Pasteur effect is due to the inhibition of glycolysis by high concentration of
ATP
Pasteur effect is the slowing or complete cessation of alcoholic fermentation in the presence of oxygen.
In the presence of oxygen, the product of glycolysis, pyruvate is used in the Krebs cycle to produce 38 moles of ATP per 1mole of glucose.
While in the absence of oxygen, pyruvate is turned into ethanol with the production of 2 moles of ATP per 1 mole of glucose.
Therfore when ATP is present in high concentrations, synthesis of ATP is stopped by the inhibition of glycolysis.