Evidence for the Presence of a New Class of Teichoic Acid in the Cell Wall of Bacterium NCTC 9742

Abstract

The composition of the cell wall of bacterium NCTC 9742, variously known as Chromobacterium iodinum or Pseudomonas iodinum and considered by some to be a species of Brevibacterium or Arthrobacter, has been studied. Walls isolated from cells grown in nutrient broth consisted predominantly of peptidoglycan and a phosphorylated polymer containing d-mannitol, glycerol, pyruvic acid, d-glucose and d-galactosamine. This phosphorus-rich polymer, which was slowly released on treatment of the walls with cold aqueous trichloroacetic acid, is considered to be a new type of teichoic acid. Quantitative analysis and the results of preliminary degradative studies indicated that the main backbone was a poly(mannitol phosphate) chain to which β-glucopyranosyl substituents and pyruvic acid residues (acetal-linked) were attached. It is suggested that the minor components, glycerophosphate and galactosamine, could form a linkage unit for the covalent attachment of the poly(mannitol phosphate) chain to peptidoglycan. In the walls of cells grown on nutrient agar, it appeared that the phosphorus-rich polymer was partly replaced by another polymer containing galactose and an unidentified component which reacted like a 2-keto-3-deoxyaldonic acid in the periodate/thiobarbituric acid test. The taxonomic implications of the cell-wall composition are discussed.