Metagenomic insights into the diversity of carbohydrate-degrading enzymes in the yak fecal microbial community

作者：Ga Gong, Saisai Zhou, Runbo Luo, Zhuoma Gesang, Sizhu Suolang · 发表于：BMC Microbiology · 年份：2020 · DOI：10.1186/s12866-020-01993-3 · 被引用次数：66 · 研究领域：Ruminant Nutrition and Digestive Physiology、Gut microbiota and health、Anaerobic Digestion and Biogas Production

BACKGROUND: Yaks are able to utilize the gastrointestinal microbiota to digest plant materials. Although the cellulolytic bacteria in the yak rumen have been reported, there is still limited information on the diversity of the major microorganisms and putative carbohydrate-metabolizing enzymes for the degradation of complex lignocellulosic biomass in its gut ecosystem. RESULTS: Here, this study aimed to decode biomass-degrading genes and genomes in the yak fecal microbiota using deep metagenome sequencing. A comprehensive catalog comprising 4.5 million microbial genes from the yak feces were established based on metagenomic assemblies from 92 Gb sequencing data. We identified a full spectrum of genes encoding carbohydrate-active enzymes, three-quarters of which were assigned to highly diversified enzyme families involved in the breakdown of complex dietary carbohydrates, including 120 families of glycoside hydrolases, 25 families of polysaccharide lyases, and 15 families of carbohydrate esterases. Inference of taxonomic assignments to the carbohydrate-degrading genes revealed the major microbial contributors were Bacteroidaceae, Ruminococcaceae, Rikenellaceae, Clostridiaceae, and Prevotellaceae. Furthermore, 68 prokaryotic genomes were reconstructed and the genes encoding glycoside hydrolases involved in plant-derived polysaccharide degradation were identified in these uncultured genomes, many of which were novel species with lignocellulolytic capability. CONCLUSIONS: Our fin...