Studies on Streptomycetes

Judging from its antibiotic spectrum and chemical properties, antibiotic No.45449-A was found to be an antibiotic belonging to the neomycin group.This antibiotic was compared with other antibiotics belonging to the neomycin group by the following three methods.First, comparison of the antibiotic spectrum of No.45449-A with those of neomycin, kanamycin hydroxymycin and paromomycin indicated that the former is different from the latter.Secondly, test for cross resistance using St. pulveraceus and St. fradiae as test microorganism showed that No.45445-A is distinguishable from neomycin and kanamycin.Thirdly, investigation of diffusion assay ratios by the method of Fischer et al. also presumed No.45449-A to be a new antibiotic differing from neomycin and kanamycin.