Cell Wall Galactofuranan of the Paenarthrobacter Actinobacteria

The composition and structure of the cell wall glycopolymers of Paenarthrobacter species (P. aurescens VKM Ac-1105T, P. histidinovorans VKM Ac-1978T, and P. nicotinovorans VKM Ac-1988T, previously assigned to the genus Arthrobacter) were studied. All strains under study were found to contain a neutral polysaccharide, (1 → 6)-linked β-D-galactofuranan with the 2,3-diacetamido-2,3-dideoxy-α-glucopyranose (α-GlcpNAc3NAc) residues that glycosylate most of the hydroxyl groups at C-2 of galactofuranose. Acid hydrolysates of the cell walls contained galactose, glucose, arabinose, glucosamine, and galactosamine. The polysaccharide structure was established by chemical and NMR spectroscopic methods. The galactofuranan structure has not been previously described for representatives of other Actinobacteria genera. The data obtained expand our understanding of the chemical structure of microbial cell walls and may be used in taxonomy of actinobacteria, especially to differentiate at the phenotype level and to justify the description of new genera in the family Micrococcaceae.