发酵木糖生产乙醇的野生菌和转基因菌的研究进展

木糖发酵是利用植物纤维原料生物转化制取乙醇工业化生产的技术基础和关键。野生酵母中有些种属菌株可以高效利用木糖产生乙醇，其中毕赤酵母（Pichiastipim）的乙醇转化速度最高达到0．99g／L／h，转化率几乎接近理论值0．5g／g，发酵液中最高乙醇浓度可迭到（61±9）g／L。但工业生产中要达到毕赤酵母所要求的微氧最佳发酵条件比较困难。近十几年来许多研究尝试根据代谢工程原理，利用基因工程技术对酿酒酵母进行改造。从而提高其发酵木糖产生乙醇的能力。这些研究大多是将毕赤酵母的一些木糖发酵关键酶基因（XYL1、XYL2、XYL3以及ADHl、ADH2等）转入酿酒酵母细胞内，并试图得到正常转录和表达。但到目前为止，大部分的重组菌株的乙醇发酵性能还没有达到工业生产的要求。

Study on the Ethanol Fermentation from Xylose by Wild Yeasts and Genetically Engineered Strains

Efficient fermentation of xylose is essential to ethanol production from biomass. Some wild yeast strains can convert xylose to ethanol effectively. Among them, productivity 0.99 g/L/h, yield 0.5 g/g, and ethanol concentration （61±9） g/L were archived by Pichia stipitis. But it is difficult to reach the limited oxygen demanded by Pichia stipitis in industrial level. During last two decades, many researchers tried to enhance the xylose fermenting ability of Saccharomyces cerevisiae using genitival engineering technology. Some key genes from pichia stipitis including XYL1, XYL2 ,XYL3 ,ADH1 and ADH2, were cloned into Saccharomyces cerevisiae strains. But until now, the fermentation performance of modified strains could not reach the request of industrial ethanol production.