Fermentation of xyloglucan by intestinal bacteria
Fermentation of xyloglucan by intestinal bacteria
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DOI：
10.1006/anae.1996.0031
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发表时间：
1996-08-01
期刊：
影响因子：
2.3
通讯作者：
Rombouts, FM
中科院分区：
文献类型：
--
作者：
Hartemink, R;VanLaere, KMJ;Rombouts, FM
木葡聚糖是一种细胞壁多糖，也是饮食中膳食纤维的一部分，可以被肠道微生物群降解。肠道细菌种类中的降解并不常见。在 138 个菌株（代表 75 个物种）中，只有 9 个菌株能够降解木葡聚糖聚合物。这些菌株（七种梭状芽胞杆菌、一种双歧杆菌和一种拟杆菌）均产生明显的胞外酶，从而降解葡聚糖主链。在单个梭菌中检测到气体产生。另外两种菌株不产生任何气体。从粪便浆液中选择性消除细菌群表明梭菌是负责木葡聚糖聚合物降解的主要肠道细菌群。除了聚合物降解菌株外，一些其他菌株能够用真菌内切 β-葡聚糖酶降解和发酵罗望子种子木葡聚糖产生的寡糖。 HPAEC 分析表明，真菌寡糖与聚合物降解物种产生的寡糖相同，表明这些细菌中存在内切 β-葡聚糖酶。据建议，木葡聚糖在体内被主要由梭状芽胞杆菌产生的内切β-葡聚糖酶降解，随后由更大的细菌群发酵寡糖。 (C) 1996 年学术出版社。
Xyloglucan, 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-beta-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-beta-glucanase in these bacteria. It is proposed that xyloglucan is degraded in vivo by endo-beta-glucanases produced mainly by clostridia, followed by fermentation of the oligosaccharides by a larger group of bacteria. (C) 1996 Academic Press.