Dynamic regulation of ROS stress in the accumulation of L-lysine in Escherichia coli

Oxidative stress in Escherichia coli during chemical production, caused by reactive oxygen species (ROS), impairs cell viability and limits output. This study addressed product accumulation and ROS stress in L-lysine-producing strains. Genetic engineering created three variants: dynamically up-regulated R1, down-regulated R2, and temporally regulatable R3 to reduce ROS during fermentation. Under stress conditions, all engineered strains showed significantly lower ROS levels versus parental strain R0, with R3 exhibiting the greatest reduction. Fermentation confirmed R3's superior performance, yielding 85.8 % more L-lysine than R0. These results demonstrate that constructing ROS mitigator achieves precise ROS control and efficient L-lysine synthesis. This dynamic regulation strategy enhances cell viability and production performance under oxidative stress, providing a viable approach for improving engineered cell factories' stress resistance.