Abstract
The treatment of Streptomyces bikiniensis with ethidium bromide or acriflavine resulted in the loss of the ability to produce streptomycin in 2-16% of the colonies isolated from the treated spores. These isolates had also lost their resistance to streptomycin. Treatment with the dyes caused partial to total loss of the ability to produce aerial mycelium by S. biki-niensis, but the isolates regained this ability upon repeated transfer to fresh medium. The dyes did not appear to effect pigment production by S. bikiniensis.