Assessment of Bacillus subtilis Spores as a Possible Bioindicator for Evaluation of the Microbicidal Efficacy of Radiation Processing of Water

Author: Pribil Walter   Gehringer Peter   Eschweiler Helmut   Cabaj Alexander   Haider Thomas   Sommer Regina  

Publisher: Water Environment Federation

ISSN: 1061-4303

Source: Water Environment Research, Vol.79, Iss.7, 2007-07, pp. : 720-724

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

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 dose-rate 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.