School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
Research Institute of Food and Biotechnology, SPC Group Co., 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
Food Microbiol. 2025 Jan;125:104643. doi: 10.1016/j.fm.2024.104643. Epub 2024 Sep 13.
Saccharomyces cerevisiae SPC-SNU 70-1 is a commercial diploid baking yeast strain valued for its excellent bread-making qualities, including superior leavening capabilities and the production of flavor-enhancing volatile organic acids. Despite its benefits, this strain faces challenges in fermenting both lean (low-sugar) and sweet (high-sugar) doughs. To address these issues, we employed the CRISPR/Cas9 genome editing system to modify genes without leaving any genetic scars. For lean doughs, we enhanced the yeast's ability to utilize maltose over glucose by deleting a gene involved in glucose repression. For sweet doughs, we increased glycerol production by overexpressing glycerol biosynthetic genes and optimizing redox balance, thereby improving the tolerence to osmotic stress during fermentation. Additionally, the glycerol-overproducing strain demonstrated enhanced freeze tolerance, and bread made from this strain exhibited improved storage properties. This study demonstrates the feasibility and benefits of using engineered yeast strains, created solely by editing their own genes without introducing foreign genes, to enhance bread making.
酿酒酵母 SPC-SNU 70-1 是一种商业性的二倍体烘焙酵母菌株，因其出色的面包制作品质而备受重视，包括优异的发酵能力和产生风味增强的挥发性有机酸。尽管有这些优点，但该菌株在发酵低脂（低糖）和高糖面团时都面临挑战。为了解决这些问题，我们使用了 CRISPR/Cas9 基因组编辑系统来修饰基因，而不会留下任何遗传痕迹。对于低脂面团，我们通过删除一个参与葡萄糖抑制的基因，增强了酵母利用麦芽糖而不是葡萄糖的能力。对于高糖面团，我们通过过表达甘油生物合成基因和优化氧化还原平衡来增加甘油的产量，从而提高发酵过程中对渗透压的耐受性。此外，甘油高产菌株表现出增强的耐冻性，用该菌株制作的面包表现出改善的储存性能。这项研究证明了仅通过编辑自身基因而不引入外源基因来增强面包制作的工程酵母菌株的可行性和优势。
