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Guo H, Tian R, Wu Y, Lv X, Li J, Liu L, Du G, Chen J, Liu Y. Facilitating stable gene integration expression and copy number amplification in Bacillus subtilis through a reversible homologous recombination switch. Synth Syst Biotechnol 2024; 9:577-585. [PMID: 38708056 PMCID: PMC11066994 DOI: 10.1016/j.synbio.2024.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 05/07/2024] Open
Abstract
Strengthening the expression level of integrated genes on the genome is crucial for consistently expressing key enzymes in microbial cell factories for efficient bioproduction in synthetic biology. In comparison to plasmid-based multi-copy expression, the utilization of chromosomal multi-copy genes offers increased stability of expression level, diminishes the metabolic burden on host cells, and enhances overall genetic stability. In this study, we developed the "BacAmp", a stabilized gene integration expression and copy number amplification system for high-level expression in Bacillus subtilis, which was achieved by employing a combination of repressor and non-natural amino acids (ncAA)-dependent expression system to create a reversible switch to control the key gene recA for homologous recombination. When the reversible switch is turned on, genome editing and gene amplification can be achieved. Subsequently, the reversible switch was turned off therefore stabilizing the gene copy number. The stabilized gene amplification system marked by green fluorescent protein, achieved a 3-fold increase in gene expression by gene amplification and maintained the average gene copy number at 10 after 110 generations. When we implemented the gene amplification system for the regulation of N-acetylneuraminic acid (NeuAc) synthesis, the copy number of the critical gene increased to an average of 7.7, which yielded a 1.3-fold NeuAc titer. Our research provides a new avenue for gene expression in synthetic biology and can be applied in metabolic engineering in B. subtilis.
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Affiliation(s)
- Haoyu Guo
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Rongzhen Tian
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Yaokang Wu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Xueqin Lv
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
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Cao Y, Tian R, Lv X, Li J, Liu L, Du G, Chen J, Liu Y. Inducible Population Quality Control of Engineered Bacillus subtilis for Improved N-Acetylneuraminic Acid Biosynthesis. ACS Synth Biol 2021; 10:2197-2209. [PMID: 34404207 DOI: 10.1021/acssynbio.1c00086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Biosynthesis by microorganisms using renewable feedstocks is an important approach for realizing sustainable chemical manufacturing. However, cell-to-cell variation in biosynthesis capability during fermentation restricts the robustness and efficiency of bioproduction, hampering the industrialization of biosynthesis. Herein, we developed an inducible population quality control system (iPopQC) for dynamically modulating the producing and nonproducing subpopulations of engineered Bacillus subtilis, which was constructed via inducible promoter- and metabolite-responsive biosensor-based genetic circuit for regulating essential genes. Moreover, iPopQC achieved a 1.97-fold increase in N-acetylneuraminic acid (NeuAc) titer by enriching producing cell subpopulation during cultivation, representing 52% higher than that of previous PopQC. Strains with double-output iPopQC cocoupling the expression of double essential genes with NeuAc production improved production robustness further, retaining NeuAc production throughout 96 h of fermentation, upon which the strains cocoupling one essential gene expression with NeuAc production abolished the production ability.
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Affiliation(s)
- Yanting Cao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Rongzhen Tian
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Xueqin Lv
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
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