Gage, Joshua AlbertRoberts, T. M.Duffy, James E.2017-07-192017-07-192005-07Gage JP, Roberts TM, Duffy JE, "Susceptibility of Pseudomonas aeruginosa biofilm to UV-A illumination over photocatalytic and non-photocatalytic surfaces," Biofilms, 2005 2(3):155-1631479-0505https://scholarworks.montana.edu/handle/1/13328The susceptibility of Pseudomonas aeruginosa (PA01) bacteria to ultraviolet-A (UV-A) light in photocatalytic and non-photocatalytic systems was investigated. Thin films of TiO2 were deposited on glass slides using a dip-coating method. Disinfection of both planktonic and biofilm bacterial cells was studied over both coated and uncoated slides exposed to low intensity (1.0mW/cm2) UV-A irradiation. Photocatalytic treatment of planktonic PA01 cultures provided a 4-log reduction in the number of viable cells in 3 h whereas UV light alone produced a 1-log reduction. For biofilm bacteria, photocatalytic treatment did not enhance killing relative to UV treatment alone; however, the UV illumination resulted in a 2- to 3-log reduction in viable cells as compared with non-illuminated controls. Possible explanations for the discrepancy between susceptibility of planktonic and biofilm bacteria to photocatalytic oxidation are discussed.Article