2025/06/01 by Xin Zhang, Xiaofang Yan, Peng Liu +3 · 1 voice
Biochemistry, Genetics and Molecular Biology · Materials Science · #Bacterial Genetics and Biotechnology #Crystallization and Solubility Studies #Microbial Metabolic Engineering and Bioproduction
paper · pdf · doi:10.1111/1751-7915.70175
openalex publication_date 2025/06/01 · openalex created_date 2025/06/11 · openalex updated_date 2026/07/23
ABSTRACT Enhancing acid tolerance of industrial microorganisms is critical for improving fermentation efficiency and sustainability. This study presents a synthetic biology approach that employs toehold switch‐based acid‐tolerance modules to engineer acid‐tolerant strains. This toehold switch‐based approach enables the construction of modules consisting of a trigger block and a switch block, generating a synthetic module library of ~10 5 constructs that integrate four acid‐responsive promoters and 18 acid‐resistance genes. Through stepwise evaluation, we identified two best synthetic modules, RE‐6 and RE‐38, which enabled an industrial lysine‐producing strain to maintain lysine titers and yields at pH 5.5 comparable to those observed in the parent strain at pH 6.8. Transcriptional analyses revealed that upregulation of key acid‐resistance genes involved in protein quality control, reactive oxygen species scavenging and redox homeostasis contributed to the enhanced acid tolerance of the engineered strains. Our study offers a powerful toehold switch‐based approach for constructing synthetic modules of interest, particularly for enhancing the robustness and productivity of industrial strains.