Reductive acetogenesis is a dominant process in the ruminant hindgut

• DOI: 10.1186/s40168-024-02018-1
• Publication Date: 2025-01-28T08:59:36Z
• Authors: Qiushuang Li; Jiabin Huo; Gaofeng Ni; Fan Zhang; Shizhe Zhang; Xiumin Zhang; Rong Wang; Jinzhen Jiao; Zhongtang Yu; Xuanxuan Pu; Yipeng Yue; Emilio M. Ungerfeld; Xiaoli Zhang; Jian Wu; Zhiliang Tan; Chris Greening; Min Wang
• Keywords: Hindgut; Acetogenesis

The microbes residing in ruminant gastrointestinal tracts play a crucial role converting plant biomass to volatile fatty acids, which serve as the primary energy source for ruminants. This tract comprises foregut (rumen) and hindgut (cecum colon), differ structures functions, particularly with respect feed digestion fermentation. While rumen microbiome has been extensively studied, cecal remains much less investigated understood, especially concerning assembling microbial communities overriding pathways of hydrogen metabolism. To address this gap, we comparatively composition, capabilities, activities cecum using goats an experimental model. In situ measurements showed significantly higher levels dissolved acetate than rumen. Increased indicated distinct processes reduced coupling between fermentative H2 production utilization, whereas could be caused by slower VFA absorption through papillae papillae. Microbial profiling that harbors greater abundance mucin-degrading producers, contains fibrolytic bacteria, hydrogenotrophic respiratory methanogenic archaea. Most strikingly, reductive acetogenic bacteria were 12-fold more abundant cecum. Genome-resolved metagenomic analysis unveiled acetogens are both phylogenetically functionally from those found Further supporting these findings, two vitro experiments demonstrated marked difference metabolism rumen, increased methanogenesis Moreover, comparative across multiple species confirmed strong enrichment hindguts, suggesting conserved functional role. These findings highlight acetogenesis key region reshape our understanding how can managed accord livestock methane mitigation efforts.