The following picture shows the process of fermentation occurring in Megasphaera elsdenii. This bacterium:

The fermentation pattern of Megasphaera exhibits the following features:

  1. pyruvate is used as an oxidising agent, performing the functions of electron acceptor to enable glycolysis to coninue and so to allow continued ATP generation by substrate level phosphorylation.
  2. the two reactions labelled 2 on the previous diagram are linked by the cycling of acetyl CoA and acetate. This saves on the use of ATP and enables further dumping of reducing equivalents to generate propionate as the waste end product organic acid.
Propionate is used to make glucose in the liver of the host ruminant.