Processes involved in the creation of buffering capacity and in substrate-induced proton extrusion in the yeast Saccharomyces cerevisiae

New applications of pHluorin—measuring intracellular pH of prototrophic yeasts and determining changes in the buffering capacity of strains with affected potassium homeostasis

“…When the capacity of the proton transporters is overloaded, intracellular biochemical processes can further extend cell-buffering capabilities. The buffering capacity of yeast cell-free extract was previously studied by two groups (Kresnowati et al, 2008;Sigler et al, 1981), who stated the amounts of acid or base necessary to change the pH of the cytosolic fluid without the influence of biological processes. We have for the first time developed a method of measuring yeast cell buffering capacity in vivo, by quantifying the short-term effects of weak base addition.…”

Quantitative Study of Yeast Growth in the Presence of Added Ethanol and Methanol Using a Calorimetric Approach

“…5) show that the pH decrease with time was slowed down by the presence of ethanol, effect that was visible both in the slope of the pH curve and in the time required to reach a certain pH value. The explanation may be based on the fact that the acidification process is accomplished with the contribution of many mechanisms, 22,23) such as CO 2 production, organic acid release by cells in the medium, and active proton efflux, and all these processes are slowed down if a delay in growth takes place. The fact that in our experiments the final pH was not influenced by the ethanol concentration is probably due to the much larger buffering capacity of the growth medium we used.…”

Ammonium acceleration of glycolysis in the ethanol fermentation in a high corn system.

“…level (18,19). It was unexpected that the addition of (NH4)2SO4 would result in such a strong expulsion of protons or that the high corn system would be unable to buffer the additional proton load.…”