Biosynthesis of streptolidine moiety of streptothricins by Streptomyces noursei JA 3890b.

The incorporation of uniformly 14C-labeled compounds into the streptothricin-type antibiotic nourseothricin was studied with a strain of Streptomyces noursei JA 3890b. 6.5% of radioactivity from U-14C-L-arginine was incorporated into the antibiotic, while glutamic acid, aspartic acid, alanine, proline, glycine and leucine displayed much lower incorporations. Furhtermore, 95% of the activity incorporated from arginine was located in the streptolidine moiety supporting the suggestion that this subunit of streptothricin antibiotics is formed via the dehydroarginine pathway.