[Sensitivity of Streptomyces globisporus 3-1--a highly active producer of landomycin E to its own and the other polyketide antibiotics].

The strain Streptomyces globisporus 3-1--a highly active producer of a new anticarcinogenic antibiotic landomycin E from the group of angucyclins has been studied for its resistance to its own and known polyketide antibiotics--tetracycline, oleandomycin and doxorubicine as well as to aminoglycoside antibiotic streptomycin. The survival of mycelium of the strain 3-1 was established to depend on antibiotics concentration. Four equal resistances of streptomycete to antibiotics within the concentration of 5-30 micrograms/ml have been shown. The survival of the strain 3-1 mycelium fragments at 5 micrograms/ml of antibiotic is for tetracycline--1.8, for olcandomycin--0.7; doxorubicin and landomycin E--(-0.7) and streptomycin--(-4.6) l g%. As to their intensity of the lethal effect on the strain 3.1 antibiotics show the following descending succession: streptomycin, landomycin E, doxorubicin, olcandomycin and tetracyclin. High sensitivity of the strain 3-1 to the lethal effect of its own antibiotic may be explained by high permeability of mycelium fragments to landomycin E as compared to the intact mycelium.