QUALITATIVE STUDIES OF SOIL MICRO-ORGANISMS: VII. THE 'RHIZOSPHERE EFFECT' IN RELATION TO THE AMINO ACID NUTRITION OF BACTERIA

1947 ◽  
Vol 25c (1) ◽  
pp. 20-26 ◽  
Author(s):  
A. G. Lochhead ◽  
R. H. Thexton
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Indirect Evidence ◽  
Maximum Growth ◽  
Acid Group ◽  
Rhizosphere Effect ◽  
Amino Acid Group ◽  
Rhizosphere Effects ◽  
Micro Organisms ◽  
Stimulation Of

Comparative studies of the relative incidence of bacteria of different nutritional requirements in soil indicate that one of the most characteristic rhizosphere effects is the preferential stimulation of bacteria requiring amino acids for maximum growth. Organisms for which amino acids are either essential or stimulative were proportionately increased in the rhizosphere. No similar effect was noted with respect to bacteria responding to growth factors.The findings suggest, by indirect evidence, that the effect is to be ascribed to the excretion of amino acids by the growing plant. However, though this may be the chief factor, the preferential stimulation of the amino acid group of bacteria may be related to associative and antibiotic effects exerted by other bacteria, stimulated in the rhizosphere, observed to have different degrees of compatibility towards those responding respectively to amino acids and growth factors.

A significant pool of amino acids is adsorbed on blood cell membranes

1991 ◽  
Vol 11 (4) ◽  
pp. 223-230 ◽  
Author(s):  
C. Picó ◽  
A. Pons ◽  
A. Palou
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Blood Cell ◽  
Whole Blood ◽  
Wistar Rats ◽  
Cell Membranes ◽  
Acid Group ◽  
High Adsorption ◽  
Polar Amino Acid ◽  
Amino Acid Group

It is well known that the amino acids in the blood are distributed between the plasma and inside the cells. This study was conducted to determine whether amino acids can be located adsorbed on blood cell membranes. The amino acid concentration in the deproteinized haemolysed blood was higher than that in the fraction of blood after removal of the blood cell membranes by centrifugation. These results showed that a pool of amino acids representing 21.1% of the whole blood cell amino acids was adsorbed on the blood cell membranes of adult Wistar rats. The non-polar amino acids showed high adsorption on the membrane, whereas out of the polar amino acid group, only the non-ionic amino acids did adsorb.

Augmented Thermic Effect of Amino Acids under General Anaesthesia Occurs Predominantly in Extra-Splanchnic Tissues

1996 ◽  
Vol 91 (4) ◽  
pp. 431-439 ◽  
Author(s):  
Eva Selldén ◽  
Robert Bränstróam ◽  
Tomas Brundin
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Oxygen Uptake ◽  
Heat Content ◽  
Acid Group ◽  
Whole Body ◽  
Amino Acid Group ◽  
Initial Reduction ◽  
Splanchnic Oxygen ◽  
Body Heat

1. Intravenous infusion of amino acid mixtures stimulates human oxidative heat production more effectively under general anaesthesia than in the unanaesthetized state. To analyse the splanchnic and extra-splanchnic regional distribution of this stimulation, whole body and splanchnic oxygen uptake, blood flow and blood temperatures were measured by a catheterization technique in 14 patients undergoing isoflurane anaesthesia for abdominal surgery. During the anaesthesia period, a mixture of 19 amino acids (240 kJ/h) was infused intravenously into seven of the patients while the others served as controls, receiving isovolumic infusions of a nutrient-free saline solution. 2. Whole body oxygen consumption fell by ≈ 40% during anaesthesia and surgery in the controls. Approximately 80–95% of the reduction occurred in the extra-splanchnic tissues. The splanchnic oxygen uptake fell by 31 ± 6% in the controls during the initial phase of anaesthesia, after which it returned to the pre-anaesthesia level. The initial reduction of the controls' splanchnic oxygen consumption accounted for only ≈23% of the simultaneous anaesthesia-induced reduction in pulmonary oxygen uptake. No initial reduction of the splanchnic oxygen uptake was observed in the patients treated with amino acid. 3. The amino acid infusion stimulated the whole body oxidative heat production by ≈18 W during anaesthesia and surgery and by ≈70 W at the emergence from anaesthesia. Approximately 74% of the stimulation occurred in the extra-splanchnic tissues. At awakening, the splanchnic oxygen uptake rose to ≈64% above the pre-anaesthesia level in the amino acid group. 4. During the entire period of anaesthesia, the whole body heat content fell by 282 ± 68 kJ in the controls and by 57 ± 25 kJ in the amino acid group. Amino acid treatment thus prevented ≈80% of the anaesthesia-induced reduction in whole body heat content. 5. During anaesthesia and surgery, cardiac output was ≈25% and ≈6% below the baseline, pre-anaesthesia levels in the control and amino acid groups, respectively. At awakening, it rose to ≈44% above baseline in the amino acid group while in the controls it remained unchanged. In both groups the splanchnic blood flow was unaffected by anaesthesia or by amino acid infusions.

Some Observations On Platelet Amino Acid Transport Systems

1981 ◽  
Author(s):  
U T Yardimci ◽  
A Özbilen ◽  
O N Ulutin
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Active Transport ◽  
Amino Acid Transport ◽  
Acid Group ◽  
Transport Systems ◽  
Acid Transport ◽  
Amino Acid Group ◽  
Active Transport System ◽  
Group Transport

We have studied the transport systems for amino acids in platelets. Na+/K+ dependent active transport systems were found to be responsible for the transport of amino acids through the platelet membrane (Km’s being at uM ranges). We have also isolated the binding proteins for amino acids from platelet membranes as the carriers involved in these active transport systems by cold osmotic shock procedure. Each amino acid besides being transported by a specific active transport system may be subject to transport by group amino acid transport systems.Group amino acid transport systems are classified by countertransport experiments as follows: Neutral amino acid group transport systems: IA: glycine, alanine, serine, threonine IB: valine, leucine, isoleucine, serine,threonine IC: cysteine, methionine, proline Basic amino acid group transport systems: lie: lysine IIB: histidine, arginine Acidic amino acid group transport systems: III A: Aspartic acid, glutamic acid Aromatic amino acid group transport systems: IVC: Phenylalanine,tyrosine, histidine, proline.

QUALITATIVE STUDIES OF SOIL MICROORGANISMS: IX. AMINO ACID REQUIREMENTS OF RHIZOSPHERE BACTERIA

1950 ◽  
Vol 28c (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. H. Wallace ◽  
A. G. Lochhead
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Soil Microorganisms ◽  
Maximum Growth ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Special Significance ◽  
Specific Amino Acid ◽  
Pronounced Decrease ◽  
Amino Acid Requirements

A study was made of the more specific amino acid requirements of bacteria from the rhizospheres of clover, flax, and wheat plants for which a chemically defined medium containing 23 amino acids provided essentials for maximum growth. Of seven groups of amino acids, the sulphur-containing group (cysteine, methionine, and taurine) was found to be of special significance, the omission of this group resulting in a pronounced decrease in the percentage of organisms able to develop. Further study of organisms dependent upon this group of amino acids for growth showed methionine to be by far the most essential compound. While evident for bacteria from the rhizosphere of all three crops, the effect was more pronounced in the case of clover than with flax or wheat.

scholarly journals Liver intracellular L-cysteine concentration is maintained after inhibition of the trans-sulfuration pathway by propargylglycine in rats

1997 ◽  
Vol 78 (5) ◽  
pp. 823-831 ◽  
Author(s):  
Ana Triguero ◽  
Teresa Barber ◽  
Concha GarcÍa ◽  
Inmaculada R. Puertes ◽  
Juan Sastre ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Degradation ◽  
Histological Examination ◽  
Blood Concentration ◽  
Urea Cycle ◽  
Blood Levels ◽  
Liver And Kidney ◽  
Amino Acid Homeostasis ◽  
Stimulation Of

To study the fate of l-cysteine and amino acid homeostasis in liver after the inhibition of the trans-sulfuration pathway, rats were treated with propargylglycine (PPG). At 4 h after the administration of PPG, liver cystathionase (EC 4.4.1.1) activity was undetectable, l-cystathionine levels were significantly higher, l-cysteine was unchanged and GSH concentration was significantly lower than values found in livers from control rats injected intraperitoneally with 0.15 M-NaCl. The hepatic levels of amino acids that are intermediates of the urea cycle, l-ornithine, l-citrulline and l-arginine and blood urea were significantly greater. Urea excretion was also higher in PPG-treated rats when compared with control rats. These data suggest a stimulation of ureagenesis in PPG-treated rats. The inhibition of γ-cystathionase was reflected in the blood levels of amino acids, because the L-methionine: l-cyst(e)ine ratio was significantly higher in PPG-treated rats than in control rats; blood concentration of cystathionine was also greater. Histological examination of liver and kidney showed no changes in PPG-treated rats when compared with controls. The administration of N-acetylcysteine (NAC) to PPG-treated rats reversed the changes in blood urea and in liver GSH. These data suggest that when liver l-cysteine production was impaired by the blockage of the trans-sulfuration pathway, the concentration of this amino acid was maintained mainly by an increase in protein degradation and by a depletion in GSH concentration that may spare l-cysteine.

Total amino acid requirements of weaned piglets 8 to 25 kg live weight given diets based on wheat and soya-bean meal fortified with free amino acids

1992 ◽  
Vol 54 (2) ◽  
pp. 281-287 ◽  
Author(s):  
F. Gatel ◽  
G. Buron ◽  
J. Fékéte
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Amino Acid Content ◽  
Live Weight ◽  
Maximum Growth ◽  
Soya Bean ◽  
Weaned Piglets ◽  
Bean Meal ◽  
Soya Bean Meal

AbstractTwo experiments were carried out with weaned piglets from 8 to 25 kg live weight in order to determine the dietary amino acid content necessary for maximum growth. Six diets based on wheat, soya-bean meal, soya-bean oil and free amino acids were compared in each experiment. Essential amino acids were in the same relative proportion for all diets: (methionine + cystine)/lysine = 0·60 to 0·65; threonine/lysine = 0·65; tryptophan/lysine = 0·19. The range of amino acid content was 9·53 to 12·52 g lysine per kg in the first experiment and 11·34 to 15·94 g lysine per kg in the second experiment. The number of piglets used per diet was 136 (20 pens) and 106 (16 pens) in respectively the first and the second experiment. The relationship between either dietary lysine content or daily lysine intake and growth rate was quadratic and significant. Dietary lysine content and daily lysine intake which enable maximum growth were calculated according to this model. Dietary lysine contents were 15·5 and 14·9 g/kg for the first 3 weeks (8 to 17 kg) and for the overall post-weaning period (8 to 25 kg) respectively. Daily lysine intakes were 10·6 and 13·3 g/day respectively for the same two periods. Reasons for these values being higher than those currently cited are discussed.

Effects of flooding amino acids on incorporation of labeled amino acids into human muscle protein

1998 ◽  
Vol 275 (1) ◽  
pp. E73-E78 ◽  
Author(s):  
Kenneth Smith ◽  
Nigel Reynolds ◽  
Shaun Downie ◽  
Ayyub Patel ◽  
Michael J. Rennie
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Large Dose ◽  
Human Skeletal Muscle ◽  
Muscle Protein ◽  
Human Muscle ◽  
Leucine Incorporation ◽  
Nonessential Amino Acids ◽  
Stimulation Of

We investigated the effects of the nature of the flooding amino acid on the rate of incorporation of tracer leucine into human skeletal muscle sampled by biopsy. Twenty-three healthy young men (24.5 ± 5.0 yr, 76.2 ± 8.3 kg) were studied in groups of four or five. First, the effects of flooding with phenylalanine, threonine, or arginine (all at 0.05 g/kg body wt) on the incorporation of tracer [13C]leucine were studied. Then the effects of flooding with labeled [13C]glycine [0.1 g/kg body wt, 20 atoms percent excess (APE)] and [13C]serine (0.05 g/kg body wt, 15 APE) on the incorporation of simultaneously infused [13C]leucine were investigated. When a large dose of phenylalanine or threonine was administered, incorporation of the tracer leucine was significantly increased (from 0.036 to 0.067 %/h and 0.037 to 0.070 %/h, respectively; each P < 0.01). However, when arginine, glycine, or serine was administered as a flooding dose, no stimulation of tracer leucine incorporation could be observed. These results, together with those previously obtained, suggest that large doses of individual essential, but not nonessential, amino acids are able to stimulate incorporation of constantly infused tracer amino acids into human muscle protein.

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