INHIBITION OF GROWTH OF PSEUDOMONAS DENITRIFICANS BY AMINO ACIDS

1966 ◽  
Vol 12 (6) ◽  
pp. 1095-1098 ◽  
Author(s):  
Horace J. Daniels
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basal Medium ◽  
Ammonium Phosphate ◽  
Complete Medium ◽  
Mineral Salts ◽  
Culture Studies ◽  
Pseudomonas Denitrificans ◽  
Inhibition Of Growth ◽  
Amino Acid Mixtures

A large number of amino acids failed to support growth of Pseudomonas denitrificans in a basal medium composed of glucose, ammonium phosphate, and other mineral salts. Inability of an amino acid to support growth correlated well with its inhibitory action in a complete medium made up by adding L-glutamic acid to the basal medium. D-Amino acids were more toxic than the corresponding L-forms, and neutral amino acids were more toxic than acidic amino acids. Basic amino acids which were least toxic supported the best growth. The danger of the indiscriminate use of amino acid mixtures for culture studies is discussed.

The Quantitative Utilization of Amino Acids and Glucose and Contact Inhibition of Growth in Cultures of the Human Diploid Cell, WI-38

1970 ◽  
Vol 6 (3) ◽  
pp. 739-749
Author(s):  
J. B. GRIFFITHS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basal Medium ◽  
Diploid Cell ◽  
Contact Inhibition ◽  
Growth Media ◽  
Acid Uptake ◽  
Human Diploid Cell ◽  
Inhibition Of Growth ◽  
Diploid Cells

There are many reports in the literature showing that contact inhibition of growth is affected by the culture medium. A quantitative study of amino acid and glucose uptake by the human diploid cell line, WI-38 was carried out to determine more precisely what effect nutritional factors have on contact inhibition of growth. Eagle's minimal essential medium (MEM) was found to support higher cell yields than Eagle's basal medium (BME) and for growth to continue beyond 96 h a medium change was essential. However, analysis of the used growth media showed that neither amino acids nor glucose were fully depleted after 96 h. The rate of glucose utilization was in the range 65-100µg/mg dry wt./h and this agreed very closely with the results of other authors. The pattern of amino acid uptake also closely resembled that for other cell lines except that the utilization of cystine was higher. The nutritional requirements were further studied as the results from the medium analyses failed to explain the growth-promoting activity of MEM. Daily medium changes greatly increased cell yields even though the medium nutrients were not exhausted. This effect was dependent upon fresh medium being used and the only medium component found to be of importance was the amino acid complement. These results are discussed in relation to the low saturation density of diploid cells in culture and a possible explanation is proposed in terms of differences in the cell membrane between normal and altered cells.

MEDIUM SUPPLEMENTATION WITHL- ANDD-AMINO ACIDS RELATIVE TO GROWTH AND EFFICIENCY OF RHIZOBIUM MELILOTI

1966 ◽  
Vol 12 (2) ◽  
pp. 275-283 ◽  
Author(s):  
B. W. Strijdom ◽  
O. N. Allen
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Rhizobium Meliloti ◽  
Basal Medium ◽  
Nitrogen Fixing ◽  
Mineral Salts ◽  
Acid Media ◽  
Maximum Loss ◽  
Serial Cultivation ◽  
Medium Supplementation

Five strains of Rhizobium meliloti serially cultivated on a basal yeast water mannitol mineral salts medium supplemented with increments of nine amino acids, respectively, produced ellipsoidal, bacteroidal, and elongated cell forms. Colonies produced on media containing D-amino acids and glycine were smaller and less opalescent than were those on the basal medium. Growth of two strains on media supplemented with the L-isomers of alanine, histidine, and phenylalanine, respectively, exceeded that in media to which the D-isomers of these amino acids were added. Growth was negative or sparse in the basal medium supplemented with 0.075% L-cysteine. Serial cultivation in media containing increments of D-cysteine, D-alanine, D-phenylalanine, and glycine produced the maximum loss in nitrogen-fixing ability; L-alanine and L-histidine were the least deleterious. Four strains became ineffective after serial cultivation on at least two of the nine amino acid media. The infective and nitrogen-fixing properties of an ineffective strain were unchanged after cultivation in amino acid supplemented media.

scholarly journals A Study of Ovarial Development and Its Relation to Adult Nutrition in the Blowfly Protophormia Terrae-Nov Ae (R.D.)

1956 ◽  
Vol 33 (4) ◽  
pp. 777-797
Author(s):  
PHYLLIS M. HARLOW
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fat Body ◽  
B Vitamins ◽  
Acid Mixture ◽  
Mineral Salts ◽  
Yolk Formation ◽  
Experimental Conditions ◽  
Amino Acid Mixtures ◽  
Accessory Factors

1. A method has been developed for obtaining 200-300 flies daily from a culture of Protophormia terrae-novae reared on whale-meat. 2. Normal growth changes in adults have been described, and five stages in ovarial development have been denned. 3. Experimental conditions affecting ovarial growth in adults have been investigated and a satisfactory routine method for examining the effect of adult nutrition on ovarial growth has been devised. Precautions were taken against bacterial contamination of food although non-sterile conditions were used. 4. Ovarial development was not related to relative humidity, if above 55% R.H., nor to the weight of the adults at emergence. 5. Evidence has been given for the conversion of food material from pupal to adult fat body and for the transfer of material from fat body to ovaries at yolk formation. 6. Healthy adult females can be maintained on a diet of sucrose and water. Addition to the diet of protein or amino-acids produces only slight enlargement of the ovaries. Yolk formation only occurs if the diet is further supplemented by accessory factors, or substances required only in small amount. Ovarial maturation requires considerable amounts of protein, though not more than 0.4 mg. per fly is needed and food solutions must be concentrated. The accessory factors have not been identified but are known to be resistant to slow boiling and are dialysable. Certain mineral salts and B vitamins are thought to be involved. 7. Tryptophane is an essential part of the amino-acid mixture. 8. Protein hydrolysates or equivalent amino-acid mixtures can be substituted for the whole protein but are less effective. The proportions of amino-acids present are very critical, particularly when the amino-acids are in a free state. The amino-acid mixtures have no toxic effect and the presence of some D-isomers do not inhibit growth, although some D-isomers cannot be used by the flies for growth. 9. A chemically defined diet similar to that used for Drosophila did not promote ovarial growth in Protophormia. A mixture containing ten B vitamins, ribose nucleic acid and mineral salts and cholesterol contained some effective accessory substances but lacked some unidentified factor required for yolk formation. The missing factor was not vitamin B12. Penicillin had no significant effect on ovarial growth whether used in minute or in antibiotic concentration.

scholarly journals Effect of co-ingestion of amino acids with rice on glycaemic and insulinaemic response

2015 ◽  
Vol 114 (11) ◽  
pp. 1845-1851 ◽  
Author(s):  
Yean Yean Soong ◽  
Joseph Lim ◽  
Lijuan Sun ◽  
Christiani Jeyakumar Henry
Keyword(s):  
Amino Acids ◽  
Blood Glucose ◽  
Amino Acid ◽  
Glycaemic Index ◽  
Amino Acid Mixture ◽  
Postprandial Blood Glucose ◽  
Acid Mixture ◽  
White Rice ◽  
Amino Acid Mixtures

AbstractConsumption of high glycaemic index (GI) and glycaemic response (GR) food such as white rice has been implicated in the development of type 2 diabetes. Previous studies have reported the ability of individual amino acids to reduce GR of carbohydrate-rich foods. Because of the bitter flavour of amino acids, they have rarely been used to reduce GR. We now report the use of a palatable, preformed amino acid mixture in the form of essence of chicken. In all, sixteen healthy male Chinese were served 68 or 136 ml amino acid mixture together with rice, or 15 or 30 min before consumption of white rice. Postprandial blood glucose and plasma insulin concentrations were measured at fasting and every 15 min after consumption of the meal until 60 min after the consumption of the white rice. Subsequent blood samples were taken at 30-min intervals until 210 min. The co-ingestion of 68 ml of amino acid mixture with white rice produced the best results in reducing the peak blood glucose and GR of white rice without increasing the insulinaemic response. It is postulated that amino acid mixtures prime β-cell insulin secretion and peripheral tissue uptake of glucose. The use of ready-to-drink amino acid mixtures may be a useful strategy for lowering the high-GI rice diets consumed in Asia.

The Effect of Cell Population Density on Nutrient Uptake and Cell Metabolism: a Comparative Study of Human Diploid and Heteroploid Cell Lines

1972 ◽  
Vol 10 (2) ◽  
pp. 515-524
Author(s):  
J. B. GRIFFITHS
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Dna Synthesis ◽  
Nutrient Uptake ◽  
Cell Lines ◽  
Acid Concentration ◽  
Contact Inhibition ◽  
Inhibition Of Growth ◽  
Extracellular Amino Acid

The possibility that contact inhibition of growth in cultures of human diploid cells is influenced by the effects of cell crowding on nutrient uptake by the cells was investigated. Two human lung cell lines were compared, the diploid line MRC-5 and the heteroploid line L-132. In pre-confluent cultures the ability of these 2 cell types to accumulate amino acids was very similar. Post-confluent L-132 cells showed very little change from the pre-confluent cultures but the ability of MRC-5 cells in post-confluent cultures was greatly reduced. The intracellular concentrations of various amino acids necessary to achieve the maximum rate of protein synthesis were found. These values were identical for sparse and crowded cultures but due to the reduced uptake ability of crowded MRC-5 cells a far higher external amino acid concentration was required in post-confluent cultures. This meant that although amino acids did not become growth-limiting until over 80% utilized in pre-confluent cultures, in post-confluent cultures they became growth-limiting when only 50% utilized. Although protein synthesis was significantly affected by extracellular amino acid concentration and cell crowding, thus contributing towards the effect of contact inhibition of growth, DNA synthesis was shown to be the major metabolic function in contact inhibition. Increased cell density had a very inhibitory effect on DNA synthesis in MRC-5 cultures, but not in L-132 cultures, and this was unaffected by extracellular amino acid and glucose concentration.

scholarly journals Die Hemmung von Agrobacterium tumefaciens durch D-Aminosäuren

1965 ◽  
Vol 20 (9) ◽  
pp. 899-905 ◽  
Author(s):  
Martin Bopp
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Agrobacterium Tumefaciens ◽  
Nutrient Solution ◽  
Complete Loss ◽  
Inhibition Of Growth

The growth of Agrobacterium tumefaciens in nutrient solution can be inhibited by all ᴅ-amino acids used in these experiments. The degree of inhibition is of different in magnitude; in some cases the inhibition is complete. The inhibition is dependent on the concentration of ᴅ-amino acid and can not be counteracted by addition of L-amino acid or glycine; it is increased by K2CO3. After 28 transfers, all ᴅ-amino acid used in these experiments lead to reduction or complete loss of virulence. It can be assumed that ᴅ-amino acids induce independently loss of virulence and inhibition of growth.

Des acides aminés stimulateurs et inhibiteurs à la croissance de Corynebacterium sepedonicum (Spieck. et Kott., Skapt. et Burkh.) dans des milieux synthétiques

1978 ◽  
Vol 24 (9) ◽  
pp. 1087-1092
Author(s):  
G. J. Ikin ◽  
H. J. Hope ◽  
R. A. Lachance
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ammonium Phosphate ◽  
Methionine Sulfoxide ◽  
High Rate ◽  
Molar Ratio ◽  
Corynebacterium Sepedonicum ◽  
Ring Rot ◽  
Acides Aminés ◽  
Synthetic Media

Some aspects of the growth and amino acid metabolism of Corynebacterium sepedonicum, the organism responsible for potato ring rot, have been studied in synthetic media. It has been demonstrated that organic sulfur is required for growth. Methionine supports growth and can be replaced by methionine sulfoxide and cystathionine. Methionine is a micrometabolite for this species as indicated by the fact that optimum growth can be obtained in an asparagines–methionine (asn-met) containing medium when the molar ratio of these amino acids is 56:1. Increasing the proportion of methionine does not increase the growth. Both asparagine and glutamine are metabolized very quickly and provide for equivalent rapid growth unlike aspartic and glutamic acids. In the case of the last two amino acids, growth can be increased if dibasic ammonium phosphate is added to the medium although this compound alone will not support growth in the culture medium. The intracellular soluble asparagine level is extremely low in cells from the asn-met medium indicating a high rate of metabolism compared to aspartic acid. Cystine and cysteine were found to be inhibitory to the organism: they do not affect the rate of uptake of asn or met but do alter the organism's metabolism as reflected by changes in the free amino acid pool. The concentrations of cystine and cysteine required for measurable inhibition are much higher than those found in soluble amino acids of potato tubers.

scholarly journals TOLERANCE TO AMINO ACID MIXTURES AND CASEIN DIGESTS GIVEN INTRAVENOUSLY

1945 ◽  
Vol 81 (5) ◽  
pp. 439-448 ◽  
Author(s):  
S. C. Madden ◽  
R. R. Woods ◽  
F. W. Shull ◽  
J. H. Remington ◽  
G. H. Whipple
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Acid Content ◽  
Essential Amino Acids ◽  
Daily Injection ◽  
Nitrogen Requirement ◽  
Amino Acid Mixtures ◽  
Nitrogen Rates ◽  
Crystalline Amino Acids

Several synthetic mixtures of natural and racemic crystalline amino acids suitable for the daily nitrogen requirement are tested in dogs for their tolerance upon intravenous injection. Certain mixtures of the ten essential amino acids plus non-essential amino acids exclusive of glutamic acid are accepted without any obvious sign of disturbance even at rates above 10 mg. nitrogen per kilo per minute for quantities greater than 300 mg. per kilo. One such mixture consists in parts per 100 of dl-threonine 7, dl-valine 15, l(-)-leucine 10.9, dl-isoleucine 9.9, l(+)-lysine· HCl·H2O 10.9, dl-tryptophane 3, dl-phenylalanine 9.9, dl-methionine 6, l(+)-histidine·HCl·H2O 5, l(+)-arginine-HCl 5, glycine 9.9, dl-α-alanine 4, dl-serine 2, l(-)-cystine 0.5, and l(-)-tyrosine 1. In addition other well tolerated mixtures included the prolines. When glutamic acid, natural or racemic, is included in similar mixtures vomiting reactions frequently occur at nitrogen rates above 4 mg. per kilo per minute. Vomiting almost always occurs on the first daily injection containing glutamic acid and usually on any subsequent injection containing more than 100 mg. glutamic acid per kilo unless given very slowly. Upon the addition of glycine certain mixtures of the ten essential amino acids show an improved tolerance. Two casein digests tested usually produced vomiting at injection rates above 2 mg. nitrogen per kilo per minute, probably because of their glutamic acid content. No serious reaction has ever occurrred to any mixture of amino acids or casein digest tested. Elimination of minor reactions such as vomiting appears possible and desirable for greater usefulness of these solutions in parenteral feeding.

THE APPLICATION OF A NUTRITIONAL GROUPING METHOD TO SOIL FUNGI

1955 ◽  
Vol 33 (3) ◽  
pp. 281-288 ◽  
Author(s):  
R. G. Atkinson ◽  
J. B. Robinson
Keyword(s):  
Amino Acids ◽  
Growth Factors ◽  
Yeast Extract ◽  
Soil Fungi ◽  
Basal Medium ◽  
Maximum Growth ◽  
Potassium Nitrate ◽  
Soil Extract ◽  
Mineral Salts ◽  
Soil Extracts

In tests with seven different liquid media in which the common nitrogen source was potassium nitrate and the carbohydrate substrate was glucose, at a concentration of only 0.1%, most of the 1914 soil fungi isolated fell into one of three nutritional groups requiring, respectively, for maximum growth amino acids, amino acids plus growth factors, or yeast extract. Relatively few isolates required growth factors alone or a combination of yeast and soil extracts. Most of the isolates grew poorly in the basal medium containing only mineral salts, and glucose, with or without soil extract. Although fungi requiring yeast extract were much less frequently isolated from soil on, rather than remote from, tubers grown in a soybean green-manured plot, isolates requiring amino acids, or yeast plus soil extracts, were correspondingly increased on immature and mature tubers, respectively. In a second plot, however, not specially treated, no differences were observed in the nutritional spectra of fungi isolated from the two kinds of soil environment.

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