The mechanism of bacterial inactivation by electric discharges (non-thermal plasma) is examined on the basis of the action of the formed peroxynitrite and hydrogen peroxide on the external membrane of bacteria. A model accounts for the gas to liquid transfer of the active species which react with the bacterial wall at the liquid surface or /and in the bulk solution. Direct exposure to the glidarc discharge induces a pseudo zero order decay of the bacterial concentration, followed by a pseudo 1st order step for low concentrations. Post-discharge reactions develop after switching off the discharge according to a 1st order mechanism and show that active species drift in the solution. Additionally the bactericidal properties of pure water exposed to the discharge (i.e., "Plasma Activated Water") was evidenced even 24 h after performing the plasma treatment.