Arginine synthesis and nitrogen excretion in the myxomycete Physarum polycephalum

1980 ◽  
Vol 26 (4) ◽  
pp. 492-495 ◽  
Author(s):  
Lansing M. Prescott ◽  
James T. Rector ◽  
Ronald K. Freund ◽  
Denley B. Jacobson
Keyword(s):  
Uric Acid ◽  
Physarum Polycephalum ◽  
Biosynthetic Pathway ◽  
Liquid Culture ◽  
Urease Activity ◽  
Ammonia Nitrogen ◽  
Nitrogen Excretion ◽  
Nutritional Requirement ◽  
Excretory Product ◽  
Variable Quantity

The nitrogen excretory metabolism of the myxomycete Physarum polycephalum was studied. When cultured in partially defined broth medium or on agar, the principal excretory product was ammonia nitrogen. A small, variable quantity of urea was excreted in liquid culture. No uric acid or other purines were detected in the cultures. When microplasmodia were incubated with sodium [14C]bicarbonate, radioisotope was incorporated into citrulline, arginine, and urea. Incubation with L-[carbamoyl-14C]citrulline yielded labelled arginine, urea, and CO2. Substantial urease activity was found in extracts of the microplasmodia. These results, in conjunction with the lack of an absolute nutritional requirement for arginine, provide evidence that Physarum has a functional arginine biosynthetic pathway, an arginase, and a urease.

Uric Acid: The Main Nitrogenous Excretory Product of Birds

Science ◽  
1970 ◽  
Vol 170 (3953) ◽  
pp. 98-98 ◽  
Author(s):  
Thomas L. Poulson ◽  
F. M. Anne McNabb
Keyword(s):  
Uric Acid ◽  
Excretory Product

Nitrogen Excretion in Ascidiacea II. Storage Excretion and the Uricolytic Enzyme System

1965 ◽  
Vol 42 (2) ◽  
pp. 299-305
Author(s):  
IVAN GOODBODY
Keyword(s):  
Uric Acid ◽  
Calcium Carbonate ◽  
Protein Metabolism ◽  
Enzyme System ◽  
Purine Metabolism ◽  
Nitrogen Excretion ◽  
Purine Base ◽  
Purine Bases ◽  
Ascidiella Aspersa

1. The evidence for the occurrence of storage excretion in ascidians is reviewed. Most species probably store uric acid or purine bases in some form. 2. The renal concretions of Ascidia nigra and Phallusia mammillata contain 50-60% uric acid, the remainder of the concretion is unidentified but is non-nitrogenous and is not calcium carbonate. In Ascidiella aspersa the concretion is predominantly composed of calcium carbonate and there is no significant quantity of uric acid or purine base. 3. Uric acid is also identified in Molgula manhattensis, Polycarpa obtecta, Pyura vittata and Herdmania momus. 4. Storage excretion probably results from a deficiency in the uricolytic enzyme system. It is concluded that while protein metabolism is ammonotelic, purine metabolism is uricotelic or xanthotelic.

Nitrogen excretion in germ-free and conventional chickens: effects of an alkali load

1978 ◽  
Vol 39 (1) ◽  
pp. 99-104 ◽  
Author(s):  
J. Okumura ◽  
D. Hewitt ◽  
Marie E. Coates
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Ammonia Excretion ◽  
Nitrogen Excretion ◽  
Acid Base Balance ◽  
Acid Base ◽  
Total N ◽  
Germ Free ◽  
Base Balance ◽  
Micro Organisms

1. Groups of three colostomized germ-free (GF) and conventional (CV) chickens aged 4 months were maintained for successive periods of 8 d on a diet containing 200 g casein/kg without and with sodium bicarbonate at the rate of 20 mmol/d and a nitrogen-free diet without and with NaHCO3at 9 mmol/d. Urine and faeces were collected during the last 3 d of each period.2. Total N, uric acid- and ammonia-N were determined in urine and total N in faeces. Amino acids were measured in hydrolysates of faeces collected during the periods when no NaHCO3was included in the diets.3. The CV birds excreted more N on the casein diets but less on the N-free diets than did their GF counterparts, the differences being mainly shown in the urine.4. On both diets hydrolysates of the faeces of CV birds contained smaller amounts of amino acids. On the N-free diet the proportions (g/160 g N) of serine, proline and threonine were reduced, suggesting some conservation of endogenous N by micro-organisms, and the proportions of histidine, alanine, lysine and methionine increased, possibly through microbial synthesis; on the casein diet, proportions of most amino acids were less, probably because bacterial deamination had occurred.5. Urinary excretion of total N, uric acid and ammonia was much greater on the casein than on the N-free diets. Inclusion of NaHCO3caused a sharp fall in urinary ammonia on both diets and in both environments.6. It was concluded that the level of dietary protein and the regulation of acid-base balance have more effect than microbial activity on the urinary ammonia excretion.

The effect of sucrose on the utilization of straw plus urea diets by sheep

1965 ◽  
Vol 16 (2) ◽  
pp. 159 ◽  
Author(s):  
GJ Faichney
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Body Weight Gain ◽  
Ammonia Nitrogen ◽  
Nitrogen Excretion ◽  
Limiting Factor ◽  
Crude Fibre ◽  
Passage Rate ◽  
Available Energy ◽  
Rumen Nitrogen

An experiment was carried out on sheep to investigate the effect of supplementary energy, in the form of sucrose, on the intake and utilization of a diet of oat straw supplemented with urea. The sucrose supplement had no significant effect on the dry matter intake, although there was a tendency for the intake of straw to decline with an increase in the sucrose supplement. There was no significant effect on the digestibility of dry matter or crude fibre, but the digestibility of crude fibre tended to decrease when the sucrose supplements were fed. This may explain an increase in faecal nitrogen excretion, which was reflected in a significant (P < 0.05) decrease in the apparent digestibility of nitrogen on the diets supplemented with sucrose. There were no significant differences between the diets in rate of passage, rate of cellulose digestion in the rumen, nitrogen balance, body weight gain, rumen pH, or concentrations of volatile fatty acids and ammonia nitrogen in the rumen. It was concluded that the lack of a supplement of readily available energy was not a limiting factor in the sheep's utilization of the diets used.

Effects of benzoic acid and inulin on ammonia–nitrogen excretion, plasma urea levels, and the pH in faeces and urine of weaner pigs

2010 ◽  
Vol 134 (1-3) ◽  
pp. 243-245 ◽  
Author(s):  
Danka Halas ◽  
Christian Fink Hansen ◽  
David J. Hampson ◽  
Jae-Cheol Kim ◽  
Bruce P. Mullan ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Ammonia Nitrogen ◽  
Nitrogen Excretion ◽  
Plasma Urea ◽  
Weaner Pigs

scholarly journals 3-Methylxanthine production through biodegradation of theobromine by Aspergillus sydowii PT-2

2020 ◽  
Author(s):  
bin-xing ZHOU ◽  
Cunqiang Ma ◽  
Chengqin Zheng ◽  
Tao Xia ◽  
Bingsong Ma ◽  
...  
Keyword(s):  
Uric Acid ◽  
Potential Application ◽  
Metal Ion ◽  
Liquid Culture ◽  
Aspergillus Sydowii ◽  
Aspergillus Tamarii ◽  
Synthetic Compounds ◽  
Aspergillus Ustus ◽  
Bacteria And Fungi ◽  
Microbial Isolates

Abstract Background: Methylxanthines, including caffeine, theobromine and theophylline, are natural and synthetic compounds in tea, which could be metabolized by certain kinds of bacteria and fungi. Previous studies confirmed that several microbial isolates from Pu-erh tea could degrade and convert caffeine and theophylline. We speculated that these candidate isolates also could degrade and convert theobromine through N-demethylation and oxidation. In this study, seven tea-derived fungal strains were inoculated into various theobromine agar medias and theobromine liquid mediums to assess their capacity in theobromine utilization. Related metabolites with theobromine degradation were detected by using HPLC in the liquid culture to investigate their potential application in the production of 3-methylxanthine. Results: Based on theobromine utilization capacity, Aspergillus niger PT-1, Aspergillus sydowii PT-2, Aspergillus ustus PT-6 and Aspergillus tamarii PT-7 have demonstrated the potential for theobromine biodegradation. Particularly, A. sydowii PT-2 and A. tamarii PT-7 could degrade theobromine significantly (p < 0.05) in all given liquid mediums. 3,7-Dimethyluric acid, 3-methylxanthine, 7-methylxanthine, 3-methyluric acid, xanthine, and uric acid were detected in A. sydowii PT-2 and A. tamarii PT-7 culture, respectively, which confirmed the existence of N-demethylation and oxidation in theobromine catabolism. 3-Methylxanthine was common and main demethylated metabolite of theobromine in the liquid culture. 3-Methylxanthine in A. sydowii PT-2 culture showed a linear relation with initial theobromine concentrations that 177.12 ± 14.06 mg/L 3-methylxanthine was accumulated in TLM-S with 300 mg/L theobromine. Additionally, pH at 5 and metal ion of Fe2+ promoted 3-methylxanthine production significantly (p < 0.05). Conclusions: This study is the first to confirm that A. sydowii PT-2 and A. tamarii PT-7 degrade theobromine through N-demethylation and oxidation, respectively. A. sydowii PT-2 showed the potential application in 3-methylxanthine production with theobromine as feedstock through the N-demethylation at N-7 position.

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