Use of Streptomycin-dependent Strains of Bacteria for Demonstrating the Ability of Microorganisms to Produce Streptomycin

Publisher Website
Google Scholar
Abstract
The growth of Escherichia coli ds (dependent strain) in ordinary streptomycin-containing broth could be measured by turbidimetric readings, using a Cenco Sheard-Sanford Photelometer. When the influence of streptomycin concn. upon the growth of this organism was measured, a definite correlation was obtained between the concn. of the antibiotic and the growth of the culture. A study was made of the effect of isolated and purified antibiotics upon growth. A highly purified streptomycin and a crude prepn. of a streptomycin-like material were compared with 2 forms of purified streptothricin. Whereas the 2 forms of streptomycin supported good growth, streptothricin did not permit growth. A study was made of crude culture filtrates of antibiotic-producing actinomycetes. Only the streptomycin-producing filtrate permitted growth. Addition of streptomycin to the cultures accelerated growth.