Fermentation of Xyloglucan by Intestinal Bacteria

• Published in: Anaerobe Vol. 2; no. 4; pp. 223 - 230
• Main Authors: Hartemink, R., Van Laere, K.M.J., Mertens, A.K.C., Rombouts, F.M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1996
• Subjects: carbohydrate degradation; clostridia; endo-ß-glucanase; Food Chemistry and Microbiology; intestinal microflora; Levensmiddelenchemie en -microbiologie; VLAG; xyloglucan; clostridia; endo-ß-glucanase; intestinal microflora; carbohydrate degradation; xyloglucan
• ISSN: 1075-9964; 1095-8274
• DOI: 10.1006/anae.1996.0031

Xlyoglucan, a cell wall polysaccharide and part of the dietary fiber fraction of the diet, can be degraded by the intestinal microflora. Degradation is not common among intestinal bacterial species. Of 138 strains (representing 75 species) only nine strains were able to degrade the xyloglucan polymer. These strains, seven clostridia, one bifidobacterium and one bacteroides, all produced apparent extracellular enzymes, which degraded the glucan backbone. Gas production was detected in the individual clostridia. The other two strains did not produce any gas. Selective elimination of bacterial groups from faecal slurries indicated that clostridia are the main group of intestinal bacteria responsible for degradation of xyloglucan polymer. In addition to the polymer-degrading strains, some other strains were able to degrade and ferment oligosaccharides produced from tamarind seed xyloglucan with a fungal endo-ß-glucanase. HPAEC analysis showed that the fungal oligosaccharides were identical to the oligosaccharides produced by the polymer-degrading species suggesting the presence of an endo-ß-glucanase in these bacteria. It is proposed that xyloglucan is degraded
in vivoby endo-ß-glucanases produced mainly by clostridia, followed by fermentation of the oligosaccharides by a larger group of bacteria.