Photorepair (photoreactivation) of micro-organisms is an important issue when UV light is used for disinfection purposes. Photoreactivation is a DNA repair process that takes place when cells that have been exposed to, and damaged by, UV light are subsequently exposed to light of a longer wavelength. Although this process has been examined in a number of micro-organisms after their exposure to continuous UV light there is no information available in the literature concerning the effect neither of pulsed UV light nor on the ability of L. monocytogenes to exhibit photorepair after UV light damage. In order to address these issues four factors were compared in this study on L. monocytogenes these being; (i) the effect of the initial dose of pulsed UV light (4 and 6 pulses); (ii) the effect of post exposure conditions on repair/recovery (light or/and dark repair); (iii) the effect of light intensity during photorepair (high intensity versus low intensity light); and (iv) the influence of growth phase (exponential and stationary phase) prior to treatment. The results demonstrate that L. monocytogenes exhibits light repair if the organism is exposed to longer wavelength light following the initial damaging exposure to pulsed high intensity UV-rich light.
|Publication status||Published - 12 Sep 2005|
|Event||SGM Meeting Abstracts - Keele University|
Duration: 12 Sep 2005 → 14 Sep 2005
|Conference||SGM Meeting Abstracts|
|Period||12/09/05 → 14/09/05|