Bacteroides xylanisolvens sp nov., a xylan-degrading bacterium isolated from human faeces
Bacteroides xylanisolvens sp nov., a xylan-degrading bacterium isolated from human faeces
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DOI：
10.1099/ijs.0.65504-0
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发表时间：
2008-04-01
影响因子：
2.8
通讯作者：
Bernalier-Donadille, Annick
中科院分区：
文献类型：
--
作者：
Chassard, Christophe;Delmas, Eve;Bernalier-Donadille, Annick
在对人类肠道中木聚糖降解群落的研究过程中，从粪便样本中分离出6株木聚糖酶、革兰氏阴性厌氧菌。16S rRNA基因序列分析表明，分离株之间亲缘关系较近(~gt；=99%)，属于拟杆菌属。根据16S rRNA基因序列的相似性，代表菌株XB1A(T)与卵形拟杆菌(97.5%)、细小拟杆菌(96.5%)和塞氏拟杆菌(95.5%)的亲缘关系最近。DNA-DNA杂交结果表明，菌株XB1A(T)与其亲缘关系较近的卵形芽孢杆菌(B.ovatus)是不同的。菌株XB1A(T)的DNA G+C含量(42.8mol%)和主要脂肪酸组成(Anteiso-C-15：0，33.8%)进一步支持其与类杆菌属的联系。新的菌株能降解不同类型的木聚糖，也能在多种碳水化合物上生长。与从人类肠道分离的大多数其他类杆菌不同，这些分离物不能降解淀粉。其他生化试验进一步证明，菌株XB1A(T)可以与最接近的类杆菌属区分开来。菌株XB1A(T)主要将木聚糖和糖转化为醋酸酯、丙酸和琥珀酸。根据生理、表型和系统发育的数据，这6个新菌株被认为代表了类杆菌属的一个新种，命名为木质类杆菌。11月是提议的。模式菌株为XB1a(T)(=DSM 18836(T)=CCUG 53782(T))。
During the course of a study on the xylan-degrading community from the human gut, six xylanolytic, Gram-negative, anaerobic rods were isolated from faecal samples. 16S rRNA gene sequence analysis showed that the isolates were closely related to each other (>= 99 % sequence similarity) and that they belonged to the genus Bacteroides. On the basis of 16S rRNA gene sequence similarity, representative strain XB1A(T) was most closely related to the type strains of Bacteroides ovatus (97.5 %), B. finegoldii (96.5 %) and B. thetaiotaomicron (95.5 %). DNA-DNA hybridization results revealed that strain XB1A(T) was distinct from its closest relative, B. ovatus. The DNA G+C content of strain XB1A(T) (42.8 mol%) and major fatty acid composition (anteiso-C-15:0, 33.8%) further supported its affiliation to the genus Bacteroides. The novel isolates degraded different types of xylan, and were also able to grow on a variety of carbohydrates. Unlike most other Bacteroides species isolated from the human gut, these isolates were not able to degrade starch. Other biochemical tests further demonstrated that strain XB1A(T) could be differentiated from the closest related Bacteroides species. Xylan and sugars were converted by strain XB1A(T) mainly into acetate, propionate and succinate. Based on physiological, phenotypic and phylogenetic data, the six novel strains are considered to represent a novel species of the genus Bacteroides, for which the name Bacteroides xylanisolvens sp. nov. is proposed. The type strain is XB1A(T) (=DSM 18836 (T) =CCUG 53782 (T)).