酿酒酵母木糖发酵酒精途径工程的研究进展

途径工程(Pathway engineering)，被称为第三代基因工程，改变代谢流向,开辟新的代谢途径是途径工程的主要目的。利用途径工程理念，对酿酒酵母（Saccharomyces cerevisiae）代谢途径进行理性设计，以拓展这一传统酒精生产菌的底物范围，使其充分利用可再生纤维质水解物中的各种糖分，是酿酒酵母酒精途径工程的研究热点之一。这里介绍了近年来酿酒酵母以木糖为底物的酒精途径工程的研究进展。

Progress in the Pathway Engineering of Ethanol Fermentation from Xylose Utilising Recombinant Saccharomyces cerevisiae

Pathway engineering was the third generation of gene engineering. Its main goals were to change metabolic flux and open a new metabolic pathway in organism. Application of recombinant DNA methods to restructure metabolic networks can improve production of metabolite and protein products by altering pathway distributions and rates. Ethanol is the most advanced liquid fuel because it is environmentally friendly. Enhancing fuel ethanol production will require developing lower cost feedstock, and only lignocellulosic feedstock is available in sufficient quantities to substitute for corn starch. Xylose is the major pentose found in lignocellulosic materials and after glucose the most abundant sugar available in nature. Recently a lot of attentions have been focused on designing metabolic pathway of Saccharomyces cerevisiae in order to expand the substrate of ethanol fermentation, because it is a traditional ethanol producing strain and has wonderful properties for ethanol industry. However, it can not utilize xylose but convert the isomer, xylulose. Many attempts are based on introducing the genes in the pathway of xylose metabolism. The further research includes overexpressing the key enzyme or decreasing the unimportant flux. The sugars in lignocellulose hydrolyzates, therefore, could be efficiently utilized. Here, we describe the ethanol pathway engineering progress in ethanol fermentation from xylose with recombinant %Saccharomyces cerevisiae%.