The Inactivation of Free Bacteriophage by Irradiation and by Chemical Agents

Abstract

SUMMARY: Shigella phage S13 and coli phage T3 are very sensitive, in the free state, to inactivation by reducing radicals produced in water by ionizing radiation. They are inactivated by ascorbic acid, and by hydrogen peroxide (H2O2) acting as a reductant; but the H2O2 must decompose into active radicals before it attacks the phage. Hydrogen peroxide decomposes under irradiation, and attacks phage much more vigorously under ionizing radiation than under ultraviolet irradiation. Free radicals may part-inactivate phage, that is, render it more sensitive to H2O2 and to ascorbic acid, though not to inactivating agents in general. Phage grown on rich medium is more sensitive than phage grown on poor medium to inactivation by reduction.