Sabater Carlos, Ruiz Lorena, Margolles Abelardo
Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias (IPLA), Consejo Superior de Investigaciones Científicas (CSIC), Paseo Río Linares S/N, 33300 Villaviciosa, Asturias, Spain.
Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Asturias, Spain.
Microorganisms. 2021 May 11;9(5):1034. doi: 10.3390/microorganisms9051034.
This study aimed to recover metagenome-assembled genomes (MAGs) from human fecal samples to characterize the glycosidase profiles of species exposed to different prebiotic oligosaccharides (galacto-oligosaccharides, fructo-oligosaccharides and human milk oligosaccharides, HMOs) as well as high-fiber diets. A total of 1806 MAGs were recovered from 487 infant and adult metagenomes. Unsupervised and supervised classification of glycosidases codified in MAGs using machine-learning algorithms allowed establishing characteristic hydrolytic profiles for , , , and , yielding classification rates above 90%. Glycosidase families GH5 44, GH32, and GH110 were characteristic of . The presence or absence of GH1, GH2, GH5 and GH20 was characteristic of , and , while families GH1 and GH30 were relevant in MAGs from . These characteristic profiles allowed discriminating bifidobacteria regardless of prebiotic exposure. Correlation analysis of glycosidase activities suggests strong associations between glycosidase families comprising HMOs-degrading enzymes, which are often found in MAGs from the same species. Mathematical models here proposed may contribute to a better understanding of the carbohydrate metabolism of some common bifidobacteria species and could be extrapolated to other microorganisms of interest in future studies.
本研究旨在从人类粪便样本中恢复宏基因组组装基因组(MAG),以表征暴露于不同益生元寡糖(低聚半乳糖、低聚果糖和人乳寡糖,HMO)以及高纤维饮食的物种的糖苷酶谱。从487个婴儿和成人宏基因组中总共恢复了1806个MAG。使用机器学习算法对MAG中编码的糖苷酶进行无监督和有监督分类,能够为双歧杆菌属、拟杆菌属、粪杆菌属和普雷沃菌属建立特征性水解谱,分类率超过90%。糖苷酶家族GH5_44、GH32和GH110是双歧杆菌属的特征。GH1、GH2、GH5和GH20的存在与否是拟杆菌属、粪杆菌属和普雷沃菌属的特征,而GH家族GH1和GH30在来自普雷沃菌属的MAG中具有相关性。这些特征谱能够区分双歧杆菌,而不考虑益生元暴露情况。糖苷酶活性的相关性分析表明,包含HMO降解酶的糖苷酶家族之间存在强关联,这些家族通常存在于同一物种的MAG中。这里提出的数学模型可能有助于更好地理解一些常见双歧杆菌物种的碳水化合物代谢,并可在未来研究中推广到其他感兴趣的微生物。