PDF(Pubmed)
Abstract：
Structurally complex corn bran arabinoxylan (CAX) was used as a model glycan to investigate gut bacteria growth and competition on different AX-based fine structures. Nine hydrolyzate segments of the CAX polymer varying in chemical structure (sugars and linkages), CAX, five less complex non-corn arabinoxylans, and xylose and glucose were ranked from structurally complex to simple. The substrate panel promoted different overall growth and rates of growth of eight Bacteroides xylan-degrading strains. For example, Bacteroides cellulosilyticus DSM 14838 (Bacteroides cellulosilyticus) grew well on an array of complex and simple structures, while Bacteroides ovatus 3-1-23 grew well only on the simple structures. In a competition experiment, B. cellulosilyticus growth was favored over B. ovatus on the complex AX-based structure. On the other hand, on the simple structure, B. ovatus strongly outcompeted B. cellulosilyticus, which was eliminated from the competitive environment by Day 11. This adaptation to fine structure and resulting competition dynamics indicate that dietary fiber chemical structures, whether complex or simple, favor certain gut bacteria. Overall, this work supports a concept that fiber degraders diversify their competitive abilities to access substrates across the spectrum of heterogeneity of fine structural features of dietary fibers.
摘要：
使用结构复杂的玉米麸皮阿拉伯木聚糖(CAX)作为模型聚糖来研究不同的基于AX的精细结构上的肠道细菌生长和竞争。CAX聚合物的9个水解物段的化学结构不同（糖和键），CAX,五种不太复杂的非玉米阿拉伯木聚糖，木糖和葡萄糖从结构复杂到简单。底物面板促进了八种拟杆菌木聚糖降解菌株的不同总体生长和生长速率。例如,DSM14838（拟杆菌）在一系列复杂而简单的结构上生长良好，而卵形拟杆菌3-1-23仅在简单结构上生长良好。在一个竞赛实验中,在复杂的基于AX的结构上，B.cellullosililyticus的生长优于B.ovatus。另一方面,在简单的结构上，卵形芽孢杆菌强烈优于赛丝青霉芽孢杆菌，在第11天被淘汰出竞争环境。这种对精细结构的适应和由此产生的竞争动力学表明，膳食纤维的化学结构，无论是复杂的还是简单的，有利于某些肠道细菌。总的来说,这项工作支持了一个概念，即纤维降解剂使其竞争能力多样化，以在膳食纤维的精细结构特征的异质性范围内访问底物。
