Photoreactivation in an archaeon from geothermal environments.

UV-inactivated cells of rapidly regained viability when exposed to white light This recovery was strictly dependent upon illumination with visible light and was not attenuated by prior dark-incubation. The kinetics of photoreactivation were determined at several temperatures and at several wavelengths of light. The results obtained were consistent with a DNA photolyase having a broad action spectrum. Photoreactivation of apparently represents the first DNA repair process to be measured in an archaeon which grows optimally near 80°C.