Microorganisms and methods used for plasma sterilization in liquid
Suspensions of vegetative cells and spores of B. subtilis, as well as of vegetative cells of E. coli, were
used. To produce the vegetative cells, B. subtilis and E. coli were grown in 1 % glucose-added the M9
medium at 37 °C for 18 h, with shaking (200 rpm). To produce spores, B. subtilis was cultured on the
FMH agar at 37 °C for 4 days. The produced spores were suspended with a saline solution. Before being
treated with plasma, the cell or spore suspensions were 100–1000-fold diluted to adjust to the final concentration
of 105–106 CFU/ml. For treating suspensions, we used a glass tube of 1 L in volume (Fig. 1).
After plasma processing, the samples were taken to determine an amount of the survived microorganisms.
The rate of survival was determined by culturing on 1 % glucose-added M9 and FMH agar.