Construction of a xylan-fermenting yeast strain through codisplay of xylanolytic enzymes on the surface of xylose-utilizing Saccharomyces cerevisiae cells
Construction of a xylan-fermenting yeast strain through codisplay of xylanolytic enzymes on the surface of xylose-utilizing Saccharomyces cerevisiae cells
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DOI：
10.1128/aem.70.9.5407-5414.2004
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发表时间：
2004-09-01
影响因子：
4.4
通讯作者：
Kondo, A
中科院分区：
文献类型：
--
作者：
Katahira, S;Fujita, Y;Kondo, A
半纤维素是木质纤维素的主要生物质形式之一，其主要成分是木聚糖。我们使用基于α-凝集素的细胞表面工程系统构建了一株酿酒酵母菌株，该酵母菌株在细胞表面共展示两种类型的木聚糖降解酶，即里氏木霉QM 9414的木聚糖酶11（XYNII）和曲霉NiaD 300的β-木糖苷酶（XyIA）。在高效液相色谱分析中，检测到木糖作为共展示XYNII和XyIA的酵母菌株的主要产物，而检测到木二糖和木三糖作为在细胞表面上展示XYNII的酵母菌株的主要产物。这些结果表明，木聚糖被共展示的XYNII和XylA依次水解成木糖。在实现木聚糖的同时糖化和发酵的进一步步骤中，利用木聚糖的S.通过共展示XYNII和XyIA并引入木糖利用基因，即来自树干毕赤酵母的编码木糖还原酶和木糖醇脱氢酶的基因和来自S.啤酒。发酵62小时后，从桦木木聚糖中直接生产出每升7.1克乙醇，并且以每克消耗的碳水化合物的乙醇克数计的产率为0.30克/克。这些结果表明，木聚糖直接转化为乙醇是由利用木聚糖的S。酿酒酵母菌株
Hemicellulose is one of the major forms of biomass in lignocellulose, and its essential component is xylan. We used a cell surface engineering system based on alpha-agglutinin to construct a Saccharomyces cerevisiae yeast strain codisplaying two types of xylan-degrading enzymes, namely, xylanase 11 (XYNII) from Trichoderma reesei QM9414 and beta-xylosidase (XyIA) from Aspergillus oryzae NiaD300, on the cell surface. In a high-performance liquid chromatography analysis, xylose was detected as the main product of the yeast strain codisplaying XYNII and XyIA, while xylobiose and xylotriose were detected as the main products of a yeast strain displaying XYNII on the cell surface. These results indicate that xylan is sequentially hydrolyzed to xylose by the codisplayed XYNII and XylA. In a further step toward achieving the simultaneous saccharification and fermentation of xylan, a xylan-utilizing S. cerevisiae strain was constructed by codisplaying XYNII and XyIA and introducing genes for xylose utilization, namely, those encoding xylose reductase and xylitol dehydrogenase from Pichia stipitis and xylulokinase from S. cerevisiae. After 62 h of fermentation, 7.1 g of ethanol per liter was directly produced from birchwood xylan, and the yield in terms of grams of ethanol per gram of carbohydrate consumed was 0.30 g/g. These results demonstrate that the direct conversion of xylan to ethanol is accomplished by the xylan-utilizing S. cerevisiae strain.