Armin Fiechter

Regulation of oxidoreductive yeast metabolism by extracellular factors

Abstract Since antiquity man has consumed ethanol produced by yeast as sugars are metabolized. Industrial alcohol and alcoholic beverages play major roles in our economy. Although the processes have been anaerobic except for the beneficial introduction of a trace of air or oxygen, the focus may shift to a novel approach to yeast bioprocessing using recent understanding of the aerobic ethanol production. In this minireview, we address glycolysis, oxidoreductive metabolism, and ion transport in yeast, and we introduce high-rate bioprocess control strategies that hinge on the effects of ionic composition. Consideration of maintenance requirements for glycolysis leads to an assessment of the role of monitoring and control of ionic concentrations for optimization of ethanol production.