Pacidamycins, a novel series of antibiotics with anti-Pseudomonas aeruginosa activity. I. Taxonomy of the producing organism and fermentation.

The pacidamycins are a new complex of nucleosidyl-peptide antibiotics with highly specific activity against Pseudomonas aeruginosa. They are produced by Streptomyces coeruleorubidus AB 1183F-64 which was isolated from a soil sample collected at Offenburg in the FRG. The mature spore masses of the producing organism are greenish gray to blue, and the spore chains are arranged in spirals. After the structures of the pacidamycins were determined, the fermentation medium was supplemented with component amino acids. This resulted in the directed biosynthesis of several members of the complex. The overall antibiotic recovered was increased from 1 approximately 2 mg/liter to more than 100 mg/liter through a combination of strain selection, medium manipulation and amino acid feeding experiments.