Studies on soil organic matter: Part I. The chemical nature of soil organic nitrogen

1949 ◽  
Vol 39 (2) ◽  
pp. 183-193 ◽  
Author(s):  
J. M. Bremner
Keyword(s):  
Amino Acids ◽  
Acid Hydrolysis ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Chemical Nature ◽  
Nitrogen Compounds ◽  
Soil Organic Nitrogen ◽  
Reducing Conditions ◽  
Nitrogen Contents ◽  
Hydrolysis Of

1. The acid hydrolysis of six soils with nitrogen contents ranging from 0·1 to 2·38% has been studied by determining the amounts of ammonia-, humin- and α-amino-N present in the soil hydrolysates after various periods of hydrolysis.2. Under the conditions of hydrolysis employed (3 ml. of 6N-HCl/g. soil) the period required for maximum liberation of amino-acids from the soils was about 12 hr. 24·2–37·1% of the total-nitrogen of the soils examined was liberated as α-amino-N in this period. Further hydrolysis led to destruction of amino-acids. Similar amounts of α-amino-N were liberated by hydrolysis of the soils with alkali (5N-NaOH).3. From 69 to 87% of the total-nitrogen of the soils was brought into solution by acid hydrolysis; the amount dissolved by hydrolysing with alkali or with alkali under reducing conditions (alkalistannite) was not significantly different. It is concluded that most of the insoluble-nitrogen found after acid hydrolysis is not derived from protein material, and it is suggested that some of this nitrogen is in the form of heterocyclic nitrogen compounds.

scholarly journals Studies on the nitrogen compounds of the faeces of dairy cows fed urea as the sole or partial source of nitrogen

1979 ◽  
Vol 51 (1) ◽  
pp. 506-513
Author(s):  
Terttu Ettala ◽  
Matti Kreula
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dairy Cows ◽  
Acid Hydrolysis ◽  
Free Amino Acid ◽  
Total Nitrogen ◽  
Free Amino ◽  
Diaminopimelic Acid ◽  
Nitrogen Compounds ◽  
Soluble Nitrogen

The nitrogen compounds of the faeces of dairy cows on purified, protein-free feed with urea and small amounts of ammonium salts as the sole source of nitrogen (0-feed). on low-protein feed in which part of the protein was replaced with urea (ULP-feed) and on normal protein-containing feed (NorP-feed) were studied. The total nitrogen contents of the dry matter of the faeces were 2.5 ± 0.7 % on 0-feed, 2.4 ± 0.4 % on ULP-feed and 2.3 ± 0.6 % on NorP-feed. The proportion of urea- and ammonium nitrogen of the total nitrogen was 3.2 ± 2.4, 4.5 ± 2.4 and 3.7 ± 1.8 % respectively, and the proportion of nitrogen soluble in 70 % ethanol 10.9 ± 5.7, 9.9 ± 2.4 and 10.4 ± 3.8 % of the total nitrogen; the proportion of nitrogen in the free amino acid fraction was 4.1 ±2.9 on 0-feed, 1.6 ± 1.4 (P < 0.05) on ULP-feed and 3.2 ± 2.9 % on NorP-feed. The nitrogen insoluble in 70 % ethanol as a proportion of the total nitrogen was 82.3 ± 7.2 on 0-feed, 85.4 ± 5.0 on ULP-feed and 82.3 ± 7.2 % on NorP-feed. Of the total nitrogen of this insoluble fraction, the following proportions were released as amino acids by acid hydrolysis: 62.15 ± 8.5 % on 0-feed, 61.6 ± 10.7 % on ULP-feed and 59.0 ± 13.9% on NorP-feed. (α, Ɛ-diaminopimelic acid was 1.7 ± 0.6, 0.7 ± 0.2 (P < 0.05) and 1.2 ± 0,4 mol % respectively of the total amino acids of the hydrolyzate. The soluble nitrogen fraction was separated into free amino acid and »peptide» fractions, and the amino acid composition of both was determined, the latter after acid hydrolysis

Studies on the estimation and decomposition of amino sugars in soil

1954 ◽  
Vol 44 (2) ◽  
pp. 152-159 ◽  
Author(s):  
J. M. Bremner ◽  
K. Shaw
Keyword(s):  
Nucleic Acid ◽  
Acid Hydrolysis ◽  
Ammonium Sulphate ◽  
Total Nitrogen ◽  
Amino Sugar ◽  
Decomposition Methods ◽  
Amino Sugars ◽  
Micro Organisms ◽  
Nitrogen Contents ◽  
Hydrolysis Of

1. The amounts of amino sugar-N present in acid hydrolysates of six soils with nitrogen contents ranging from 0·17 to 2·82% have been estimated by colorimetric and alkaline decomposition methods.2. Recovery of amino sugar-N after hydrolysis of chitin or glucosamine was found to be unaffected by the presence of soil during hydrolysis.3. Substances known to interfere with the methods of amino sugar analysis employed were not detectable in the soil hydrolysates.4. From the amounts of amino sugar-N liberated by acid hydrolysis it is deduced that 5·10% of the total-nitrogen of the soils examined was in the form of amino sugars.5. The decomposition of amino sugars in soil has been studied by comparing the rates of decomposition of chitin, glucosamine, casein and yeast nucleic acid when incubated with soil under conditions found to produce rapid nitrification of ammonium sulphate.6. Glucosamine and chitin are readily decomposed by soil micro-organisms but not so rapidly as casein or yeast nucleic acid.

The autotrophic nutrition of symbiotic marine coelenterates with special reference to hermatypic corals. I. Movement of photosynthetic products between the symbionts

1971 ◽  
Vol 178 (1050) ◽  
pp. 111-129 ◽  
Keyword(s):  
Amino Acids ◽  
Organic Nitrogen ◽  
Sea Water ◽  
Nitrogen Compounds ◽  
Organic Substances ◽  
Low Concentrations ◽  
Steady Rate ◽  
Hermatypic Corals ◽  
Photosynthetic Products ◽  
Related Compounds

When symbiotic coelenterates, especially hermatypic corals, were incubated in the light in sea water containing NaH 14 CO 3 , small quantities of fixed 14 C were released from the tissues at a steady rate over 4 h. The rate of release was greatly increased in the presence of glycerol, glucose and alanine; the additional 14 C released was in the same substance as that added to the medium. The following related compounds had little or no effect on 14 C release : ethylene glycol, sorbose, fructose, glucosamine, glycine, proline, serine and glutamic acid. Such results have been previously reported in other symbiotic systems, and the substances causing the specific release of fixed 14 C are believed to be those which move from the autotrophic to the heterotrophic symbiont. This belief is supported here by previous observations that glycerol, glucose and alanine are among the most important organic substances released by freshly isolated zooxanthellae. Ammonium chloride increased the amount of fixed 14 C released by corals into alanine media, possibly due to conversion of ammonia to amino acids by zooxanthellae. Appreciable release of 14 C fixed in the dark also occurred into alanine solutions. These results suggest possible roles of zooxanthellae in supplying organic nitrogen compounds to the host cell at night as well as during the day. The involvement of zooxanthellae in ‘recycling’ nitrogen compounds within the association may help to explain the success of corals in seas poor in nutrients. There was substantial utilization of external glycerol and glucose when supplied at either high or low concentrations. Corals may well be able to utilize some of the small amounts of organic matter dissolved in sea water in the natural environment.

An Improved Raney Catalyst Powder Method for Determination of Nitrogen in Fertilizers

1965 ◽  
Vol 48 (6) ◽  
pp. 1111-1115
Author(s):  
W G Burch ◽  
J A Brabson
Keyword(s):  
Sulfuric Acid ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Nitrogen Compounds ◽  
Test Results ◽  
Powder Method ◽  
Catalyst Powder ◽  
Good Agreement

Abstract With a Raney catalyst powder containing 10% Co, 40%; Ni, and 50% Al, nitrates are reduced to ammonia in 8N sulfuric acid in 10 minutes. Neither chlorides nor organic nitrogen compounds interfere with the reduction, and the reduction passed Youden’s ruggedness test. Results of analyses of fertilizers for total nitrogen that included reduction with the powder were in good agreement with those of accepted methods.

scholarly journals Acid Hydrolysis of Phenylthiohydantoins of Amino Acids

1971 ◽  
Vol 24 (4) ◽  
pp. 1247 ◽  
Author(s):  
AS Inglis ◽  
PW Nicholls ◽  
CM Roxburgh
Keyword(s):  
Amino Acids ◽  
Hydrochloric Acid ◽  
Thin Layer ◽  
Acid Hydrolysis ◽  
Free Amino ◽  
Hydriodic Acid ◽  
Ultraviolet Spectroscopy ◽  
Quantitative Identification ◽  
Layer Chromatography ◽  
Hydrolysis Of

The phenylthiohydantoins (PTHs) derived from amino acids were hydrolysed in boiling hydriodic acid for 24 hr. Good yields of free amino acids were obtained for all PTH derivatives except methionine. In contrast to hydrolysis with hydrochloric acid, hydrolysis with hydriodic acid converts PTH-threonine, PTH-serine, and PTH-tryptophan respectively to oc-amino-n-butyric acid, alanine, and a mixture (approx. 2: 1) of glycine and alanine. This procedure provides a useful adjunct to thin-layer chromatography and ultraviolet spectroscopy for quantitative identification of the PTH derivative.

Tellurium as Catalyst in Semimicro Kjeldahl Method for Total Nitrogen Determination

1982 ◽  
Vol 65 (4) ◽  
pp. 786-790
Author(s):  
Christina F-H Liao
Keyword(s):  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Complete Recovery ◽  
Nitrogen Compounds ◽  
Nitrogen Determination ◽  
Plant Soil ◽  
Clearing Time ◽  
Kjeldahl Digestion ◽  
Kjeldahl Method ◽  
Agricultural Materials

Abstract A modified semimicro Kjeldahl procedure is described for total nitrogen determination in agricultural materials and refractory organic nitrogen compounds, in which tellurium, alone or in combination with copper, is used as a catalyst. Tellurium alone is adequate for complete recovery of nitrogen from nicotinic acid if the acid:salt ratio is carefully controlled to nearly 1. However, when a mixture of tellurium and copper is used, complete nitrogen recovery could be obtained at a higher acidrsalt ratio. Use of a mixture also reduces clearing time when compared with copper alone in the Kjeldahl digestion. For samples containing nitrate, a Devarda's alloy (Cu:Al:Zn = 10:9:1) is proposed as a reducing agent in the pretreatment procedure to convert nitrate to ammonium in 6N H2SO4, with subsequent digestion of the sample by using a mixture of K2S04-catalyst and concentrated H2SO4. The proposed method is applicable for total nitrogen determination including NO3-N in plant, soil, and fertilizer samples.

D-Mannitol Interferes with Amino Acid Analysis of Marine Organisms

1979 ◽  
Vol 36 (9) ◽  
pp. 1134-1137 ◽  
Author(s):  
W. Fong ◽  
R. K. O'dor
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Hydrolysis ◽  
Key Words ◽  
Amino Acid Analysis ◽  
Chromatographic Analysis ◽  
Marine Algae ◽  
Protein S ◽  
New Compounds ◽  
Hydrolysis Of

Acid hydrolysis of a protein in the presence of D-mannitol, a common constituent of marine algae, can cause significant reductions in the recovery of a number of amino acids. The new compounds formed by the interactions of D-mannitol and these amino acids may interfere in the chromatographic analysis of other amino acids. The recoveries of most of the amino acids appear to be either directly or inversely proportional to the amount of D-mannitol added to a protein sample before acid hydrolysis. These results suggest that it is necessary to determine the effects of contaminants in a sample of protein(s) on the recoveries of amino acids during routine acid hydrolysis. Key words: kelp, amino acids, carbohydrates, D-mannitol

ASSIMILATE DISTRIBUTION AND UTILIZATION IN MAIZE

1978 ◽  
Vol 58 (3) ◽  
pp. 719-730 ◽  
Author(s):  
N. A. FAIREY ◽  
T. B. DAYNARD
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Organic Nitrogen ◽  
Initial Rate ◽  
Nitrogen Compounds ◽  
Stem Tissue ◽  
Crop Canopy ◽  
The Third ◽  
Structural Carbohydrate

The dynamics of distribution and utilization of assimilates from three leaf positions, i.e. the ear leaf (0) and the third leaves above (+3) and below (−3) the ear leaf, in a maize canopy were determined for plants labelled with 14CO2 at 10 days after silk emergence. The initial rate of translocation of assimilates (principally sugars) from leaf blades increased with the height of the leaf in the crop canopy. However, by 21 days after labelling no differences in 14C retention among leaf positions were evident. Sugars from source leaves were gradually utilized in the synthesis of starch and residual matter (principally protein and structural carbohydrate) as they were distributed throughout the plant. Carbon incorporated by the −3 leaf was recovered in free amino acids plus amides and organic acids to a greater extent than that incorporated by the +3 or 0 leaves. Temporary storage of sugars in stem tissue was evident for all three labelled-leaf treatments; the sugars were ultimately used in the synthesis of starch, lipid plus pigment and residual matter of kernels. Some carbon incorporated by lower leaves appeared to be cycled through the root system, possibly being returned to the shoot in organic nitrogen compounds.

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