Microbial Interactions in the Rumen and Their Potential Impact on the Survival of Escherichia coli O157

Cellulose and other plant fibre polymers are fermented in the rumen by a cellulolytic biofilm containing a complex mixture of microbial species. Polymer hydrolysis and fermentation are accompanied by the release of plant secondary “defence” chemicals such as tannins, saponins and coumarins. The release and microbial transformation of these compounds [4] modifies the gut environment and the processes therein. Although ruminants have traditionally been seen as “mobile fermentors” [11], there is increasing awareness of their contribution to global warming through methane production and their possible role as reservoirs for pathogens such as Escherichia coli O157.