文档介绍：: .
食品与发酵工等 UDP-葡萄糖的其他消耗途径，积累更多的
UDP-葡萄糖用于目的产物-葡聚糖的合成。除此之外，通过引入木糖还原酶基因 xyl1，木糖醇脱氢酶基因 xyl2 和木
***糖激酶基因 xyl3，构建了木糖氧化还原途径；进一步通过过表达转运蛋白 Hxt7（F79S），敲除 snf1 基因，提高了
对木糖的利用能力，并最终将-葡聚糖的产量提高至 mg/g。最后，利用半乳糖诱导型启动子 Pgal1 动态调控内切
葡聚糖酶基因（eng1）表达，使酿酒酵母中-葡聚糖的分子质量从 1×106 ~2×106 g/mol 降低至 ×105 g/mol，实现
了低分子质量-葡聚糖的高效合成，为-葡聚糖的生产提供了重要参考。
关键词 酿酒酵母；-葡聚糖；代谢工程；木糖-葡萄糖共利用；分子质量
DOI: .11-1802/
Metabolic engineering of Saccharomyces cerevisiae to synthesize -glucan
efficiently
LI Xi1,2, YU Wenwen1,2, LYU Xueqin 1,2, LIU Yanfeng 1,2, LI Jianghua 1,2, DU Guocheng 1,2, CHEN Jinghua1,2,
LIU Long1,2
1 (Science Center for Future Foods, Jiangnan University, Wuxi 214122, China)
2 (Key Laboratory of Carbohydrate Chemistry and Biotechnology, Jiangnan University, Wuxi 214122, China)
Abstract -glucan is a polysaccharide found in the cell wall of yeast. It has important anti-inflammatory and antioxidant
properties. To increase the production of -glucan in Saccharomyces cerevisiae, this study used a "push-pull-inhibit" strategy,
which is commonly used in metabolic engineering. Firstly, we have overexpressed the key enzyme FKS1 and its regulatory
subunits Rho1 in in -glucan synthesis pathway in . After increasing their copy numbers, the key precursor UDP-
glucose were "pulled" towards the -glucan synthesis pathway. Secondly, via enhancing the precursor UDP-glucose pathway
enzymes, the metabolic flux was "pushed" towards the pathway. Finally, other UDP-glucose consumption pathways such as
protein glycosylation were inhibited. More UDP-glucose were accumulated for the synthesis of the target produc