Fsy1, the sole hexose-proton transporter characterized in Saccharomyces yeasts, exhibits a variable fructose:H(+) stoichiometry.

In the model yeast Saccharomyces cerevisiae, hexose uptake is mediated exclusively by a family of facilitators (Hxt, hexose transporters). Some other Saccharomyces species (e.g.

L-Arabinose transport and catabolism in yeast.

Two yeasts, Candida arabinofermentans PYCC 5603(T) and Pichia guilliermondii PYCC 3012, which show rapid growth on L-arabinose and very high rates of L-arabinose uptake on screening, were selected for characterization of L-arabinose transport and the first steps of intracellular L-arabinose metabolism. The kinetics of L-arabinose uptake revealed at least two transport systems with distinct substrate affinities, specificities, functional mechanisms and regulatory properties. The L-arabinose catabolic pathway proposed for filamentous fungi also seems to operate in the yeasts studied.

Differential regulation by glucose and fructose of a gene encoding a specific fructose/H+ symporter in Saccharomyces sensu stricto yeasts.

Saccharomyces cerevisiae transports fructose through a facilitated diffusion system common to other hexoses and mediated by the Hxt proteins. The related species S. pastorianus (carlsbergensis) and S.