Development of resistance to streptomycin by Bact . lactis aerogenes ( Aerobacter aerogenes ) - III. Responsibility of radiation for naturally occurring mutants

Abstract

Cultures derived from single colonies of Bact . lactis aerogenes , isolated in the dark, contain a greatly reduced proportion of first-stage streptomycin resistant mutants. When con­tinuously grown with normal exposure to all natural radiations the cultures regain the normal proportion much more rapidly than if screened with lead.