THE INCORPORATION OF LABELLED AMINO SUGARS BY BACILLUS SUBTILIS

Abstract

N-Acet-yl[1-C14]glucosamine (10 [mu][image]-5m[image]) is incorporated by cells of B. subtilis at a constant rate (0.2-2m[mu]moles/mg dry wt./hr.). The rate of [1-C14]-glucosamine (2.5 [mu][image]-5m[image]) incorporation is proportional to the concentration; it approaches that of N-acetyl[1-C14]glucosamine at 5m[image]. Label from N-acetyl[1-Cl4]glucosamine and [1-C14]glucosamine is incorporated predominantly into the "hot-trichloroacetic acid-soluble" and "residue" fractions of cells. Acid hydrolysis of the hot-trichloroacetic acid-soluble fraction yields mainly [C14]glucosamine; hydrolysis of the residue fraction yields [C14]glucosamine and [C14]muramic acid. The label from N-[1-C14]acetylglucosamine and sodium [1-C14]acetate enters most cell fractions. Incorporation of N-[1-C14]acetylglucosamine is inhibited by the addition of unlabelled acetate. Glucose competes with [1-C14]glucosamine for incorporation. N-Propionylglucosamine and N-formylglucosamine compete with N-acetyl[1-C14]glucosamine. Cells pregrown on N-acetylglucosamine or glucosamine incorporate up to 10 times as much N-acetyl[1-C14]glucosamine or [1-C14]-glucosamine in a given time as cells pregrown on glucose.