Destruction of Bacillus subtilis using a low pressure glow discharge plasma

Abstract

Sterilization with low pressure glow discharge was investigated. Bacillus subtilis was used as test organism to test the efficiency of the sterilization method. Hydrogen peroxide with 3% concentration and oxygen were used as feed gas. For the hydrogen peroxide, discharge voltage was varied at 450 and 500 V. For oxygen, the gas flow was varied at 20 and 60 sccm. The samples were exposed in the plasma from 30 to 60 minutes. For the hydrogen peroxide plasma at a voltage of 500 V the decimal reduction value is 11.83 minutes with a 99.6% reduction of microorganisms in 60 minutes. With oxygen gas, the decimal reduction value is 10.57 minutes and 99.33% reduction in 60 minutes. Sample temperature for oxygen was lower than with hydrogen peroxide.