Acceleration of the rate of fermentation by Saccharomyces cerevisiae in the presence of ammonium ion

The rate of fermentation of both d-glucose and maltose in a defined medium by a brewing strain of Saccharomyces cerevisiae was found to be dependent on the availability of NH₄⁺. The glycolytic rate did not correlate with intracellular NH₄⁺ and activation by NH₄⁺ was blocked by cycloheximide. The ability of several amino acids to activate glycolysis followed the same order as their effectiveness as sole sources of nitrogen. It therefore seems that NH₄⁺ does not stimulate fermentation through direct activation of glycolytic enzymes, but through its function as a substrate for protein synthesis. © 1984.