A PARAMETRIC STUDY OF THE DESTRUCTION EFFICIENCY OF BACILLUS SPORES IN LOW-PRESSURE OXYGEN-BASED PLASMAS

The destruction of Bacillus spores in oxygen-based plasmas sustained i n the millitorr pressure range has been studied as functions of variou s biological and plasma parameters,namely Bacillus species, surface co ncentration of spores, treatment temperature, and gas composition. In an oxygen plasma, Bacillus stearothermophilus appears less plasma-resi stant than the other spores tested. Oxygen, H2O2 and chiefly CO2 plasm as are clearly shown to be much more efficient in destroying Bacillus subtilis spores than pure argon plasma. The bacterial surface concentr ation on the spore carriers and the treatment temperature also lead to significant variations in the destruction efficiency of spores when u sing CO2 plasma.