Effect of VUV Excimer Lamps on Microorganisms

Abstract

The work is devoted to the effect of vacuum ultraviolet (VUV) radiation of excimer lamps (λ 172 nm) on the spores of various species of microscopic fungi. The dependences of the survival probability on the VUV radiation dose have been obtained. It was found that the survival probability depends on the spore s phase of growth and cell wall pigmentation. The doses of spore inactivation in stationary phase were found to be higher as compared with the ones of exponential phase. The FTIR spectra indicate that the VUV radiation leads to degradation of proteins and polysaccharides. The atomic force microscopy indicates the possible photochemical nature of the spore inactivation. The inactivation of microfungi by VUV irradiation potentially can be caused by two mechanisms: cell wall damage and DNA destruction. The VUV doses of microfungi spores monolayer inactivation (λ 172 nm) were found to be lower in comparison with the ones of germicidal UV light sources (λ 254 nm).