PREPARATION OF A NOVEL (1-]4)-BETA-D-GLYCAN BY ACETOBACTER-XYLINUM - A PROPOSED MECHANISM FOR INCORPORATION OF A N-ACETYLGLUCOSAMINE RESIDUE INTO BACTERIAL CELLULOSE

A novel polysaccharide having a N-acetylglucosamine (GlcNAc) residue a s one of the constituents was synthesized by incubation of Acetobacter xylinum in a modified Schramm-Hestrin medium containing lysozyme-susc eptible phosphoryl chitin (P-chitin) and D-glucose. HPLC of the cultur e medium showed that the P-chitin added was depolymerized to monomeric and oligomeric P-chitins during the incubation, and the P-chitins wit h permeable sizes were utilized as a carbon source by the bacteria. C- 13 NMR analysis revealed that the P-chitin consists mainly of GlcNAc 6 -P residues. Furthermore, monomeric GlcNAc 6-phosphate was also found to enhance the incorporation of GlcNAc residues into the polysaccharid e. However, no incorporation of the GlcNAc residues was observed when A. xylinum was incubated in a medium containing either highly phosphor ylated chitin (DS=1.90) or its oligomers produced by acid hydrolysis. (C) 1997 Elsevier Science Ltd.