Studies on Streptomycetes

Investigation was made on the mycological properties of a strain No. 45449 isolated from a sample of soil collected in Fukuchiyama. Since the antibiotics produced by the strain resembled hydroxymycin and paromomycin, the strain was compared with the hydroxymycin and paromomycin-producing strains, S. paucisporogenes and S. rimosus forma paromomycinus, and as a result the strain No. 45449 was found to be different from the latter two strains. Among known strains, S. flavogriseus resembles the present strain, but they are different morphologically and in the kind of the antibiotics they produce. Thus, as the strain No. 45449 was found to be a new strain, it was named S. pulveraceus nov. sp. The antibiotics produced by the present strain are physiologically basic substances active against Gram-positive and negative bacteria and acid fast bacteria, and they are considered to belong to the neomycin-kanamycin group.