Microbial-Rich Niches in Herbivores

Herbivorous animals rely on their gastrointestinal microbiota to derive nutrients from plant biomass which in addition to cell wall polysaccharides contain various other phytochemicals. Among herbivorous vertebrates, ruminants possess a complex rumen microbial ecosystem involved in enzymatic degradation and fermentation of fibrous dietary forage, utilization of non-protein nitrogen (NPN) to synthesize microbial proteins, and degrade toxic phytochemicals. Rumen microbiome comprises all microbiological domains viz., Eucarya, methanogenic Archaea, Bacteria, and phages. Non-ruminant herbivores or hindgut fermenters have microorganisms-enriched caecum, though they are less efficient utilizers of plant components. Short-chain fatty acids (SCFAs), oligosaccharides, microbial proteins, peptides, CO2, H2, NH3, and CH4 are major end products of digested plant biomass.