Inhibition of Antibiotic Formation by Bromthymol Blue and Other Indicators in Streptomyces rimosus

Abstract

ANTIBIOTIC production can be altered either by the induction of stable genotypic changes through mutation of a culture or by the addition of compounds which modify the biosynthesis of the antibiotic. Alikhanian et al.¹ described the antagonistic effects of high inorganic phosphate-levels on oxytetracycline formation and the isolation of mutants which required the addition of increased phosphate for maximal antibiotic production. Ševčík, Musílek and Komersová² examined the effect of various inhibitors of terminal oxidases on production of oxytetracycline and oxidation of glucose by washed S. rimosus mycelia, and found that such compounds as potassium cyanide, sodium azide and quinacrine markedly inhibited synthesis of oxytetracycline. Arsenite has also been found to inhibit production of chlortetracycline³. Gadó, Horváth and Magyar⁴ reported on the reversal of the inhibitory effect of iron on formation of oxytetracycline by methylene blue in S. rimosus. There is only limited information available, however, with the previously described compounds as to the specificity with which they inhibit tetracycline formation as opposed to antagonizing growth processes in general.