School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada.
Bioresour Technol. 2011 Nov;102(21):9965-9. doi: 10.1016/j.biortech.2011.08.027. Epub 2011 Aug 10.
Two genome-shuffled Scheffersomyces stipitis strains, GS301 and GS302, exhibiting improved tolerance to hardwood spent sulphite liquor, were tested for growth and fermentation performance on three wood hydrolysates: (a) steam-pretreated enzymatically hydrolyzed poplar hydrolysate from Mascoma Canada, (b) steam pretreated poplar hydrolysate from University of British Columbia Forest Products Biotechnology Laboratory, and (c) mixed hardwoods pre-hydrolysate from FPInnovations (FPI). In the FPI hydrolysate, the wild type (WT) died off within 25 h, while GS301 and GS302 survived beyond 100 h. In fermentation tests, GS301 and GS302 completely utilized glucose and xylose in each hydrolysate and produced 0.39-1.4% (w/v) ethanol. In contrast, the WT did not utilize or poorly utilized glucose and xylose and produced non-detectable to trace amounts of ethanol. The results demonstrated cross tolerance of the mutants to inhibitors in three different wood hydrolysates and reinforced the utility of mating-based genome shuffling approach in industrial yeast strain improvement.
两株经基因组改组的毕赤酵母（Scheffersomyces stipitis）菌株 GS301 和 GS302，表现出对硬木亚硫酸盐废液更高的耐受性，被用于测试在三种木质水解物上的生长和发酵性能：（a）Mascoma 加拿大公司的蒸汽预处理酶解杨木水解物，（b）不列颠哥伦比亚大学林产品生物技术实验室的蒸汽预处理杨木水解物，和（c）FPInnovations（FPI）的混合硬木预水解物。在 FPI 水解物中，野生型（WT）在 25 小时内死亡，而 GS301 和 GS302 则存活超过 100 小时。在发酵测试中，GS301 和 GS302 完全利用了每种水解物中的葡萄糖和木糖，并产生了 0.39-1.4%（w/v）的乙醇。相比之下，WT 既没有利用或很差地利用葡萄糖和木糖，也没有产生可检测到的乙醇。这些结果表明突变体对三种不同木质水解物中的抑制剂具有交叉耐受性，强化了基于交配的基因组改组方法在工业酵母菌株改良中的应用。
