Addition Of Glutamic Acid Research Articles

Beziehungen zwischen Pflanzen und epiphytischen Bakterien hinsichtlich ihres Auxinstoffwechsels: XII. Die Ausscheidung von Aminosäuren und Vitaminen durch epiphytische Bakterien

Summary This investigation was undertaken in order to detect substances which are, besides IAA excreted by epiphytic bacteria. Two possible ways by which such substances could affect the auxin content of the host plants of the bacteria are regarded: Firstly they could serve as precursors for the IAA production performed by other epiphytic bacteria, secondly they could enter the host plants and interfere with their auxin metabolism. Tryptophan would be an example of the first mode of action, niacin and niacide examples of the second one. Epiphytic bacteria, isolated from pea and corn plants and grown in batch culture, excreted into the culture medium sixteen ninhydrine positive substances, probably amino acids. Mainly living bacteria cells seemed to be able to excrete these substances. Six of nine bacteria strains isolated from corn plants excreted tryptophan, even in the absence of an organic nitrogen source. The rate of tryptophan excretion increased with increasing duration of culturing, the main amount being accumulated during the stationary phase of bacteria growth. Tryptophan was not detectable in a suspension of dead bacteria cells having been killed by autoclaving. The tryptophan produced by living bacteria cells probably contributes to the tryptophan pool existing on the plant surface. Even when cultivated in media without organic nitrogen sources, epiphytic bacteria strains produced niacin. Addition of glutamic acid or tryptophan stimulated niacin production and lead, in one of three strains tested, to niacide production, too. As tryptophan was not more effective than glutamic acid, the former seemed not to be a niacin precursor in these bacteria. There was no correlation between the abilities of the tested epiphytic bacteria strains to produce niacin and niacide and to increase the auxin content of their host plants. Moreover, the produced niacin and niacide amounts were too low for being able to exert an influence on the IAA production in the host plants as demonstrated by the comparison with previous results regarding the effect of niacide applications on the auxin content in the plant. There are also some other experimental reasons for the statement that epiphytic bacteria are able to raise the auxin level of their host plant not by excretion of niacin or niacide, but only by IAA excretion.

Mineral Mixture Composition—A Factor in Chick Bioassays of the Protein Quality of Fish Meals

MILLER and Kifer (1970b) showed that the evaluation of the quality of the protein in fish meal, when the meal was fed as the sole source of protein, was influenced by excesses of lysine present in fish meal over the concentration needed in the diet and by various anionic components in the mineral mixture. The excess of lysine was overcome by a dilution of the concentration of lysine in the diet by the addition of glutamic acid (free-base form) or was overcome by counteraction from the addition of arginine. The excess of anionic components was overcome by the inclusion in the diet of the antiacids Al(OH)3 and NaHC03. The detrimental anionic effect was evident when the addition of HCl salt of glutamic acid depressed growth. In contrast, the free-base form of glutamic acid improved growth significantly, owing to two possibilities: (1) the elimination of the detrimental HCl portion of this…

Influence of glutamic acid on the endogenous respiration of Bacillus subtilis.

Clifton, C. E. (Stanford University, Stanford, Calif.), and John Cherry. Influence of glutamic acid on the endogenous respiration of Bacillus subtilis. J. Bacteriol. 91:546-550. 1966.-Amino acids serve as the major initial endogenous substrate for Bacillus subtilis. The endogenous activity of freshly harvested washed cells is high and falls off rapidly with time of shaking at 30 C to lower but still significant levels. The rate of O(2) consumption after the addition of glutamic acid also decreases as the cells age, but more slowly than noted for endogenous respiration. When cells were fed glutamate as soon as possible after harvesting, an apparent stimulation of endogenous respiration was noted. However, endogenous activity was inhibited if the cell suspensions were shaken for at least 1 hr before addition of the glutamate. Similar results were obtained with glycerol or glucose as exogenous substrates. Variation in rates of respiration with age of the cells, inherent instability of B. subtilis, and possible utilization of substances initially excreted by the cells appear to account for the variations noted regarding the influence of an exogenous substrate on endogenous respiration.

Biochemical effects of the vinca alkaloids: III. The synthesis of ribonucleic acid and the incorporation of amino acids in Ehrlich ascites cells in vitro

The incorporation of [ 3H]uridine into RNA by Ehrlich ascites cells in vitro, was inhibited by colchicine, vinblastine and vincristine, the percentage reductions for a drug level of 0.2 μmole/ml being 20, 58 and 26, respectively. Addition of glutamic acid at 1–8 μmoles/ml reduced or prevented this depression; lesser antagonistic effects were observed with aspartic or α-ketoglutaric acids, while arginine and glutamine were inactive at comparable levels. The incorporation of [ 14C]glutamic acid, but not of [ 14C]glycine, into the acid-soluble fraction was markedly reduced (40 % at 0.2 μmole/ml) by vinblastine and vincristine, but only slightly depressed by colchicine. Cells harvested from mice treated 2–13 h before sacrifice with vinblastine (2 mg/kg) exhibited a reduced rate of uptake of [ 14C]glutamic acid into the acid-soluble fraction. Some reduction in the amount of [ 14C]glutamic acid entering cellular proteins was also observed after treatment with vinblastine both in vivo and in vitro. Development of resistance to vinblastine was accompanied by elevation in the baseline rate of uptake of [ 3H]uridine into RNA, and a profound reduction in the rate of entry of [ 14C]glutamic acid into the acid-soluble fraction; both these parameters were less sensitive to vinblastine treatment in vitro.

The effect of isoniazid, carbutamide, propamidine and pentamidine on the transaminases and growth of Escherichia coli, strain 15, mutant M 2

1. 1. Overnight growth of cultures of E. coli, 15, M 2, is prevented by 5·10 −3 M isoniazid, 5·10 −4 M carbutamide, 10 −4 M pentamidine, and 5·10 −5 M propamidine. 2. 2. The growth inhibition produced by the four drugs is overcome by addition of glutamic acid or mixtures of aspartic acid, alanine and valine to the growth medium. 3. 3. Isoniazid, 10 −2 M, is without effect on the transaminase activity of whole cell suspensions but inhibits the valine/glutamic acid and aspartic acid/glutamic acid transaminases of cell-free extracts by about 65% and 75% respectively. 4. 4. Carbutamide, 10 −2 M, inhibits the valine/glutamic acid transaminase by about 18% and the aspartic acid/glutamic acid transaminase by 28%. 5. 5. Propamidine, 10 −3 M, has little effect on either enzyme. 6. 6. Pentamidine, 10 −3 M, inhibits the valine/glutamic acid transaminase by about 40%, but has little effect on the aspartic acid/glutamic acid enzyme. It also inhibits the oxidation of amino acids. 7. 7. It is concluded that the inhibition by these drugs of the growth of cultures of E. coli, strain 15, M 2, is not primarily due to inhibition of transaminase activity.

PROTEIN METABOLISM OF RAT BRAIN SLICES

Rat brain slices respiring in a Krebs–Ringer phosphate medium were found to incorporate glycine-2-C14and DL-glutamic acid-1-C14into the protein.The addition of succinate as the substrate reduced the incorporation of glycine-2-C14into the protein of brain slices. The addition of glutamic acid, glutamine, and methionine sulphoxide into the glucose Krebs–Ringer phosphate medium inhibited the incorporation.The incorporation was also inhibited by 2,4-DNP in concentrations that do not decrease oxygen consumption.The respiration and the incorporation of glycine-2-C14were inhibited progressively with an increase in the concentration of isomytal, azacyclonol, chlorpromazine, and acetylpromazine. In the presence of succinate as the substrate these drugs did not inhibit the respiration of brain slices.

Sequence in which Indispensable and Dispensable Amino Acids Become Limiting for Growth of Rats Fed Diets Low in Fibrin

The results of growth experiments indicate that in diets containing 6% of fibrin as the only source of protein leucine, isoleucine, valine and histidine are all equally the most limiting amino acids for the growth of the rat; methionine and phenylalanine are equally next limiting; lysine is the third limiting amino acid and threonine, arginine and tryptophan are least limiting. Diets containing 6% of fibrin supplemented with a mixture of the indispensable amino acids to satisfy the accepted amino acid requirements of the rat do not support optimal growth. Addition of a mixture of dispensable amino acids containing glutamic acid, glycine, aspartic acid and alanine or addition of glutamic acid alone stimulates growth considerably.

PROTEIN METABOLISM OF RAT BRAIN SLICES

Rat brain slices respiring in a Krebs–Ringer phosphate medium were found to incorporate glycine-2-C14and DL-glutamic acid-1-C14into the protein.The addition of succinate as the substrate reduced the incorporation of glycine-2-C14into the protein of brain slices. The addition of glutamic acid, glutamine, and methionine sulphoxide into the glucose Krebs–Ringer phosphate medium inhibited the incorporation.The incorporation was also inhibited by 2,4-DNP in concentrations that do not decrease oxygen consumption.The respiration and the incorporation of glycine-2-C14were inhibited progressively with an increase in the concentration of isomytal, azacyclonol, chlorpromazine, and acetylpromazine. In the presence of succinate as the substrate these drugs did not inhibit the respiration of brain slices.

THE USE OF GLUCOSE INORGANIC SALTS MEDIA IN THE CLASSIFICATION OF THE COLI‐AEROGENES BACTERIA. I. THE METHYL RED AND VOGES‐PROSKAUER REACTIONS

SUMMARY: A chemically defined glucose ammonium phosphate medium gave methy red and Voges‐Proskauer reactions which were superior to those in glucose peptone phosphate. Optimum condition for both tests require a starting pH of 6·8 and incubation for 3 days at 30°. The medium gave a negative correlation between the two reactions with 34 out of 35 strains that were positive to both tests in the peptone medium. The addition of glutamic acid helped to eliminate doubtful positive M. R. reactions but seemed to suppress acetylmethylcarbinol production by weakly V.‐P. positive strains.

Glutamic Acid in Milk Anemia. Effect on Hemoglobin Regeneration in "Cystine Deficient" Animals.

Certain investigators1 have reported that glutamic acid supplements Fe in the treatment of milk anemia in rats, but this finding has not been confirmed by others.2, 3 In our experiments4 carried out with normal rats from our stock colony the addition of glutamic acid to various metals did not produce any supplementary effect on Hb regeneration and growth.Certain observations,5 however, appeared to indicate that factors other than the composition of the milk ration and the supplements per se might play a role in Hb regeneration. Accordingly the following experiments were undertaken.A group of 8 rats which had been on a deficient diet was selected. These animals had received for approximately 3 months a ration of the following composition: corn starch 54.5, lard 24.5, casein 9, salt mixture (O.M.) 4.5, sugar 4.5, and cod liver oil 3%.6 It should be noted that this diet is low in protein and deficient in cystine. This ration was continued for an additional 2 months, supplemented by fresh green lettuce (appro...