| abstract |
An improved process is provided for producing A-21978C cyclic peptide derivatives having a C 2 -C 14 alkonoyl side chain which comprises feeding a C 2 -C 14 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. |