[Induction of antibiotic production in inactive cultures of actinomycetes. Monensin production by a mutant strain 2608 EB-1].

An actinomycete strain designated as 2608 was isolated from a soil sample. When cultivated on various solid and liquid media, the strain was inactive. The strain exposure to ethidium bromide resulted in formation of a mutant producing an antibiotic active against some gram-positive bacteria. The property of the antibiotic production proved to be stable. The antibiotic was identified by IR, NMR and mass spectroscopy as monensin. Strain 2608 producing monensin differs from the described monensin-producing culture Streptomyces cinnamonensis ATCC 15413 and is a new culture producing monensin.