FR-900148, a new antibiotic. I. Taxonomy, fermentation, isolation and characterization.

A strain of Streptomyces, isolated from a soil sample and identified as Streptomyces xanthocidicus, has been found to produce FR-900148, a new antibiotic containing chlorine in its molecule. The antibiotic inhibits both Gram-positive and negative bacteria. However, it is not effective against wild type of Pseudomonas aerguinosa. Its antibacterial action is considered to result from cell wall synthesis inhibition since it causes spheroplast formation from susceptible cells.