Responses of microbial community composition and CAZymes encoding gene enrichment in ensiled Elymus nutans to altitudinal gradients in alpine region

作者：Fuhou Li, Mengya Jia, Chen Hu, Mengyan Chen, Rina Su, Samaila Usman, Zitong Ding, Lizhuang Hao, Marcia Franco, Xusheng Guo · 发表于：Applied and Environmental Microbiology · 年份：2024 · DOI：10.1128/aem.00986-24 · 被引用次数：8 · 研究领域：Genomics and Phylogenetic Studies、Microbial Metabolic Engineering and Bioproduction、Gut microbiota and health

ABSTRACT High-throughput metagenomic sequence technology was employed to evaluate changes in microbial community composition and carbohydrate-active enzymes encoding gene enrichment status in Elymus nutans silages to altitudinal gradients in the world’s highest alpine region of Qinghai-Tibetan Plateau (QTP). E. nutans were collected from three different altitudes in QTP: 2,600 m (low altitude), 3600 m (moderate altitude), and 4,600 m [high (H) altitude], and ensiled for 7, 14, 30, and 60 d. Results indicated an improvement in silage quality with the increasing altitude, although the acetic acid concentration and dry matter loss were greater in H altitude silages after 30 d of ensiling. Harmful bacteria or potential pathogens predominated in the microbial community on d 7 and 14 of fermentation, while genera belonging to lactic acid bacteria gradually became the main microorganisms with the increasing altitude on d 30 and 60 of ensiling. The abundance of carbohydrate-active enzymes genes responsible for macromolecular carbohydrate degradation in silage increased with increasing altitude, and those genes were mainly carried by Lactiplantibacillus and Pediococcus at 30 and 60 d of ensiling. The abundance of key enzymatic genes associated with glycolysis and organic acid production in carbohydrate metabolism pathway was higher in H altitude silages, and Lactiplantibacillus and Pediococcus were also the main hosts after 30 d of silage fermentation, except for the fact that acetic ...