Nitrogen requirements of the fungal endophytes of Arundina chinensis

1971 ◽  
Vol 49 (3) ◽  
pp. 407-410 ◽  
Author(s):  
R. C. Stephen ◽  
K. K. Fung

The nitrogen requirements of two Rhizoctonia fungus endophytes of the orchid Arundina chinensis are reported. Both isolates were capable of using ammonium and organic nitrogen but not nitrate or atmospheric nitrogen. Glutamic acid and urea were the best of the nitrogen sources tested followed by arginine, then asparagine. Proline and methionine were not used. The addition of a mixture of vitamins to the amino acids increased growth of one of the isolates but not the other. Yeast extract supported greatest growth.


1981 ◽  
Vol 59 (11) ◽  
pp. 2102-2107 ◽  
Author(s):  
Robert C. Evans ◽  
Candace L. Black

The effect of 23 organic and 3 inorganic nitrogen sources on growth, sporulation, and polyphenoloxidase activity was measured in Bipolaris maydis race T incubated with or without a xylose supplement. Mycelial dry weight tends to be highest on acidic and other polar amino acids and least on nonpolar ones; organic nitrogen sources generally result in greater dry weight than inorganic ones. Changes in nitrogen concentration and pH of media influence growth and sporulation, but only pH alters the relative effectiveness of the nitrogen sources on these processes. The addition of xylose to the growth media has little effect on growth. However, in the presence of lysine, serine, asparagine, glycine, γ-alanine, alanine, and α-aminobutyrate, xylose causes an increase in sporulation and a concomitant decrease in polyphenoloxidase activity. There is no consistent pattern resulting from xylose addition in the presence of the other nitrogen sources.



1977 ◽  
Vol 23 (10) ◽  
pp. 1360-1372 ◽  
Author(s):  
Mariette Carels ◽  
David Shepherd

Thirty-nine strains from the genus Monascus were cultivated aerobically to study the relation between nitrogen nutrition and sporulation and pigment production. The effects of yeast extract, nitrate, ammonium, and ammonium nitrate have been compared. During cultivation the pHs of the different media are not the same, resulting in the formation of different coloured pigments. When the source of nitrogen is yeast extract or nitrate the pH is around 6.5 and red pigments are formed, whereas with ammonium or ammonium nitrate the pH is around 2.5 and the pigments are orange. It is proposed that only the orange pigments, monascorubrin and rubropunctatin, are produced biosynthetically and that the other pigments are formed from these by chemical transformations depending on the cultural conditions. The presence of organic nitrogen is optimal for growth and unfavourable for pigment production. Reduced growth and best pigment formation occurs with the three other nitrogen sources. Nitrate stimulates conidiation and sexual reproduction, while ammonium is inhibitory. Pigment production is better when conidiation is reduced. A mechanism is proposed for the control of sporulation and pigment production.



1968 ◽  
Vol 3 (4) ◽  
pp. 515-527
Author(s):  
J. PIATIGORSKY ◽  
A. TYLER

Unfertilized and fertilized eggs of the sea urchin Lytechinus pictus were preloaded with [14C]valine and exposed to individual solutions of each of the twenty ‘coded’ [12C]amino acids in artificial sea water. After 1 h incubation the amount of radioactivity in the medium was determined. The radioactivity was effectively displaced by most of the other neutral [12C]amino acids that are known to compete with valine for uptake. A chromatographic test with fertilized eggs showed the displaced radioactivity to be [14C]valine and not some metabolic product. Addition of acidic, basic or some neutral amino acids that are known to be poor inhibitors of valine uptake did not cause significant quantities of label to appear in the medium. For the unfertilized eggs, the concentration of acid-soluble label remained many hundreds of times greater in the egg fluid than in the sea water. Tests indicated that efflux of [14C]valine and subsequent competition for re-entry is a primary factor responsible for the displacement phenomenon. That this may not be the sole factor is suggested by the fact that some amino acids that are known to be powerful inhibitors of valine uptake were found to be only weak displacers of [14C]valine. Neither [14C]arginine nor [14C]glutamic acid were displaced in significant amounts from preloaded unfertilized or fertilized eggs by any of the tested [12C]amino acids. Attempts were made to utilize the displacement of [12C]valine to elevate the incorporation of [14C]valine and of other labelled amino acids into protein by intact eggs. Unfertilized and fertilized eggs were pretreated with related [12C]amino acids and then exposed to [14C]valine or a mixture of [14C]amino acids. The results varied in the different tests, ranging from no significant increase to 2-fold.



2013 ◽  
Vol 726-731 ◽  
pp. 127-130
Author(s):  
Hua Jing Wang ◽  
Jin Li ◽  
Liang Huan Wu

A hydroponic experiment was carried out to determine influences of partial replacement of nitrate by ammonium and 20 amino acids of alanine (Ala), valine (Val), leucine (Leu), isoleucine (Ile), proline (Pro), phenylalanine (Phe), tryptophane (Trp), methionine (Met), aspartic acid (Asp), glutamic acid (Glu), lysine (Lys), arginine (Arg), histidine (His), glycine (Gly), serine (Ser), threonine (Thr), cysteine (Cys), tyrosine (Tyr), asparagines (Asn) and glutamine (Gln) on growths and concentrations of mineral elements of pakchoi (Brassica chinensis L.). Most of amino acids inhibit shoot growths of pakchoi. Different amino acids have various effects on concentrations of calcium (Ca), manganese (Mn), magnesium (Mg), iron (Fe), copper (Cu) and zinc (Zn) in shoots of pakchoi. There are differences in shoot fresh weights, dry weights and concentrations of mineral elements of pakchoi supplied with amino acids and ammonium.



1941 ◽  
Vol 14 (2) ◽  
pp. 300-307 ◽  
Author(s):  
R. F. A. Altman

Abstract In a previous paper the separation and analysis of proteins remaining in rubber serum, after coagulating the rubber with formic acid, were described. The present paper is concerned with the properties and identification of the products thus isolated. As for nonamino acids, it may be recalled that these are composed mainly of the unsaponifiable thick brownish red oil A4. Of the other byproducts remaining to be identified, which were designated as BII, BIII, BV and BVI, only small amounts were obtained. Of the amino acids, alanine, arginine, asparagic acid, glutamic acid, histidine, leucine, ornithine, hydroxyproline, proline, tyrosine and valine were isolated in weighable amounts. In addition to these, it was possible to identify dihydroxyphenylalanine. In this connection the results obtained by Midgley, Henne and Renoll are of interest. These investigators found, as the principal components of proteins occurring in crepe rubber, the following amino acids: arginine, asparagic acid, glycine, histidine, leucine, lysine and proline. They considered it highly probable that alanine, phenylalanine, hydroxyproline and serine were also present in these proteins. On the other hand, it was definitely established that cystine, glutamic acid and tyrosine were not present. Table I summarizes the results of Midgley and his coworkers in comparison with ours. From this table it is evident that certain proteins, viz., those containing, among other compounds, tyrosine, glutamic acid and valine, do not coagulate with the rubber, but remain in the serum. The absence of sulfur-containing amino acids can probably be attributed to certain shortcomings in the analytical method. At any rate, the presence of sulfur in proteins precipitated from latex was established when the test was repeated.



2020 ◽  
Vol 117 (46) ◽  
pp. 28572-28575
Author(s):  
Masayori Inouye ◽  
Risa Takino ◽  
Yojiro Ishida ◽  
Keiko Inouye

Among the 20 amino acids, three of them—leucine (Leu), arginine (Arg), and serine (Ser)—are encoded by six different codons. In comparison, all of the other 17 amino acids are encoded by either 4, 3, 2, or 1 codon. Peculiarly, Ser is separated into two disparate Ser codon boxes, differing by at least two-base substitutions, in contrast to Leu and Arg, of which codons are mutually exchangeable by a single-base substitution. We propose that these two different Ser codons independently emerged during evolution. In this hypothesis, at the time of the origin of life there were only seven primordial amino acids: Valine (coded by GUX [X = U, C, A or G]), alanine (coded by GCX), aspartic acid (coded by GAY [Y = U or C]), glutamic acid (coded by GAZ [Z = A or G]), glycine (coded by GGX), Ser (coded by AGY), and Arg (coded by CGX and AGZ). All of these were derived from GGX for glycine by single-base substitutions. Later in evolution, another class of Ser codons, UCX, were derived from alanine codons, GCX, distinctly different from the other primordial Ser codon, AGY. From the analysis of theEscherichia coligenome, we find extensive disparities in the usage of these two Ser codons, as some genes use only AGY for Ser in their genes. In contrast, others use only UCX, pointing to distinct differences in their origins, consistent with our hypothesis.



1981 ◽  
Vol 46 (1) ◽  
pp. 159-171 ◽  
Author(s):  
M. R. Taverner ◽  
I. D. Hume ◽  
D. J. Farrell

1. Pigs prepared with re-entrant ileal cannulas were used to determine the ileal availability of amino acids in nine cereal grains including five wheats, sorghum (Sorghum vulgare Pers.), maize, barley and Triticale.2. The average true availability of amino acids in these grains was 0·88 but there were consistent differences in availability among amino acids. Generally, lysine and threonine were among the least available amino acids while glutamic acid and arginine were among the most available amino acids in cereal protein.3. There was as much variation in amino acid availability within a grain species (wheat) as among the other grains.



Parasitology ◽  
1958 ◽  
Vol 48 (1-2) ◽  
pp. 149-164 ◽  
Author(s):  
June P. Thurston

1. Standard conditions are described for preparing suspensions of washed Trypanosoma lewisi and T. equiperdum in modified Ringer–phosphate solution.2. Oxygen consumption was measured with differential manometers, using microflasks containing 2–5 × 107 trypanosomes in 0·9 ml. of reaction mixture. Measurements of oxygen uptake were carried out at 37° C.3. T. lewisi respired slowly in the absence of substrate for up to 2 hr. The trypanosomes suffered little damage when stored at 5° C. for 24 hr. without substrate. No oxygen uptake was observed with T. equiperdum in the absence of substrate. The trypanosomes were viable after 24 hr. at 5° C. with glucose or glycerol as substrate, but not in the absence of substrate.4. With glucose as substrate, the rate of oxygen consumption by T. lewisi increased with the age of infection. This change was more marked with glutamine as substrate.5. With glucosamine as substrate, the oxygen uptake of T. lewisi was at a slightly lower rate than with glucose. The rate of oxygen uptake was still lower with Na l-glutamic acid, asparagine, aspartic acid, casein hydrolysate, yeast extract and Difco Bacto-peptone. Thirteen other amino-acids had no effect on the motility of the trypanosomes.6. With glycerol as substrate, the oxygen uptake of T. equiperdum was at a slightly lower rate than with glucose. The rate of oxygen uptake was very low with yeast extract, casein hydrolysate and Difco Bacto-peptone. No oxygen uptake or motility was recorded with glutamine, Na l-glutamic acid, glucosamine, asparagine, aspartic acid, dl-alanine, or Na acetate. Thirteen other amino-acids had no effect on the motility of the trypanosomes.7. Ammonia was liberated from glutamine by adult and reproductive phase T. lewisi.



1971 ◽  
Vol 49 (3) ◽  
pp. 411-415 ◽  
Author(s):  
R. C. Stephen ◽  
K. K. Fung

The vitamin requirements of two Rhizoctonia fungus endophytes of the orchid Arundina chinensis are reported. Addition of a mixture of nine vitamins to a basal medium supplemented by five amino acids increased the growth of one isolate (R29) but not the other (R14). The inclusion of proline and methionine in the medium inhibited the response of R14 to the vitamins present. Both isolates were partially deficient in, if not completely heterotrophic for, thiamin and p-aminobenzoic acid, and R14 required added biotin for optimum growth under the conditions of the experiment.



2004 ◽  
Vol 79 (2) ◽  
pp. 265-271 ◽  
Author(s):  
V. Ravindran ◽  
W. H. Hendriks

AbstractEndogenous flows of nitrogen and amino acids at the terminal ileum of broilers (6 weeks old), layers (70 weeks old) and adult roosters (70 weeks old) were determined using the peptide alimentation method. The ileal endogenous output of nitrogen and total amino acids in broilers, layers and roosters, expressed as mg/kg dry matter intake, were similar (F > 0-05). Endogenous flows were similar (F > 0-05) for nine of the 17 amino acids analysed, but the flows of serine, glutamic acid, proline, alanine, isoleucine, tyrosine, arginine and methionine differed (P < 0-05) among the classes of chickens. The amino acid profile of endogenous protein, expressed asg/100 g crude protein, did not differ (F > 0-05) between the three classes of chickens, except for serine, glutamic acid, proline and isoleucine. The concentrations of proline were higher (F < 0-05) in broilers, compared with the other two groups. The concentrations of glutamic acid in layers were lower (F < 0-05) than the other two groups. The concentrations of serine and isoleucine were higher (F < 0-05) in roosters than the other two groups. In all three groups, the most abundant amino acid in the ileal endogenous protein was glutamic acid, followed by aspartic acid, proline, serine, glycine and threonine. The present study provides estimates for endogenous amino acid flow at the terminal ileum in broilers, layers and adult roosters under normal physiological conditions.



Sign in / Sign up

Export Citation Format

Share Document