SUMMARY: Trehalose, a storage sugar of baker's yeast, is known not to be metabolized when added to a cell suspension in water or a growth medium and to support growth only after a lag of about 10 h. However, it was transported into cells by at least two transport systems, the uptake being active, with a pH optimum at 5·5. There was no stoicheiometry with the shift of protons into cells observed at high trehalose concentrations. Trehalose remained intact in cells and was not appreciably lost to a trehalose-free medium. The uptake systems were present directly after growth on glucose, then decayed with a half-life of about 25 min but could be reactivated by aerobic incubation with trehalose, maltose, α-methyl-D-glucoside, glucose or ethanol. The uptake systems thus induced were different as revealed by competition experiments. At least one of the systems for trehalose uptake showed cooperative kinetics. Comparative analysis with other disaccharides indicated the existence in Saccharomyces cerevisiae, after induction with trehalose, of at least four systems for the uptake of α-methyl-D-glucoside, four systems for maltose, together with the two for trehalose, variously shared by the sugars, the total of α-glucoside-transporting systems being five.
GörtsC. P. M.1969; Effect of glucose on the activity and the kinetics of the maltose uptake system and of α-glucosidase in Saccharomyces cerevisiae. Antonie van Leeuwenhoek 35:233–234
HolzerH.1977; Function and regulation of yeast intracellular proteinases.. In EUCHEM Conference on Metabolic Reactions in the Yeast Cell, Helsinki, pp. 21–22
HorákJ.,
KotykA.,
ŘíhováL.1978; Stimulation of amino acid transport in Saccharomyces cerevisiae by metabolic inhibitors. Folia micro-biologica 23:286–291
KotykA.,
MichaljaničováD.1974; Nature of uptake of d-galactose, d-glucose and α-methyl-d-glucoside by Saccharomyces cerevisiae. Biochimica et biophysica acta 332:104–113
OkadaH.,
HalvorsonH. O.1964; Uptake of α-thioethyl-d-pyranoside by Saccharomyces cerevisiae. II. General characteristics of an active transport system. Biochimica et biophysica acta 82:547–555
SiroM. R.,
HauteraP.,
LövgrenT.1977; Influence of glucose on the maltose uptake of Saccharomyces cerevisiae.. In EUCHEM Conference on Metabolic Reactions in the Yeast Cell, Helsinki, pp. 61–62
ZimmermannF. K.,
KhanN. A.,
EatonN. R.1973; Identification of new genes involved in disaccharide fermentation in yeast. Molecular and General Genetics 123:29–41