Ionic nutrition of yeast-physiological mechanisms involved and implications for biotechnology

Saccharomyces cerevisiae and other yeasts are used widely in traditional industries and are subject to increasing frequency of use in the new biotechnology industries. With this in mind, the mechanisms regulating ion uptake and nutrition in yeast are discussed. A lack of industrially relevant studies is painfully evident, and this review has endeavored to interpret the results of the more fundamental studies that have been conducted over the years. The cyclical nature of ion transport is raised as a major factor regulating the growth of yeast, as is the role of cell vacuolar compartments in the storage of excess cationic and anionic species. The role of pH in the regulation of ion uptake is also discussed and possible mechanisms for overcoming some forms of ionic inhibition are raised. The need for further studies of specific interest to the industrial cultivation of yeast is stressed.