photoreactivation

In most organisms (excluding placental mammals such as humans) they can be repaired by photoreactivation.

This enzyme mechanism requires visible light, preferentially from the violet/blue end of the spectrum, and is known as photoreactivation.

Photoreactivation is a repair process in which photolyase enzymes directly reverse CPDs via photochemical reactions.

Dimers may be repaired by photoreactivation or nucleotide excision repair, but unrepaired dimers are mutagenic.

The photoreactivation process directly reverses this damage by the action of the enzyme photolyase, whose activation is obligately dependent on energy absorbed from blue/UV light (300-500 nm wavelength) to promote catalysis.

This takes into consideration a phenomenon known as light and dark repair (photoreactivation and excision (BER) respectively) in which the DNA in the bacterium will fix itself after being damaged by UV light.