Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
Int J Food Microbiol. 2013 Aug 1;165(3):241-5. doi: 10.1016/j.ijfoodmicro.2013.05.015. Epub 2013 May 28.
During the bread-making process, yeast cells are exposed to many types of baking-associated stress. There is thus a demand within the baking industry for yeast strains with high fermentation abilities under these stress conditions. The POG1 gene, encoding a putative transcription factor involved in cell cycle regulation, is a multicopy suppressor of the yeast Saccharomyces cerevisiae E3 ubiquitin ligase Rsp5 mutant. The pog1 mutant is sensitive to various stresses. Our results suggested that the POG1 gene is involved in stress tolerance in yeast cells. In this study, we showed that overexpression of the POG1 gene in baker's yeast conferred increased fermentation ability in high-sucrose-containing dough, which is used for sweet dough baking. Furthermore, deletion of the POG1 gene drastically increased the fermentation ability in bread dough after freeze-thaw stress, which would be a useful characteristic for frozen dough baking. Thus, the engineering of yeast strains to control the POG1 gene expression level would be a novel method for molecular breeding of baker's yeast.
在面包制作过程中，酵母细胞会暴露在许多与烘焙相关的压力下。因此，烘焙行业需要具有高发酵能力的酵母菌株，以适应这些压力条件。POG1 基因编码一种与细胞周期调控有关的假定转录因子，是酵母酿酒酵母 E3 泛素连接酶 Rsp5 突变体的多拷贝抑制子。 pog1 突变体对各种应激敏感。我们的研究结果表明，POG1 基因参与酵母细胞的应激耐受。在这项研究中，我们表明，在面包酵母中过表达 POG1 基因可赋予其在高蔗糖含量面团中的高发酵能力，而高蔗糖含量面团用于甜面团烘焙。此外，POG1 基因缺失可显著提高冷冻-解冻应激后面团的发酵能力，这对冷冻面团烘焙是一个有用的特性。因此，控制酵母菌株中 POG1 基因表达水平的工程将是面包酵母分子育种的一种新方法。
