The metabolism of acetate by rumen microorganisms

1974 ◽  
Vol 20 (2) ◽  
pp. 183-185 ◽  
Author(s):  
B. Emmanuel ◽  
L. P. Milligan ◽  
B. V. Turner

Rumen contents were incubated in vitro with acetate-1-14C. Significant amounts of 14C were incorporated into rumen microbial proteins, nucleic acids, and lipids. Serine, glutamic acid, methionine, and cystine were highly labeled, whereas less, or insignificant radioactivity was found in other amino acids. Acetate was incorporated into a wide range of microbial fatty acids. The quantitative significance of acetate metabolism is discussed.

1964 ◽  
Vol 10 (2) ◽  
pp. 201-219 ◽  
Author(s):  
D. J. Royle ◽  
C. J. Hickman

Pythium aphanidermatum zoospores in distilled water suspension showed differential responses towards a range of single compounds, and mixtures, diffusing from the ends of capillary tubes containing these materials in agar. All substances caused an initial disorientation of zoospore movement followed, according to the substance under test, by indifference, repulsion, attraction, trapping, and encystment, or, at extreme pH, by loss of motility and death. Of a wide range of substances and mixtures tested, including sugars, amino acids, inorganic salts, organic acids, auxins, and vitamins, only glutamic acid, after weak base adjustment, and mixtures of sugars combined with mixtures of amino acids, induced the pattern of response observed with roots and root materials. Comparison of the activity of glutamate and structurally related compounds indicated that the effectiveness of glutamate was dependent on the presence of several moieties of the glutamate ion.Short photographic exposures allowed counts to be made of zoospores and cysts around the capillary mouth and provided a method for comparing, quantitatively, the accumulation of zoospores in response to different substances over a period of time.The substances inducing activity were readily detected in pea root exudate and extract and are, in fact, of general occurrence in roots. The effectiveness of the active principle(s) in root exudate and extract was roughly proportional to the concentration of these root materials in terms of their content of carbon and nitrogen but no such relation could be established for glutamic acid and a joint mixture of amino acids and sugars, suggesting the existence in root materials of additional factor(s).


1964 ◽  
Vol 42 (1) ◽  
pp. 139-142 ◽  
Author(s):  
S. J. Patrick ◽  
L. C. Stewart

The effects of hypoglycin A on the metabolism of L-leucine-C14, L-alanine-C14, and L-glutamic-acid-C14 by rat liver slices have been investigated. Hypoglycin exerted markedly inhibitory effects on the conversion of leucine-C14 to fatty acid, cholesterol, and CO2. Conversion of alanine-C14 and glutamic acid-C14 to fatty acids was also inhibited by hypoglycin. No effects of hypoglycin on the conversion of C14-amino acids into protein or glycogen were demonstrated.


1966 ◽  
Vol 101 (3) ◽  
pp. 591-597 ◽  
Author(s):  
R M O'Neal ◽  
R E Koeppe ◽  
E I Williams

1. Free glutamic acid, aspartic acid, glutamic acid from glutamine and, in some instances, the glutamic acid from glutathione and the aspartic acid from N-acetyl-aspartic acid were isolated from the brains of sheep and assayed for radioactivity after intravenous injection of [2-(14)C]glucose, [1-(14)C]acetate, [1-(14)C]butyrate or [2-(14)C]propionate. These brain components were also isolated and analysed from rats that had been given [2-(14)C]propionate. The results indicate that, as in rat brain, glucose is by far the best precursor of the free amino acids of sheep brain. 2. Degradation of the glutamate of brain yielded labelling patterns consistent with the proposal that the major route of pyruvate metabolism in brain is via acetyl-CoA, and that the short-chain fatty acids enter the brain without prior metabolism by other tissue and are metabolized in brain via the tricarboxylic acid cycle. 3. When labelled glucose was used as a precursor, glutamate always had a higher specific activity than glutamine; when labelled fatty acids were used, the reverse was true. These findings add support and complexity to the concept of the metabolic; compartmentation' of the free amino acids of brain. 4. The results from experiments with labelled propionate strongly suggest that brain metabolizes propionate via succinate and that this metabolic route may be a limited but important source of dicarboxylic acids in the brain.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1899
Author(s):  
Lech Wojciech Szajdak ◽  
Stanisław Bałazy ◽  
Teresa Meysner

The content of bounded amino acids in six entomopathogenic fungi was identified and determined. Analyzing the elements characterizing the pathogenicity of individual species of fungi based on infectivity criteria, ranges of infected hosts, and the ability to induce epizootics, these can be ranked in the following order: Isaria farinosa, Isaria tenuipes, Isaria fumosorose, Lecanicillium lecanii, Conidiobolus coronatus, Isaria coleopterorum. These fungi represent two types of Hyphomycetales-Paecilomyces Bainier and Verticillium Nees ex Fr. and one type of Entomophtorales-Conidiobolus Brefeld. Our study indicates that there are significant quantitative and qualitative differences of bounded amino acids in the entomopathogenic fungal strains contained in the mycelium between high and low pathogenicity strains. The richest composition of bounded amino acids has been shown in the mycelium of the Isaria farinosa strain, which is one of the most commonly presented pathogenic fungi in this group with a very wide range of infected hosts and is the most frequently recorded in nature as an important factor limiting the population of insects.


Weed Science ◽  
1973 ◽  
Vol 21 (2) ◽  
pp. 135-138 ◽  
Author(s):  
R. G. Harvey ◽  
T. J. Muzik

Two clones of field bindweed (Convolvulus arvensisL.) which differed in their susceptibility to (2,4-dichlorophenoxy)acetic acid (2,4-D) under field and greenhouse conditions also exhibited similar differences when stem cells were cultured in liquid and agar media. Amino acids added to the culture media altered the response to 2,4-D. Glutamic acid increased the tolerance of the susceptible (S) clone, but reduced the tolerance of the resistant (R) clone. Glutamine increased the susceptibility of the S clone to a much greater degree than it did the R clone. No significant differences were noted in the rates of absorption of metabolism of 2,4-D by the two clones. Glutamine increased and glutamic acid decreased 2,4-D absorption by both clones. Levels of nitrate reductase activity (NRA), soluble protein (SP), and gross RNA (GR) increased in the S tissues but decreased or remained constant in the R tissues exposed to 4.5 × 10−5M 2,4-D. Correlations between 2,4-D susceptibility and NRA demonstrated a relationship between the effects of 2,4-D and nitrogen metabolism. Differential binding of 2,4-D within the cells appears to be the most likely explanation for the differences in response to 2,4-D.


1999 ◽  
Vol 1999 ◽  
pp. 212-212 ◽  
Author(s):  
C. Atasoglu ◽  
C.J. Newbold ◽  
R.J. Wallace

Ammonia is thought to be the main source of nitrogen for protein synthesis by the rumen microorganisms, but peptides and amino acids derived from protein degradation are also incorporated into microbial protein. Recent experiments carried out by Atasogluet al.(1998) demonstrated that preformed amino acids decrease the uptake of ammonia into microbial protein and microbial amino acids in a concentration-dependent manner. However, little is known about how rumen ammonia concentrations affect ammonia uptake into microbial protein. The present study was undertaken to determine the influence of rumen ammonia concentrations on ammonia incorporation andde novosynthesis of individual amino acids by the mixed rumen microorganismsin vitro.


1973 ◽  
Vol 132 (4) ◽  
pp. 663-671 ◽  
Author(s):  
Maija Aalto ◽  
Kirsti Lampiaho ◽  
J. Pikkarainen ◽  
E. Kulonen

1. The intracellular volume in granulation tissue was about 15% of the total urea space. 2. The experimental granuloma has a greater ability to retain amino acids during the proliferation phase than later during the synthesis of collagen. 3. The synthesis of collagen and other proteins by granulation tissue is related to the concentrations of proline and glutamic acid in the medium. 4. The rate of synthesis of proline from glutamic acid in granulation-tissue slices is greatest during collagen synthesis. It is enhanced by lactate. 5. Extracellular cations influence the synthesis of collagen and ouabain is inhibitory. Synthesis of other proteins is less sensitive in this respect. 6. It is suggested that the synthesis of collagen is related to the supply of certain amino acids, especially proline, and hence to the redox balance, and also to the function of the cell wall.


Sign in / Sign up

Export Citation Format

Share Document