己糖转运蛋白在酿酒酵母生长与酒精发酵中的作用

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

酿酒酵母(Saccharomyces cerevisiae)的生长和发酵与其己糖转运蛋白家族紧密相关。酵母己糖转运蛋白家族包括Hxt1p至Hxt17p、Gal2p、以及同源蛋白Snf3p和Rgt2p这两个葡萄糖感应器。其中Hxt1p～Hxt7p对酵母生长及发酵发挥重要作用,缺失这7个蛋白的酵母无法从培养基中摄取己糖进行生长和发酵。根据对己糖的亲和力的不同,这几个转运蛋白可分为低亲和力转运子,包括Hxt1p和Hxt3p;高亲和力转运子,包括Hxt6p和Hxt7p;以及中等亲和力转运子Hxt2p和Hxt4p;而Hxt5p在生长发酵过程中没有发现有任何诱导表达。本文介绍了Hxt1p～Hxt7p等己糖转运蛋白在酵母生长发酵不同阶段中所发挥的作用,以期为构建高乙醇发酵效率的工业酵母菌株提供参考。

The growth and fermentation of Saccharomyces cerevisiae is close related to its hexose transporter family. The hexose transporter family of S.cerevisiae includes Hxtlp-Hxtl7p,Ga12p,and two homologue proteins Snf3p and Rgt2pas glucose ,sensors. Among these transporters only Hxtlp-HxtTp 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,Hxtlp and Hxt3p are low-affinity transporters;Hxt6p and Hxt7p are high-afflnity 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 Hxtlp-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.