Lee Young-Oh, Do Sang-Hun, Won Jae Yoon, Chin Young-Wook, Chewaka Legesse S, Park Bo-Ram, Kim Soo-Jung, Kim Sun-Ki
Department of Food Science and Technology, Chung-Ang University, Anseong, Gyeonggi, Republic of Korea.
Traditional Food Research Group, Korea Food Research Institute, Wanju, Republic of Korea.
Biotechnol J. 2023 Sep;18(9):e2300014. doi: 10.1002/biot.202300014. Epub 2023 Jun 9.
Production of Saccharomyces cerevisiae-based single cell protein (SCP) has recently received great attention due to the steady increase in the world's population and environmental issues. In this study, an inverse metabolic engineering approach was applied to improve the production of yeast SCP. Specifically, an S. cerevisiae mutant library, generated using UV-random mutagenesis, was screened for three rounds to isolate mutants with improved protein content and/or concentration. The #1021 mutant strain exhibited a respective 31% and 23% higher amino acid content and concentration than the parental S. cerevisiae D452-2 strain. Notably, the content, concentration, and composition of amino acids produced by the PAN2* strain, with a single nucleotide polymorphism in PAN2 coding for a catalytic subunit of the poly(A)-nuclease (PAN) deadenylation complex, were virtually identical to those produced by the #1021 mutant strain. In a glucose-limited fed-batch fermentation, the PAN2* strain produced 19.5 g L amino acids in 89 h, which was 16% higher than that produced by the parental D452-2 strain. This study highlights the benefits of inverse metabolic engineering for enhancing the production titer and yield of target molecules without prior knowledge of rate-limiting steps involved in their biosynthetic pathways.
由于世界人口的稳步增长和环境问题，基于酿酒酵母的单细胞蛋白（SCP）生产最近受到了极大关注。在本研究中，采用逆向代谢工程方法来提高酵母SCP的产量。具体而言，使用紫外线随机诱变产生的酿酒酵母突变体文库经过三轮筛选，以分离出蛋白质含量和/或浓度有所提高的突变体。#1021突变菌株的氨基酸含量和浓度分别比亲本酿酒酵母D452-2菌株高31%和23%。值得注意的是，在编码聚（A）核酸酶（PAN）去腺苷酸化复合体催化亚基的PAN2中具有单核苷酸多态性的PAN2菌株所产生的氨基酸的含量、浓度和组成，与#1021突变菌株所产生的几乎相同。在葡萄糖限制的补料分批发酵中，PAN2菌株在89小时内产生了19.5 g/L氨基酸，比亲本D452-2菌株产生的氨基酸高出16%。本研究突出了逆向代谢工程在提高目标分子的生产滴度和产量方面的优势，而无需事先了解其生物合成途径中涉及的限速步骤。
