Cold Atmospheric Plasma Brush Effect on Population Reduction of Different Bacterial Spectrums

The main objective of this work was to design a large-scale cold atmospheric plasma brush (LSCAPB) that can produce a perfectly homogenous large area capable of producing plasma with a length of about 5 cm for studying the inactivation effect of plasma on Gram-positive and Gram-negative bacteria that commonly implicated in Food infections. Gram-positive ( Listeria monocytogenes , Bacillus cereus ) and Gram-negative ( Salmonella typhi , Vibrio cholerae ) bacteria with an initial population density of 1.5 × 10 8 CFU mL −1 were treated, and their survivability with plasma exposure was examined. The effect of plasma exposure in the reduction of bacteria population was investigated using OD600 absorbance, and changes in cell structure and the membrane were studied by scanning electron microscopy analysis. For applied voltage 25 kV and after 10 min the reduction of cold plasma treatment for S. typhi , V. cholerae , B. cereus , and L. monocytogenes were decreased from 1.5 × 10 8 to 0.3 × 10 2 , 1.5 × 10 2 , 0.6 × 10 3 , and 0.7 × 10 5 CFU mL −1 , respectively. Comet assay analysis was used for studying the effect of plasma exposure on DNA damage, and changes in chemical bonds were analyzed by FTIR analysis. So, the best destruction is obtained at the voltage of 25 kV for all types of bacteria. This study indicates that the inactivation effect of LSCAPB correlates with the kind of bacteria. We demonstrated LSCAPB can be one of the most efficient methods for the inactivation of different types of bacteria.