Some nutritional aspects of the biology of ericaceous mycorrhizas

1985 ◽  
Vol 85 (3-4) ◽  
pp. 317-331 ◽  
Author(s):  
D. J. Read ◽  
R. Bajwa
Keyword(s):  
Amino Acids ◽  
Mycorrhizal Fungus ◽  
Amino Nitrogen ◽  
Nitrogen Sources ◽  
Acid Protease ◽  
Mycorrhizal Symbiosis ◽  
Mycorrhizal Infection ◽  
Plant Nitrogen ◽  
Low Concentrations

SynopsisSome aspects of the role of the ericoid mycorrhizal symbiosis in the ecology and physiology of ericaceous plants are described. Mycorrhizal infection leads to enhancement of plant nitrogen content and an experimental analysis of the basis of this effect is reported. In addition to improving the efficiency of ammonium absorption at low concentrations, the mycorrhizal endophyte utilises amino acids, peptides and proteins as nitrogen substrates for growth. These are the predominant nitrogen sources in organic heathland soil. It is suggested that the success of ericaceous plants in such soils may arise through the capacity of the mycorrhizal fungus to provide its host with access to this nutrient resource. A model is described in which absorption of ammonium and amino nitrogen leads to soil acidification, increased acid protease activity and improved vigour of the ericaceous plants.

EFFECT OF AMMONIUM NITROGEN AND AMINO ACIDS ON PERITHECIAL FORMATION OF VENTURIA INAEQUALIS

1971 ◽  
Vol 51 (1) ◽  
pp. 29-33 ◽  
Author(s):  
R. G. ROSS ◽  
FRANCES D. J. BREMNER
Keyword(s):  
Amino Acids ◽  
Ammonium Carbonate ◽  
Venturia Inaequalis ◽  
Amino Nitrogen ◽  
Basal Medium ◽  
Nitrogen Sources ◽  
Ammonium Nitrogen ◽  
Racemic Mixture ◽  
Appreciable Change ◽  
The Media

Perithecia of Venturia inaequalis did not form in a basal medium to which was added ammonium sulfate, chloride, phosphate or tartrate as the sole sources of nitrogen, when the pH of the medium was allowed to fall to inhibitory levels. Perithecia formed with these ammonium salts as nitrogen sources when calcium carbonate was added to control the pH. With ammonium carbonate and oxalate there was no appreciable change in pH, and perithecia formed with these salts as nitrogen sources. Perithecia did not form in media with leucine as a nitrogen source. Formation of perithecia with other amino acids depended on the concentration of amino-nitrogen in the media. A substance toxic to perithecial formation may form in cultures containing leucine; if so, it is produced in different amounts by the two isomers and the racemic mixture of this amino acid.

Nitrogen nutrition and regulation of cephalosporin production in Streptomyces clavuligerus

1979 ◽  
Vol 25 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Yair Aharonowitz ◽  
Arnold L. Demain
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Nitrogen Nutrition ◽  
Antibiotic Production ◽  
Inorganic Nitrogen ◽  
Amino Nitrogen ◽  
Nitrogen Sources ◽  
Streptomyces Clavuligerus ◽  
Defined Medium ◽  
Repressive Effect

When used as sole nitrogen source, certain amino acids (e.g., proline, asparagine) supported both growth and sporulation by Streptomyces clavuligerus streaked onto solid defined medium. Ammonium supported growth but suppressed sporulation. Amino nitrogen was best for cephalosporin production in liquid defined medium, although urea was almost as useful. A comparison of amino acids showed asparagine and glutamine to be the best nitrogen sources and arginine to be almost as good. Ammonium salts supported a somewhat lower growth rate than asparagine, but antibiotic production was very poor on these inorganic nitrogen sources. Addition of ammonium to asparagine did not affect growth rate but increased mycelial mass; cephalosporin production was reduced by about 75%. Antibiotic production was more closely associated with growth in the absence of ammonium than in its presence, indicating a strong inhibitory and (or) repressive effect of NH4+ on antibiotic production. Ammonium exerted its negative effect when added at 24 h or earlier, i.e. before antibiotic formation began.

scholarly journals Free Amino Nitrogen in Brewing

Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 22 ◽  
Author(s):  
Annie Hill ◽  
Graham Stewart
Keyword(s):  
Amino Acids ◽  
Free Amino ◽  
Amino Nitrogen ◽  
Aroma Compounds ◽  
Ethanolic Fermentation ◽  
Methods Of Analysis

The role of nitrogenous components in malt and wort during the production of beer has long been recognized. The concentration and range of wort amino acids impact on ethanolic fermentation by yeast and on the production of a range of flavour and aroma compounds in the final beer. This review summarizes research on Free Amino Nitrogen (FAN) within brewing, including various methods of analysis.

scholarly journals Influence of Amino Acid Feeding on Production of Calcimycin and Analogs in Streptomyces chartreusis

2021 ◽  
Vol 18 (16) ◽  
pp. 8740
Author(s):  
Kirstin I. Arend ◽  
Julia E. Bandow
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Sources ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Defined Medium ◽  
Glutamine Supplementation ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters

Streptomyces chartreusis NRRL 3882 produces the polyether ionophore calcimycin and a variety of analogs, which originate from the same biosynthetic gene cluster. The role of calcimycin and its analogs for the producer is unknown, but calcimycin has strong antibacterial activity. Feeding experiments were performed in chemically defined medium systematically supplemented with proteinogenic amino acids to analyze their individual effects on calcimycin synthesis. In the culture supernatants, in addition to known calcimycin analogs, eight so far unknown analogs were detected using LC-MS/MS. Under most conditions cezomycin was the compound produced in highest amounts. The highest production of calcimycin was detected upon feeding with glutamine. Supplementation of the medium with glutamic acid resulted in a decrease in calcimycin production, and supplementation of other amino acids such as tryptophan, lysine, and valine resulted in the decrease in the synthesis of calcimycin and of the known intermediates of the biosynthetic pathway. We demonstrated that the production of calcimycin and its analogs is strongly dependent on amino acid supply. Utilization of amino acids as precursors and as nitrogen sources seem to critically influence calcimycin synthesis. Even amino acids not serving as direct precursors resulted in a different product profile regarding the stoichiometry of calcimycin analogs. Only slight changes in cultivation conditions can lead to major changes in the metabolic output, which highlights the hidden potential of biosynthetic gene clusters. We emphasize the need to further study the extent of this potential to understand the ecological role of metabolite diversity originating from single biosynthetic gene clusters.

NUTRITIONAL STUDIES ON THE GENUS HIRSUTELLA: II. NITROGEN UTILIZATION IN A SYNTHETIC MEDIUM

1959 ◽  
Vol 37 (5) ◽  
pp. 819-834 ◽  
Author(s):  
D. M. MacLeod
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Synthetic Medium ◽  
Total Yield ◽  
Amino Nitrogen ◽  
Nitrogen Sources ◽  
Ammonium Tartrate ◽  
Growth Responses ◽  
Nitrogenous Compounds ◽  
Nutritional Studies

The growth responses of Hirsutella gigantea to different nitrogen sources were studied. Experiments showed that the mycelium hydrolyzate contained at least 14 of the amino acids, that the fungus was unable to utilize inorganic nitrogenous compounds, that ammonium tartrate was inferior to amino-nitrogen, and that the L or DL isomers of the different amino acids induced better growth than did the D form.The 10 most suitable nitrogen sources in order of decreasing growth were: L-glutamic acid, L-tyrosine, ammonium tartrate, DL-aspartic acid, L-proline, L-arginine, L-leucine, DL-α-alanine, DL-serine, and DL-histidine. The total yield, however, obtained in a synthetic medium with each of these substances was shown to be directly dependent upon the quantity of inoculum used. The enhanced growth resulting from the addition of increased inoculum is ascribed to accessory growth factors carried over with the mycelial fragments despite six washings in saline.The maximum growth of H. gigantea developed in a dextrose–salts medium containing L-glutamic acid as a source of nitrogen, and yeast extract, inoculum filtrate, and liver fraction "L" as a source of growth factors.The lack of uniformity associated with nutritional studies conducted in chemically defined media has been briefly mentioned.

scholarly journals Integrative Study Supports the Role of Trehalose in Carbon Transfer From Fungi to Mycotrophic Orchid

2021 ◽  
Vol 12 ◽  
Author(s):  
Jan Ponert ◽  
Jan Šoch ◽  
Stanislav Vosolsobě ◽  
Klára Čiháková ◽  
Helena Lipavská
Keyword(s):  
Amino Acids ◽  
High Performance ◽  
Specific Inhibitor ◽  
Soluble Carbohydrates ◽  
Mycorrhizal Symbiosis ◽  
Trehalase Activity ◽  
Carbon Transfer ◽  
Integrative Study ◽  
The Common

Orchids rely on mycorrhizal symbiosis, especially in the stage of mycoheterotrophic protocorms, which depend on carbon and energy supply from fungi. The transfer of carbon from fungi to orchids is well-documented, but the identity of compounds ensuring this transfer remains elusive. Some evidence has been obtained for the role of amino acids, but there is also vague and neglected evidence for the role of soluble carbohydrates, probably trehalose, which is an abundant fungal carbohydrate. We therefore focused on the possible role of trehalose in carbon and energy transfer. We investigated the common marsh orchid (Dactylorhiza majalis) and its symbiotic fungus Ceratobasidium sp. using a combination of cultivation approaches, high-performance liquid chromatography, application of a specific inhibitor of the enzyme trehalase, and histochemical localization of trehalase activity. We found that axenically grown orchid protocorms possess an efficient, trehalase-dependent, metabolic pathway for utilizing exogenous trehalose, which can be as good a source of carbon and energy as their major endogenous soluble carbohydrates. This is in contrast to non-orchid plants that cannot utilize trehalose to such an extent. In symbiotically grown protocorms and roots of adult orchids, trehalase activity was tightly colocalized with mycorrhizal structures indicating its pronounced role in the mycorrhizal interface. Inhibition of trehalase activity arrested the growth of both symbiotically grown protocorms and trehalose-supported axenic protocorms. Since trehalose constitutes only an inconsiderable part of the endogenous saccharide spectrum of orchids, degradation of fungal trehalose likely takes place in orchid mycorrhiza. Our results strongly support the neglected view of the fungal trehalose, or the glucose produced by its cleavage as compounds transported from fungi to orchids to ensure carbon and energy flow. Therefore, we suggest that not only amino acids, but also soluble carbohydrates are transported. We may propose that the soluble carbohydrates would be a better source of energy for plant metabolism than amino acids, which is partially supported by our finding of the essential role of trehalase.

THE METABOLISM OF YEAST SPORULATION: V. STIMULATION AND INHIBITION OF SPORULATION AND GROWTH BY NITROGEN COMPOUNDS

1963 ◽  
Vol 9 (2) ◽  
pp. 259-277 ◽  
Author(s):  
J. J. Miller
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Ammonium Sulphate ◽  
Slow Growth ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Nitrogen Compounds ◽  
Sporulation Medium ◽  
Carbon And Nitrogen ◽  
Low Concentrations

The effects of a variety of nitrogen compounds, mainly amino acids, on ascus production by S. cerevisiae in sporulation media containing several carbon sources were compared. With acetate, glucose, ethanol, pyruvate, and lactate all the amino acids (0.01 M) and most other nitrogen compounds inhibited sporulation. With dihydroxyacetone fewer nitrogen compounds inhibited and alanine, phenylalanine, glycine, and lysine (especially the latter) increased sporulation, even at low concentrations (0.0001 M). Sporulation in buffer resembled sporulation in dihydroxyacetone in its response to amino acids. For greatest inhibition of sporulation the simultaneous presence of carbon and nitrogen sources was necessary. With dihydroxyacetone as carbon source, glutamic acid increased the average number of spores per ascus, but decreased it with all other carbon sources.No correlation was evident between the effects of the amino acids on sporulation and their value as nitrogen sources for growth or with changes in the oxygen uptake of cells in their presence. Dihydroxyacetone did not support growth when the nitrogen source was ammonium sulphate, but slow growth resulted when ammonium sulphate was replaced by glutamic acid or casein hydrolyzate.A sporulation medium is recommended containing, in water (or buffer) agar, 0.02 M dihydroxyacetone and 0.01 M lysine.

Effect of genotype of Trifolium repens on mycorrhizal symbiosis with Glomus mosseae

2001 ◽  
Vol 137 (1) ◽  
pp. 27-36 ◽  
Author(s):  
W. R. EASON ◽  
K. J. WEBB ◽  
T. P. T. MICHAELSON-YEATES ◽  
M. T. ABBERTON ◽  
G. W. GRIFFITH ◽  
...  
Keyword(s):  
Trifolium Repens ◽  
Root Length ◽  
Mycorrhizal Fungus ◽  
Plant Response ◽  
Mycorrhizal Symbiosis ◽  
Parental Genotype ◽  
Root Weight ◽  
Mycorrhizal Infection ◽  
Infection Rates ◽  
Important Species

Forty-three near-isogenic lines (NILs) of white clover (Trifolium repens), derived from four parental self-compatible genotypes containing the rare self-fertility allele, were inoculated with the arbuscular mycorrhizal fungus Glomus mossae. Plant growth response (shoot and root weight and root length), shoot P uptake and mycorrhizal root infection rates were recorded 12 weeks after inoculation. There was generally a high degree of variation between individual lines in all recorded parameters. The most sensitive indicator of plant response to mycorrhizal infection was root length with almost half of all lines showing significant responses (in most cases a decrease in root length). Shoot weight was significantly different between mycorrhizal and nonmycorrhizal plants in nine lines. Parental genotype significantly affected both plant response to mycorrhiza as well as mycorrhizal infection rates. The results suggest that the NILs will prove useful for further studies to elucidate the molecular genetic control of the symbiosis and inform plant breeding strategies of this agronomically important species.

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