Ozone Inactivation of Microorganisms in Water: Gram positive Bacteria and Yeast

Abstract

Inactivation kinetics of referent and isolate strains of Streptococcus faecalis. Staphylococcus aureus and Candida albicans towards ozone in water were analyzed in this paper. Water suspensions of 104 - 106 CFU/mL of Streptococcus faecalis ATCC 10541, Staphylococcus aureus ATCC 29213, Candida albicans ATCC 10231 and wild strains were prepared in sterile conditions and treated in a 100 mL bubble reactor with ozone, achieving concentrations from 0.3 to 2.5 mg of dissolved ozone / L of water, in contact with microorganisms. Inactivation kinetics of these bacterial strains was similar to gram-negative bacteria; first order inactivation kinetics respect to both the concentrations of ozone and microorganisms were found,. resulting an overall second order inactivation kinetics. Staphylococcus aureus isolate was more resistant than Streptococcus faecalis and Candida albicans strain. The longest time required to achieve total inactivation was 10 minutes.