Scattering phenomena effects on growth of 308-nm laser-irradiated bacteria in suspension.
In this study we analyzed the effect of 308-nm laser exposure on recovery of irradiated Staphylococcus epidermidis held in liquid after irradiation and before plating. Coexistence of bacterial growth inhibition and stimulation phenomena was observed. Under certain conditions, bacterial recovery was about fivefold higher in irradiated samples than in the controls. The available evidence suggests that the growth inhibition was due to the bactericidal activity of the 308-nm wavelength light, whereas the growth stimulation effect was associated with broadband radiation generated by scattering phenomena in the bacterial suspensions. Spectroscopic investigations revealed that the nutrient broth plays a decisive role in the scattering of laser radiation within the suspension.
Pompa
P P
PP
Department of Physics, Laboratory of Applied Electronics, C.P. 193, 73100 Lecce, Italy.
Nassisi
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V
Alifano
P
P
D007834:Lasers; D012542:Scattering, Radiation; D013212:Staphylococcus epidermidis / Q000254:growth & development / Q000528:radiation effects*; D013535:Suspensions; D014466:Ultraviolet Rays
D013535:Suspensions