scholarly journals CELL DIVISION AND DNA SYNTHESIS IN TETRAHYMENA PYRIFORMIS DEPRIVED OF ESSENTIAL AMINO ACIDS

1964 ◽  
Vol 21 (2) ◽  
pp. 275-281 ◽  
Author(s):  
G. E. Stone ◽  
D. M. Prescott
Keyword(s):  
Amino Acids ◽  
Cell Division ◽  
Amino Acid ◽  
Dna Synthesis ◽  
Tetrahymena Pyriformis ◽  
Essential Amino Acids ◽  
The Other ◽  
Cent Increase ◽  
Amino Acid Requirements

The question of amino acid requirements for DNA synthesis and cell division has been studied in Tetrahymena pyriformis by depriving cells of histidine and tryptophan at defined stages in the interdivision interval. Deprivation any time before DNA synthesis does not prevent the initiation of such synthesis but completely inhibits the following division and limits the increase in DNA, as measured microspectrophotometrically, to 20 per cent. H3-thymidine added to the medium is not incorporated during the 20 per cent increase. Deprivation after DNA synthesis is initiated does not prevent the continuation (to completion) of DNA synthesis, and cell division ensues. H3-thymidine added to the medium under these conditions is incorporated into macronuclear DNA. The data indicate that some amino acid-dependent event occurs, about the time of the beginning of the DNA synthesis period, which is not essential for initiation of DNA synthesis but which is essential for the maintenance of synthesis once it has begun. These results are further discussed in terms of enzymes required to convert thymidine (and possibly the other three deoxyribonucleosides) to the immediate precursor of DNA synthesis.

scholarly journals THE AMINO ACID REQUIREMENTS OF RABBIT FIBROBLASTS, STRAIN RM3-56

1957 ◽  
Vol 41 (1) ◽  
pp. 91-100 ◽  
Author(s):  
R. F. Haff ◽  
H. E. Swim
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Good Condition ◽  
Essential Amino Acids ◽  
The Other ◽  
Isoleucine Leucine ◽  
Cellular Degeneration ◽  
Amino Acid Requirements ◽  
Dialyzed Serum

Strain RM3-56 of rabbit fibroblasts was found to require arginine, cystine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, serine, threonine, tryptophan, tyrosine, and valine for growth in a medium containing 2 per cent dialyzed serum as the only undefined component. The requirement for serine is less specific than that of the other 13 amino acids and it is partially replaced by glycine, or alanine, or by several combinations of so called accessory amino acids. The concentrations of essential amino acids which permit maximal proliferation range from 0.005 to 0.3 mM. Cystine, glutamine, lysine, tryptophan, tyrosine, valine are toxic at concentrations of 5 mM. The rate of proliferation of RM3-56 in a medium containing all 14 essential amino acids is increased significantly by the addition of alanine and to a lesser extent by the addition of aspartic and glutamic acids and glycine. A deficiency of cystine or glutamine results in cellular degeneration within 3 to 5 days, whereas the cells remain in good condition for 2 to 3 weeks in the absence of each of the remaining 12 essential amino acids. The results obtained with RM3-56 are compared with strains HeLa, L, and U12, whose amino acid requirements have been investigated under similar conditions.

Plasma essential amino acids concentrations of early lactating Holstein dairy cows fed diet containing raw or roasted Iranian soybean

2007 ◽  
Vol 2007 ◽  
pp. 182-182
Author(s):  
Forouzan Tabatabaie ◽  
Hassan Fathi ◽  
Mohsen Danesh
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dairy Cows ◽  
Physical Method ◽  
Essential Amino Acids ◽  
High Energy ◽  
Early Lactation ◽  
High Amino Acid ◽  
Amino Acid Requirements ◽  
Physical Treatments

Whole soybean has 40-42 percent CP and used as high energy-protein supplement for early lactation dairy cows. However, the protein is highly degradable, so small amounts of amino acids can be reached to small intestine to meet high amino acid requirements of early lactating cows. Therefore, various chemical and physical treatments have been suggested to decrease ruminal protein degradability of soybeans. The practical use and application of any one method to lower ruminal feed degradability is dependent not only on its efficacy but also on its cost effectiveness, safety and ease of application. For these reasons, heat treatment is the most commonly used physical method (Plegge et al., 1985). The purpose of this study was to determine how roasting of soybeans affect plasma essential amino acid concentrations in early lactation cows.

Amino Acid Requirements of Children: Nitrogen Balance at the Minimal Level of Essential Amino Acids

1964 ◽  
Vol 83 (2) ◽  
pp. 115-118 ◽  
Author(s):  
Itsiro Nakagawa ◽  
Tetsuzo Takahashi ◽  
Takeshi Suzuki ◽  
Katsumi Kobayashi
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Balance ◽  
Essential Amino Acids ◽  
Minimal Level ◽  
Amino Acid Requirements

The Contribution of Caseins to the Amino Acid Supply for Lactococcus lactis Depends on the Type of Cell Envelope Proteinase

1998 ◽  
Vol 64 (6) ◽  
pp. 1991-1996 ◽  
Author(s):  
Benedicte Flambard ◽  
Sandra Helinck ◽  
Jean Richard ◽  
Vincent Juillard
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Amino Acid ◽  
Lactococcus Lactis ◽  
Cell Envelope ◽  
Essential Amino Acids ◽  
Genetically Engineered ◽  
Amino Acid Requirements ◽  
Rate Limiting

ABSTRACT The ability of caseins to fulfill the amino acid requirements ofLactococcus lactis for growth was studied as a function of the type of cell envelope proteinase (PI versus PIII type). Two genetically engineered strains of L. lactis that differed only in the type of proteinase were grown in chemically defined media containing αs1-, β-, and κ-caseins (alone or in combination) as the sources of amino acids. Casein utilization resulted in limitation of the growth rate, and the extent of this limitation depended on the type of casein and proteinase. Adding different mixtures of essential amino acids to the growth medium made it possible to identify the nature of the limitation. This procedure also made it possible to identify the amino acid deficiency which was growth rate limiting for L. lactis in milk (S. Helinck, J. Richard, and V. Juillard, Appl. Environ. Microbiol. 63:2124–2130, 1997) as a function of the type of proteinase. Our results were compared with results from previous in vitro experiments in which casein degradation by purified proteinases was examined. The results were in agreement only in the case of the PI-type proteinase. Therefore, our results bring into question the validity of the in vitro approach to identification of casein-derived peptides released by a PIII-type proteinase.

scholarly journals Studies of amino acid requirements of adult rats

1967 ◽  
Vol 21 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Elizabeth B. Smith ◽  
B. C. Johnson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Proteins ◽  
Latin Square ◽  
Essential Amino Acids ◽  
Adult Rats ◽  
Adult Rat ◽  
Amino Acid Requirements ◽  
Series Of Experiments ◽  
Whole Egg

1. A series of experiments was carried out to determine the minimum essential amino acid requirements of the adult rat.2. After testing four amino acid patterns taken from the literature, a basal pattern was formulated in which each amino acid appeared at the lowest level at which it was presented in any of the original diets.3. Nitrogen balance was the main criterion used to judge any benefit arising from modest increases in individual amino acids tested in a modified Latin-square design. They were given at a protein level of 3.6% of the diet. Non-essential amino acids were in the same proportions as in whole egg.4. It appeared that three amino acids, namely tryptophan, threonine and isoleucine, brought about more favourable balances when presented at concentrations higher than basal.5. Reduced levels of each amino acid were then tested in order to ensure that no surpluses were present.6. N retentions indicated that lysine, phenylalanine plus tyrosine, leucine and valine could be reduced below the basal level and still meet the needs of the rat for these amino acids.7. When the pattern of amino acids arising from these latter trials was tested in combination, rather than as trios, pairs, or single changes, positive N balances gave confidence that these were minimal levels of the essential amino acids required for meeting the maintenance needs of adult rats.8. Plasma proteins from the rats on the evolved pattern were found to be in no way different from those found for normal animals. This gave further support to the belief that the pattern was adequate for the rats.

scholarly journals Naturally occurring amino acids differentially influence the development of Chlamydia trachomatis and Chlamydia (Chlamydophila) pneumoniae

2006 ◽  
Vol 55 (7) ◽  
pp. 879-886 ◽  
Author(s):  
Hesham M. Al-Younes ◽  
Joscha Gussmann ◽  
Peter R. Braun ◽  
Volker Brinkmann ◽  
Thomas F. Meyer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chlamydia Trachomatis ◽  
Essential Amino Acids ◽  
Chlamydophila Pneumoniae ◽  
The Other ◽  
Naturally Occurring ◽  
Novel Treatment ◽  
Amino Acid Levels ◽  
Considerable Enhancement

The differential influence of individual amino acids on the growth of Chlamydia trachomatis versus Chlamydia (Chlamydophila) pneumoniae was investigated. Certain essential amino acids added in excess at the middle of the infection course resulted in varying degrees of abnormality in the development of the two species. If amino acids were added as early as 2 h post-infection, these effects were even more pronounced. The most effective amino acids in terms of C. trachomatis growth inhibition were leucine, isoleucine, methionine and phenylalanine. These amino acids elicited similar effects against C. pneumoniae, except methionine, which, surprisingly, showed a lower inhibitory activity. Tryptophan and valine marginally inhibited C. trachomatis growth and, paradoxically, led to a considerable enhancement of C. pneumoniae growth. On the other hand, some non-essential amino acids administered at the middle of or throughout the infection course differentially affected the development of the two species. For example, C. trachomatis growth was efficiently inhibited by glycine and serine, whereas C. pneumoniae was relatively less sensitive to these agents. Another difference was apparent for glutamate, glutamine and aspartate, which stimulated C. pneumoniae growth more than that of C. trachomatis. Overall, several distinctive patterns of susceptibility to excess amino acid levels were revealed for two representative C. trachomatis and C. pneumoniae isolates. Perturbation of amino acid levels, e.g. of leucine and isoleucine, might form a basis for the development of novel treatment or preventive regimens for chlamydial diseases.

SUBSTITUTION OF CHOLINE BY RELATED COMPOUNDS AND FURTHER STUDIES ON AMINO ACID REQUIREMENTS IN NUTRITION OF PHORMIA REGINA (MEIG.)

1956 ◽  
Vol 34 (6) ◽  
pp. 527-532 ◽  
Author(s):  
Ernest Hodgson ◽  
Vernon H. Cheldelin ◽  
R. W. Newburgh
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Essential Amino Acids ◽  
Phormia Regina ◽  
Acid Growth ◽  
Dietary Requirement ◽  
Amino Acid Requirements ◽  
Related Compounds

Phormia regina grown on a chemically defined diet under sterile conditions has been shown to have a specific dietary requirement for choline. The present work shows that carnitine and 2,2-dimethylaminoethanol can completely replace this in the diet whereas betaine is ineffective in this respect. Deletion of single amino acids from a mixture of 18 adequate for growth has previously shown the following 10 amino acids to be essential: arginine, histidine, leucine, lysine, phenylalanine, threonine, tryptophan, valine, proline, and isoleucine. The present work: shows by the inability of the organism to grow on these essential amino acids that this method is not adequate to detect amino acid combinations for which alternate requirements exist. By the deletion of groups of two or more amino acids it has been shown that P. regina has a dietary requirement for either methionine or cystine and for either glutamic acid or aspartic acid. Growth on the 10 essential amino acids is stimulated by yeast extract. This is apparently not due to a simple replacement of missing amino acids, since the addition of yeast creates an increased requirement for thiamine.

scholarly journals The Nitrogen Requirements of Some Members of the Viridans Group of Streptococci

1961 ◽  
Vol 14 (4) ◽  
pp. 567 ◽  
Author(s):  
Jean I Paul
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Chemical Nature ◽  
Essential Amino Acids ◽  
Active Factor ◽  
Organic Complexes ◽  
Amino Acid Requirements

The amino acid. requirements of certain members of the viridans group of streptococci have been investigated. These requirements have not been found to be uniform among strains of StreptoooccUB bovis. Rumen strains of Strep. bows require, in addition to 20 amino acids, rumen liquor or an extract of rumen liquor or certain other organic complexes. The chemical nature of the active factor suggests a peptide . . The essential amino acids for the faecal strains of Strep. boviB were glutamic acid, aspartic acid, leucine, valine, asparagine, and histidine.

scholarly journals Changes in the plasma concentrations of free amino acids in relation to egg formation in the hen

1970 ◽  
Vol 24 (4) ◽  
pp. 1071-1081 ◽  
Author(s):  
T. G. Taylor ◽  
J. J. Waring ◽  
R. K. Scougall
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Egg Production ◽  
Nutritive Value ◽  
Plasma Concentrations ◽  
Essential Amino Acids ◽  
Egg Formation ◽  
Amino Acid Requirements

1. The changes occurring in the free amino acids of the plasma of laying hens in relation to egg formation have been investigated in fed and starved hens in three experiments, each with eight birds.2. The mean concentrations of most amino acids and of the totals were higher at night than in the morning.3. In general, egg formation was associated with increases in the concentrations of non- essential and decreases in the concentrations of essential amino acids. Cystine and glutamic acid tended to behave like the essential amino acids.4. After 40 h starvation seven amino acids, particularly serine, histidine and lysine, in- creased in concentration and only three, proline, ornithine and arginine, decreased significantly.5. When eight cocks were injected with oestrogen most of the amino acids increased in con-centration. The essential amino acids (with the exception of phenylalanine), serine, proline, cystine and ornithine showed the greatest increases.6. The results are discussed in relation to the possibility that the voluntary food intake of hens may be influenced by changes in the plasma levels of one or more essential amino acids associated with the synthesis of egg albumen. Arginine appeared to be the only amino acid that might possibly fulfil this role.7. It was concluded that investigations of changes in the free amino acids of hen plasma are unlikely to provide a useful approach to a study of the amino acid requirements or the nutritive value of particular proteins for egg production.

scholarly journals Amino Acid Profiles of the Flesh of the Heterosexual Pairs of Neopetrolisthes maculatus

2017 ◽  
Vol 61 ◽  
pp. 23-35 ◽  
Author(s):  
Emmanuel Ilesanmi Adeyeye
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
Efficiency Ratio ◽  
Amino Acids Composition ◽  
Amino Acid Requirements ◽  
Amino Acid Profiles ◽  
Limiting Amino Acid ◽  
Acid Index

This paper reports on amino acid profiles of the flesh of heterosexuals of porcellanids collected from the Atlantic Ocean at Orimedu beach in Ibeju-Lekki, Lagos, Nigeria. Results showed that high values of amino acids were observed in the heterosexual flesh of Neopetrolisthes maculatus (g 100g-1 protein): 17.7 – 17.8 (Glu), 9.90 – 10.0 (Asp), 8.70 – 9.07 (Arg), 7.23 – 7.94 (Leu) and 5.81 – 6.06 (Gly). Total essential amino acid values ranged from 45.2 – 46.2 g 100-1g. Predicted protein efficiency ratio was 3.82 – 4.14, the range of essential amino acid index was 86.9 – 89.9, the biological values ranged from 83.0 – 86.3. The Lys/Trp was 3.31-4.27. Serine was limiting amino acid (0.513 – 0.516) in the egg score comparison; under the essential amino acids scores, Lys (0.840) was limiting in female but Val (0.823) was limiting in the male; Lys (0.796 – 0.905) was limiting in both samples in the pre-school child amino acid requirements. It was observed that out of the twenty parameters determined, male flesh was more concentrated in 60% values than the female flesh and 40% better in female than male. Correlation coefficient result showed that significant differences existed in the amino acids composition at r = 0.01 of the N. maculatus samples.

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