Isolation, purification and preliminary characterization of megalomicin.

Isolation and Purification Megalomicin is an antibiotic mixture most readily isolated from the fermentation broth by adjusting the whole broth to a pH of 9.5 with dilute aqueous sodium hydroxide and extracting with approximately 2 volumes of ethyl acetate for each volume of broth. The solvent phase was separated and concentrated under vacuum to an oily residue. The biological activity of a 1:20 dilution of this residue gave a zone of inhibition diameter of approximately 25 mmagainst Staphylococcus aureus ATCC 6538P.