Core Insights - The article discusses the enhancement of acid tolerance in industrial E. coli strains, which can reduce fermentation costs by improving robustness in low pH environments [1][8]. Group 1: Research Findings - A study from South China University of Technology developed acid-tolerance modules using a "toehold switch" approach, allowing E. coli to maintain lysine production at pH 5.5 comparable to pH 6.8 [1][5]. - The acid response module consists of two plasmids: one with acid-responsive promoters expressing trigger RNAs, and another with toehold switches expressing acid tolerance-related genes [3][5]. Group 2: Mechanisms and Components - The study identified four functional groups of acid tolerance genes: proton consumption system, protein protection system, cell membrane modification and redox homeostasis system, and peroxide clearance system [3][5]. - Key genes include gadB, gadE, and others for proton consumption, and degP and sthA for protein protection and hydrogenase activity, respectively [6][8]. Group 3: Experimental Results - The research utilized a high-throughput platform to create a library of acid tolerance modules, resulting in 1140 colonies after selection, with 26 combinations showing over 120% growth compared to wild-type strains [5][6]. - Two specific combinations were introduced into an industrial lysine-producing E. coli strain, leading to increased lysine yield and glucose conversion rates [5][6]. Group 4: Implications for Industry - The strategies developed in this research provide valuable insights for enhancing the robustness and productivity of industrial strains under moderate acidic conditions, potentially benefiting the biomanufacturing sector [8].