Glucuronic acid fermentation

Xanthan (Figure 11) is a commercially important polysaccharide produced by the bacterium Xanthomonas campestris.187 188 The xanthan backbone consists of a P(l-4)-linked D-glucopyranose chain with a trisaccharide side chain attached at C3 to alternate glucose residues. These side chains consist of an acetylated mannose residue, a glucuronic acid residue, and a pyruvate ketal linked to a terminal mannose residue. The acetate and pyruvate content depend on the fermentation and isolation conditions used by the supplier. 

Xanthan Gum occurs as a cream colored powder. It is a high-molecular-weight polysaccharide gum produced by a pure-culture fermentation of a carbohydrate with Xanthomonas campestris, purified by recovery with isopropyl alcohol, dried, and milled. It contains D-glucose and D-mannose as the dominant hexose units, along with D-glucuronic acid and pyruvic acid, and it is prepared as the sodium, potassium, or calcium salt. It is readily soluble in hot or cold water, but it is insoluble in alcohol. Its solutions are neutral. 

Hyaluronic acid Natural polysaccharide (e.g., in rooster comb) also a bacterial fermentation product -C-O C -C-OH -C-NHCO CH3 -COOH Substituted pyranose sequences of acetyl Glucosamine and glucuronic acid... 

Xanthan Made primarily of linear glucose chain with side chains based on mannose and glucuronic acid residues A microbial gum made by glucose fermentation, forms viscous pseudoplastic solutions Emulsifying or suspending agent, particularly in toothpaste and ointments... 

Hyaluronic acid Made of acetyl glucosamine and glucuronic acid (partially neutralized to dissolve) sequences Obtained by the extraction of rooster comb or as a bacterial fermentation product, molecular weight ranges from 0.5 to 3 X 10 Exceptional lubricant for living tissues... 

The major products, catechol, 2,3-dihydroxyacetophenone, and 3,8-dihydroxy-2-methylchromone, as well as 2-furaldehyde, were quantitatively determined in the acidic reaction mixtures of xylose and glucuronic acid. Considerable variation of these components occurred within pH 1.7-4.0. Such products, potentially produced during biomass hydrolysis, may have an inhibiting effect on subsequent fermentation processes. 

It is evident from the results of this research that phenolic products, especially 3, may be obtained by the acidic hydrothermolysis of xylose and glucuronic acid containing materials. The phenolics and 2-furaldehyde could contribute toward the inhibition of fermentation organisms if acidic pretreatment procedures are not carefully controlled. 

Classification Polysaccharide gum Definition High m.w. hetero polysaccharide gum produced by a pure-culture fermentation of a carbohydrate with Xanthomonas campesths] contains D-glucose, D-mannose, and D-glucuronic acid and is prepared as the sodium, potassium, or calcium salt... 

Xanthan is an exo-cellular biopolymer produced by bacteria of the Xanthomonas genus. It is composed of glucose, mannose, glucuronic acid, pyruvate and acetate units. Its sugar composition is generally constant, but acetate and pyruvate contents may depend on the strain used 3,4) and on fermentation conditions such as nature and concentration of the carbon source, dissolved oxygen content and other nutrient limitations (5,6). 

Hyaluronic acid Animal (synovial fluid, vitreous humour of the eye, umbilical tissue microbial (fermentation Bacillus subtflis) P-glucuronic acid and N-acetyl-P-glucosamine (GlcNAc) linked by a-(l/3) bond. [35]... 

Wise and Appling 40) determine D-galactose in the presence of D-man-nose, D-glucose, D-fructose, D-xylose, L-arabinose, and D-glucuronic acid by use of a yeast Saccharomyces carlsbergensis) which ferments D-galactose and one (S. bayanus) which does not. Both yeasts ferment the mannose, glucose, and fructose but have no action on the xylose, arabinose, and... 

Cimini, D., De Rosa, M., Schiraldi, C., 2012. Production of glucuronic acid-based polysaccharides by microbial fermentation for biomedical apphcations. Biotechnol. J. 7, 237-250. Colliec-Jouault, S., Bavington, C., Delbarre-Ladrat, C., 2012. Heparin-hke entities from marine organisms. Handb. Exp. Pharmacol. 207,423-449. 

The simple components xylose, glucuronic acid, and arabinose are rapidly fermented by rumen microorganisms with the formation of the volatile fatty acids (Heald and McNaught ), acetic, propionic, and butyric acids, with acetic acid predominating. 

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