Syntrophy often involves: A. hydrogen B.Oxygen C. fermentation byproducts D. all of the above E. all but B Solution Syntrophy is a phenomenon where one species lives off the products of other species. The examples are Hydrogen transfer and fermentation byproducts. In syntrophic association, one partner growth depends on the nutrients provided by other partner. Interspecies hydrogen transfer is an excellent example of Syntrony. Some fermenting microbes degrade organic matter to short chain fatty acids and hydrogen..