抄録
The influence of streptomycin on the reverse mutation of E. coli from auxotrophy to protoprophy was investigated. Cells recovered from cultures of auxotrophic strains were exposed to this agent in a phosphate buffer, or cultured in a broth contaning a subinhibitory dose of the drug. In both cases, the increase of reverse mutation was observed. Prototrophy was not, in general, associated with the resistance to streptomycin. The results mentioned above, together with those reported in the previous papers, led the authors to the conclusion that streptomycin is a chemical mutagen and its effect is non-specific and non-directed.
The authors are indebted to Dr. F.J. Ryan of Columbia University for his advice on this investigation during his stay at the University of Tokyo.
