Comparison of glucose uptake kinetics in different yeasts.

The kinetics of glucose uptake were investigated in laboratory wild-type strains of Saccharomyces cerevisiae of differing genetic backgrounds, in other species of Saccharomyces, and in other yeasts, both fermentative and respiratory. All yeasts examined displayed more than one uptake system for glucose. Variations in apparent Km values, velocity of uptake, and effects of glucose concentration on carrier activity were observed. The three type strains for the species S. cerevisiae, Saccharomyces bayanus, and Saccharomyces carlsbergensis gave distinctive patterns, and each of the laboratory strains was similar to one or another of the type strains. Other fermentative yeasts (Pichia guillermondi and Pichia strasburgensis) regulated glucose uptake in a manner similar to that of Saccharomyces spp. Such was not true for the respiratory yeasts investigated, Pichia heedi and Yarrowia lipolytica, which did not demonstrate glucose repression of carrier activity; this finding suggests that this mechanism of control of transporter activity may be associated with fermentative ability.