Meta-functional genomics of the bovine rumen

Abstract

Scope and Method of Study:

Findings and Conclusions:

Rumen microbes play an important role in nutrient digestion. The synergistic relationship between the bacteria within the rumen and the animal provides ruminants with nutrients that are not available to monogastric animals. This relationship between the animal and rumen microbes is a complex relationship. Understanding this relationship and the functional role of these microbes within the rumen is of critical importance. However, the current understanding of the diversity and functional role of rumen bacterial species is very limited as most existing studies were based on culture dependent techniques while around 99.9% of the rumen bacteria are resistant to in-vitro culture. In an effort to better understand rumen microbial population diversity and function, we undertook a meta-genomics approach to analyze rumen biome. We have analyzed real-time population fluctuations within the rumen during the adaptation of an animal to a high concentrate diet from a forage-based diet, during ionophore treatment and also as an animal develops acidosis, an important metabolic disorder in cattle, using TRFLP analyses, sequence analysis of 16S rDNA libraries and by real-time PCR analysis. We also performed a large-scale, community level transcriptome, analysis of the rumen microbes using a pyro-sequencing strategy combined with several bioinfomatic approaches. This helped us better understand the functional role of bacteria within communities as well as determine the rate of metabolic pathways within the rumen. Finally, we have in-vitro cultured and biochemically characterized several previously unknown rumen microbes.