Biosynthesis xanthan

Figure 7.10 Simplified scheme for the biosynthesis of xanthan. Adapted from Exopolysaccharides in Plant Bacterial Interactions. J A Leight and D L Coplin. Annu Rev Microbial 1992 46 pp 307-46 (see text).

Scheme 4.—Proposed Pathway for the Biosynthesis of Bacterial Xanthan Gum (PEP, enolpyruvate phosphate.)2 231...

Increasing knowledge of the biosynthesis and nutritional requirements that affect the yield and acyl composition of xanthan gum should allow production of an improved and unvarying product 96,198,277... 

Becker, A. Katzen, F. Piihler, A. lelpi, L. Xanthan gum biosynthesis and application a biochemical-genetic perspective. Appl. Microbiol. Biotechnol. 1998, 50, 145-152. 

Vorholter FJ, Schneiker S, Goesmaim A, Krause L, Bekel T, Kaiser O, et al. The genome of Xanthomonas campestris pv. campestris BlOO and its use for the reconstruction of metabolic pathways involved in xanthan biosynthesis.J Biotechnol 2008 134 33-45. 

Biosynthesis of xanthan in Xanthomonas campestris is regulated by eight chromosomal gene loci, and gene loci eps7... 

Schematic representation of gene cluster involve in microbial exopolysaccharide biosynthesis, (a) gum gene cluster responsible for xanthan biosynthesis in Xanthomonas campestris and (b) eps gene cluster involve in EPS biosynthesis in Streptococcus thermophilus Sfi6...

The complete biosynthesis of xanthan, a water-soluble bacterial polysaccharide with a cellulose backbone (see Chapter 6, Fig. 6.18 for the structure), has been worked out by Dankert et al. [111-114]. The pentasaccharide repeating unit is attached to a polyprenol pyrophosphate lipid carrier [111], and the polymerization takes place by the addition of the repeating pentasaccharide from the polyprenol pyrophosphate pentasaccharide to the reducing end of the growing xanthan chain [114]. The mechanism of xanthan chain elongation is an insertion mechanism similar to those of murein. Salmonella 0-antigen, the dextrans, mutan, and alteman. 

Polysaccharides are usually obtained by biosynthesis in plants including algae or in animals some microbial polysaccharides are also now developed such as bacterial hyaluronan (HA), gellan or xanthan.[7-9]... 

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