Kinetics of yeast growth: inhibition-threshold substrate concentrations

1975 ◽  
Vol 21 (7) ◽  
pp. 994-1003 ◽  
Author(s):  
Murray Men-chung Tseng ◽  
Morris Wayman
Keyword(s):  
Acetic Acid ◽  
Growth Rates ◽  
Substrate Concentration ◽  
The Other ◽  
Yeast Growth ◽  
Inhibition Concentration ◽  
Total Inhibition ◽  
Yeast Growth Inhibition ◽  
Kinetics Of ◽  
Substrate Concentrations

Two Candida species and a Saccharomyces were grown on ethyl alcohol, acetic acid, ethyl acetate, and 1-butanol, and their growth rates at a series of concentrations of each substrate are reported. Substrate concentrations higher than a characteristic threshold substrate concentration S0 inhibited growth in accordance with a new relationship:[Formula: see text]where i is an inhibition constant and the other symbols have their usual meanings. Complete inhibition, that is, no growth, takes place when S = Si, the total inhibition concentration. Values of S0, Si, and i were calculated for the examples studied. Also discussed are the observed lag periods and also the lowered yields at high substrate concentrations.

Métabolisme de l'acide indolyl-3-acétique dans les cultures de cellules d'Acer pseudoplatanus cultivés in vitro

1977 ◽  
Vol 55 (19) ◽  
pp. 2530-2534 ◽  
Author(s):  
F. Maillard ◽  
J.-P. Zrÿd
Keyword(s):  
Cell Wall ◽  
Acetic Acid ◽  
Culture Medium ◽  
Degradation Products ◽  
Cell Suspensions ◽  
The Other ◽  
Acer Pseudoplatanus ◽  
Kinetics Of

Incubation of cell suspensions of sycamore (Acer pseudoplatanus) with β-indoyl-3-acetic acid (IAA) first led to the formation of IAA-glycosides, then to that of IAA-aspartate. Great differences are observed between the kinetics of IAA transformed by two distinct strains: one, auxin dependent (S), the other, auxin independent (MB). Other degradation products are only found in the culture medium. The localization of IAA-degrading systems in the cell wall is postulated. The auxin requirement of the S strain is discussed.

scholarly journals DOES THE KINETICS OF TRYPSIN DIGESTION DEPEND ON THE FORMATION OF A COMPOUND BETWEEN ENZYME AND SUBSTRATE

1922 ◽  
Vol 4 (5) ◽  
pp. 487-509 ◽  
Author(s):  
John H. Northrop
Keyword(s):  
Experimental Evidence ◽  
Substrate Concentration ◽  
Relative Velocity ◽  
Mass Action ◽  
Law Of Mass Action ◽  
Rate Of Hydrolysis ◽  
Gelatin Concentration ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Substrate Concentrations

1. The velocity of hydrolysis of gelatin by trypsin increases more slowly than the gelatin concentration and finally becomes nearly independent of the gelatin concentration. The relative velocity of hydrolysis of any two substrate concentrations is independent of the quantity of enzyme used to make the comparison. 2. The rate of hydrolysis is independent of the viscosity of the solution. 3. The percentage retardation of the rate of hydrolysis by inhibiting substances, is independent of the substrate concentration. 4. There is experimental evidence that the enzyme and inhibiting substance are combined to form a widely dissociated compound. 5. If the substrate were also combined with the enzyme, an increase in the substrate concentration should affect the equilibrium between the enzyme and the inhibiting substance. This is not the case. 6. The rate of digestion of a mixture of casein and gelatin is equal to the sum of the rates of hydrolysis of the two substances alone, as it should be if the rate is proportional to the concentration of free enzyme. This contradicts the saturation hypothesis. 7. If the reaction is followed by determining directly the change in the substrate concentration, it is found that this change agrees with the law of mass action; i.e., the rate of digestion is proportional to the substrate concentration.

Flow Kinetics of β-Galactosidase Chemically Attached to Nylon Tubing

1975 ◽  
Vol 53 (10) ◽  
pp. 1061-1069 ◽  
Author(s):  
D. Narinesingh ◽  
T. T. Ngo ◽  
K. J. Laidler
Keyword(s):  
Flow Rate ◽  
Substrate Concentration ◽  
Diffusion Control ◽  
Theoretical Treatment ◽  
Enzyme Reactors ◽  
Diffusion Controlled ◽  
Nylon Tubing ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Substrate Concentrations

β-Galactosidase (EC 3.2.1.23) has been attached covalently to the inner surface of nylon tubing. An experimental study has been made of the flow kinetics for the hydrolysis of o-nitrophenylgalactose, the substrate concentration and flow rate being varied. The results were analyzed in the light of the theoretical treatment of Kobayashi and Laidler, three different methods of analysis being employed. It is concluded that at the lower substrate concentrations and flow rates employed, the reactions are largely diffusion controlled; with increase in flow rate and substrate concentration the width of the Nernst diffusion layer decreases, and there is found to be less diffusion control. The values of Km(app) vary with flow rate VF, being linear in VF−1/3, and the value extrapolated to very high flow rate agrees well with the Km value for β-galactosidase in free solution. The theory and results are shown to provide guidelines for the design of open tubular heterogeneous enzyme reactors for industrial, biomedical, and analytical applications.

Multiplication of a Klebsiella pneumoniae Strain in Water at Low Concentrations of Substrates

1988 ◽  
Vol 20 (11-12) ◽  
pp. 117-123 ◽  
Author(s):  
D. van der Kooij ◽  
W. A. M. Hijnen
Keyword(s):  
Amino Acids ◽  
Water Treatment ◽  
Klebsiella Pneumoniae ◽  
Substrate Concentration ◽  
Treatment System ◽  
Water Treatment System ◽  
Low Concentrations ◽  
Ks Values ◽  
Substrate Concentrations

A K.pneumoniae strain, isolated from a water treatment system, was tested in growth measurements for its ability to multiply at substrate concentrations of a few micrograms per liter. The organism multiplied on mixtures of carbohydrates and amino acids at a substrate concentration of 1 µg of C of each compound per liter. Tests with individual compounds revealed that especially carbohydrates were utilized at low concentrations. The Ks values obtained for maltose and maltopentaose were 53 µg of C/l and 114 µg of C per liter, respectively. The significance of the growth of K.pneumoniae at low substrate concentrations is discussed.

Kinetics of the Crystallization of Potassium Sulfate

1993 ◽  
Vol 58 (8) ◽  
pp. 1848-1854 ◽  
Author(s):  
Miroslav Karel ◽  
Jaroslav Nývlt
Keyword(s):  
Experimental Data ◽  
Crystal Growth ◽  
Growth Rates ◽  
Potassium Sulfate ◽  
Kinetics Of

The kinetics of the crystallization of potassium sulfate has been determined using the MSMPR technique. Values of the nucleation and crystal growth rates evaluated from the experimental data are compared with the corresponding literature data.

The Reactivity of Different Active Forms of Sodium Carbonate with Respect to Sulfur Dioxide

1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Active Form ◽  
The Other ◽  
Kinetics Of

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.

On the kinetics of Hadamard-type fractional differential systems

2020 ◽  
Vol 23 (2) ◽  
pp. 553-570 ◽  
Author(s):  
Li Ma
Keyword(s):  
Differential Operator ◽  
Numerical Simulations ◽  
Type Inequality ◽  
The Other ◽  
Differential Systems ◽  
Fractional Differential Systems ◽  
Fractional Differential Operator ◽  
Fractional Differential ◽  
Kinetics Of ◽  
Theoretical Results

AbstractThis paper is devoted to the investigation of the kinetics of Hadamard-type fractional differential systems (HTFDSs) in two aspects. On one hand, the nonexistence of non-trivial periodic solutions for general HTFDSs, which are considered in some functional spaces, is proved and the corresponding eigenfunction of Hadamard-type fractional differential operator is also discussed. On the other hand, by the generalized Gronwall-type inequality, we estimate the bound of the Lyapunov exponents for HTFDSs. In addition, numerical simulations are addressed to verify the obtained theoretical results.

scholarly journals The determination of binding parameters when the total and free substrate concentrations are not approximately equal

1979 ◽  
Vol 179 (3) ◽  
pp. 697-700 ◽  
Author(s):  
N Gains
Keyword(s):  
Substrate Concentration ◽  
Graphical Method ◽  
Enzyme Concentration ◽  
Binding Parameters ◽  
Free Concentration ◽  
Equilibrium Binding ◽  
Substrate Concentrations

By using a standard graphical method values of Km and V may be found that are independent of the conditions and assumptions that the total substrate concentration approximates to its free concentration and that Km is much larger than the enzyme concentration. The procedure is also applicable to the determination of equilibrium binding parameters of a ligand to a macromolecule.

Kinetics of the acid-catalyzed isomerization of phenylbutenes in glacial acetic acid

1972 ◽  
Vol 94 (4) ◽  
pp. 1247-1249 ◽  
Author(s):  
R. S. Schwartz ◽  
H. Yokokawa ◽  
E. W. Graham
Keyword(s):  
Acetic Acid ◽  
Glacial Acetic Acid ◽  
Acid Catalyzed ◽  
Kinetics Of
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