Of bacterial polysaccharides

Enzymatic Production of Bacterial Polysaccharides, M. Stacey, Nature. 149 (1942) 639. 

In two articles published in this Series in 1946, the chemistry of bacterial polysaccharides was discussed. All the sugar and non-sugar components of such polysaccharides that were known at that time had previously been isolated from plant or animal polysaccharides. It was thus not known that... 

Five pentoses, namely, D-ribose, d- and L-arabinose, and D- and L-xylose, have been found in hydrolyzates of bacterial polysaccharides. D-Riboseisthe most common of these, and is a component of different LPS, capsular polysaccharides, and teichoic acid type of polymers. In all these polymers, it occurs as the /I-furanosyl group or residue. 

D-Xylose, which is one of the most abundant sugars in plant polysaccharides, is a rare component of bacterial polysaccharides. It is found in the LPS of Type 1 Neisseria gonorrhoeae strain" GC 6. L-Xylose and its 3-methyI ether are components of the LPS of Pseudomonas maltophila strain NCTC 10257, and are j -pyranosidic. The d- and L-sugars, and different methyl ethers of these, have also been found in the LPS of some photosynthetic bacteria."... 

Two 6-deoxyheptoses, namely 6-deoxy-D-wa o-heptose and 6-deoxy-D-a//ra-heptose, are components of bacterial polysaccharides. The former occurs as o-pyranosyl residues in the LPS from some strains of Yersinia pseudotuberculosis,and the latter as terminal a-furanosyl groups (II) in... 

Six 2-amino-2,6-dideoxyhexoses are known as components of bacterial polysaccharides, namely, those having the d- and h-gluco, i.-manno, d- and L-galacto, and L-talo configurations. 2-Amino-2,6-dideoxy-D-glucose (d-quinovosamine) occurs in some LPS for example, that from Pseudomonas... 

Several glyculosonic acids have been identified as components of bacterial polysaccharides. D-/yxo-Hexulosonic acid, as Q -D-pyranosyl residues (23), is a component of the extracellular polysaccharide from a Rhodococcus species. The LPS from Acinetobacter calcoaceticus NCTC 10305 contains - D-g/ycero-D-/a/o-octulosonic acid (24). It is isosteric with 3-deoxy-D-mnnno-octulosonic acid (25), which is a constituent of bacterial LPS and links the polysaccharide part to the lipid A region. It seems possible that D-g/ycero-D-tfl/o-octulosonic acid replaces 3-deoxy-D-/wan o-octulosonic acid in the A. calcoaceticus LPS. 

The different methylated sugars known as components of bacterial polysaccharides are summarized in Table 1. When possible, references to publications in which the methylated sugar is part of a known structure are preferred to references in which the component has merely been identified. References to sugars of undetermined configuration or absolute configuration have been omitted when there is reason to assume that they are identical to better characterized compounds from other sources. 

Polyisoprenol compounds exist in both bacteria and eukaryotic cells. They participate in the synthesis of bacterial polysaccharides and in the biosynthesis of N-... 

The marked advances made in the study of bacterial polysaccharides serve only to emphasize the vast amount of work still to be carried out in this field. The recent remarkable achievements in enzymic chemical synthesis (starch, crystalline sucrose, etc.) indicate the growing necessity for greater cooperation11 between enzymologist and chemist in the solution of many biological phenomena. 

NMR can also be used to elucidate the structural features of a repeating unit in a polysaccharide and to investigate the conformation and dynamics of polysaccharides.21 A unique polysaccharide structure results in a characteristic proton NMR spectrum. Therefore, NMR is a powerful tool for identifying polysaccharide structures. This remarkable specificity has led to the development of a routine NMR-based identity assay, recently reported by Abeygunawardana et al. for quality control testing of bacterial polysaccharide to be used in formulating a polyvalent pneumococcal polysaccharide vaccine.22... 

It has been discovered that galactomannans interact with a number of bacterial polysaccharides.168 The most studied has been the interaction with the exo-polysaccharide from Xanthomonas campestris. Mixtures of this non-gelling polysaccharide with locust-bean gum form firm, rubbery gels at total-polysaccharide concentrations181 211 greater than 0.5%. The gels are firmest at a Xanthomonas polysaccharide locust-bean gum ratio of 1 3. 

BIOSYNTHESIS OF BACTERIAL POLYSACCHARIDE CHAINS COMPOSED OF REPEATING UNITS... 

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