Production of A-21978C derivatives.

摘要

An improved process is provided for producing A-21978C cyclic peptide derivatives having a C2-C14 alkonoyl side chain which comprises feeding a C2-C14 alkanoic acid, or an ester or salt thereof, to the A-21978C-producing culture during the production stages of the fermentation. In addition, a new process is provided for producing the A-21978C antibiotics which comprises cultivating under aerobic conditions a new strain of microorganism.