Effects of 120- to 165-nm Vacuum-uv Light on Wet Yeast Cells

Publisher Website
Google Scholar
Abstract
The effects of short wavelength light on wet yeast cells were studied with special reference to the vacuum-UV region using a deuterium discharge lamp with MgF2 exit window. Vacuum UV (120-165 nm) inactivated the cells mainly through damage inflicted near the surface, presumably in the cytoplasmic membrane. Concomitant genetic effects were ascribed to the far-UV component of the emission based on the photoreactivation evidence and wavelength considerations using results with cutoff filters. The inactivation was not photoreactivated, nor did it occur when a SiO2 filter was inserted in the beam path, which cut off wavelengths shorter than 165 nm. The capability of vacuum-UV light for cell inactivation via non-DNA damage was further demonstrated by the correlation between the decrease in the inactivation rate and the attenuation of the vacuum-UV (120-165 nm) intensity in experiments where the thickness of water vapor between the exit window and cell samples was changed. These findings are consistent with previous results with different types of vacuum-UV sources and also extend the physical bases of vacuum-UV effects on wet cells.