An Acetobacter xylinum adapted to a medium containing N-acetylglucosamine (GlcNAc) has been used to prepare a novel polysaccharide containing residual GlcNAc in cellulose. The maximum amount of incorporation was found to be 4 mol% in cellulose, when a mixed medium containing 1.4% glucose (Glc) and 0.6% GlcNAc was used for the culture of A. xylinum. The resulting polysaccharide was lysozyme-susceptible. The aminosugar residue incorporated into bacterial cellulose was found to be only GlcNAc, even if galactosamine (GalN) and glucosamine (GlcN) were applied, whereas there was little effect by mannosamine (ManN). As the major component of the resulting polysaccharide was Glc residues, even if the only carbon source in the culture medium was GlcNAc, it was suggested that there must be several enzyme systems to convert GlcNAc into Glc in the bacteria. Several ammonium salts were also found to be effective for the incorporation of GlcNAc residues when the incubation system was converted to rotatory and aerobic incubation from static incubation. The amount of residual GlcNAc was remarkably increased by the addition of lysozyme-susceptible phosphoryl-chitin (P-chitin) and increased slightly with addition of P-chitin that was less lysozyme-susceptible. However, little effect was found on addition of highly substituted P-chitin.