Zheng Daoqiong, Zhang Ke, Gao Kehui, Liu Zewei, Zhang Xing, Li Ou, Sun Jianguo, Zhang Xiaoyang, Du Fengguang, Sun Peiyong, Qu Aimin, Wu Xuechang
Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China.
State Key Laboratory of Motor Vehicle Biofuel Technology (Tianguan Group Co., Ltd.), Nanyang, Henan Province, China.
PLoS One. 2013 Dec 23;8(12):e85022. doi: 10.1371/journal.pone.0085022. eCollection 2013.
The application of active dry yeast (ADY) in bioethanol production simplifies operation processes and reduces the risk of bacterial contamination. In the present study, we constructed a novel ADY strain with improved stress tolerance and ethanol fermentation performances under stressful conditions. The industrial Saccharomyces cerevisiae strain ZTW1 showed excellent properties and thus subjected to a modified whole-genome shuffling (WGS) process to improve its ethanol titer, proliferation capability, and multiple stress tolerance for ADY production. The best-performing mutant, Z3-86, was obtained after three rounds of WGS, producing 4.4% more ethanol and retaining 2.15-fold higher viability than ZTW1 after drying. Proteomics and physiological analyses indicated that the altered expression patterns of genes involved in protein metabolism, plasma membrane composition, trehalose metabolism, and oxidative responses contribute to the trait improvement of Z3-86. This work not only successfully developed a novel S. cerevisiae mutant for application in commercial bioethanol production, but also enriched the current understanding of how WGS improves the complex traits of microbes.
活性干酵母（ADY）在生物乙醇生产中的应用简化了操作流程并降低了细菌污染风险。在本研究中，我们构建了一种新型ADY菌株，其在压力条件下具有更高的胁迫耐受性和乙醇发酵性能。工业酿酒酵母菌株ZTW1表现出优异的特性，因此对其进行改良的全基因组重排（WGS）过程，以提高其乙醇产量、增殖能力以及用于生产ADY时的多重胁迫耐受性。经过三轮WGS后获得了性能最佳的突变体Z3-86，其乙醇产量比ZTW1高4.4%，干燥后活力比ZTW1高2.15倍。蛋白质组学和生理学分析表明，参与蛋白质代谢、质膜组成、海藻糖代谢和氧化应激反应的基因表达模式改变有助于Z3-86的性状改善。这项工作不仅成功开发了一种新型酿酒酵母突变体用于商业生物乙醇生产，还丰富了目前对WGS如何改善微生物复杂性状的认识。
