MUTANS WITH ALTERED DNA-BASE COMPOSITION

The base compositions of DNA's from Bacillus subtilis 168, Bacterium paracoli 5099 and from mutants and other strains related to these bacteria have been determined. The degree of DNA homology between these strains has been calculated from DNA hybridization experiments. The results show that so-called mutants with altered DNA composition are not related to their respective parent types. They also support a recent report that the mutant indicated as B. paracoli 1975 belongs to the genus Flavobacterium. This mutant also has much genetic information in common with another mutant described in the literature, UV2, with altered DNA composition and stated to have been isolated from Staphylococcus aureus 209. Attempts to repeat mutation experiments with B. subtilis and B. paracoli as described in the literature did not yield mutants whose DNA-base composition was found to be altered. © 1969.