Streptomycin as an Essential Nutrilite

Abstract

Summary

Streptomycin-requiring mutants were obtained from 2 of 3 strains of meningococci and 3 of 4 strains of E. coli. In the case of 2 E. coli strains such mutants grew readily on a synthetic medium in the presence of streptomycin. Such mutants appear more stable when isolated from low rather than from high streptomycin concentrations. In the case of the E. coli mutants, they exhibit optimal growth at concentrations from 20 to 80 units/ml of a commercial streptomycin or of pure streptomycin A. Growth of the mutants can be promoted by pure preparations of streptomycin A, dihydrostreptomycin A, and streptomycin B and the relative stimulatory activities of these compounds for the mutant agrees closely with the relative antibacterial activities against the parent strain.