Effects of aqueous ozone on Pseudomonas syringae viability and ice nucleating activity

The destruction curve followed a shoulder pattern with a slight reduction in population with CT values between 0 and 8 min. For an initial population of 9.3 log CFU mL−1, the cultivability was lost starting at 14 min and a loss of viability was observed after 16 min of ozone treatment at 0.45 mg L−1. Microscopic observations at this point revealed whole but aggregated bacilli. INA decreased after 8 min of ozone treatment but did not disappear. This decrease could be due to the progressive disruption of ice nucleating sites in the outer membrane. It was however partially restored after long storage at 4 °C of dead cells treated for 16 min.