Bactericidal mechanism of Ag/Al2O3 against Escherichia coli.
The bactericidal process of Ag/Al2O3 to Escherichia coli has been investigated to clarify the bactericidal mechanism. In SEM images, the configuration of E. coli cells contacting with the catalyst surface was quite different from that contacting with AgNO3 solution, which indicated that the Ag+ eluted from the catalyst did not play an important role in the bactericidal process. The bactericidal experiments strongly confirmed the contribution of multiform reactive oxygen species (ROS) (super oxide dismutase (SOD) and catalase as the scavengers for O2*- and H2O2, respectively) to bactericidal effect on the catalyst surface. Furthermore, the surface modification of Ag/Al2O3 by ultraviolet and formaldehyde influenced the bactericidal effect obviously, which not only confirmed the bactericidal mechanism of catalytic oxidation but also provided evidence for the synergistic effect between Ag and Al2O3 on the catalyst surface.
Chang
Qingyun
Q
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Yan
Lizhu
L
Chen
Meixue
M
He
Hong
H
Qu
Jiuhui
J
D000327:Adsorption; D000537:Aluminum Oxide / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002374:Catalase / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D005557:Formaldehyde; D016166:Free Radical Scavengers / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D017382:Reactive Oxygen Species / Q000378:metabolism; D012834:Silver / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000494:pharmacology; D013499:Surface Properties; D014466:Ultraviolet Rays
D000900:Anti-Bacterial Agents; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D005557:Formaldehyde; D012834:Silver; D002374:Catalase; D013482:Superoxide Dismutase; D000537:Aluminum Oxide