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

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.

1968 ◽  
Vol 14 (11) ◽  
pp. 1253-1258 ◽  
Author(s):  
V. P. Agnihotri

The effects of different nitrogen sources on growth and sclerotial production by Aspergillus niger were determined on a synthetic agar medium. The organism used inorganic, organic, and ammonium nitrogen for growth and sclerotial production. Among the ammonium compounds tested, the chloride, phosphate, sulfate, and carbonate were used poorly, but the nitrate was well utilized. Addition of organic acids to ammonium compounds increased sclerotial production. Raising the concentration of sodium nitrate to a certain level (0.15%) increased the number of sclerotial initials and the number and weight of those which matured. Sodium nitrite curtailed mycelial growth and prevented production of sclerotia. Utilization of nitrite was accelerated by adjusting the pH on the alkaline side from 7.5 to 9.0. Urea supported poor sclerotial production; thiourea inhibited it. Of the amino acids, histidine yielded the most and arginine the least number of sclerotia. In lysine medium, the white cottony sclerotial initials remained fluffy even after 20 days. Sclerotial production decreased significantly when proline, glutamic acid, or leucine were omitted from the basal medium containing 10 amino acids. In general, no correlation existed between the number of sclerotia formed and the dry weight they attained on different nitrogen sources. With certain nitrogen sources sclerotial initials failed to mature.


1979 ◽  
Vol 25 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Yair Aharonowitz ◽  
Arnold L. Demain

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.


Author(s):  
D. J. Read ◽  
R. Bajwa

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.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Zahra Ajdari ◽  
Afshin Ebrahimpour ◽  
Musaalbakri Abdul Manan ◽  
Muhajir Hamid ◽  
Rosfarizan Mohamad ◽  
...  

This paper describes the nutritional requirements for the improvement of growth and sporulation of several strains ofMonascus purpureuson solid state cultivation. The findings revealed that glucose enhanced growth of allM. purpureusstrains tested but inhibited the sporulation rate. On the other hand, sucrose induced sporulation but inhibited production of cell mass. A combination of glucose and sucrose greatly enhanced sporulation and cell mass production ofM. purpureus. Although growth and sporulation rate were related to the ratio of carbon to nitrogen (C/N ratio), the types and concentrations of carbon and nitrogen sources also greatly influenced the growth kinetics. Among the media tested, Hiroi-PDA medium was the most preferred medium for allM. purpureusstrains tested for the enhancement of radial growth rate, sporulation, and cell production. Hence, Hiroi-PDA could be suggested as the generic basal medium for the cultivation ofM. purpureus. However, individual medium optimization is required for significant enhancement in growth and sporulation of each strain ofM. purpureus.


Author(s):  
J. A. Serrano

Morphology of the cell wall and organization of the cytoplasm of Nocardia corynebacterioides nom nov and Nocardia asteroides ATCC 14597, were examined by electron microscopy after the induction of autolysis using 0.012M ammonium carbonate. Organisms were cultured in casaminic acidbroth modified according to Abrams (1955), medium PPLO (Difco) modified according to Sharp (1954), a modified mixture of electrolytes according to Dienes (1956) and a medium based on amino-acids in proportions of 0.05 mg %. In all of these media we used in an alternate or combined form 1.000 U/ml of penicillin or 100 mg/ml of cycloserine (Sigma). After treatment in ammonium carbonate and culture in the media mentioned above, incubated at 37°C, the growth of the colonies on Agar-peptone and Agar-amino-acid presented a smooth surface and alterations of pigmentation.Cultures in solid or liquid media were observed by phase contrast and with a JEM 7-A electron microscope. The cells were negatively stained with sodium silicotungstate pH 7.6 and fixed in 2% osmium according to Ryter and Kellenberger.


1965 ◽  
Vol 43 (11) ◽  
pp. 1367-1378 ◽  
Author(s):  
Brother Joseph Cain

Axenic cultures of 38 organisms, half of these available from culture collections of algae and half newly isolated, were investigated for nitrogen utilization. When NaNO3, NaNO2, (NH4)2SO4, and NH4NO3 were used as sole sources of nitrogen in an organic basal medium, it was evident that most of the organisms used NaNO3 and NaNO2 with equal facility. (NH4)2SO4 was utilized to about the same extent as NH4NO3, and both were used with less facility than NaNO3 and NaNO2. Growth in the basal medium with any of nine amino acids as sole nitrogen sources (namely, asparagine, ornithine, aspartic acid, lysine, serine, glycine, glutamic acid, alanine, and glutamine) was sufficiently differential to suggest possible taxonomic utility. When study was made of certain nitrogenous bases as sole nitrogen sources, it was found that adenine and uric acid were widely utilized, but cytosine, thymine, and uracil supported little or no growth. Again, when acetamide and succinamide were used as sole sources of nitrogen, and growth was compared with that in media containing glutamine and asparagine, patterns of growth differed from organism to organism. In summary, it can be said that these experiments provide data on growth patterns which may be significant as supplements to strictly morphological attributes of the organisms.


1967 ◽  
Vol 13 (4) ◽  
pp. 351-360 ◽  
Author(s):  
K. K. Al-Hassan ◽  
C. L. Fergus

Stilbella thermophila Fergus was grown on a chemically denned medium of D-glucose, KNO3, MgSO4, KH2PO4, agar, and microelements to determine the effect of environment and nutrition on growth and synnemata production. An exogenous supply of thiamine stimulated growth markedly on pyridine-purified agar, but both thiamine and biotin were required for synnemata to form. Pyrimidine was the effective moiety, not thiazole. S. thermophila grew on a large number of carbon and nitrogen compounds substituted singly into the basal medium, but synnemata formed on less than half of such media. Sucrose did not inhibit synnemata formation with glucose present, but no synnemata formed with sucrose in the medium even with a number of different nitrogen sources. Synnemata production followed chance mold contamination on a few of the media that normally did not allow their production. The carbon–nitrogen ratio significantly affected synnemata formation. So did pH, concentration of phosphate buffer, and temperature. At suboptimal temperatures, reduced synnemata, or only loose bundles of conidiophores, formed. Light was not required for synnemata initiation nor for maturation. Synnemata formation occurred over a narrower range of temperature, pH, vitamin concentration, nutrient concentration, and nutrient spectrum (carbon and nitrogen sources) than did mycelial growth.


1956 ◽  
Vol 2 (7) ◽  
pp. 747-756 ◽  
Author(s):  
Robert Rabin ◽  
Leonard N. Zimmerman

Some nutritive aspects of proteinase biosynthesis by non-proliferating cells of Streptococcus liquefaciens, strain 31, were investigated by substituting constituents in a basal medium containing casein, lactose, purines, pyrimidines, vitamins, and salts. The casein of the medium could be replaced by a mixture of 12 "essential" amino acids (glutamic acid, histidine, valine, serine, methionine, leucine, isoleucine, arginine, cystine, lysine, tryptophane, and threonine), thus demonstrating that proteinase synthesis can occur in a medium devoid of protein. Proteinase biosynthesis appeared to depend upon an inordinately high concentration of arginine, required a fermentable carbohydrate, and occurred optimally at pH 6.3. Sodium fluoride and iodoacetate did not inhibit the proteinase activity but radically curbed its synthesis.


1959 ◽  
Vol 37 (5) ◽  
pp. 819-834 ◽  
Author(s):  
D. M. MacLeod

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.


1968 ◽  
Vol 14 (12) ◽  
pp. 1341-1346 ◽  
Author(s):  
H. N. Singh ◽  
B. S. Srivastava

Spore germination, heterocyst production, hormogone formation, and sporulation are the morphogenetic stages in the developmental cycle of Anabaena doliolum Bharadwaja. In basal medium sporulation is simultaneous while heterocyst formation is sequential. Nitrate, nitrite, and ammonium nitrogen inhibit sporulation and heterocyst formation. The degree of inhibition depends on the concentration and source of inorganic nitrogen. Nitrate and nitrite induce lysis which is concentration dependent and circumscribed by time, i.e., up to a certain stage the lytic events are preventable by transfer to basal medium, but beyond this stage they become inevitable and complete lysis occurs even in the absence of nitrate or nitrite. The sequential differentiation and spatial relations of heterocysts in a growing filament are characteristic of each nitrogen source and indicative of the polarity involved in the gradient of heterocyst formation.


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