FR-900137, a new antibiotic. I. Taxonomy and fermentation of the organism, and isolation and characterization of the antibiotic.

A strain of Streptomyces, isolated from a soild sample and identified as Streptomyces unzenensis sp. nov. has been found to produce FR-900137, an interesting new antibiotic, containing phosphorus in its molecule. The antibiotic, obtained as white powder, was shown to inhibit a wide variety of Gram-positive and Gram-negative bacteria except Pseudomonas aeruginosa.