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Effendi SW, Ng IS. Innovations, Challenges and Future Directions of T7RNA Polymerase in Microbial Cell Factories. ACS Synth Biol 2025; 14:1381-1396. [PMID: 40209062 PMCID: PMC12090346 DOI: 10.1021/acssynbio.5c00139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2025] [Revised: 03/28/2025] [Accepted: 03/31/2025] [Indexed: 04/12/2025]
Abstract
The study of "resource allocator" bacteriophage T7 RNA polymerase (T7RNAP) has garnered significant interest, particularly for optimizing transcriptional systems in microbial cell factories (MCFs). Most previous reviews have primarily focused on T7RNAP by dissecting specific aspects of its molecular structure and functional dynamics; this critical review seeks to broaden the scope. We emphasize a comprehensive guide in utilizing the versatile T7RNAP variants, covering both fundamental principles and fine-tuned circuit designs for synthetic biology applications. Recent advancements in engineered T7RNAP with enhanced specificity and controllability are also highlighted. Furthermore, we discuss the host compatibility considerations for implementing T7RNAP systems in sustainable bioproduction. Finally, key challenges of regulatory complexities and emerging opportunities for next-generation T7RNAP technology are discussed, reinforcing future directions for improving MCF performance.
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Affiliation(s)
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
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2
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Xue C, Ting WW, Juo JJ, Ng IS. New insight into acid-resistant enzymes from natural mutations of Escherichia coli Nissle 1917. Enzyme Microb Technol 2024; 181:110526. [PMID: 39447280 DOI: 10.1016/j.enzmictec.2024.110526] [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: 09/16/2024] [Revised: 10/11/2024] [Accepted: 10/12/2024] [Indexed: 10/26/2024]
Abstract
The probiotic Escherichia coli Nissle 1917 (EcN), known for its superior acid resistance (AR), serves as a promising chassis for live therapeutics due to the effective colonization capabilities. However, the enzymatic activity regarding AR in EcN remains poorly understood. First, we investigated the AR systems of EcN by measuring cell growth under acidic stress and exploring the relationship of mutations to their corresponding enzymatic activities. As a result, the catalytic activity of inducible decarboxylases of GadB, AdiA and CadA, responsible for metabolizing glutamate, arginine, and lysine, exhibited an average 2-fold increase in EcN compared to the reference strain MG1655. Furthermore, we discovered that the glutamate-dependent AR2 system in EcN was meticulously regulated by specific regulons such as GadW. This study not only revealed the physiology of EcN under acidic conditions, but also highlighted that the mutated core enzymes in the AR system of EcN exhibit improved activities.
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Affiliation(s)
- Chengfeng Xue
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Wan-Wen Ting
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Jiun-Jang Juo
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan.
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3
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Shen B, Zhang L, Zhou Y, Song F, You S, Su R, Qi W. Efficient synthesis of 5-hydroxytryptophan in Escherichia coli by bifunctional utilization of whey powder as a substrate for cell growth and inducer production. J Biotechnol 2024; 393:100-108. [PMID: 39097100 DOI: 10.1016/j.jbiotec.2024.07.021] [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: 04/24/2024] [Revised: 07/18/2024] [Accepted: 07/31/2024] [Indexed: 08/05/2024]
Abstract
5-Hydroxytryptophan (5-HTP), a precursor of the neurotransmitter serotonin in mammals, has demonstrated efficacy in treating various diseases such as depression, fibromyalgia and obesity. However, conventional biosynthesis methods of 5-HTP are limited by low yield and high reagent and process costs. In this study, the strain C1T7-S337A/F318Y with optimized promoter distribution was obtained, and the 5-HTP yield was 60.30 % higher than that of the initial strain. An efficient fermentation process for 5-HTP synthesis was developed using strain C1T7-S337A/F318Y with whey powder as a substrate for cell growth and inducer production. Shake flask fermentation experiments yielded 1.302 g/L 5-HTP from 2.0 g/L L-tryptophan (L-Trp), surpassing the whole-cell biocatalysis by 42.86 %. Scale-up to a 5 L fermenter further increased the yield to 1.649 g/L. This fermentation strategy substantially slashed reagent cost by 95.39 %, providing a more economically viable and environmentally sustainable route for industrial biosynthesis of 5-HTP. Moreover, it contributes to the broader utilization of whey powder in various industries.
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Affiliation(s)
- Bowen Shen
- Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China
| | - Lin Zhang
- Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China
| | - Yu Zhou
- Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China
| | - Feifei Song
- Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China
| | - Shengping You
- Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China; Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072, PR China.
| | - Rongxin Su
- Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China; State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin 300350, PR China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China; Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072, PR China
| | - Wei Qi
- Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, PR China; State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin 300350, PR China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China; Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072, PR China.
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4
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Liu J, He C, Tan W, Zheng JH. Path to bacteriotherapy: From bacterial engineering to therapeutic perspectives. Life Sci 2024; 352:122897. [PMID: 38971366 DOI: 10.1016/j.lfs.2024.122897] [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: 01/11/2024] [Revised: 06/30/2024] [Accepted: 07/03/2024] [Indexed: 07/08/2024]
Abstract
The major reason for the failure of conventional therapies is the heterogeneity and complexity of tumor microenvironments (TMEs). Many malignant tumors reprogram their surface antigens to evade the immune surveillance, leading to reduced antigen-presenting cells and hindered T-cell activation. Bacteria-mediated cancer immunotherapy has been extensively investigated in recent years. Scientists have ingeniously modified bacteria using synthetic biology and nanotechnology to enhance their biosafety with high tumor specificity, resulting in robust anticancer immune responses. To enhance the antitumor efficacy, therapeutic proteins, cytokines, nanoparticles, and chemotherapeutic drugs have been efficiently delivered using engineered bacteria. This review provides a comprehensive understanding of oncolytic bacterial therapies, covering bacterial design and the intricate interactions within TMEs. Additionally, it offers an in-depth comparison of the current techniques used for bacterial modification, both internally and externally, to maximize their therapeutic effectiveness. Finally, we outlined the challenges and opportunities ahead in the clinical application of oncolytic bacterial therapies.
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Affiliation(s)
- Jinling Liu
- The Affiliated Xiangtan Central Hospital of Hunan University, School of Biomedical Sciences, Hunan University, Changsha 410082, China; College of Biology, Hunan University, Changsha 410082, China
| | - Chongsheng He
- College of Biology, Hunan University, Changsha 410082, China
| | - Wenzhi Tan
- School of Food Science and Bioengineering, Changsha University of Science & Technology, Changsha, Hunan 410114, China.
| | - Jin Hai Zheng
- The Affiliated Xiangtan Central Hospital of Hunan University, School of Biomedical Sciences, Hunan University, Changsha 410082, China.
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Effendi SW, Ng IS. Non-native Pathway Engineering with CRISPRi for Carbon Dioxide Assimilation and Valued 5-Aminolevulinic Acid Synthesis in Escherichia coli Nissle. ACS Synth Biol 2024; 13:2038-2044. [PMID: 38954490 PMCID: PMC11264323 DOI: 10.1021/acssynbio.4c00318] [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: 05/05/2024] [Revised: 06/27/2024] [Accepted: 06/28/2024] [Indexed: 07/04/2024]
Abstract
Carbon dioxide emission and acidification during chemical biosynthesis are critical challenges toward microbial cell factories' sustainability and efficiency. Due to its acidophilic traits among workhorse lineages, the probiotic Escherichia coli Nissle (EcN) has emerged as a promising chemical bioproducer. However, EcN lacks a CO2-fixing system. Herein, EcN was equipped with a simultaneous CO2 fixation system and subsequently utilized to produce low-emission 5-aminolevulinic acid (5-ALA). Two different artificial CO2-assimilating pathways were reconstructed: the novel ribose-1,5-bisphosphate (R15P) route and the conventional ribulose-5-phosphate (Ru5P) route. CRISPRi was employed to target the pfkAB and zwf genes in order to redirect the carbon flux. As expected, the CRISPRi design successfully strengthened the CO2 fixation. The CO2-fixing route via R15P resulted in high biomass, while the engineered Ru5P route acquired the highest 5-ALA and suppressed the CO2 release by 77%. CO2 fixation during 5-ALA production in EcN was successfully synchronized through fine-tuning the non-native pathways with CRISPRi.
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Affiliation(s)
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
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Hu M, Zhang T, Miao M, Li K, Luan Q, Sun G. Expectations for employing Escherichia coli Nissle 1917 in food science and nutrition. Crit Rev Food Sci Nutr 2024; 65:1802-1810. [PMID: 38189668 DOI: 10.1080/10408398.2023.2301416] [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] [Indexed: 01/09/2024]
Abstract
As a promising probiotic strain, Escherichia coli Nissle 1917 (EcN) has been demonstrated to confer beneficial effects on intestinal health, immune function, and pathogen prevention. Additionally, EcN has also been widely studied due to its clear genomic information, tractable gene regulation, and simple growth conditions. This review summarizes the various applications potential of EcN in food science and nutrition, including inflammation prevention, tumor-targeting therapy, antibacterial agents for food, and nutrient production with a focus on specific case studies. Moreover, we highlight the major challenges of employing EcN in food science and nutrition, including regulatory approval, stability during food processing, and consumer acceptance. Finally, we conclude with a discussion on perspectives related to employing EcN in food science and nutrition.
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Affiliation(s)
- Miaomiao Hu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu, China
| | - Tao Zhang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu, China
| | - Ming Miao
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu, China
| | - Kewen Li
- Baolingbao Biology Co., Ltd, Yucheng, Shandong, China
| | - Qingmin Luan
- Baolingbao Biology Co., Ltd, Yucheng, Shandong, China
| | - Guilian Sun
- Baolingbao Biology Co., Ltd, Yucheng, Shandong, China
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7
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Ba F, Zhang Y, Ji X, Liu WQ, Ling S, Li J. Expanding the toolbox of probiotic Escherichia coli Nissle 1917 for synthetic biology. Biotechnol J 2024; 19:e2300327. [PMID: 37800393 DOI: 10.1002/biot.202300327] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/11/2023] [Accepted: 09/27/2023] [Indexed: 10/07/2023]
Abstract
Escherichia coli Nissle 1917 (EcN) is a probiotic microbe that has the potential to be developed as a promising chassis for synthetic biology applications. However, the molecular tools and techniques for utilizing EcN remain to be further explored. To address this opportunity, the EcN-based toolbox was systematically expanded, enabling EcN as a powerful platform for more applications. First, two EcN cryptic plasmids and other compatible plasmids were genetically engineered to enrich the manipulable plasmid toolbox for multiple gene coexpression. Next, two EcN-based technologies were developed, including the conjugation strategy for DNA transfer, and quantification of protein expression capability. Finally, the EcN-based applications were further expanded by developing EcN native integrase-mediated genetic engineering and establishing an in vitro cell-free protein synthesis (CFPS) system. Overall, this study expanded the toolbox for manipulating and making full use of EcN as a commonly used probiotic chassis, providing several simplified, dependable, and predictable strategies for researchers working in synthetic biology fields.
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Affiliation(s)
- Fang Ba
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yufei Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xiangyang Ji
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Wan-Qiu Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Shengjie Ling
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Jian Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
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Effendi SSW, Ng IS. Challenges and opportunities for engineered Escherichia coli as a pivotal chassis toward versatile tyrosine-derived chemicals production. Biotechnol Adv 2023; 69:108270. [PMID: 37852421 DOI: 10.1016/j.biotechadv.2023.108270] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 08/30/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
Growing concerns over limited fossil resources and associated environmental problems are motivating the development of sustainable processes for the production of high-volume fuels and high-value-added compounds. The shikimate pathway, an imperative pathway in most microorganisms, is branched with tyrosine as the rate-limiting step precursor of valuable aromatic substances. Such occurrence suggests the shikimate pathway as a promising route in developing microbial cell factories with multiple applications in the nutraceutical, pharmaceutical, and chemical industries. Therefore, an increasing number of studies have focused on this pathway to enable the biotechnological manufacture of pivotal and versatile aromatic products. With advances in genome databases and synthetic biology tools, genetically programmed Escherichia coli strains are gaining immense interest in the sustainable synthesis of chemicals. Engineered E. coli is expected to be the next bio-successor of fossil fuels and plants in commercial aromatics synthesis. This review summarizes successful and applicable genetic and metabolic engineering strategies to generate new chassis and engineer the iterative pathway of the tyrosine route in E. coli, thus addressing the opportunities and current challenges toward the realization of sustainable tyrosine-derived aromatics.
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Affiliation(s)
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan.
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9
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Yu M, Hu S, Tang B, Yang H, Sun D. Engineering Escherichia coli Nissle 1917 as a microbial chassis for therapeutic and industrial applications. Biotechnol Adv 2023; 67:108202. [PMID: 37343690 DOI: 10.1016/j.biotechadv.2023.108202] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 05/19/2023] [Accepted: 06/17/2023] [Indexed: 06/23/2023]
Abstract
Genetically engineered microbes, especially Escherichia coli, have been widely used in the biosynthesis of proteins and metabolites for medical and industrial applications. As a traditional probiotic with a well-established safety record, E. coli Nissle 1917 (EcN) has recently emerged as a microbial chassis for generating living therapeutics, drug delivery vehicles, and microbial platforms for industrial production. Despite the availability of genetic tools for engineering laboratory E. coli K-12 and B strains, new genetic engineering systems are still greatly needed to expand the application range of EcN. In this review, we have summarized the latest progress in the development of genetic engineering systems in EcN, as well as their applications in the biosynthesis and delivery of valuable small molecules and biomacromolecules of medical and/or industrial interest, followed by a glimpse of how this rapidly growing field will evolve in the future.
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Affiliation(s)
- Mingjing Yu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China
| | - Shilong Hu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China
| | - Biao Tang
- Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, Zhejiang, China
| | - Hua Yang
- Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, Zhejiang, China
| | - Dongchang Sun
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China.
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Diankristanti PA, Effendi SSW, Hsiang CC, Ng IS. High-level itaconic acid (IA) production using engineered Escherichia coli Lemo21(DE3) toward sustainable biorefinery. Enzyme Microb Technol 2023; 167:110231. [PMID: 37003250 DOI: 10.1016/j.enzmictec.2023.110231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 03/31/2023]
Abstract
Itaconic acid (IA) serves as a prominent building block for polyamides as sustainable material. In vivo IA production is facing the competing side reactions, byproducts accumulation, and long cultivation time. Therefore, the utilization of whole-cell biocatalysts to carry out production from citrate is an alternative approach to sidestep the current limitations. In this study, in vitro reaction of IA was obtained 72.44 g/L by using engineered E. coli Lemo21(DE3) harboring the aconitase (Acn, EC 4.2.1.3) and cis-aconitate decarboxylase (CadA, EC 4.1.1.6) which was cultured in glycerol-based minimal medium. IA productivity enhancement was observed after cold-treating the biocatalysts in - 80 °C for 24 h prior to the reaction, reaching 81.6 g/L. On the other hand, a new seeding strategy in Terrific Broth (TB) as a nutritionally rich medium was employed to maintain the biocatalysts stability up to 30 days. Finally, the highest IA titer of 98.17 g/L was attained using L21::7G chassis, that has a pLemo plasmid and integration of GroELS to the chromosome. The high-level of IA production along with the biocatalyst reutilization enables the economic viability toward a sustainable biorefinery.
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Genetic design of co-expressing a novel aconitase with cis-aconitate decarboxylase and chaperone GroELS for high-level itaconic acid production. Process Biochem 2023. [DOI: 10.1016/j.procbio.2023.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/22/2023]
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12
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Tseng YC, Xue C, Ng IS. Symbiosis culture of probiotic Escherichia coli Nissle 1917 and Lactobacillus rhamnosus GG using lactate utilization protein YkgG. Process Biochem 2023. [DOI: 10.1016/j.procbio.2023.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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