Microbiologic studies with ozone. Quantitative lethality of ozone for Escherichia coli.

Abstract

A series of studies designed to provide an understanding of the biologic activity of ozone at the cellular level is described. A critical analysis of the quantitative lethality of ozone was undertaken. Maximum lethal effects of ozone over a wide concentration range were expressed in 1 minute or less on the bacterial population. The number of cells surviving exposure is a function of approximately the cube of the initial cell concentration. This holds true over a wide range of ozone values. Percent kill increased sharply over a narrow range of ozone concentrations, and then leveled off. The ozone tolerance of strains B and B/r of Escherichia coli appears to be similar, if not identical. Several factors which contribute to an understanding of the biologic activity of ozone are presented. The importance of free radicals in biologic processes is discussed. Literature on the formation of these radicals during the absorption of ozone in aqueous solution is reviewed.