Relationship of Potassium Ion Transport to Metabolism in Acid-Induced Fermentation in Yeast. ∗

Summary

1. In acid-induced fermentation in commercial baker's yeast, no direct relationship was seen between acid penetration and K+ uptake. A dependency of K+ uptake on metabolism was seen, however. 2. Evidence is presented in support of the concept of an “active” process in the transport of K+ into yeast. This evidence conflicts with recent contentions of a “passive” process in K+ transport in yeast. 3. A direct approach may be afforded to studies of energy expenditure by the yeast cell and K+ transport.