Han Jae-Ho, Jung Sang Taek, Oh Min-Kyu
Department of Chemical and Biological Engineering, Korea University, Seoul, South Korea.
BK21 Graduate Program, Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, South Korea.
Front Microbiol. 2021 Mar 15;12:655072. doi: 10.3389/fmicb.2021.655072. eCollection 2021.
Protein production requires a significant amount of intracellular energy. Eliminating the flagella has been proposed to help improve protein production by reducing energy consumption. In this study, the gene encoding a subunit of FlhC, a master regulator of flagella assembly, was deleted to reduce the expression of flagella-related genes. FlhC knockout in the -deleted strain triggered significant growth retardation with increased ATP levels and a higher NADPH/NADP ratio. Metabolic flux analysis using a C-labeled carbon substrate showed increased fluxes toward the pentose phosphate and tricarboxylic acid cycle pathways in the - and -deleted strains. Introduction of a high copy number plasmid or overexpression of the recombinant protein in this strain restored growth rate without increasing glucose consumption. These results suggest that the metabolic burden caused by deletion was resolved by recombinant protein production. The recombinant enhanced green fluorescent protein yield per glucose consumption increased 1.81-fold in the mutant strain. Thus, our study demonstrates that high-yield production of the recombinant protein was achieved with reduced flagella formation.
蛋白质生产需要大量的细胞内能量。有人提出消除鞭毛有助于通过减少能量消耗来提高蛋白质产量。在本研究中，编码鞭毛组装主调节因子FlhC亚基的基因被删除，以减少鞭毛相关基因的表达。缺失菌株中的FlhC基因敲除引发了显著的生长迟缓，同时ATP水平升高，NADPH/NADP比值更高。使用C标记的碳底物进行的代谢通量分析表明，在缺失菌株和缺失菌株中，通向磷酸戊糖和三羧酸循环途径的通量增加。在该菌株中引入高拷贝数质粒或重组蛋白的过表达恢复了生长速率，而不增加葡萄糖消耗。这些结果表明，缺失引起的代谢负担通过重组蛋白生产得到了解决。突变菌株中每消耗葡萄糖产生的重组增强型绿色荧光蛋白产量增加了1.81倍。因此，我们的研究表明，通过减少鞭毛形成实现了重组蛋白的高产。
