Methanogenesis and Hydrogenotrophy in Ruminant Livestock

摘要

Methane is a potent greenhouse gas and is implicated in global warming.Ruminant livestock are the focus of mitigation strategies since they are the main source of anthropogenic methane emissions globally.Methanogenesis is a critical component of the energetically efficient process of anaerobic microbial degradation of plant cell walls in the digestive tract of ruminants.Management of H2 in the rumen is the most important factor to be considered when developing strategies to control ruminant methane emissions.We have been examining the effects of increased hydrogen concentration on digestion,fermentation and microbial communities in the rumen by using an anti-methanogenic compound to suppress methanogenesis.Recent studies on the diversity of rumen methanogens has demonstrated that this functional group is represented by several taxonomic orders including the Methanobacteriales,Methanomicrobiales,Methanosarcinales and a large group of uncultured archaea which are similar but distinct from the Thermoplasmatales.Through the use of metagenomic and culture based technologies,we have gained a better understanding of the physiology of these uncultured methanogens.These studies are providing new knowledge about hydrogenotrophic rumen microbial populations which will aid in the development of strategies to reduce methanogenesis.