Ozone is mutagenic in salmonella

Abstract

Ozone is a highly reactive gas that has been tested for genotoxicity in a number of systems. Induced genetic damage resulting from ozone treatment may not be readily observed because of the high toxicity of the chemical and difficulties in generating and administering controlled concentrations. The mutagenicity of ozone was investigated in Salmonella typhimurium using a plate test protocol designed for reactive vapours and gases. Ozone, at two to three consecutive doses, induced weak, albeit statistically significant, mutagenic responses in tester strain TA102 with and without Aroclor-induced rat liver s9 (lowest effective mean concentration of 0.019 ppm; 35 min total exposure). However, dose-related responses were not always obtained. No mutagenicity was detected in strains TA98, TA100, or TA1535, with or without S9. In strain TA104, ozone induced a weak response only at a single dose with S9; this response was not reproducible. Mutagenicity was dependent on the ozone flow rate and total exposure time, with variations in the optimum dase-time regimen leading to toxicity or complete inactivity. The data show that ozone is a very weak bacterial mutagen and only when tested under narrowly prescribed, subtoxic dosing conditions. 0 1992 Wiley-Liss, Inc.

Mechanisms of Bacillus subtilis spore resistance to and killing by aqueous ozone

“…Late exponential growth phase B. subtilis cells were ‡10-fold more ozone sensitive than spores (data not shown), as found previously for growing cells and spores of B. cereus and B. megaterium (Broadwater et al 1973;Foegeding 1985). Ozone can be genotoxic for bacteria (Dillon et al 1992;Victorin 1992), so it was possible that this was the mechanism whereby ozone kills spores. However, B. subtilis spores deficient in RecAdependent DNA repair were no more ozone sensitive than wild-type spores (Fig.…”

“…Although ozone can damage DNA and mutagenize bacteria (Dillon et al. 1992; Victorin 1992), it seems most likely that ozone does not kill spores by DNA damage.…”

“…Although ozone can damage DNA and mutagenize bacteria (Dillon et al 1992;Victorin 1992), it seems most likely that ozone does not kill spores by DNA damage. It might be argued that ozone kills spores by DNA damage that is neither repaired in a RecA-dependent fashion nor mutagenic.…”

“…1973; Foegeding 1985). Ozone can be genotoxic for bacteria (Dillon et al. 1992; Victorin 1992), so it was possible that this was the mechanism whereby ozone kills spores.…”

Monitoring the Removal Efficiency of Pharmaceuticals and Hormones in Different Treatment Processes of Source-Separated Urine with Bioassays

“…( 1 -C i (after treatment) C i (before treatment) ) ‚ 100% (10) VOL. 40 and retentate. Nevertheless, the relative removal efficiency could be calculated with a modification of eq 9:…”