抄録
The silver-doped ceramics is the whitewares coated with low-temperature lime zinc glaze containing silver, and has bactericidal activity. In this study, the mechanism of the bactericidal action of the silver-doped ceramics against bacteria, mainly Escherichia coli K12 W3110, was investigated. The silver-doped ceramics had high bactericidal activity when it was irradiated by visible light. Since the eluted silver ions from the surface of ceramics were not detected by ICP measurement and the supernatant had no bactericidal activity, it was proved that the eluted silver ions do not contribute to the bactericidal action of the ceramics. The bactericidal activity was extremely inhibited in the presence of radical scavengers such as L-cysteine, L-alanine or I-. After the silver-doped ceramics was removed from the cell suspension irradiated for 60 min, the bactericidal activity was still maintained, and was inhibited by L-cysteine. The silver-doped ceramics also had bactericidal activity against Bacillus subtilis ATCC6633.
These results suggest that the bactericidal action of silver-doped ceramics is caused by the hydroxyl radical which is generated on the surface of the ceramics by light irradiation and is converted to a living radical in bacterial cells.
