Activity of Distamycin A on the Induction of Adaptive Enzymes in Escherichia coli

Abstract

We have studied the effect of distamycin A on the synthesis of inducible enzymes in Escherichia coli strain K12. Distamycin A did not inhibit the growth of E. coli K12 when the micro-organism already contained constitutive or inducible enzymes for the metabolism of sugars. The growth of E. coli was prevented when distamycin A was present during the enzymic induction. Distamycin A inhibited the formation of inducible [beta]-galactosidase; the activity of the antibiotic was directly related to its concentration, but independent of the concentration of the inducer. Thus it does not seem that distamycin A causes a decrease of the concentration of inducer. The enzyme synthesized in the presence of subinhibitory concentrations of distamycin A showed the same kinetic behaviour as [beta]-galactosidase induced under normal conditions.