COMPARATIVE RESPONSE OF TWO SAPROPHYTIC AND TWO PLANT PARASITIC SOIL FUNGI TO TEMPERATURE, HYDROGEN-ION CONCENTRATION, AND NUTRITIONAL FACTORS

1961 ◽  
Vol 39 (1) ◽  
pp. 65-79 ◽  
Author(s):  
E. W. B. Ward ◽  
A. W. Henry
Keyword(s):  
Soil Fungi ◽  
Inorganic Nitrogen ◽  
Synthetic Medium ◽  
Trichoderma Viride ◽  
Nitrogen Sources ◽  
Ion Concentration ◽  
Good Growth ◽  
Hydrogen Ion Concentration ◽  
Nutritional Factors ◽  
Ph Values

The behavior of two soil saprophytes, Trichoderma viride and Trichocladium asperum, and two root-infecting fungi, Ophiobolus graminis and Fomes annosus, was compared under various conditions in laboratory culture.On an agar-solidified organic medium optimum temperatures for growth were approximately: T. viride 25–30 °C, T. asperum 20–25 °C, O. graminis 20–25 °C, F. annosus 25 °C. T. viride rapidly outgrew the other fungi in the optimum range but this relationship changed at lower temperatures, its growth rate being equalled by that of O. graminis at 10 °C. T. viride was the only fungus to grow at 35 °C. In a synthetic liquid medium adjusted to pH values from 3.0–7.0 with a citrate–phosphate buffer, growth of O. graminis and F. annosus was sharply reduced at pH values below 5.0. T. viride made good growth at pH 3.1 and reduction in growth of T. asperum occurred only below pH 4.0. Both parasites required thiamine for growth in a synthetic medium and O. graminis also required biotin; in addition they showed a preference for organic as opposed to inorganic nitrogen sources. T. viride and T. asperum grew well with KNO3 as nitrogen source and neither required vitamins. D-Glucose, D-fructose, and D-mannose were readily utilized, and D-arabinose poorly utilized, by all four fungi. Utilization of other hexoses, pentoses, disaccharides, and polysaccharides varied considerably between the fungi.The relationship of the results obtained to the observations of others on the ecology of soil fungi is discussed and the possibility that combinations of physical and nutritional factors may favor specific fungi in the soil is considered.

Heat Resistance of Alicyclobacillus acidoterrestris Spores as Affected by Various pH Values and Organic Acids‡

1998 ◽  
Vol 61 (1) ◽  
pp. 41-46 ◽  
Author(s):  
APRIL J. PONTIUS ◽  
JOHN E. RUSHING ◽  
PEGGY M. FOEGEDING
Keyword(s):  
Heat Resistance ◽  
Fruit Juice ◽  
Ion Concentration ◽  
Thermal Processes ◽  
Alicyclobacillus Acidoterrestris ◽  
Hydrogen Ion Concentration ◽  
Ph Values ◽  
Acid Type ◽  
Acidic Conditions ◽  
D Values

Alicyclobacillus acidoterrestris, a thermoacidophilic sporeformer, has caused spoilage of fruit juices which had been treated with thermal processes intended to commercially sterilize the juice. The objective of this research was to document the effect of pH, acid, and temperature on the heat resistance of spores of three fruit-juice isolates of A. acidoterrestris. The thermal resistance of spores of A. acidoterrestris strains VF, WAC, and IP were studied in a model fruit-juice system composed of 12% glucose and 30 mM of either citric, malic, or tartaric acid, adjusted to selected pH values ranging from 2.8 to 4.0. Decimal reduction times (D values) and inactivation rates were determined. Spores of strains VF and WAC were similarly resistant to heat under acidic conditions, while strain IP spores were less resistant. In the range of pH 2.8 to 4.0, a statistically significant effect of hydrogen ion concentration on heat resistance was observed at lower temperatures, but not at the higher temperatures. For example, at 91 °C and pH 3.1 and 3.7, D values were 31.3 and 54.3 min, respectively, while at 97°C D values at pH 3.1 and 3.7 were 7.9 and 8.8 min, respectively. The type of acid did not significantly affect the heat resistance. The zD values ranged from 5.9 to 10°C, depending on the acid, pH, and the strain. The models generated from this research can be used to determine adequate thermal processes, accounting for the acid type, pH, and temperature, to destroy A. acidoterrestris spores in beverages, since this organism is able to survive the typical hot-fill and hold process (2 min at 88 to 96°C) currently used to process fruit juice.

THE ELECTRODE POTENTIAL OF IRON IN RELATION TO HYDROGEN ION CONCENTRATION

1936 ◽  
Vol 14b (1) ◽  
pp. 31-40 ◽  
Author(s):  
J. W. Shipley ◽  
J. H. Shipley
Keyword(s):  
Electrode Potential ◽  
Chloride Ion ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Iron Electrode ◽  
General Corrosion ◽  
Citrate Buffer ◽  
Hydrogen Ion Concentration ◽  
Electrically Conducting ◽  
Ph Values

The electrode potential of iron immersed in phosphate, borate and citrate buffers of varying hydrogen ion concentration was measured, using a normal calomel electrode as the second half of the cell. Breaks in the potential of the iron electrode amounting to as much as 0.7 volts were found to occur at definite pH values for each series of buffers. The electrode exhibited an "initial" and "final" potential depending on the pH of the electrolyte and the time of immersion, the "final" value requiring several days to become established. The "final" break in the electrode potential of 0.74 volts in the pure phosphate buffer occurred between a pH of 3.1 and 4.0, that in the pure borate buffer, of 0.75 volts, occurred between a pH of 4.3 and 4.6, and in the pure citrate buffer, of 0.77 volts, between a pH of 10.1 and 10.9. The effect of chloride ion and de-aeration on the electrode potential was observed. It is suggested that the potential of the iron electrode is determined by the presence or absence of a non electrically conducting film or deposit on the iron, the formation of which is a function of the nature of the electrolyte and its hydrogen ion concentration. De-aeration apparently had no effect on the electrode potential, but the presence of chloride ion affected the establishing of the "final" potential and caused the break in voltage to appear irregularly at a much lower hydrogen ion concentration.At pH values below that at which the break in potential occurred, corrosion of the iron electrode was marked, and the electrode potential remained high, while, at pH values above the break, corrosion was virtually inhibited or confined to local spots on the electrode, and the electrode potential remained low. The presence of the chloride ion stimulated local corrosion and permitted general corrosion to proceed at a lower hydrogen ion concentration.

scholarly journals Acidity of Snow and its Reduction by Alkaline Aerosols

1985 ◽  
Vol 6 ◽  
pp. 92-94 ◽  
Author(s):  
Motoi Kumai
Keyword(s):  
Electric Power ◽  
Power Plants ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Electric Power Plants ◽  
Ph Values ◽  
Calcium Silicon ◽  
The Mean ◽  
Snow Crystals ◽  
Snow Samples

Snow crystals scavenge aerosols in the atmosphere during the processes of growth and precipitation. Several kinds of flyash are found in acid snow by scanning electron microscope examination. Flyash particles from coal fired electric power plants in Fairbanks, Alaska, were found to be spherical or irregular in shape with a 0.2 to 50μm diameter, and were rich in calcium, silicon, aluminum and iron. The pH of 35 snow samples in Fairbanks ranged from 5.60 to 7.48. The acid snow was changed to alkaline snow by dry fallout of calcium-rich flyash from the electric power plants, which were using calcium-rich Alaskan coal.Flyash particles from three oil fired heating plants in Hanover, New Hampshire, were spherical and 10 to 80 μm in diameter, with gas escape holes, and were always sulfur rich. The pH values of fresh snow from 44 snowfalls were measured to range from pH 3.96 to 5.45 in Hanover. The mean hydrogen ion concentration was calculated to be 10-448 mol/L for 22 snowfalls in 1980-84, and 10-4 mol/L for 22 snowfalls in 1972-73.

scholarly journals The Hydrogen Ion Concentration of the Cells of some Marine Algæ

1922 ◽  
Vol 12 (4) ◽  
pp. 785-788 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Marine Algae ◽  
Plant Cells ◽  
Hydrogen Ion ◽  
Land Plants ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Ph Values ◽  
Optimum Ph ◽  
Acid Character

The measurements recorded for marine algæ of various groups show that the reaction of the sap is in most cases almost neutral, and in no case is the sap of the pronounced acid character met with in many land plants. This being so it follows that the enzymes concerned in the metabolism of these algæ must be quite different from those which effect corresponding changes in land plants, as may be seen on referring to the optimum pH values for various enzymes quoted in the writer's previous paper on the reaction of plant cells (1922).

scholarly journals Acidity of Snow and its Reduction by Alkaline Aerosols

1985 ◽  
Vol 6 ◽  
pp. 92-94 ◽  
Author(s):  
Motoi Kumai
Keyword(s):  
Electric Power ◽  
Power Plants ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Electric Power Plants ◽  
Ph Values ◽  
Calcium Silicon ◽  
The Mean ◽  
Snow Crystals ◽  
Snow Samples

Snow crystals scavenge aerosols in the atmosphere during the processes of growth and precipitation. Several kinds of flyash are found in acid snow by scanning electron microscope examination. Flyash particles from coal fired electric power plants in Fairbanks, Alaska, were found to be spherical or irregular in shape with a 0.2 to 50μm diameter, and were rich in calcium, silicon, aluminum and iron. The pH of 35 snow samples in Fairbanks ranged from 5.60 to 7.48. The acid snow was changed to alkaline snow by dry fallout of calcium-rich flyash from the electric power plants, which were using calcium-rich Alaskan coal. Flyash particles from three oil fired heating plants in Hanover, New Hampshire, were spherical and 10 to 80 μm in diameter, with gas escape holes, and were always sulfur rich. The pH values of fresh snow from 44 snowfalls were measured to range from pH 3.96 to 5.45 in Hanover. The mean hydrogen ion concentration was calculated to be 10-4 48 mol/L for 22 snowfalls in 1980-84, and 10-4 mol/L for 22 snowfalls in 1972-73.

scholarly journals THE EFFECT OF HYDROGEN ION CONCENTRATION ON SWELLING OF CELLS

1926 ◽  
Vol 9 (5) ◽  
pp. 709-714 ◽  
Author(s):  
Baldwin Lucke ◽  
Morton McCutcheon
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Ph Values ◽  
Wide Range

1. The effect of HCl, NaOH, CO2, and NH3 on the volume of unfertilized Arbacia eggs was tested over a wide range of pH values. 2. No swelling occurred, except in HCl solutions, and there not until after injury or death had occurred. 3. Whereas the volume of erythrocytes and of proteins such as gelatin is known to be dependent on the pH of the solution, such a relation does not exist in the case of living and uninjured cells, at least of the type tested.

scholarly journals Chemical characteristics of precipitation and hydrogen input in throughfall and stemflow under some eastern Canadian forest stands

1983 ◽  
Vol 13 (5) ◽  
pp. 948-955 ◽  
Author(s):  
M. K. Mahendrappa
Keyword(s):  
Weighted Average ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Chemical Characteristics ◽  
Weighted Mean ◽  
Hydrogen Ion Concentration ◽  
Average Value ◽  
Ph Values ◽  
Nitrate N ◽  
Forest Experiment Station

At the Acadia Forest Experiment Station (AFES) in central New Brunswick chemical characteristics of rain samples collected at five different locations were determined during the 1977–1981 period. Throughfall and stemflow samples from six softwood and three hardwood stands were collected and chemically characterized starting from the early 70's. In 1976 two of four plots in each of the stands were treated with urea at a rate of 225 kg N•ha−1. Both the quantities of rain and their pH values varied considerably between collections, months, and years. The weighted mean pH of summer (May–October) rain collected intensively during the 1977–1981 period ranged from 4.5 to 5.1, with an overall weighted average value of 4.75 for the 5 years. Sulfur and nitrate N measured during May–October 1982 amounted to 6.18 and 1.52 kg•ha−1, respectively, for the 6-month period. The concentration of hydrogen ion in the throughfall was less than that in the rain. Hardwood throughfall had lower hydrogen levels (higher pH) than the softwood throughfall. The pH of the stemflow from softwoods was lower than that of rain in most cases. Although not significantly, the hydrogen ion concentration of both throughfall and stemflow on the fertilized plots was lower than on the untreated plots. The hydrogen load of rain was reduced by all tree species, but there was considerable variation between species in their abilities to decrease total hydrogen reaching the soil.

scholarly journals THE PENETRATION OF DYES AS INFLUENCED BY HYDROGEN ION CONCENTRATION

1923 ◽  
Vol 5 (6) ◽  
pp. 727-740 ◽  
Author(s):  
Marian Irwin
Keyword(s):  
Ph Value ◽  
Gradual Increase ◽  
Ion Concentration ◽  
Active Protein ◽  
Hydrogen Ion Concentration ◽  
Brilliant Cresyl Blue ◽  
Cresyl Blue ◽  
Buffer Solutions ◽  
Ph Values ◽  
Dye Solutions

When cells of Nitella are placed in buffer solutions at pH 9, there is a very slow and gradual increase in the pH of the sap from pH 5.6 to 6.4 (when death of the cells takes place). If the living cells are placed in 0.002 per cent dye solutions of brilliant cresyl blue at different pH values (from pH 6.6 to pH 9), it is found that the rate of penetration of the dye, and the final equilibrium attained, increases with increase in pH value, which can be attributed to an increase in the active protein (or other amphoteric electrolyte) in the cell which can combine with the dye.

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