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Zhou HY, Ding WQ, Zhang X, Zhang HY, Hu ZC, Liu ZQ, Zheng YG. Fine and combinatorial regulation of key metabolic pathway for enhanced β-alanine biosynthesis with non-inducible Escherichia coli. Biotechnol Bioeng 2024. [PMID: 38978393 DOI: 10.1002/bit.28799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 06/22/2024] [Accepted: 06/27/2024] [Indexed: 07/10/2024]
Abstract
β-Alanine is the only β-amino acid in nature and one of the most important three-carbon chemicals. This work was aimed to construct a non-inducible β-alanine producer with enhanced metabolic flux towards β-alanine biosynthesis in Escherichia coli. First of all, the assembled E. coli endogenous promoters and 5'-untranslated regions (PUTR) were screened to finely regulate the combinatorial expression of genes panDBS and aspBCG for an optimal flux match between two key pathways. Subsequently, additional copies of key genes (panDBS K104S and ppc) were chromosomally introduced into the host A1. On these bases, dynamical regulation of the gene thrA was performed to reduce the carbon flux directed in the competitive pathway. Finally, the β-alanine titer reached 10.25 g/L by strain A14-R15, 361.7% higher than that of the original strain. Under fed-batch fermentation in a 5-L fermentor, a titer of 57.13 g/L β-alanine was achieved at 80 h. This is the highest titer of β-alanine production ever reported using non-inducible engineered E. coli. This metabolic modification strategy for optimal carbon flux distribution developed in this work could also be used for the production of various metabolic products.
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Affiliation(s)
- Hai-Yan Zhou
- National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Wen-Qing Ding
- National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Xi Zhang
- National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Hong-Yu Zhang
- National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Zhong-Ce Hu
- National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Zhi-Qiang Liu
- National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yu-Guo Zheng
- National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
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2
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Lin Z, Ali MM, Yi X, Zhang L, Wang S. Fast and High-Efficiency Synthesis of Capsanthin in Pepper by Transient Expression of Geminivirus. Int J Mol Sci 2023; 24:15008. [PMID: 37834456 PMCID: PMC10573693 DOI: 10.3390/ijms241915008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/05/2023] [Accepted: 10/08/2023] [Indexed: 10/15/2023] Open
Abstract
The color of the chili fruit is an important factor that determines the quality of the chili, as red chilies are more popular among consumers. The accumulation of capsanthin is the main cause of reddening of the chili fruit. Capsanthin is an important metabolite in carotenoid metabolism, and its production level is closely linked to the expression of the genes for capsanthin/capsorubin synthase (CCS) and carotenoid hydroxylase (CrtZ). We reported for the first time that the synthesis of capsanthin in chili was enhanced by using a geminivirus (Bean Yellow Dwarf Virus). By expressing heterologous β-carotenoid hydroxylase (CrtZ) and β-carotenoid ketolase (CrtW) using codon optimization, the transcription level of the CCS gene and endogenous CrtZ was directly increased. This leads to the accumulation of a huge amount of capsanthin in a very short period of time. Our results provide a platform for the rapid enhancement of endogenous CCS activity and capsanthin production using geminivirus in plants.
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Affiliation(s)
- Zhimin Lin
- Fujian Academy of Agricultural Sciences Biotechnology Institute, Fuzhou 350003, China
| | - Muhammad Moaaz Ali
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China (X.Y.); (L.Z.); (S.W.)
| | - Xiaoyan Yi
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China (X.Y.); (L.Z.); (S.W.)
| | - Lijuan Zhang
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China (X.Y.); (L.Z.); (S.W.)
| | - Shaojuan Wang
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China (X.Y.); (L.Z.); (S.W.)
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3
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Wu F, Wang S, Peng Y, Guo Y, Wang Q. Metabolic engineering of fast-growing Vibrio natriegens for efficient pyruvate production. Microb Cell Fact 2023; 22:172. [PMID: 37667234 PMCID: PMC10476420 DOI: 10.1186/s12934-023-02185-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/20/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND Pyruvate is a widely used value-added chemical which also serves as a hub of various metabolic pathways. The fastest-growing bacterium Vibrio natriegens is a promising chassis for synthetic biology applications with high substrate uptake rates. The aim of this study was to investigate if the high substrate uptake rates of V. natriegens enable pyruvate production at high productivities. RESULTS Two prophage gene clusters and several essential genes for the biosynthesis of byproducts were first deleted. In order to promote pyruvate accumulation, the key gene aceE encoding pyruvate dehydrogenase complex E1 component was down-regulated to reduce the carbon flux into the tricarboxylic acid cycle. Afterwards, the expression of ppc gene encoding phosphoenolpyruvate carboxylase was fine-tuned to balance the cell growth and pyruvate synthesis. The resulting strain PYR32 was able to produce 54.22 g/L pyruvate from glucose within 16 h, with a yield of 1.17 mol/mol and an average productivity of 3.39 g/L/h. In addition, this strain was also able to efficiently convert sucrose or gluconate into pyruvate at high titers. CONCLUSION A novel strain of V. natriegens was engineered which was capable to provide higher productivity in pyruvate synthesis. This study lays the foundation for the biosynthesis of pyruvate and its derivatives in fast-growing V. natriegens.
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Affiliation(s)
- Fengli Wu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China.
| | - Shucai Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, China
| | - Yanfeng Peng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Yufeng Guo
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Qinhong Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China.
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4
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Bouin A, Zhang C, Lindley ND, Truan G, Lautier T. Exploring linker's sequence diversity to fuse carotene cyclase and hydroxylase for zeaxanthin biosynthesis. Metab Eng Commun 2023; 16:e00222. [PMID: 37168436 PMCID: PMC10165439 DOI: 10.1016/j.mec.2023.e00222] [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: 03/14/2023] [Revised: 04/12/2023] [Accepted: 04/16/2023] [Indexed: 05/13/2023] Open
Abstract
Fusion of catalytic domains can accelerate cascade reactions by bringing enzymes in close proximity. However, the design of a protein fusion and the choice of a linker are often challenging and lack of guidance. To determine the impact of linker parameters on fusion proteins, a library of linkers featuring various lengths, secondary structures, extensions and hydrophobicities was designed. Linkers were used to fuse the lycopene cyclase (crtY) and β-carotene hydroxylase (crtZ) from Pantoea ananatis to create fusion proteins to produce zeaxanthin. The fusion efficiency was assessed by comparing the carotenoids content in a carotenoid-producer Escherichia coli strain. It was shown that in addition to the orientation of the enzymes and the size of the linker, the first amino acid of the linker is also a key factor in determining the efficiency of a protein fusion. The wide range of sequence diversity in our linker library enables the fine tuning of protein fusion and this approach can be easily transferred to other enzyme couples.
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Affiliation(s)
- Aurélie Bouin
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Congqiang Zhang
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore
- Corresponding author.
| | - Nic D. Lindley
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Gilles Truan
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- Corresponding author.
| | - Thomas Lautier
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- CNRS@CREATE, 1 Create Way, #08-01 Create Tower, 138602, Singapore
- Corresponding author. Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore.
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5
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Wang N, Peng H, Yang C, Guo W, Wang M, Li G, Liu D. Metabolic Engineering of Model Microorganisms for the Production of Xanthophyll. Microorganisms 2023; 11:1252. [PMID: 37317226 DOI: 10.3390/microorganisms11051252] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/19/2023] [Accepted: 05/06/2023] [Indexed: 06/16/2023] Open
Abstract
Xanthophyll is an oxidated version of carotenoid. It presents significant value to the pharmaceutical, food, and cosmetic industries due to its specific antioxidant activity and variety of colors. Chemical processing and conventional extraction from natural organisms are still the main sources of xanthophyll. However, the current industrial production model can no longer meet the demand for human health care, reducing petrochemical energy consumption and green sustainable development. With the swift development of genetic metabolic engineering, xanthophyll synthesis by the metabolic engineering of model microorganisms shows great application potential. At present, compared to carotenes such as lycopene and β-carotene, xanthophyll has a relatively low production in engineering microorganisms due to its stronger inherent antioxidation, relatively high polarity, and longer metabolic pathway. This review comprehensively summarized the progress in xanthophyll synthesis by the metabolic engineering of model microorganisms, described strategies to improve xanthophyll production in detail, and proposed the current challenges and future efforts needed to build commercialized xanthophyll-producing microorganisms.
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Affiliation(s)
- Nan Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Huakang Peng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Caifeng Yang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wenfang Guo
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Mengqi Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Gangqiang Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Dehu Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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6
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Xu S, Gao S, An Y. Research progress of engineering microbial cell factories for pigment production. Biotechnol Adv 2023; 65:108150. [PMID: 37044266 DOI: 10.1016/j.biotechadv.2023.108150] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 03/14/2023] [Accepted: 04/06/2023] [Indexed: 04/14/2023]
Abstract
Pigments are widely used in people's daily life, such as food additives, cosmetics, pharmaceuticals, textiles, etc. In recent years, the natural pigments produced by microorganisms have attracted increased attention because these processes cannot be affected by seasons like the plant extraction methods, and can also avoid the environmental pollution problems caused by chemical synthesis. Synthetic biology and metabolic engineering have been used to construct and optimize metabolic pathways for production of natural pigments in cellular factories. Building microbial cell factories for synthesis of natural pigments has many advantages, including well-defined genetic background of the strains, high-density and rapid culture of cells, etc. Until now, the technical means about engineering microbial cell factories for pigment production and metabolic regulation processes have not been systematically analyzed and summarized. Therefore, the studies about construction, modification and regulation of synthetic pathways for microbial synthesis of pigments in recent years have been reviewed, aiming to provide an up-to-date summary of engineering strategies for microbial synthesis of natural pigments including carotenoids, melanins, riboflavins, azomycetes and quinones. This review should provide new ideas for further improving microbial production of natural pigments in the future.
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Affiliation(s)
- Shumin Xu
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China; College of Food Science, Shenyang Agricultural University, Shenyang, China
| | - Song Gao
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Yingfeng An
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China; College of Food Science, Shenyang Agricultural University, Shenyang, China; Shenyang Key Laboratory of Microbial Resources Mining and Molecular Breeding, Shenyang, China; Liaoning Provincial Key Laboratory of Agricultural Biotechnology, Shenyang, China.
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7
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Niu K, Fu Q, Mei ZL, Ge LR, Guan AQ, Liu ZQ, Zheng YG. High-Level Production of l-Methionine by Dynamic Deregulation of Metabolism with Engineered Nonauxotroph Escherichia coli. ACS Synth Biol 2023; 12:492-501. [PMID: 36701126 DOI: 10.1021/acssynbio.2c00481] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
l-Methionine is the only sulfur-containing amino acid among the essential amino acids, and it is mainly produced by the chemical method in industry so far. The fermentation production of l-methionine by genetically engineered strains is an attractive alternative. Due to the complex metabolic mechanism and multilevel regulation of the synthesis pathway in the organism, the fermentation production of l-methionine by genetically engineered strains was still not satisfied. In this study, the biosynthesis pathway of l-methionine was regulated based on the previous studies. As the competitive pathway and an essential amino acid for cell growth, the biosynthesis pathway of l-lysine was first repaired by complementation of the lysA gene in situ on the genome and then replaced the in situ promoter with the dynamically regulated promoter PfliA to construct a nonauxotroph strain. In addition, the central metabolic pathway and l-cysteine catabolism pathway were further modified to promote the cell growth and enhance the l-methionine production. Finally, the l-methionine fermentation yield in a 5 L bioreactor reached 17.74 g/L without adding exogenous amino acids. These strategies can effectively balance the contradiction between cell growth and l-methionine production and alleviate the complexity of fermentation operation and the cost with auxotroph strains, which provide a reference for the industrial production of l-methionine by microbial fermentation.
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Affiliation(s)
- Kun Niu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Qiang Fu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Zi-Long Mei
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Li-Rong Ge
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - An-Qi Guan
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Zhi-Qiang Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
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8
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Song Y, He S, Abdallah II, Jopkiewicz A, Setroikromo R, van Merkerk R, Tepper PG, Quax WJ. Engineering of Multiple Modules to Improve Amorphadiene Production in Bacillus subtilis Using CRISPR-Cas9. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:4785-4794. [PMID: 33877851 PMCID: PMC8154554 DOI: 10.1021/acs.jafc.1c00498] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
Engineering strategies to improve terpenoids' production in Bacillus subtilis mainly focus on 2C-methyl-d-erythritol-4-phosphate (MEP) pathway overexpression. To systematically engineer the chassis strain for higher amorphadiene (precursor of artemisinin) production, a clustered regularly interspaced short palindromic repeat-Cas9 (CRISPR-Cas9) system was established in B. subtilis to facilitate precise and efficient genome editing. Then, this system was employed to engineer three more modules to improve amorphadiene production, including the terpene synthase module, the branch pathway module, and the central metabolic pathway module. Finally, our combination of all of the useful strategies within one strain significantly increased extracellular amorphadiene production from 81 to 116 mg/L after 48 h flask fermentation without medium optimization. For the first time, we attenuated the FPP-derived competing pathway to improve amorphadiene biosynthesis and investigated how the TCA cycle affects amorphadiene production in B. subtilis. Overall, this study provides a universal strategy for further increasing terpenoids' production in B. subtilis by comprehensive and systematic metabolic engineering.
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Affiliation(s)
- Yafeng Song
- Department
of Chemical and Pharmaceutical Biology, Groningen Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Siqi He
- Department
of Chemical and Pharmaceutical Biology, Groningen Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Ingy I. Abdallah
- Department
of Chemical and Pharmaceutical Biology, Groningen Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
- Department
of Pharmacognosy, Faculty of Pharmacy, Alexandria
University, 21521 Alexandria, Egypt
| | - Anita Jopkiewicz
- Department
of Chemical and Pharmaceutical Biology, Groningen Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Rita Setroikromo
- Department
of Chemical and Pharmaceutical Biology, Groningen Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Ronald van Merkerk
- Department
of Chemical and Pharmaceutical Biology, Groningen Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Pieter G. Tepper
- Department
of Chemical and Pharmaceutical Biology, Groningen Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Wim J. Quax
- Department
of Chemical and Pharmaceutical Biology, Groningen Research Institute
of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
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9
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Gilman J, Walls L, Bandiera L, Menolascina F. Statistical Design of Experiments for Synthetic Biology. ACS Synth Biol 2021; 10:1-18. [PMID: 33406821 DOI: 10.1021/acssynbio.0c00385] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The design and optimization of biological systems is an inherently complex undertaking that requires careful balancing of myriad synergistic and antagonistic variables. However, despite this complexity, much synthetic biology research is predicated on One Factor at A Time (OFAT) experimentation; the genetic and environmental variables affecting the activity of a system of interest are sequentially altered while all other variables are held constant. Beyond being time and resource intensive, OFAT experimentation crucially ignores the effect of interactions between factors. Given the ubiquity of interacting genetic and environmental factors in biology this failure to account for interaction effects in OFAT experimentation can result in the development of suboptimal systems. To address these limitations, an increasing number of studies have turned to Design of Experiments (DoE), a suite of methods that enable efficient, systematic exploration and exploitation of complex design spaces. This review provides an overview of DoE for synthetic biologists. Key concepts and commonly used experimental designs are introduced, and we discuss the advantages of DoE as compared to OFAT experimentation. We dissect the applicability of DoE in the context of synthetic biology and review studies which have successfully employed these methods, illustrating the potential of statistical experimental design to guide the design, characterization, and optimization of biological protocols, pathways, and processes.
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Affiliation(s)
- James Gilman
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH8 9YL, U.K
| | - Laura Walls
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH8 9YL, U.K
| | - Lucia Bandiera
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH8 9YL, U.K
| | - Filippo Menolascina
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh EH8 9YL, U.K
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10
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Young R, Haines M, Storch M, Freemont PS. Combinatorial metabolic pathway assembly approaches and toolkits for modular assembly. Metab Eng 2020; 63:81-101. [PMID: 33301873 DOI: 10.1016/j.ymben.2020.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 11/16/2020] [Accepted: 12/03/2020] [Indexed: 12/18/2022]
Abstract
Synthetic Biology is a rapidly growing interdisciplinary field that is primarily built upon foundational advances in molecular biology combined with engineering design principles such as modularity and interoperability. The field considers living systems as programmable at the genetic level and has been defined by the development of new platform technologies and methodological advances. A key concept driving the field is the Design-Build-Test-Learn cycle which provides a systematic framework for building new biological systems. One major application area for synthetic biology is biosynthetic pathway engineering that requires the modular assembly of different genetic regulatory elements and biosynthetic enzymes. In this review we provide an overview of modular DNA assembly and describe and compare the plethora of in vitro and in vivo assembly methods for combinatorial pathway engineering. Considerations for part design and methods for enzyme balancing are also presented, and we briefly discuss alternatives to intracellular pathway assembly including microbial consortia and cell-free systems for biosynthesis. Finally, we describe computational tools and automation for pathway design and assembly and argue that a deeper understanding of the many different variables of genetic design, pathway regulation and cellular metabolism will allow more predictive pathway design and engineering.
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Affiliation(s)
- Rosanna Young
- Department of Infectious Disease, Sir Alexander Fleming Building, South Kensington Campus, Imperial College London, SW7 2AZ, UK
| | - Matthew Haines
- Department of Infectious Disease, Sir Alexander Fleming Building, South Kensington Campus, Imperial College London, SW7 2AZ, UK
| | - Marko Storch
- Department of Infectious Disease, Sir Alexander Fleming Building, South Kensington Campus, Imperial College London, SW7 2AZ, UK; London Biofoundry, Imperial College Translation & Innovation Hub, London, W12 0BZ, UK
| | - Paul S Freemont
- Department of Infectious Disease, Sir Alexander Fleming Building, South Kensington Campus, Imperial College London, SW7 2AZ, UK; London Biofoundry, Imperial College Translation & Innovation Hub, London, W12 0BZ, UK; UK DRI Care Research and Technology Centre, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.
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11
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Wu Z, Zhao D, Li S, Wang J, Bi C, Zhang X. Combinatorial modulation of initial codons for improved zeaxanthin synthetic pathway efficiency in Escherichia coli. Microbiologyopen 2019; 8:e930. [PMID: 31532062 PMCID: PMC6925171 DOI: 10.1002/mbo3.930] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 11/09/2022] Open
Abstract
A balanced and optimized metabolic pathway is the basis for efficient production of a target metabolite. Traditional strategies mostly involve the manipulation of promoters or ribosome-binding sites, which can encompass long sequences and can be complex to operate. In this work, we found that by changing only the three nucleotides of the initiation codons, expression libraries of reporter proteins RFP, GFP, and lacZ with a large dynamic range and evenly distributed expression levels could be established in Escherichia coli (E. coli). Thus, a novel strategy that uses combinatorial modulation of initial codons (CMIC) was developed for metabolic pathway optimization and applied to the three genes crtZ, crtY, and crtI of the zeaxanthin synthesis pathway in E. coli. The initial codons of these genes were changed to random nucleotides NNN, and the gene cassettes were assembled into vectors via an optimized strategy based on type II restriction enzymes. With minimal labor time, a combinatorial library was obtained containing strains with various zeaxanthin production levels, including a strain with a titer of 6.33 mg/L and specific production value of 1.24 mg/g DCW-a striking 10-fold improvement over the starting strain. The results demonstrated that CMIC was a feasible technique for conveniently optimizing metabolic pathways. To our best knowledge, this is the first metabolic engineering strategy that relies on manipulating the initiation codons for pathway optimization in E. coli.
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Affiliation(s)
- Zaiqiang Wu
- Center for Molecular Metabolism, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Dongdong Zhao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Park, Tianjin, 300308, China
| | - Siwei Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Park, Tianjin, 300308, China
| | - Junsong Wang
- Center for Molecular Metabolism, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Changhao Bi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Park, Tianjin, 300308, China
| | - Xueli Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Park, Tianjin, 300308, China
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