This work aimed to investigate the ability of two human-derived bifidobacterial strains, i.e. Bifidobacterium breve UCC2003 and Bifidobacterium longum NCIMB 8809, to utilize various oligosaccharides (i.e., 4-galactosyl-kojibiose, lactulosucrose, lactosyl-oligofructosides, raffinosyl-oligofructosides and lactulose-derived galacto-oligosaccharides) synthesized by means of microbial glycoside hydrolases. With the exception of raffinosyl-oligofructosides, these biosynthetic oligosaccharides were shown to support growth acting as a sole carbon and energy source of at least one of the two studied strains. Production of short-chain fatty acids (SCFAs) as detected by HPLC analysis corroborated the suitability of most of the studied novel oligosaccharides as fermentable growth substrates for the two bifidobacterial strains, showing that acetic acid is the main metabolic end product followed by lactic and formic acids. Transcriptomic and functional genomic approaches carried out for B. breve UCC2003 allowed the identification of key genes encoding glycoside hydrolases and carbohydrate transport systems involved in the metabolism of 4-galactosyl-kojibiose and lactulosucrose. In particular, the role of β-galactosidases in the hydrolysis of these particular trisaccharides was demonstrated, highlighting their importance in oligosaccharide metabolism by human bifidobacterial strains.

中文翻译：

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人源短双歧杆菌UCC2003和长双歧杆菌NCIMB 8809代谢生物合成寡糖。

这项工作旨在研究两种人源双歧杆菌菌株，即短双歧杆菌UCC2003和长双歧杆菌NCIMB 8809，利用各种寡糖（即4-半乳糖基-曲霉二糖，乳果糖，乳糖基-寡果糖苷，棉子糖基-寡果糖苷和棉子糖基-寡果糖苷）的能力。微生物半乳糖苷水解酶的合成）。除了棉子糖基-低聚果糖苷外，这些生物合成的低聚糖被证明支持生长，这是所研究的两种菌株中至少一种的唯一碳和能源。通过HPLC分析检测到的短链脂肪酸（SCFA）的产生，证实了大多数已研究的新型寡糖作为两种双歧杆菌菌株可发酵生长底物的适用性，表明乙酸是主要的代谢终产物，其次是乳酸和甲酸。为短双歧杆菌UCC2003进行的转录组学和功能基因组学方法鉴定了编码参与4-半乳糖基-曲霉二糖和乳果​​糖代谢的糖苷水解酶和碳水化合物转运系统的关键基因。特别地，证明了β-半乳糖苷酶在这些特定的三糖的水解中的作用，突出了它们在人双歧杆菌菌株的寡糖代谢中的重要性。简而言之，UCC2003允许鉴定编码参与4-半乳糖基-曲二糖和乳果​​糖代谢的糖苷水解酶和碳水化合物转运系统的关键基因。特别地，证明了β-半乳糖苷酶在这些特定的三糖的水解中的作用，突出了它们在人双歧杆菌菌株的寡糖代谢中的重要性。简而言之，UCC2003允许鉴定编码参与4-半乳糖基-曲二糖和乳果​​糖代谢的糖苷水解酶和碳水化合物转运系统的关键基因。特别地，证明了β-半乳糖苷酶在这些特定的三糖的水解中的作用，突出了它们在人双歧杆菌菌株的寡糖代谢中的重要性。