Genome multiplicity and radiation resistance in Micrococcus radiodurans.

The number of genome equivalents of DNA per cell of M. radiodurans changed from approximately 5 to 10 depending on the media used. The sensitivity to ultraviolet light or gamma-rays was not different between the cells with different genome multiplicity. This suggests that the efficient repair process for DNA damage expressed in M. radiodurans is not influenced by the multiplicity of genomes in a cell.