Effective of Bacterial repair systems in near UV radiation-induced damage.

Inactivation of seven strains derived from Escherichia coli B differing in their capacity to repair damage to their DNA (exc, pol, rec) after irradiation with far (254 nm) and middle and near (300 to 380 and 320--400 nm) UV light was investigated. The same bacterial strains were also used as hosts for the UV-irradiated phage T7. The damage induced in bacteria and the phage by the near UV radiation was repaired only to a lesser extent by the investigated repair mechanisms or was not repaired at all.