EFFECT OF DIHYDROSTREPTOMYCIN ON TETRAZOLIUM DYE REDUCTION IN ESCHERICHIA COLI.

Bragg, P. D. (University of British Columbia, Vancouver, British Columbia, Canada) and W. J. Polglase. Effect of dihydrostreptomycin on tetrazolium dye reduction in Escherichia coli. J. Bacteriol. 85:795-800. 1963.-Sonic-disrupted extracts of Escherichia coli, grown without added antibiotic (sensitive and resistant), contained (in supernatant of fraction centrifuged at 100,000 x g) a dihydrostreptomycin-inhibitable, succinate-triphenyltetrazolium chloride (TTC) reductase activity. The succinate-TTC reductase activities of extracts of E. coli grown in the presence of dihydrostreptomycin (resistant and dependent) were relatively low and were not inhibited by the antibiotic. At a moderate magnesium concentration, the degree of inhibition by dihydrostreptomycin of succinate-TTC reductase activity was sufficiently marked to indicate an important site of action of the antibiotic. Magnesium, putrescine, and spermidine antagonized the action of dihydrostreptomycin in the succinate-TTC reductase system.