Full text loading...
Abstract
The importance of photon radiation for the microbicidal effect of electrical discharges in water has appeared from a series of experiments. (a) An ultraviolet (u.v.)-sensitive strain of Escherichia coli was more susceptible to discharges than a u.v.-resistant mutant derived from it. (b) The kinetics of the inactivation by discharges were under certain conditions similar to those of continuous u.v. irradiation. (c) Addition of u.v.-absorbing substances to the discharge liquid decreased the bactericidal efficiency of the discharges to an extent which paralleled the u.v. absorbance. (d) The bactericidal effect decreased as the distance from the spark increased. (e) Bacteria enclosed in a cellophan bag were killed by discharges outside the bag, even when the bag was kept in the air above the discharge liquid. (f) Also discharges in air were active. (g) Bacteria inactivated by discharges were accessible to photoreactivation, but the magnitude of the reactivation was generally less than that obtained with bacteria inactivated by continuous u.v.-irradiation. In addition to direct radiation effects other kinds of microbicidal activities were produced by the electric discharges.
- Accepted:
- Published Online: