The sterilizing effect againstBacillus subtilisspores of hydrogen peroxide at different temperatures and concentrations

Abstract

Summary: An investigation was made of the death-rate ofBacillus subtilisspores in suspension in hydrogen peroxide concentrations of 10, 15 and 20% at 25, 50, 60, 70 and 80°C. Average logarithmic survival curves were plotted against normal time and death-rate constants andQ₁₀values were calculated from the graphically determined decimal reduction times. This treatment of the experimental findings was found to be warranted in the temperature range 60–80°C. The first-order death-rate constant was ∽ 0·1 s⁻¹for 10% hydrogen peroxide solution at 60°C and theQ₁₀was about 1·6. Increases in the concentration from 10 to 15% and from 15 to 20% each gave an increase of about 50% in the rate constant. The application of these data to commercial practice is discussed.