Combining biosensor and metabolic network optimization strategies for enhanced l-threonine production in Escherichia coli
Abstract l-threonine is an integral nutrient for mammals, often used in animal feeds to enhance growth and reduce breeding costs. Developing l-threonine engineered strains that meet industrial production specifications has significant economic value. Here, we developed a biosensor that monitors l-th...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2025-03-01
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| Series: | Biotechnology for Biofuels and Bioproducts |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13068-025-02640-7 |
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| Summary: | Abstract l-threonine is an integral nutrient for mammals, often used in animal feeds to enhance growth and reduce breeding costs. Developing l-threonine engineered strains that meet industrial production specifications has significant economic value. Here, we developed a biosensor that monitors l-threonine concentration to assist in high-throughput screening to capture high-yielding l-threonine mutants. Among them, the P cysK promoter and CysB protein were used to construct a primary l-threonine biosensor, and then the CysBT102A mutant was obtained through directed evolution resulting in a 5.6-fold increase in the fluorescence responsiveness of biosensor over the 0–4 g/L l-threonine concentration range. In addition, the metabolic network of mutant was further optimized through multi-omics analysis and in silico simulation. Ultimately, the THRM13 strain produced 163.2 g/L l-threonine, with a yield of 0.603 g/g glucose in a 5 L bioreactor. The biosensor constructed here could be employed for iterative upgrading of subsequent strains, and these engineering strategies described provide guidance for other chemical overproducers. Graphical Abstract |
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| ISSN: | 2731-3654 |