Streptomycin as an Essential Nutrilite

Abstract

Streptomycin-requiring mutants were obtained from 2 of 3 strains of meningococci and 3 of 4 strains of Escherichia 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 concns. In the case of the E. coli mutants, they exhibit optimal growth at concns. from 20 to 80 U./ml. of a commercial streptomycin or of pure streptomycin A. Growth of the mutants can be promoted by pure prepns. of streptomycin A., dihydrostreptomycin A, and streptomycin B and the relative stimulatory activities of these compounds for the mutant agree closely with the relative antibacterial activities vs. the parent strain.