SPONTANEOUS MUTATION TO STREPTOMYCIN RESISTANCE AND DEPENDENCE IN ESCHERICHIA COLI

Abstract

Mutation rates of E. coli strain B/r to streptomycin resistance and dependence were both found, by the 2 standard formulae, to be approx. 1 x 10-10 per bacterium per division cycle. Since the mutation rate to phage resistance does not yield equal values, the possibility of a dominance of the gene for streptomycin resistance or an absence of phenotypic delay is suggested. The mutation rate of Hemophilus influenzae to streptomycin resistance is similar to that of E. coli.