ACTIVATION OF THE POTASSIUM UPTAKE SYSTEM DURING FERMENTATION IN SACCHAROMYCES-CEREVISIAE

Fermentable sugars activated the K+ uptake system, increasing the V(max)s of Rb+, Na+, and Li+ influxes, but sugars did not affect the effluxes of these cations. This activation seems to be a direct effect of fermentation and not the consequence of the H+ pump ATPase activation or internal pH decrease produced by fermentation.