[Formation of antibiotic JI-20B by a culture of Streptomyces flavovirens].

An actinomycetous culture having an antibiotic action on gram-positive and gram-negative bacteria was isolated from a soil sample collected in the region of the Balaton Lake. As a result of the taxonomic study the culture was classified as Str. flavovirens. Waksman, Henrici (1948). Examination of antimicrobial properties of the antibiotic and chromatographic and mass-spectroscopic studies allowed one to classify it as an aminoglycoside belonging to the gentamicin group. The antibiotic was designated as J120-B. Until recently such antibiotics were known to be produced only by Micromonospora.