[Nutrient medium for determining the biological activity of heliomycin]

It was shown that a nutrient medium containing only salt components except agar-agar could be used for assay of the biological activity of heliomycin. The optimal results were observed on the medium containing ammonium chloride, urea, disubstituted sodium phosphate, glucose and agar-agar. The medium provided satisfactory growth of Bac. subtilis ATCC 6633 as the test culture and formation of clear inhibition growth zones of the sufficient size. The medium is standard and its use allows obtaining reproducible results in assay of the heliomycin biological activity.