title: Sterilization effect of UV light on Bacillus spores using TiO(2) films depends on wavelength.
abstract: UV light and photocatalysts such as titanium dioxide (TiO(2)) and silver (Ag) are useful for disinfection of water and surfaces. However, the effect of UV wavelength on photocatalytic disinfection of spores is not well understood. Inactivation of Bacillus spores has been examined using different UV wavelengths and TiO(2) or TiO(2)/Ag composite materials. The level of UVA disinfection of Bacillus anthracis and Bacillus brevis vegetative cells increased with the presence of the TiO(2) and Ag photocatalysts, but had little effect on their spores. B. brevis spores were slightly more sensitive to UVB and UVC than the spores of B. atrophaeus. Photocatalytic sterilization against spores was strongest in UVC and UVB and weakest in UVA. The rate of inactivation of Bacillus spores was significantly increased by the presence of TiO(2), but was not markedly different from that induced by the presence of Ag. Therefore, TiO(2)/Ag plus UVA can be used for the sterilization of vegetative cells, while TiO(2) and UVC are effective against spores.
authors.affiliation: Department of Preventive Environment and Nutrition, Institute of Health Biosciences, the University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Le Thi Tuyet
authors.initials: le TT
authors.lastname: Nhung
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nagata
authors.forename: Akira
authors.initials: A
authors.lastname: Takahashi
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Aihara
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Okamoto
authors.forename: Takaaki
authors.initials: T
authors.lastname: Shimohata
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Mawatari
authors.forename: Masatake
authors.initials: M
authors.lastname: Akutagawa
authors.forename: Yhosuke
authors.initials: Y
authors.lastname: Kinouchi
authors.forename: Masanobu
authors.initials: M
authors.lastname: Haraguchi
mesh_terms: D001408:Bacillus anthracis / Q000254:growth & development* / Q000528:radiation effects*; D012834:Silver; D013171:Spores, Bacterial / Q000528:radiation effects*; D013242:Sterilization / Q000379:methods*; D014025:Titanium; D014466:Ultraviolet Rays
chemical_list: C009495:titanium dioxide; D012834:Silver; D014025:Titanium