Ozone inactivation of microorganisms in water. Gram positive bacteria and yeast

Inactivation kinetics of referent and isolate strains of Streptococcus faec alis, Staphylococcus aureus and Candida albicans towards ozone in water wer e analyzed in this paper. Water suspensions of 10(4) - 10(6) CFU/mL of Stre ptococcus faecalis ATCC 10541, Staphylococcus aureus ATCC 29213, Candida al bicans ATCC 10231 and wild strains were prepared in sterile conditions and treated in a 100 mt bubble reactor with ozone, achieving concentrations fro m 0.3 to 2.5 mg of dissolved ozone / L of water, in contact with microorgan isms. Inactivation kinetics of these bacterial strains was similar to gram- negative bacteria; first order inactivation kinetics respect to both the co ncentrations of ozone and microorganisms were found, resulting,an overall s econd order inactivation kinetics. Staphylococcus aureus isolate was more r esistant than Streptococcus faecalis and Candida albicans strain. The longe st time required to achieve total inactivation was 10 minutes.