PMA (Biotium Inc., Hayward, California) was dissolved in 20% dimethyl sulfoxide (DMSO) (Nuclear, Sao Paulo, Brazil), and added to 500 uL of B. sporothermodurans cell suspension (viable and dead cells) at a concentration of approximately 10 cells/mL, to achieve final concentrations of 2,5,10,20, and 30 ug/mL.