Xanthan Gum - Fermentatively Derived Polysaccharide Powder, Rheology Modifier With Glycosyltransferase-driven Synthesis

Product Description is a polysaccharide used as a food additive and rheology modifier. It is produced by fermentation of glucose or sucrose by the Xanthomonas campestris bacterium. After a fermentation period, the polysaccharide is precipitated from a growth medium with dried and ground into a fine powder. Later, it is added to a liquid medium to form the gum.

Product Feature
Synthesis originates from glucose as substrate for synthesis of the sugar nucleotides precursors UDP-glucose, UDP-glucuronate, and GDP-mannose that are required for building the pentasaccharide repeat unit. This links the synthesis of xanthan to the central carbohydrate metabolism. The repeat units are built up at undecaprenylphosphate lipid carriers that are anchored in the cytoplasmic membrane. Specific glycosyltransferases sequentially transfer the sugar moieties of the nucleotide sugar xanthan precursors to the lipid carriers. Acetyl and pyruvyl residues are added as non-carbohydrate decorations. Mature repeat units are polymerized and exported in a way resembling the Wzy-dependent polysaccharide synthesis mechanism of Enterobacteriaceae. Products of the gum gene cluster drive synthesis, polymerization, and export of the repeat unit.