THE UTILIZATION OF AMMONIUM CHLORIDE-15N BY UREDOSPORES OF WHEAT STEM RUST

1966 ◽  
Vol 44 (11) ◽  
pp. 1511-1518 ◽  
Author(s):  
W. B. McConnell ◽  
E. W. Underhill

When uredospores of wheat stem rust, Puccinia graminis van tritici (race 15B), were incubated with a 3 mM solution of ammonium chloride-15N, a significant amount of nitrogen 15 was converted into organic nitrogen. Most of this organic nitrogen 15 was found in the ethanol and water extracts, with lesser amounts in the buffer and in extracted spores.Amino acids extracted from the spores all contained excess nitrogen 15. Nitrogen 15 from the inorganic source was diluted by factors of 1.7 and 2.7 in free aspartic and glutamic acids respectively; these amino acids were the most heavily labeled with the isotope. Proline was the most weakly labeled amino acid, the nitrogen 15 being diluted by a factor of 102. Good incorporation of nitrogen 15 into glutamic acid compared to simultaneous poor incorporation into the biochemically related amino acid, proline, parallels previous observations made during carbon 14 experiments with rust uredospores.Fourteen "bound" amino acids were isolated after acid hydrolysis of extracted spores. All contained nitrogen 15, the dilution of the added ammonia nitrogen ranging from 96 for glutamic acid to 7660 for proline.The results are taken as evidence that uredospores of wheat stem rust can incorporate ammonium nitrogen into free amino acids and into proteins.

1963 ◽  
Vol 41 (3) ◽  
pp. 737-743 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell ◽  
G. A. Ledingham

When uredospores of wheat stem rust were shaken for 3 hours with phosphate buffer (pH 6.2) containing propionate-1-C14, -2-C14, or -3-C14, about 55% of the carbon-14 was removed from the solution. With propionate-1-C14, most of the carbon-14 taken up was released as carbon dioxide-C14, whereas about 20% and 31% of propionate carbon 2 and carbon 3, respectively, was incorporated into the spores. The specific activity of a fraction consisting of the free amino acids of a hot-alcohol and hot-water extract of the spores increased markedly with increase in the position number of propionate in which the carbon-14 was located. A similar relation was observed for other fractions such as soluble carbohydrates, ether-soluble material, organic acids, and insoluble residue from spores. The most active amino acids isolated were glutamic acid, γ-aminobutyric acid, and alanine. Partial degradations showed that with propionate-2-C14 the carboxyl groups of glutamic acid were especially radioactive, whereas with propionate-3-C14 the internal carbons were most radioactive.It is concluded that propionate metabolism in the rust spores involved conversion of carbon 1 to carbon dioxide, and utilization of carbons 2 and 3 as acetate with carbon 2 behaving as the carboxyl carbon.


1963 ◽  
Vol 41 (1) ◽  
pp. 737-743 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell ◽  
G. A. Ledingham

When uredospores of wheat stem rust were shaken for 3 hours with phosphate buffer (pH 6.2) containing propionate-1-C14, -2-C14, or -3-C14, about 55% of the carbon-14 was removed from the solution. With propionate-1-C14, most of the carbon-14 taken up was released as carbon dioxide-C14, whereas about 20% and 31% of propionate carbon 2 and carbon 3, respectively, was incorporated into the spores. The specific activity of a fraction consisting of the free amino acids of a hot-alcohol and hot-water extract of the spores increased markedly with increase in the position number of propionate in which the carbon-14 was located. A similar relation was observed for other fractions such as soluble carbohydrates, ether-soluble material, organic acids, and insoluble residue from spores. The most active amino acids isolated were glutamic acid, γ-aminobutyric acid, and alanine. Partial degradations showed that with propionate-2-C14 the carboxyl groups of glutamic acid were especially radioactive, whereas with propionate-3-C14 the internal carbons were most radioactive.It is concluded that propionate metabolism in the rust spores involved conversion of carbon 1 to carbon dioxide, and utilization of carbons 2 and 3 as acetate with carbon 2 behaving as the carboxyl carbon.


1964 ◽  
Vol 42 (3) ◽  
pp. 327-332 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell

Uredospores of wheat stem rust took up about 90% of the carbon-14 present either as valerate-3-C14 or as valerate-5-C14 in M/30 phosphate buffer pH 6.2 in 3 hours. The initial valerate concentration was 0.017 mM and spores were supplied at the rate of 250 mg/30 ml of buffer. Carbon 3 of the valerate was largely respired as carbon dioxide but carbon 5 was extensively incorporated into spore components. Free amino acids contained about 40% of the radioactivity in the spores labelled with valerate-5-C14 and glutamic acid was highly labelled. Carbon 1 contained 8.1% and carbon 5, 3.8% of the carbon-14 in this glutamic acid and thus internal carbons contained 88%. The results with valerate-3-C14 and with valerate-5-C14 compare well with those of experiments done earlier with propionate-1-C14 and propionate-3-C14 respectively. It is concluded that propionate is formed from carbons 3, 4, and 5 of valerate, and thus that carbon 3 is converted to carbon dioxide, and carbons 4 and 5 to the carboxyl and methyl groups respectively of acetate.


1964 ◽  
Vol 96 (8) ◽  
pp. 1133-1137 ◽  
Author(s):  
R. Kasting ◽  
A. J. McGinnis

AbstractGlucose-U-C14 was incorporated into immature larvae of the wheat stem sawfly, Cephus cinctus Nort., by vacuum-infiltration. These insects were too small to be conveniently injected and could not be easily fed on artificial diets. About half of them survived the infiltration treatment. C14O2 was produced by the organism showing that the radioactive substrate was metabolized. Of the amino acids isolated from the larvae, proline, alanine, glutamic acid, serine, aspartic acid, and glycine contained relatively large quantities of carbon-14 indicating biosynthesis, and are classed as nutritionally non-essential. In contrast, arginine, isoleucine, leucine, lysine, phenylalanine, threonine, tyrosine, and valine contained little, if any, radioactivity and are classed as nutritionally essential. The concentrations of some of the amino acids in the larval tissues are also presented.


1965 ◽  
Vol 43 (1) ◽  
pp. 91-96 ◽  
Author(s):  
S. Suryanarayanan ◽  
W. B. McConnell

Uredospores of Puccinia graminis var. tritici were incubated in phosphate buffer (pH 6.2) containing pelargonic acid-1-C14. After 3 hours 97.5% of the tracer was assimilated. Fifty-five percent of this was released as C14O2 and 36.2% was incorporated into the spores. About one-half of the carbon-14 in the spores was soluble in ethanol and water, whereas nearly a third was ether extractable. The amino acid and carbohydrate fractions contained about equal amounts of carbon-14 and together accounted for two-thirds of the radioactivity in the ethanol–water extract. The organic acids were also radioactive. Glutamic acid, γ-aminobutyric acid, aspartic acid, and alanine were the most highly labelled amino acids. Fifty-three percent of the radioactivity in glutamic acid was found in carbon 1 and 46% in carbon 5. This distribution suggests β-oxidation of pelargonic acid to acetyl CoA and extensive utilization of the latter by means of the glyoxylate cycle.


1956 ◽  
Vol 2 (6) ◽  
pp. 559-563 ◽  
Author(s):  
P. Shu ◽  
A. C. Neish ◽  
G. A. Ledingham

Uredospores of wheat stem rust utilized a number of externally-supplied, labelled carbohydrates, amino acids, and volatile fatty acids. The carbon of these substrates appeared in the spore materials and in the carbon dioxide. This metabolic activity, though very weak, is definite. D-Mannose, D-mannitol, D-glucose, sucrose, and D-fructose were utilized better than the other carbohydrates. Glutamic acid gave the highest yield of carbon dioxide while the basic amino acids, L-arginine and L-lysine, were more efficiently incorporated into the spore material.


1971 ◽  
Vol 17 (10) ◽  
pp. 1319-1325 ◽  
Author(s):  
J. A. Leal ◽  
M. E. Gallegly ◽  
V. G. Lilly

The value of 21 amino acids as nitrogen sources for Phytophthora cactorum (Leb. and Cohn) Schroet. and P. heveae Thompson has been studied using the dry weights of mycelium, changes in the pH values of the culture media, and the accumulation of ammonium nitrogen in the culture media as the criteria. Two concentrations of each amino acid were used to furnish 106 and 424 mg N/liter. The three parameters mutually supported each other in dividing the amino acids into two groups, poor and good.The following amino acids were poor sources of nitrogen for both species: L-hydroxyproline, L-isoleucine, L-leucine, L-lysine, L-methionine, and L-tryptophan. L-Phenylalanine was a good amino acid for P. cactorum, and a poor amino acid for P. heveae. L-Cysteine and L-valine were good sources of nitrogen for P. heveae, but poor nitrogen sources for P. cactorum. The following amino acids were good sources of nitrogen for both species: L-α-alanine, L-arginine, L-asparagine, L-aspartic acid, L-glutamine, L-glutamic acid, glycine, L-histidine, L-proline, L-serine, L-threonine, and L-tyrosine.


1967 ◽  
Vol 168 (1013) ◽  
pp. 421-438 ◽  

The uptake of thirteen essential amino acids by mouse LS cells in suspension culture was determined by bacteriological assay methods. Chemostat continuous-flow cultures were used to determine the effect of different cell growth rates on the quantitative amino acid requirements for growth. The growth yields of the cells ( Y = g cell dry weight produced/g amino acid utilized) were calculated for each of the essential amino acids. A mixture of the non-essential amino acids, serine, alanine and glycine increased the cell yield from the essential amino acids. The growth yields from nearly all the essential amino acids in batch culture were increased when glutamic acid was substituted for the glutamine in the medium. The growth yields from the amino acids in batch culture were much less at the beginning than at the end of the culture. The highest efficiencies of conversion of amino acids to cell material were obtained by chemostat culture. When glutamic acid largely replaced the glutamine in the medium the conversion of amino acid nitrogen to cell nitrogen was 100 % efficient (that is, the theoretical yield was obtained) at the optimum growth rate (cell doubling time, 43 h). The maximum population density a given amino acid mixture will support can be calculated from the data. It is concluded that in several routinely used tissue culture media the cell growth is limited by the amino acid supply. In batch culture glutamine was wasted by (1) its spontaneous decomposition to pyrrolidone carboxylic acid and ammonia, and (2) its enzymic breakdown to glutamic acid and ammonia, but also glutamine was used less efficiently than glutamic acid. Study of the influence of cell growth rate on amino acid uptake rates per unit mass of cells indicated that a marked change in amino acid metabolism occurred at a specific growth rate of 0.4 day -1 (cell doubling time, 43 h). With decrease in specific growth rate below 0.4 day -1 there was a marked stimulation of amino acid uptake rate per cell and essential amino acids were consumed increasingly for functions other than synthesis of cell material.


Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2431
Author(s):  
Nicola Landi ◽  
Sara Ragucci ◽  
Antimo Di Maro

Cow, sheep and goat raw milk raised in Ailano and Valle Agricola territories (‘Alto Casertano’, Italy) were characterized (raw proteins, free and total amino acids content) to assess milk quality. Raw milk with the highest total protein content is sheep milk followed by goat and cow milk from both localities. Total amino acid content in cow, goat and sheep raw milk is 4.58, 4.81 and 6.62 g per 100 g, respectively, in which the most abundant amino acid is glutamic acid (~20.36 g per 100 g of proteins). Vice versa, the free amino acids content characteristic profiles are different for each species. In particular, the most abundant free amino acid in cow, sheep and goat raw milk is glutamic acid (9.07 mg per 100 g), tyrosine (4.72 mg per 100 g) and glycine (4.54 mg per 100 g), respectively. In addition, goat raw milk is a source of taurine (14.92 mg per 100 g), retrieved in low amount in cow (1.38 mg per 100 g) and sheep (2.10 mg per 100 g) raw milk. Overall, raw milk from ‘Alto Casertano’ show a high total protein content and are a good source of essential amino acids.


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