Investigation of the mating system ofPseudomonas aeruginosastrain 1: V. The effect ofN-methyl-N′-nitro-N-nitrosoguanidine on a donor strain

N-methyl-N′-nitro-N-nitrosoguanidine treatment of a donor strain ofPseudomonas aeruginosaresulted in the isolation of strains which were presumably cured of their sex factors, strains which possibly contained mutant defective sex factors and one strain which showed enhanced donor activity. The latter was apparently due to a change in the bacterium and the sex factors of OT 302 and OT 15 were both shown to be similar to the original in OT 1 when the three were transferred into the same strain.