Polysaccharide bacterial

Many different types of polysaccharides are produced and excreted by bacteria into their immediate surroundings. These exopolysaccharides serve a variety of 

The chemical compositions of cell-wall polysaccharides of mycobacteria have been ably reviewed.  

Acidic polysaccharides can be detected by a combination of electrophoresis in an agar gel and precipitation with Cetavlon.  

Flocculating, but not non-flocculating, strains of Rhizobium species have been found to produce microfibrils the microfibrils isolated from R. trifolii are composed of cellulose, D-P C]Glucose from UDP-D-[ C]glucose was 

A smooth strain of E. coli synthesizes a polysaccharide exhibiting blood-group H activity. Enzymic and chemical investigations indicated that the side-chain of the polysaccharide contains a tetrasaccharide unit (16), to which a 

D-glucopyranosyl residue is attached. Removal of some of the L-fucosyl residues from the polysaccharide with ct-L-fucosidase resulted in loss of blood-group activity. 

has been applied to three types of problem in the bacterial polysaccharide area assigning compositions (including the number and type of O-acyl groups), sequencing, and identifying cyclic structures. The last application is covered in Section VI,5. 

Recently, considerable development has been made in exploring new bacterial polysaccharides that exhibit novel and highly functional properties, e.g. the association between the exclusive properties of xanthan gum (the foremost microbial 

Jina W, Lia Z, Lianga H, Wanga Y, Shaha BR, lia Y, Lia B. Synthesis and characterization of nanoparticles based on negatively charged xanthan gum and lysozyme. Food Res Int. 2015 71 83-90. 

Kennedya JRM, Kent KE, Brown JR. Rheology of dispersions of xanthan gum, locust bean gum and mixed biopolymer gel with silicon dioxide nanoparticles. Mater Sci Eng C. 2015 48 347-53. 

Sharma N, Deshpande RD, Sharma D, Sharma RK. Development of locust bean gum and xanthan gum based biodegradable microparticles of celecoxib using a central composite design and its evaluation original research article. Ind Crops Prod. 2016 82 161-70. 

Hwang J, Kang H, Choi J. Chlorhexidine-loaded xanthan gum-based biopolymers for targeted, sustained release of antiseptic agent. J Ind Eng Chem. 2015 32 44-8. 

For example, the native, capsular polysaccharide from Klebsiella aero-genes type K54 incubated with a bacteriophage-induced enzyme, gave an 

Oligosaccharides Released by Phage Hydrolysis of Klebsiella Polysaccharides 

Serotype Oligosaccharide released Bond hydrolyzed References 

When the extracellular, acidic polysaccharide from Rhizobium meliloti IFO 13336 was hydrolyzed with extracellular /3-D-glycanase and then intracellular endo-(l - 6)-/J-D-glucanase, two tetrasaccharides were 

Four types of specific antigen have been isolated from the intact bacteria or from the cell walls of a large number of strains of Lactobacillus acidophilus Inhibition of antibody-antigen reactions with trehalose and maltose indicated that a-D-glucopyranosyl residues are immunodominant in these antigens. 

Hofstad and H. Lygre, Acta Pathol. Microbiol. Scand. (B), 1977, 85, 14. 

Mycobacterial polysaccharides are able to accelerate the diffusion of long-chain acylated derivatives of coenzyme A away from fatty-acid synthase. A general mechanism has been proposed to account for variations in the rates and products of reactions catalysed by the fatty-acid synthase from M. smegmatis over a wide range of experimental conditions. Mycobacterial polysaccharides are considered to form ternary complexes with enzyme-bound coenzyme A, causing the rapid release of fatty-acid derivatives. 

Sequential degradation of the extracellular polysaccharide from R. meliloti has shown that it is composed of the octasaccharide repeating-unit (27). ° Thus, after removal of pyruvic acid residues from the methylated polysaccharide, the four p-D-glucopyranosyl residues in the side-chain were removed by oxidation, P-elimination, and, where necessary, hydrolysis with acid (see Vol. 10, p. 18). The sequence of hexopyranosyl residues in the main chain of the polysaccharide was determined by a modified Smith degradation in which the polyalcohol was methylated prior to hydrolysis with acid. 

The melting points and heats of junction formation of curdlan gels depend on the concentration and DP of the polysaccharide [a (1 3)-P-D-glucan from Alcaligenes faecalis. The junction zones of the gels appear to form in regions of aggregation of intertwined helices. X-Ray diffraction studies have revealed that curdlan assumes a triple-helical structure.  

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Agar, which is low in metabolizable or inhibitory substances, debris, and thermoduric spores, is ideal for the propagation and pure culture of yeasts, molds, and bacteria. Agar also meets the other requirements of ready solubiUty, good gel firmness and clarity, and a gelation temperature of 35—40°C and a gel melting temperature of 75—85°C. A clarified and purified form of the bacterial polysaccharide, geUan gum, is the only known satisfactory substitute. 

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

Once a general conformation type or preliminary classification has been established it is possible to use sedimentation data to obtain more detailed information about polysaccharide conformation. For example, the low value of ks/[v 0 25 found for the bacterial polysaccharide xylinan has been considered to be due to asymmetry [115]. If we then assume a rigid structure the approximate theory of Rowe [36,37] can be applied in terms of a prolate ellipsoid of revolution to estimate the aspect ratio p L/d for a rod, where L is the rod length and d is its diameter) 80. 

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... 

Shortly afterwards, Westphal, Liideritz, and their coworkers using the newly developed method of paper chromatography, found a new class of sugars in lipopolysaccharides (LPS) from Gram-negative bacteria, and identified them as 3,6-dideoxyhexoses. This work is summarized in Ref. 4. These discoveries initiated more-systematic investigations of hydrolyzates from bacterial polysaccharides, and a number of new monosaccharides were completely or partially identified. This development has been summarized by Ashwell and Hickman. ... 

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."... 

Six of the 18 aldohexoses, namely, D-glucose, d- and L-mannose, D-galac-tose, D-allose, and L-altrose have been found in bacterial polysaccharides. 

Deoxyhexoses have not been found in bacterial polysaccharides, but there is one example of a 4-deoxyhexose, namely, 4-deoxy-D-arah//io-hex-ose. This sugar is a component of some 0-antigens from Citrobacter, for... 

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... 

Before 1983, branched-chain sugars had not been found in bacterial polysaccharides, but there are now five examples belonging to this class. The LPS from Coxiella burned phase I contains both 6-deoxy-3-C-methyl-L-gulose (L-virenose) as pyranoside (12) and 3-C-(hydroxymethyl)-L-lyxose as furan-oside (13). Another 6-deoxy-3-C-methylhexose, having the manno configuration, is a component of the Nitrobacter hamburgiensis 0-antigen. ... 

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... 

The acidic sugars discussed in this Section are glycuronic acids and glycu-losonic acids. Bacterial polysaccharides may also become acidic by substitution of sugar residues, for example by etherification with lactic acid, acetala-tion with pyruvic acid, or phosphorylation, and these possibilities will be discussed in the following Sections. A sugar that does not fall into any of... 

The capsular polysaccharide from Rhizobium meliloti IFO 13336 contains terminal ct-D-ribofuranosyluronic groups (19). With this obvious exception, all known glycuronic acids in bacterial polysaccharides are py-ranosidic. 

A group of 2,3-diamino-2,3-dideoxyhexuronic acids has been found in bacterial polysaccharides, mainly in different O-antigens from Pseudomonas aeruginosa. The D-gulo isomer (20) was first found in the O-antigen from P. aeruginosa 06. The D-manno and h-gulo isomers (21 and 22) are... 

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. 

Some sugar residues in bacterial polysaccharides are etherified with lactic acid. The biosynthesis of these involves C)-alkylation, by reaction with enol-pyruvate phosphate, to an enol ether (34) of pyruvic acid, followed by reduction to the (R) or (5) form of the lactic acid ether (35). The enol ether may also react in a different manner, giving a cyclic acetal (36) of pyruvic acid. 

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