The Mechanism of Ozone Inactivation of Water Borne Viruses

Abstract

Environmental Microbiology, volume 39, pages 210-218, January 1980. INTRODUCTION Ozone has received much recent attention as an alternative disinfec tant to chlorine in water and wastewater treatment practices due to its quicker, powerful germicidal activity and no reported side effects as can be produced by chlorination, such as taste, odor, and toxic byproducts (2). Inactivation kinetics with ozone have been actively studied in laboratory or pilot-plant scale using a variety of microorganisms including viruses (12, 17, 32). Much information has accumulated attest ing to its superiority over other chemical disinfectants (10, 33) Lower concentrations of ozone and shorter contact times are required than are needed when using chlorine or other agents, and it is more effective than other disinfectants against resistant organisms, such as amoebic cysts and viruses.Although the earlier all-or-none phenomenon of ozone inactivation was explained as an ozone demand exerted by the organisms themselves (23) recent reports indicate a threshold effect in virus ozonation (11,15) Katzenelson and Biedermann (10) reported a two-stage inactivation of ozone, in which 99 percent of the test organisms were inactivated in 8 seconds and the remainder only after several minutes of contact. They demonstrated that their two stage kinetics could be ascribed to virus aggregation. Limited information is available on the mechanism of ozone inactivation of bacteria and viruses, even though ozone has been increas ingly used in disinfection practices in water The RNA containing bacteriophage f2 which is chemically and physi cally very similar to enteric viruses was first introduced in 1964 (9) as a model for inactivation study of the enteric viruses. Since then, the phage f2 has been used by many researchers (5, 21, 22, 28) for the study of inactivation kinetics and inactivation mechanisms using various disinfecting agents. Hsu et a k (9) showed that the phage f2 RNA and poliovirus RNA were resistant to iodination and that inactivation of both f2 and poliovirus were inhibited by increasing iodide ion concentration.The phage f2 was used by Olivieri et a]_-(21) to study the mode of action of chlorine, bromine, and iodine. They found that the mode of action depended upon the element. Chlorine inactivated naked f2 RNA at the same rate as R\A in the intact phage at pH 7.5 or lower. The protein of the inactivated phage was still able to adsorb to the host. Bromine inacti vated the naked RNA at the same rate as the intact phage, but the RNA prepared from bromine-treated virus was significantly less inactivated than the intact virus They suggested that the primary site of bromine inactivation was more likely to be the protein moiety of the virus.Iodine functioned through iodination of the ami no acid tyrosine in the protein moiety of the phage with almost no effect on the nucleic acid.The inactivation mechanism of ozone has been only partially studied for viruses and bacteria. Using ozone in secondary effluent Pavoni et al.(22) reported that the mechan...

Microbiological Aspects of Ozone Applications in Food: A Review

“…The DNA released from T4 bacteriophage was rapidly inactivated by ozone at about the same rate as that in the intact phage. CK Kim and others (1984 ) confirmed the results of Sproul and Kim (1980) about bacteriophage T4; they found that ozone randomly destroyed the head, collar, contractile sheath, end plate, and tail fibers and liberated the DNA from the head. Yoshizaki and others (1988) found that aqueous ozone caused the coat proteins subunits of tobacco mosaic virus (TMV) to aggregate with each other and cross-link with the viral RNA.…”

“…Viruses. Sproul and Kim (1980) and CK Kim and others (1980) found that aqueous ozone inactivated both f2 and T4 bacteriophages by attacking capsid protein, with liberation and inactivation of the nucleic acid. The RNA from f2 bacteriophage was partially inactivated prior to release from the capsid.…”

Effect of Ozone Treatment on Toxocara canis Eggs.

“…The mechanism of ozone inactivation of virus has been implicated as first the alteration of the protein coat or capsid and subsequent damage in the viral nucleic acid itself [9, [13][14][15]. Similarly, ozone had been reported to penetrate the cell membrane of bacteria and causing disruption of chromosomal DNA [7].…”

Mixture of Sodium Hypochlorite and Hydrogen Peroxide on Adhered Aeromonas hydrophila to Solid Substrate in Water: Impact of Concentration and Assessment of the Synergistic Effect

“…Most studies carried out so far provided some information on the doses of disinfectants and adequate contact duration period to effectively control pathogens of public health importance that are commonly used to develop regulations and strategies treatment. Chemical disinfectants cause lethal or nonlethal changes in proteins [ 14 ], lipids [ 15 ], membrane [ 16 ], and DNA [ 17 ] of microorganisms. In addition, the mechanisms of disinfection are also highly dependent on the type of microorganism, cell growth stage, and disinfectant [ 18 ].…”