Effects on the Sporicidal Activity by Using Various Metal Ions in the Formulation Combining Ferric Chloride, Ethylenediaminetetraacetic acid and Ethanol

Abstract

We studied the effects on the sporicidal activity against Bacillus subtilis spores by replacing Fe3+ with various kinds of metal ions in the formulation of FeCl3·6H2O, EDTA-2Na and ethanol, herein called the ethanol reagent and one which has already shown potent sporicidal activity (Kida et al., 2003). Metal ions used for comparison in the sporicidal activity of the ethanol reagent were Cu2+, Ni2+, Co2+, Zn2+ and Al3+, and each sporicidal activity was examined at various pHs and temperatures. Among them, the ethanol-Cu2+ reagent showed potent sporicidal activity at 20°C and 37°C at pH 0.3 and the ethanol-Ni2+ reagent also showed a potent one at both temperatures at pH 0.6 comparable to the ethanol reagent. These results show that the ethanol reagents with metal ions even other than Fe3+ show sporicidal activity which may be available for practical use.