Inactivation of Bacillus spores by gaseous ozone

J Appl Bacteriol. 1986 Jan;60(1):67-72. doi: 10.1111/j.1365-2672.1986.tb01067.x.


The sporicidal activity of ozone in the gas phase was investigated. Spores of six strains of Bacillus species deposited on filter paper or glass fibre filter were conditioned at different relative humidities (r.h.), and then exposed to ozone ranging in concentration from 0.5 to 3.0 mg/l at different r.h. There was a lag phase in the initial stage of exposure followed by an exponential decrease in the number of survivors with time, although no lag phase was observed with one strain. Inactivation rates increased with increasing exposure r.h. while no significant inactivation was attained at a r.h. of 50% or below. The conditioning r.h. influenced the duration of the lag phase. The D-values (decimal reduction time) in the logarithmic phase varied roughly in inverse proportion to the ozone concentration.

MeSH terms

  • Bacillus / drug effects
  • Bacillus / physiology*
  • Bacillus cereus / physiology
  • Bacillus megaterium / physiology
  • Bacillus subtilis / physiology
  • Disinfection / methods*
  • Humidity
  • Ozone / pharmacology*
  • Spores, Bacterial / drug effects
  • Sterilization / methods*
  • Time Factors


  • Ozone