N-demethylvancomycin, a novel antibiotic produced by a strain of Nocardia orientalis. Taxonomy and fermentation.

A novel vancomycin analog, N-demethylvancomycin, is produced by a soil isolate collected in Yucatan, Mexico. Taxonomic studies indicated this microorganism, designated NRRL 15232, is a strain of Nocardia orientalis. Unlike some glycopeptide antibiotics, virtually none of the N-demethylvancomycin synthesized remained bound to the cells of the producing culture. Antibiotic production was markedly depressed by the addition of orthophosphate to the fermentation medium. Enrichment of the medium with tyrosine, p-hydroxyphenylglycine, p-hydroxyphenylglyoxylic acid, or leucine, all putative precursors of the aglycone, stimulated the biosynthesis of N-demethylvancomycin.