INACTIVATION OF BACTERIOPHAGE-LAMBDA, ESCHERICHIA-COLI, AND CANDIDA-ALBICANS BY OZONE

The effects of ozone (O-3) on three types of microbes were studied. Te st suspensions were exposed to 600 ppm O-3 at room temperature. Contro l experiments were performed under identical conditions using oxygen g as. Bacteriophage lambda was completely inactivated at 10 min while Es cherichia coli and Candida albicans were only inactivated by factors o f 10(5) and 10(4) respectively at 40 min. Exposure of a mixed microbia l suspension to O-3 for 5 min resulted in 100% killing of bacteriophag es while the viability of E. coli remained unchanged. Various body flu ids containing phages were exposed to O-3 Compared to buffered solutio n, the decrease in phage titers was significantly slower in whole bloo d, plasma, and albumin. Both E. coli and C. albicans had increased pro duction of thiobarbituric-acid-reactive substances with increased O-3 exposure. H-3-labelled amino acids were incorporated into E. coli. O-3 treatment resulted in a loss of radioactivity, indicating leakage of cytoplasmic contents. The data indicate that microbes are inactivated by O-3 at different rates, possibly related to differential membrane p ermeability. The milieu in which microbes are present determines the e ffectiveness and outcome of O-3 treatment.