Assessment of Bacillus subtilis spores as a possible bioindicator for evaluation of the microbicidal efficacy of radiation processing of water.
Gamma and electron-beam irradiation of Bacillus subtilis spores suspended in different types of water was studied to evaluate the inactivation of the spores and assess their possible use as a bioindicator for radiation processing. We found that the inactivation proceeded endogenously, being dose-rate-dependent and affected by oxygen. The radiation resistance of the suspended spores was found to be rather high; therefore, B. subtilis spores used as a bioindicator for efficiency of water treatment by radiation under practical conditions might result in the spores being overly conservative surrogates for pathogenic microorganisms. Moreover, the doserate dependency impedes the use of the spores as a bioindicator. Thus, B. subtilis spores cannot be recommended as a bioindicator for evaluation of the microbicidal efficacy of ionizing radiation processing of water.
Pribil
Walter
W
Medical University, Vienna, Austria.
Gehringer
Peter
P
Eschweiler
Helmut
H
Cabaj
Alexander
A
Haider
Thomas
T
Sommer
Regina
R
D001412:Bacillus subtilis / Q000302:isolation & purification / Q000528:radiation effects*; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D004784:Environmental Monitoring / Q000379:methods; D006861:Hydrogen Peroxide / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology; D011839:Radiation, Ionizing; D013171:Spores, Bacterial / Q000302:isolation & purification / Q000528:radiation effects; D014873:Water Pollutants / Q000302:isolation & purification / Q000528:radiation effects*; D018508:Water Purification / Q000379:methods*
D014873:Water Pollutants; D006861:Hydrogen Peroxide; D010100:Oxygen