Process for production of antibiotic U-64,767 using Streptomyces macronensis NRRL 12566

A process for preparing antibiotic U-64,767 which in its essentially pure crystalline form has the following characteristics:

• (a) molecular weight of 1191 (mass spectrometry);
• (b) color and form of pure solid:
• white
• (c) is highly soluble in 1:1 water:methanol and in glacial acetic acid and poorly soluble in methanol or water alone;
• (d) a characteristic .sup.13 C-NMR spectrum as shown in FIG. 3 of the drawings;
• (e) a characteristic UV spectrum with a maximum absorption at 223 nm
• (f) a characteristic infrared absorption spectrum when dissolved in a mineral oil mull as shown in FIG. 1 of the drawings;
• (g) has a molecular formula C.sub.57 H.sub.109 N.sub.1 O.sub.24 ;
• and
• (h) a melting point of 153.degree.-155.degree. C. with decomposition, which comprises cultivating Streptomyces macronensis Dietz sp.n., NRRL 12566, in an aqueous nutrient medium under aerobic conditions until substantial antibiotic U-64,767 activity is imparted to said medium.