INRA, UR454 Unité de Microbiologie, Centre de Recherches de Clermont-Ferrand/Theix, Saint-Genès-Champanelle, France.
Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Bratislava, Slovak Republic.
J Appl Microbiol. 2010 Aug;109(2):451-460. doi: 10.1111/j.1365-2672.2010.04671.x. Epub 2010 Jan 11.
To characterize fibre degradation, colonization and fermentation, and xylanase activity of two xylanolytic bacteria Bacteroides xylanisolvens XB1A(T) and Roseburia intestinalis XB6B4 from the human colon.
The bacteria grew well on all the substrates chosen to represent dietary fibres: wheat and corn bran, pea, cabbage and leek fibres, and also on purified xylans. Roseburia intestinalis colonized the substrates more efficiently than Bact. xylanisolvens. For the two bacteria, 80-99% of the total xylanase activity was associated with the cells whatever the substrate and time of growth. Optimal specific activities of cells were obtained on oat spelt xylan; they were higher than those previously measured for xylanolytic bacteria from the human gut. Roseburia intestinalis produced high molecular mass xylanases (100-70 kDa), while Bact. xylanisolvens produced lower molecular mass enzymes, including a cell-associated xylanase of 37 kDa.
The two bacteria display very high xylanolytic activity on the different substrates. Differences were observed on substrate attachment and enzyme systems, suggesting that the two species occupy different niches within the gut microbiota.
This study characterizes xylan degradation by two major species of the human intestine.
描述来自人结肠的两种木聚糖分解菌拟杆菌属木聚糖分解菌 XB1A(T)和罗斯伯里氏菌 XB6B4 的纤维降解、定殖和发酵以及木聚糖酶活性。
细菌在所有选择的代表膳食纤维的底物上生长良好：小麦和玉米麸皮、豌豆、卷心菜和韭菜纤维，以及纯化的木聚糖。罗斯伯里氏菌比拟杆菌属木聚糖分解菌更有效地定殖底物。对于这两种细菌，无论底物和生长时间如何，总木聚糖酶活性的 80-99%都与细胞相关。在燕麦斯佩尔特木聚糖上获得了细胞最佳比活性；它们高于以前从人肠道中测量的木聚糖分解菌的比活性。罗斯伯里氏菌产生高分子质量的木聚糖酶（100-70 kDa），而拟杆菌属木聚糖分解菌产生低分子质量的酶，包括 37 kDa 的细胞相关木聚糖酶。
两种细菌在不同的底物上表现出非常高的木聚糖分解活性。在底物附着和酶系统上观察到差异，表明这两个物种在肠道微生物群中占据不同的生态位。
本研究描述了两种主要的人类肠道木聚糖降解菌的木聚糖降解。
