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Jiang X, Ke X, Tian X, Chu J. An inducible CRISPRi circuit for tunable dynamic regulation of gene expression in Saccharopolyspora erythraea. Biotechnol Lett 2024; 46:161-172. [PMID: 38279045 DOI: 10.1007/s10529-023-03462-z] [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: 10/08/2023] [Revised: 11/14/2023] [Accepted: 12/17/2023] [Indexed: 01/28/2024]
Abstract
Actinomyces are gram-positive bacteria known for their valuable secondary metabolites. Redirecting metabolic flux towards desired products in actinomycetes requires precise and dynamic regulation of gene expression. In this study, we integrated the CRISPR interference (CRISPRi) system with a cumate-inducible promoter to develop an inducible gene downregulation method in Saccharopolyspora erythraea, a prominent erythromycin-producing actinobacterium. The functionality of the cumate-inducible promoter was validated using the gusA gene as a reporter, and the successful inducible expression of the dCas9 gene was confirmed. The developed inducible CRISPRi strategy was then employed to downregulate the expression of target genes rppA in the wild-type strain NRRL2338 and sucC in the high erythromycin-producing strain E3. Through dynamic control of sucC expression, a significant enhancement in erythromycin production was achieved in strain E3. This study demonstrated the effectiveness of an inducible gene downregulation approach using CRISPRi and a cumate-inducible promoter, providing valuable insights for optimizing natural product production in actinomyces.
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Affiliation(s)
- Xing Jiang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Xiang Ke
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Xiwei Tian
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Ju Chu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
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Ye J, Yang P, Zhou J, Du G, Liu S. Efficient Production of a Thermostable Mutant of Transglutaminase by Streptomyces mobaraensis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:4207-4216. [PMID: 38354706 DOI: 10.1021/acs.jafc.3c07621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
The transglutaminase (TGase) from Streptomyces mobaraensis is widely used to improve the texture of protein-based foods. However, wild-type TGase is not heat-resistant, which is unfavorable for its application. In this study, we successfully constructed a S. mobaraensis strain that can efficiently produce TGm2, a thermostable mutant of S. mobaraensis TGase. First, S. mobaraensis DSM40587 was subjected to atmospheric room temperature plasma mutagenesis, generating mutant smY2022 with a 12.2-fold increase in TGase activity. Then, based on the double-crossover recombination, we replaced the coding sequence of the TGase with that of TGm2 in smY2022, obtaining the strain smY2022-TGm2. The extracellular TGase activity of smY2022-TGm2 reached 61.7 U/mL, 147% higher than that of smY2022. Finally, the catalytic properties of TGm2 were characterized. The half-life time at 60 °C and specific activity of TGm2 reached 64 min and 71.15 U/mg, 35.6- and 2.9-fold higher than those of the wild-type TGase, respectively. As indicated by SDS-PAGE analysis, TGm2 exhibited demonstrably better protein cross-linking ability than the wild-type TGase at 70 °C, although both enzymes shared a similar ability at 40 °C. With improved enzyme production and thermal stability, smY2022-TGm2 could be a competitive strain for the industrial production of transglutaminase.
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Affiliation(s)
- Jiacai Ye
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Penghui Yang
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Guocheng Du
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Song Liu
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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3
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G C B, Zhou P, Naha A, Gu J, Wu C. Development of a xylose-inducible promoter and riboswitch combination system for manipulating gene expression in Fusobacterium nucleatum. Appl Environ Microbiol 2023; 89:e0066723. [PMID: 37695289 PMCID: PMC10537658 DOI: 10.1128/aem.00667-23] [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: 04/21/2023] [Accepted: 07/05/2023] [Indexed: 09/12/2023] Open
Abstract
Inducible gene expression systems are important for studying bacterial gene function, yet most exhibit leakage. In this study, we engineered a leakage-free hybrid system for precise gene expression controls in Fusobacterium nucleatum by integrating the xylose-inducible expression system with the theophylline-responsive riboswitch. This innovative method enables concurrent control of target gene expression at both transcription and translation initiation levels. Using luciferase and the indole-producing enzyme tryptophanase (TnaA) as reporters, we demonstrated that the hybrid system displays virtually no observable signal in the absence of inducers. We employed this system to express FtsX, a protein related to fusobacterial cytokinesis, in an ftsX mutant strain, unveiling a dose-dependent manner in FtsX production. Without inducers, cells form long filaments, while increasing FtsX levels by increasing inducer concentrations led to a gradual reduction in cell length until normal morphology was restored. Crucially, this system facilitated essential gene investigation, identifying the signal peptidase lepB gene as vital for F. nucleatum. LepB's essentiality stems from depletion, affecting outer membrane biogenesis and cell division. This novel hybrid system holds the potential for advancing research on essential genes and accurate gene regulation in F. nucleatum. IMPORTANCE Fusobacterium nucleatum, an anaerobic bacterium prevalent in the human oral cavity, is strongly linked to periodontitis and can colonize areas beyond the oral cavity, such as the placenta and gastrointestinal tract, causing adverse pregnancy outcomes and promoting colorectal cancer growth. Given F. nucleatum's clinical significance, research is underway to develop targeted therapies to inhibit its growth or eradicate the bacterium specifically. Essential genes, crucial for bacterial survival, growth, and reproduction, are promising drug targets. A leak-free-inducible gene expression system is needed for studying these genes, enabling conditional gene knockouts and elucidating the importance of those essential genes. Our study identified lepB as the essential gene by first generating a conditional gene mutation in F. nucleatum. Combining a xylose-inducible system with a riboswitch facilitated the analysis of essential genes in F. nucleatum, paving the way for potential drug development targeting this bacterium for various clinical applications.
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Affiliation(s)
- Bibek G C
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Peng Zhou
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Arindam Naha
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Jianhua Gu
- Houston Methodist Hospital Research Institute, Houston, Texas, USA
| | - Chenggang Wu
- Department of Microbiology & Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
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4
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Yang L, Hatanaka T. Construction and development of a novel dual-gene coexpression system to promote heterologous protein secretion for Streptomyces. Biosci Biotechnol Biochem 2023; 87:349-357. [PMID: 36526268 DOI: 10.1093/bbb/zbac205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022]
Abstract
Streptomyces lividans is a potent host for the extracellular overproduction of heterologous proteins. To further improve the usability and productivity of S. lividans, a dual gene expression vector of "pTSKr duet" containing two strong constitutive promoters, scmpPc and kasOp*, was constructed. The success in the overproduction of two secretory enzymes simultaneously without interference with each other indicated that the "pTSKr duet" vector can realize the coexpression of two genes simultaneously and independently. Further, using the two-gene coexpression vector, we screened the effects of the overexpression of five factors that possibly promote secretion on the extracellular overproduction of heterologous secretory proteins. Interestingly, the coexpression of a quality control regulator (CssR) promoted the overproduction level to 1.3-fold for a stable heterologous protein of SMTG (transglutaminase from S. mobaraensis), while other four factors limited the overproduction of SMTG at different degrees.
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Affiliation(s)
- Lingli Yang
- Okayama Prefectural Technology Center for Agriculture, Forestry and Fisheries, Research Institute for Biological Sciences (RIBS), Okayama, 7549-1 Kibichuo-cho, Kaga-gun, Okayama, Japan
| | - Tadashi Hatanaka
- Okayama Prefectural Technology Center for Agriculture, Forestry and Fisheries, Research Institute for Biological Sciences (RIBS), Okayama, 7549-1 Kibichuo-cho, Kaga-gun, Okayama, Japan
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5
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Novel switchable ECF sigma factor transcription system for improving thaxtomin A production in Streptomyces. Synth Syst Biotechnol 2022; 7:972-981. [PMID: 35756964 PMCID: PMC9194655 DOI: 10.1016/j.synbio.2022.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/23/2022] Open
Abstract
The application of the valuable natural product thaxtomin A, a potent bioherbicide from the potato scab pathogenic Streptomyces strains, has been greatly hindered by the low yields from its native producers. Here, we developed an orthogonal transcription system, leveraging extra-cytoplasmic function (ECF) sigma (σ) factor 17 (ECF17) and its cognate promoter Pecf17, to express the thaxtomin gene cluster and improve the production of thaxtomin A. The minimal Pecf17 promoter was determined, and a Pecf17 promoter library with a wide range of strengths was constructed. Furthermore, a cumate inducible system was developed for precise temporal control of the ECF17 transcription system in S. venezuelae ISP5230. Theoretically, the switchable ECF17 transcription system could reduce the unwanted influences from host and alleviate the burdens introduced by overexpression of heterologous genes. The yield of thaxtomin A was significantly improved to 202.1 ± 15.3 μ g/mL using the switchable ECF17 transcription system for heterologous expression of the thaxtomin gene cluster in S. venezuelae ISP5230. Besides, the applicability of this transcription system was also tested in Streptomyces albus J1074, and the titer of thaxtomin A was raised to as high as 239.3 ± 30.6 μg/mL. Therefore, the inducible ECF17 transcription system could serve as a complement of the generally used transcription systems based on strong native constitutive promoters and housekeeping σ factors for the heterologous expression of valuable products in diverse Streptomyces hosts.
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Hwang S, Lee Y, Kim JH, Kim G, Kim H, Kim W, Cho S, Palsson BO, Cho BK. Streptomyces as Microbial Chassis for Heterologous Protein Expression. Front Bioeng Biotechnol 2022; 9:804295. [PMID: 34993191 PMCID: PMC8724576 DOI: 10.3389/fbioe.2021.804295] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/30/2021] [Indexed: 12/29/2022] Open
Abstract
Heterologous production of recombinant proteins is gaining increasing interest in biotechnology with respect to productivity, scalability, and wide applicability. The members of genus Streptomyces have been proposed as remarkable hosts for heterologous production due to their versatile nature of expressing various secondary metabolite biosynthetic gene clusters and secretory enzymes. However, there are several issues that limit their use, including low yield, difficulty in genetic manipulation, and their complex cellular features. In this review, we summarize rational engineering approaches to optimizing the heterologous production of secondary metabolites and recombinant proteins in Streptomyces species in terms of genetic tool development and chassis construction. Further perspectives on the development of optimal Streptomyces chassis by the design-build-test-learn cycle in systems are suggested, which may increase the availability of secondary metabolites and recombinant proteins.
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Affiliation(s)
- Soonkyu Hwang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Yongjae Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Ji Hun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Gahyeon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Hyeseong Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Woori Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Suhyung Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States.,Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States.,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Byung-Kwan Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,Innovative Biomaterials Research Center, KAIST Institutes, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
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7
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Wang X, Fu Y, Wang M, Niu G. Synthetic Cellobiose-Inducible Regulatory Systems Allow Tight and Dynamic Controls of Gene Expression in Streptomyces. ACS Synth Biol 2021; 10:1956-1965. [PMID: 34347449 DOI: 10.1021/acssynbio.1c00152] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Precise control of microbial gene expression is crucial for synthetic biotechnological applications. This is particularly true for the bacterial genus Streptomyces, major producers of diverse natural products including many antibiotics. Although a plethora of genetic tools have been developed for Streptomyces, there is still an urgent need for effective gene induction systems. We herein created two novel cellobiose-inducible regulatory systems referred to as Cel-RS1 and Cel-RS2. The regulatory systems are based upon the well-characterized repressor/operator pair CebR/cebO from Streptomyces scabies and the well-defined constitutive kasO* promoter. Both Cel-RS1 and Cel-RS2 exhibit a high level of induced reporter activity and virtually no leaky expression in three model Streptomyces species, which are commonly used as surrogate hosts for expression of natural product biosynthetic gene clusters. Cel-RS2 has been proven successful for programmable control of gene expression and controllable production of specialized metabolites in multiple Streptomyces species. The strategy can be used to expand the toolkit of inducible regulatory systems that will be broadly applicable to various Streptomyces.
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Affiliation(s)
- Xia Wang
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Yudie Fu
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Meiyan Wang
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
| | - Guoqing Niu
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
- Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Southwest University, Chongqing, 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China
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8
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The Design-Build-Test-Learn cycle for metabolic engineering of Streptomycetes. Essays Biochem 2021; 65:261-275. [PMID: 33956071 DOI: 10.1042/ebc20200132] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 02/08/2023]
Abstract
Streptomycetes are producers of a wide range of specialized metabolites of great medicinal and industrial importance, such as antibiotics, antifungals, or pesticides. Having been the drivers of the golden age of antibiotics in the 1950s and 1960s, technological advancements over the last two decades have revealed that very little of their biosynthetic potential has been exploited so far. Given the great need for new antibiotics due to the emerging antimicrobial resistance crisis, as well as the urgent need for sustainable biobased production of complex molecules, there is a great renewed interest in exploring and engineering the biosynthetic potential of streptomycetes. Here, we describe the Design-Build-Test-Learn (DBTL) cycle for metabolic engineering experiments in streptomycetes and how it can be used for the discovery and production of novel specialized metabolites.
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9
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Berini F, Marinelli F, Binda E. Streptomycetes: Attractive Hosts for Recombinant Protein Production. Front Microbiol 2020; 11:1958. [PMID: 32973711 PMCID: PMC7468451 DOI: 10.3389/fmicb.2020.01958] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/24/2020] [Indexed: 01/28/2023] Open
Abstract
Enzymes are increasingly applied as biocatalysts for fulfilling industrial needs in a variety of applications and there is a bursting of interest for novel therapeutic proteins. Consequently, developing appropriate expression platforms for efficiently producing such recombinant proteins represents a crucial challenge. It is nowadays widely accepted that an ideal ‘universal microbial host’ for heterologous protein expression does not exist. Indeed, the first-choice microbes, as Escherichia coli or yeasts, possess known intrinsic limitations that inevitably restrict their applications. In this scenario, bacteria belonging to the Streptomyces genus need to be considered with more attention as promising, alternative, and versatile platforms for recombinant protein production. This is due to their peculiar features, first-of-all their natural attitude to secrete proteins in the extracellular milieu. Additionally, streptomycetes are considered robust and scalable industrial strains and a wide range of tools for their genetic manipulation is nowadays available. This mini-review includes an overview of recombinant protein production in streptomycetes, covering nearly 100 cases of heterologous proteins expressed in these Gram-positives from the 1980s to December 2019. We investigated homologous sources, heterologous hosts, and molecular tools (promoters/vectors/signal peptides) used for the expression of these recombinant proteins. We reported on their final cellular localization and yield. Thus, this analysis might represent a useful source of information, showing pros and cons of using streptomycetes as platform for recombinant protein production and paving the way for their more extensive use in future as alternative heterologous hosts.
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Affiliation(s)
- Francesca Berini
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Flavia Marinelli
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Elisa Binda
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
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10
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Sha Y, Qiu Y, Zhu Y, Sun T, Luo Z, Gao J, Feng X, Li S, Xu H. CRISPRi-Based Dynamic Regulation of Hydrolase for the Synthesis of Poly-γ-Glutamic Acid with Variable Molecular Weights. ACS Synth Biol 2020; 9:2450-2459. [PMID: 32794764 DOI: 10.1021/acssynbio.0c00207] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Poly-γ-glutamic acid (γ-PGA) is a decomposable polymer and has been useful in various industries. The biological functions of γ-PGA are closely linked with its molecular weight (MW). In this study, we established an efficient method to produce variable MWs of γ-PGA from renewable biomass (Jerusalem artichoke) by Bacillus amyloliquefaciens. First, a systematic engineering strategy was proposed in B. amyloliquefaciens to construct an optimal platform for γ-PGA overproduction, in which 24.95 g/L γ-PGA generation was attained. Second, 27.12 g/L γ-PGA with an MW of 20-30 kDa was obtained by introducing a γ-PGA hydrolase (pgdS) into the platform strain constructed above, which reveals a potential correlation between the expression level of pgdS and MW of γ-PGA. Then, a Clustered Regularly Interspaced Short Palindromic Repeats interference (CRISPRi) system was further designed to regulate pgdS expression levels, resulting in γ-PGA with variable MWs. Finally, a combinatorial approach based on three sgRNAs with different repression efficiencies was developed to achieve the dynamic regulation of pgdS and obtain tailor-made γ-PGA production in the MW range of 50-1400 kDa in one strain. This study illustrates a promising approach for the sustainable making of biopolymers with diverse molecular weights in one strain through the controllable expression of hydrolase using the CRISPRi system.
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Affiliation(s)
- Yuanyuan Sha
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, Jiangsu 211816, P. R. China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu 211816, P. R. China
| | - Yibin Qiu
- Department of Food Science and Technology, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China
| | - Yifan Zhu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, Jiangsu 211816, P. R. China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu 211816, P. R. China
| | - Tao Sun
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, Jiangsu 211816, P. R. China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu 211816, P. R. China
| | - Zhengshan Luo
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, Jiangsu 211816, P. R. China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu 211816, P. R. China
| | - Jian Gao
- School of Marine and Bioengineering, Yancheng Institute of Technology, Yancheng, Jiangsu 224051, P. R. China
| | - Xiaohai Feng
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, Jiangsu 211816, P. R. China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu 211816, P. R. China
| | - Sha Li
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, Jiangsu 211816, P. R. China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu 211816, P. R. China
| | - Hong Xu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, Jiangsu 211816, P. R. China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, Jiangsu 211816, P. R. China
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11
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Xylose-Inducible Promoter Tools for Pseudomonas Species and Their Use in Implicating a Role for the Type II Secretion System Protein XcpQ in the Inhibition of Corneal Epithelial Wound Closure. Appl Environ Microbiol 2020; 86:AEM.00250-20. [PMID: 32414795 DOI: 10.1128/aem.00250-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/08/2020] [Indexed: 12/17/2022] Open
Abstract
Tunable control of gene expression is an invaluable tool for biological experiments. In this study, we describe a new xylose-inducible promoter system and evaluate it in both Pseudomonas aeruginosa and Pseudomonas fluorescens The Pxut promoter, derived from the P. fluorescens xut operon, was incorporated into a broad-host-range pBBR1-based plasmid and was compared to the Escherichia coli-derived PBAD promoter using gfp as a reporter. Green fluorescent protein (GFP) fluorescence from the Pxut promoter was inducible in both Pseudomonas species, but not in E. coli, which may facilitate the cloning of genes toxic to E. coli to generate plasmids. The Pxut promoter was activated at a lower inducer concentration than PBAD in P. fluorescens, and higher gfp levels were achieved using Pxut Flow cytometry analysis indicated that Pxut was leakier than PBAD in the Pseudomonas species tested but was expressed in a higher proportion of cells when induced. d-Xylose as a sole carbon source did not support the growth of P. aeruginosa or P. fluorescens and is less expensive than many other commonly used inducers, which could facilitate large-scale applications. The efficacy of this system was demonstrated by its use to reveal a role for the P. aeruginosa type II secretion system gene xcpQ in bacterial inhibition of corneal epithelial cell wound closure. This study introduces a new inducible promoter system for gene expression for use in Pseudomonas species.IMPORTANCE Pseudomonas species are enormously important in human infections, in biotechnology, and as model systems for investigating basic science questions. In this study, we have developed a xylose-inducible promoter system, evaluated it in P. aeruginosa and P. fluorescens, and found it to be suitable for the strong induction of gene expression. Furthermore, we have demonstrated its efficacy in controlled gene expression to show that a type II secretion system protein from P. aeruginosa, XcpQ, is important for host-pathogen interactions in a corneal wound closure model.
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12
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Zhang F, Gao D, Lin J, Zhu M, Zhuang Z, Duan Y, Zhu X. Construction of Inducible Genetic Switch for the Global Regulator WblA To Sustain Both Overproduction of Tiancimycins and On-Demand Sporulation in Streptomyces sp. CB03234. ACS Synth Biol 2020; 9:1460-1467. [PMID: 32379959 DOI: 10.1021/acssynbio.0c00114] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The complex life cycle of streptomycetes is closely related to their secondary metabolisms, all controlled by cascade regulations. Tiancimycins (TNMs) are ten-membered enediynes possessing great potential for antitumor drug development. However, their low yields in Streptomyces sp. CB03234 have greatly limited subsequent studies. Through transcriptome analysis and genetic characterization, we proved that WblA is one pivotal global regulator to repress the biosynthesis of TNMs. The deletion of wblA could significantly enhance the production of TNMs, but also abolish the sporulation in CB03234. By constructing the NitR-ε-caprolactam inducible genetic switch, the expression of wblA was governed in CB03234-NRW, thereby sustaining the overproduction of TNMs and recovering the normal sporulation upon induction, which were practical for the scaled-up production of TNMs. Considering the prevalence and conserved regulatory roles of WblA in streptomycetes, our developed strategy shall provide an effective and practical approach to facilitate titer improvement and discovery of natural products.
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Lu X, Liu X, Chen Z, Li J, van Wezel GP, Chen W, Wen Y. The ROK-family regulator Rok7B7 directly controls carbon catabolite repression, antibiotic biosynthesis, and morphological development in Streptomyces avermitilis. Environ Microbiol 2020; 22:5090-5108. [PMID: 32452104 DOI: 10.1111/1462-2920.15094] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 05/10/2020] [Accepted: 05/19/2020] [Indexed: 11/30/2022]
Abstract
Carbon catabolite repression (CCR) is a common phenomenon in bacteria that modulates expression of genes involved in uptake of alternative carbon sources. In the filamentous streptomycetes, which produce half of all known antibiotics, the precise mechanism of CCR is yet unknown. We report here that the ROK-family regulator Rok7B7 pleiotropically controls xylose and glucose uptake, CCR, development, as well as production of the macrolide antibiotics avermectin and oligomycin A in Streptomyces avermitilis. Rok7B7 directly repressed structural genes for avermectin biosynthesis, whereas it activated olmRI, the cluster-situated activator gene for oligomycin A biosynthesis. Rok7B7 also directly repressed the xylose uptake operon xylFGH, whose expression was induced by xylose and repressed by glucose. Both xylose and glucose served as Rok7B7 ligands. rok7B7 deletion led to enhancement and reduction of avermectin and oligomycin A production, respectively, relieved CCR of xylFGH, and increased co-uptake efficiency of xylose and glucose. A consensus Rok7B7-binding site, 5'-TTKAMKHSTTSAV-3', was identified within aveA1p, olmRIp, and xylFp, which allowed prediction of the Rok7B7 regulon and confirmation of 11 additional targets involved in development, secondary metabolism, glucose uptake, and primary metabolic processes. Our findings will facilitate methods for strain improvement, antibiotic overproduction, and co-uptake of xylose and glucose in Streptomyces species.
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Affiliation(s)
- Xiaorui Lu
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xingchao Liu
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhi Chen
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jilun Li
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Gilles P van Wezel
- Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Wei Chen
- Clinical Research Center, the Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Ying Wen
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
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Zhou Q, Ning S, Luo Y. Coordinated regulation for nature products discovery and overproduction in Streptomyces. Synth Syst Biotechnol 2020; 5:49-58. [PMID: 32346621 PMCID: PMC7176746 DOI: 10.1016/j.synbio.2020.04.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/04/2020] [Accepted: 04/08/2020] [Indexed: 12/19/2022] Open
Abstract
Streptomyces is an important treasure trove for natural products discovery. In recent years, many scientists focused on the genetic modification and metabolic regulation of Streptomyces to obtain diverse bioactive compounds with high yields. This review summarized the commonly used regulatory strategies for natural products discovery and overproduction in Streptomyces from three main aspects, including regulator-related strategies, promoter engineering, as well as other strategies employing transposons, signal factors, or feedback regulations. It is expected that the metabolic regulation network of Streptomyces will be elucidated more comprehensively to shed light on natural products research in the future.
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Affiliation(s)
- Qun Zhou
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Shuqing Ning
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Yunzi Luo
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072, China
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Ji CH, Kim H, Kang HS. Synthetic Inducible Regulatory Systems Optimized for the Modulation of Secondary Metabolite Production in Streptomyces. ACS Synth Biol 2019; 8:577-586. [PMID: 30807691 DOI: 10.1021/acssynbio.9b00001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Biosynthesis of secondary metabolites is a highly complex process that often requires tight control of their production, as overproduction of metabolites could be toxic and also may cause metabolic burden to their hosts. Tight control of metabolite production could be achieved by expressing key biosynthetic genes under control of an inducible regulatory system. In this study, we employed the modular design approach to build a high performance synthetic inducible regulatory system that displays a large dynamic range and thus is well-suited for the modulation of secondary metabolite production in Streptomyces. To this end, an inducible regulatory system was divided into three separate functional modules: (1) the induction module, (2) the target expression module, and (3) the repressor expression module. Then, these three separate modules were individually optimized in a stepwise manner and assembled to a new system. First, the cumate (CMT) induction module was chosen as the best performing induction module based on the large dynamic range and moderate inducer sensitivity. Then the CMT induction module maintained its performance when combined with diverse constitutive target expression modules, in which overall dynamic ranges varied depending on maximum promoter strengths. Lastly, the repressor expression module was optimized to achieve complete elimination of leaky expression, further increasing the dynamic range of the system. We also demonstrate that any strong constitutive regulatory system could be converted into an inducible regulatory system by simple CRISPR/Cas9-aided markerless insertion of an operator sequence whenever tight control of gene expression is required. We believe that the synthetic inducible regulatory system we report here would become a useful tool in modulating secondary metabolite production in Streptomyces.
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Affiliation(s)
- Chang-Hun Ji
- Department of Biomedical Science and Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Hiyoung Kim
- Department of Biomedical Science and Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Hahk-Soo Kang
- Department of Biomedical Science and Engineering, Konkuk University, Seoul 05029, Republic of Korea
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Palazzotto E, Tong Y, Lee SY, Weber T. Synthetic biology and metabolic engineering of actinomycetes for natural product discovery. Biotechnol Adv 2019; 37:107366. [PMID: 30853630 DOI: 10.1016/j.biotechadv.2019.03.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/01/2019] [Accepted: 03/05/2019] [Indexed: 12/15/2022]
Abstract
Actinomycetes are one of the most valuable sources of natural products with industrial and medicinal importance. After more than half a century of exploitation, it has become increasingly challenging to find novel natural products with useful properties as the same known compounds are often repeatedly re-discovered when using traditional approaches. Modern genome mining approaches have led to the discovery of new biosynthetic gene clusters, thus indicating that actinomycetes still harbor a huge unexploited potential to produce novel natural products. In recent years, innovative synthetic biology and metabolic engineering tools have greatly accelerated the discovery of new natural products and the engineering of actinomycetes. In the first part of this review, we outline the successful application of metabolic engineering to optimize natural product production, focusing on the use of multi-omics data, genome-scale metabolic models, rational approaches to balance precursor pools, and the engineering of regulatory genes and regulatory elements. In the second part, we summarize the recent advances of synthetic biology for actinomycetal metabolic engineering including cluster assembly, cloning and expression, CRISPR/Cas9 technologies, and chassis strain development for natural product overproduction and discovery. Finally, we describe new advances in reprogramming biosynthetic pathways through polyketide synthase and non-ribosomal peptide synthetase engineering. These new developments are expected to revitalize discovery and development of new natural products with medicinal and other industrial applications.
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Affiliation(s)
- Emilia Palazzotto
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
| | - Yaojun Tong
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark
| | - Sang Yup Lee
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark; Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Institute for the BioCentury, Korea Advanced Institute of Science and Technology, 34141 Daejeon, Republic of Korea.
| | - Tilmann Weber
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs. Lyngby, Denmark.
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