21978 - antibiotics and processes for their production.

摘要

Antibiotic A-21978 complexes, in particular the A-21978C complex, comprising microbiologically active, related factors C0, C1, C2, C3, C4, and C5. A-21978 complex and A-21978C complex are produced by submerged aerobic fermentation of Streptomyces roseosporus NRRL 11379. The individual A-29178C factors are separated and isolated by chromatography. The A-21978 and A-21978C complexes; the A-21978C factors; and pharmaceutically acceptable salts thereof are antibacterial agents and improve growth promotion in poultry.