It is interesting to compare the flow of carbon in the ruminant with that of the anaerobic digester. In the animal the main source of methane is H2/CO2; little comes from acetate. The acetate passes through the intestinal wall to enter the bloodstream, where it is aerobically metabolized as a primary carbon and energy source. That's the "idea" of being a ruminant. In the AD, approx. 2/3 of the methane comes from acetate and most of the remainder from H2/CO2. Where else would the acetate and other simple breakdown products go?
Mel > I also noticed in an earlier post the comment about methanogens being > present in our digestive tract (I agree that they are), but why? I think > it > has been suggested they balance the H+ and H2 system so our digestive > system > can operate (so they may be "good" bugs) but it may also be that we > provide > an environment for their survival so they compete for nutrients. I know > CSIRO have done work on reducing methane emissions from cattle so I will > try > to follow that up and I will also ask a gastroenterology colleague here as > well, but comments are welcome. _______________________________________________ Digestion mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org for more information about digestion, see Beginner's Guide to Biogas http://www.adelaide.edu.au/biogas/ and the Biogas Wiki http://biogas.wikispaces.com/
