| abstract |
ABSTRACT OF THE DISCLOSURE An improved process for preparing Nocardicin A by cul-turing a Nocardicin A-producing microorganism in a fermentation medium comprises, adding to the fermentation medium, at least one additive selected from shikimic acid, a carboxylic acid of the formula: (I) wherein A is alkylene group having hydroxy, amino, acylamino or oxo group, and n is an integer of 0-4; glycine, alanine, serine, homoserine, ?-aminobutyric acid and ?,.beta.-diaminopropionic acid, and derivatives of the carboxy group of these compounds, Nocardicin A is a known antibiotic. |