reported similar results on the lack of repair of
UV damage. Their study indicated that neither 1 h of light exposure
nor 1 h of dark treatment post-UV treatment significantly influenced
the photoreactivation or dark repair ability of S. Typhimurium
on shell eggs. However, photoreactivation of S. dysenteriae and
S. Typhimurium was detected in a study done by Hu et al., (2012).
After UV light treatment, contaminated surfacewater samples were
exposed to a fluorescent lamp with an intensity of 0.066 mW/cm2
at a wavelength of 360 nm for 3 h. They noticed that photoreactivation
decreased significantly with higher UV doses.
Various factors may affect photoreactivation. Lindenauer and
Darby (1994) noted that the number of pyrimidine dimers
formed, the amount of photolyase present, the temperature during
the formation of the photoreactivation enzyme and dimer complex,
and the dose of photoreactivation radiation could affect photoreactivation.
Photoreactivation is dependent on the genetic and
physiological state of the exposed cell