with a spectrophotometer HACH DR/2000 (Hach Inc., Loveland, United States) with software version 3.0. Absorbance was measured at a wavelength λ = 425 nm.…”

Section: Physicochemical Properties Of Fermentation Substrates Biomamentioning

confidence: 99%

Characterization and Influence of a Multi-enzymatic Biopreparation for Biogas Yield Enhancement

Oszust¹,

Pawlik²,

Janusz³

et al. 2017

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A multi-enzymatic biopreparation of Trichoderma atroviride G79/11 origin was characterized. The fungus showed relatively high cellulase production in a soybean flour-cellulose-lactose medium. Subsequently, based on its post-culture liquid, the biopreparation of the enzyme mixture was developed and characterized. The liquid form of the enzyme mixture reached 22 U cm -3 of cellulolytic activity and its lyophilisate exhibited 1.09 U cm -3 at pH 5.1 and 50 °C. The enzyme mixture was characterized by the following activities: xylanase, β-glucosidase, carboxymethyl cellulase, polygalactouronase, pectinesterase, amylase, lactase, and protease. A method for an efficient conditioning process of organic waste (fruit processing waste, dairy sewage sludge, corn silage, and grain broth) for biogas yield enhancement using the enzyme mixture was proposed. The enzyme mixture increased the efficacy of biogas production by 30% when the lyophilizate (0.5 mg g -1 d.m.) was applied prior to fermentation. A method for conducting the enzymatic conditioning process of organic waste using the enzyme mixture as a pretreatment was proposed. This was part of the optimization of the methane fermentation process to increase the biogas yield. Consequently, after application of the biopreparation, the efficiency of anaerobic digestion of organic waste was improved.

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Section: Physicochemical Properties Of Fermentation Substrates Biomamentioning

confidence: 99%

Characterization and Influence of a Multi-enzymatic Biopreparation for Biogas Yield Enhancement

Oszust¹,

Pawlik²,

Janusz³

et al. 2017

BioResources

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“…Following enzyme addition, 0.5-mL aliquots were removed and mixed with equal volumes of Nessler reagent (Merck), which had been diluted 1:3 with water. The amount of ammonia formed was determined by monitoring the absorbance at 420 nm within 1-5 min after addition of the Nessler reagent [42]. One unit of cyanase is defined as the amount of enzyme which catalyses the formation of 1 µmol of ammonia per minute under the assay conditions described above.…”

Section: Cyanase Activity Determinationmentioning

confidence: 99%

Flow-injection spectrophotometric determination of cyanate in bioremediation processes by use of immobilised inducible cyanase

et al. 2003

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A new flow injection (FI) method for photometric monitoring of cyanate in bioremediation processes using immobilised native cyanase is described. The method is based on the catalytic reaction between cyanate and bicarbonate to produce ammonia and carbon dioxide in the presence of an inducible native cyanase, immobilised in a reactor packed with glass beads. Two degrees of purification of the biocatalyst were used-heated cell-free extract and purified extract of cyanase from Pseudomonas pseudoalcaligenes CECT 5344. The ammonia produced by the enzymatic reaction is finally monitored photometrically at 700 nm using a modification of the conventional Berthelot method. The method furnishes different calibration curves depending on the degree of purification of the cyanase, with linear ranges between 1.23 and 616.50 micromol L(-1) ( r(2)=0.9979, n=7) and between 1.07 and 308.25 micro mol L(-1) ( r(2)= 0.9992, n=7) for the heated cell-free extract and the purified cyanase extract, respectively. No statistically significant differences between the samples were found in the precision study evaluated at two cyanate concentration levels using one-way analysis of variance. A sampling frequency of 15 h(-1) was achieved. The method was used to monitor cyanate consumption in a cyanate bioremediation tank inoculated with Pseudomonas pseudoalcaligenes CECT 5344 strain. The correlation between cyanate degradation and ammonia production was tested using a conventional method. Finally, the method was applied to different samples collected from the bioremediation tank using the standard addition method; recoveries between 85.9 and 97.4% were obtained.

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“…Bacterial growth was monitored by following OD 600 . Ammonium concentration was determined using Nessler reagent, as described by Morrison (1971). Free cyanide concentration was determined colorimetrically (Asmus & Garschagen, 1953).…”

Section: Methodsmentioning

confidence: 99%

Cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 involves a malate : quinone oxidoreductase and an associated cyanide-insensitive electron transfer chain

et al. 2011

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The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 is able to grow with cyanide as the sole nitrogen source. Membrane fractions from cells grown under cyanotrophic conditions catalysed the production of oxaloacetate from L-malate. Several enzymic activities of the tricarboxylic acid and glyoxylate cycles in association with the cyanide-insensitive respiratory pathway seem to be responsible for the oxaloacetate formation in vivo. Thus, in cyanide-grown cells, citrate synthase and isocitrate lyase activities were significantly higher than those observed with other nitrogen sources. Malate dehydrogenase activity was undetectable, but a malate : quinone oxidoreductase activity coupled to the cyanide-insensitive alternative oxidase was found in membrane fractions from cyanide-grown cells. Therefore, oxaloacetate production was linked to the cyanide-insensitive respiration in P. pseudoalcaligenes CECT5344. Cyanide and oxaloacetate reacted chemically inside the cells to produce a cyanohydrin (2-hydroxynitrile), which was further converted to ammonium. In addition to cyanide, strain CECT5344 was able to grow with several cyano derivatives, such as 2-and 3-hydroxynitriles. The specific system required for uptake and metabolization of cyanohydrins was induced by cyanide and by 2-hydroxynitriles, such as the cyanohydrins of oxaloacetate and 2-oxoglutarate.

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Microchemical determination of organic nitrogen with nessler reagent

Cited by 45 publications

References 6 publications

Characterization and Influence of a Multi-enzymatic Biopreparation for Biogas Yield Enhancement

Characterization and Influence of a Multi-enzymatic Biopreparation for Biogas Yield Enhancement

Flow-injection spectrophotometric determination of cyanate in bioremediation processes by use of immobilised inducible cyanase

Cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 involves a malate : quinone oxidoreductase and an associated cyanide-insensitive electron transfer chain

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