Streptomyces nodosus host strains optimized for polyene glycosylation engineering.

The AmphDI glycosyltransferase transfers a mycosaminyl sugar residue from GDP onto 8-deoxyamphoteronolide B, the aglycone of the antifungal amphotericin B. In this study the amphDI gene was inactivated in Streptomyces nodosus strains lacking the AmphN cytochrome P450. The new mutants produced 8-deoxy-16-methyl-16-descarboxyl amphoteronolides in high yield. These strains and aglycones should prove valuable for in vivo and in vitro glycosylation engineering.