Roles of Hexose Transporters to the Growth and Alcoholic Fermentation of Saccharomyces cerevisiae

The growth and fermentation of Saccharomyces cerevisiae is close related to its hexose transporter family.The hexose transporter family of S.cerevisiae includes Hxt1p-Hxt17p,Gal2p,and two homologue proteins Snf3p and Rgt2p as glucose sensors.Among these transporters only Hxt1p-Hxt7p are essential for the growth and fermentation,the strain without expression of these 7 transporters has a deficiency in hexose uptake for growth or fermentation.These transporters are classified by their hexose affinities,Hxt1p and Hxt3p are low-affinity transporters;Hxt6p and Hxt7p are high-affinity transporters;Hxt2p and Hxt4p are moderate-affinity transporters;and any induction of Hxt5p is not detectable during growth and fermentation.This paper gave out an overall introduction of the specific roles of these hexose transporters(mainly Hxt1p-Hxt7p)in different stages of the growth and fermentation of S.cerevisiae,in order to give some references in the construction of high ethanol productivity industrial yeast strains.