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Enright AL, Heelan WJ, Ward RD, Peters JM. CRISPRi functional genomics in bacteria and its application to medical and industrial research. Microbiol Mol Biol Rev 2024; 88:e0017022. [PMID: 38809084 PMCID: PMC11332340 DOI: 10.1128/mmbr.00170-22] [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] [Indexed: 05/30/2024] Open
Abstract
SUMMARYFunctional genomics is the use of systematic gene perturbation approaches to determine the contributions of genes under conditions of interest. Although functional genomic strategies have been used in bacteria for decades, recent studies have taken advantage of CRISPR (clustered regularly interspaced short palindromic repeats) technologies, such as CRISPRi (CRISPR interference), that are capable of precisely modulating expression of all genes in the genome. Here, we discuss and review the use of CRISPRi and related technologies for bacterial functional genomics. We discuss the strengths and weaknesses of CRISPRi as well as design considerations for CRISPRi genetic screens. We also review examples of how CRISPRi screens have defined relevant genetic targets for medical and industrial applications. Finally, we outline a few of the many possible directions that could be pursued using CRISPR-based functional genomics in bacteria. Our view is that the most exciting screens and discoveries are yet to come.
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Affiliation(s)
- Amy L. Enright
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- DOE Great Lakes Bioenergy Research Center University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - William J. Heelan
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ryan D. Ward
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- DOE Great Lakes Bioenergy Research Center University of Wisconsin-Madison, Madison, Wisconsin, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jason M. Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- DOE Great Lakes Bioenergy Research Center University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Geyman LJ, Tanner MP, Rosario-Meléndez N, Peters JM, Mandel MJ, van Kessel JC. Mobile-CRISPRi as a powerful tool for modulating Vibrio gene expression. Appl Environ Microbiol 2024; 90:e0006524. [PMID: 38775491 PMCID: PMC11218623 DOI: 10.1128/aem.00065-24] [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: 01/19/2024] [Accepted: 04/28/2024] [Indexed: 05/25/2024] Open
Abstract
CRISPRi (Clustered Regularly Interspaced Palindromic Repeats interference) is a gene knockdown method that uses a deactivated Cas9 protein (dCas9) that binds a specific gene target locus dictated by an encoded guide RNA (sgRNA) to block transcription. Mobile-CRISPRi is a suite of modular vectors that enable CRISPRi knockdowns in diverse bacteria by integrating IPTG-inducible dcas9 and sgRNA genes into the genome using Tn7 transposition. Here, we show that the Mobile-CRISPRi system functions robustly and specifically in multiple Vibrio species: Vibrio cholerae, Vibrio fischeri, Vibrio vulnificus, Vibrio parahaemolyticus, and Vibrio campbellii. We demonstrate efficacy by targeting both essential and non-essential genes that function to produce defined, measurable phenotypes: bioluminescence, quorum sensing, cell division, and growth arrest. We anticipate that Mobile-CRISPRi will be used in Vibrio species to systematically probe gene function and essentiality in various behaviors and native environments.IMPORTANCEThe genetic manipulation of bacterial genomes is an invaluable tool in experimental microbiology. The development of CRISPRi (Clustered Regularly Interspaced Palindromic Repeats interference) tools has revolutionized genetics in many organisms, including bacteria. Here, we optimized the use of Mobile-CRISPRi in five Vibrio species, each of which has significant impacts on marine environments and organisms that include squid, shrimp, shellfish, finfish, corals, and multiple of which pose direct threats to human health. The Mobile-CRISPRi technology is easily adaptable, moveable from strain to strain, and enables researchers to selectively turn off gene expression. Our experiments demonstrate Mobile-CRISPRi is effective and robust at repressing gene expression of both essential and non-essential genes in Vibrio species.
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Affiliation(s)
- Logan J. Geyman
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Madeline P. Tanner
- Department of Microbiology, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Natalia Rosario-Meléndez
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jason M. Peters
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mark J. Mandel
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Bacon EE, Tran JS, Nadig N, Peters JM. Modular, inducible, and titratable expression systems for Escherichia coli and Acinetobacter baumannii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.596346. [PMID: 38853957 PMCID: PMC11160707 DOI: 10.1101/2024.05.28.596346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Gene expression systems that transcend species barriers are needed for cross-species analysis of gene function. In particular, expression systems that can be utilized in both model and pathogenic bacteria underpin comparative functional approaches that inform conserved and variable features of bacterial physiology. Here, we develop replicative and integrative vectors alongside a novel, IPTG-inducible promoter that can be used in the model bacterium Escherichia coli K-12 as well as strains of the antibiotic-resistant pathogen, Acinetobacter baumannii. We generate modular vectors that transfer by conjugation at high efficiency and either replicate or integrate into the genome, depending on design. Embedded in these vectors, we also developed a synthetic, IPTG-inducible promoter, P abstBR , that induces to a high level, but is less leaky than the commonly used trc promoter. We show that P abstBR is titratable at both the population and single cell level, regardless of species, highlighting the utility of our expression systems for cross-species functional studies. Finally, as a proof of principle, we use our integrating vector to develop a reporter for the E. coli envelope stress σ factor, RpoE, and deploy the reporter in E. coli and A. baumannii, finding that A. baumannii does not recognize RpoE-dependent promoters unless RpoE is heterologously expressed. We envision that these vector and promoter tools will be valuable for the community of researchers that study fundamental biology of E. coli and A. baumannii.
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Affiliation(s)
- Emily E Bacon
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Jennifer S Tran
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Nischala Nadig
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Jason M Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53726
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI 53706
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Russell SJ, Garcia AK, Kaçar B. A CRISPR interference system for engineering biological nitrogen fixation. mSystems 2024; 9:e0015524. [PMID: 38376168 PMCID: PMC10949490 DOI: 10.1128/msystems.00155-24] [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: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/21/2024] Open
Abstract
A grand challenge for the next century is in facing a changing climate through bioengineering solutions. Biological nitrogen fixation, the globally consequential, nitrogenase-catalyzed reduction of atmospheric nitrogen to bioavailable ammonia, is a vital area of focus. Nitrogen fixation engineering relies upon extensive understanding of underlying genetics in microbial models, including the broadly utilized gammaproteobacterium, Azotobacter vinelandii (A. vinelandii). Here, we report the first CRISPR interference (CRISPRi) system for targeted gene silencing in A. vinelandii that integrates genomically via site-specific transposon insertion. We demonstrate that CRISPRi can repress transcription of an essential nitrogen fixation gene by ~60%. Further, we show that nitrogenase genes are suitably expressed from the transposon insertion site, indicating that CRISPRi and engineered nitrogen fixation genes can be co-integrated for combinatorial studies of gene expression and engineering. Our established CRISPRi system fills an important gap for engineering microbial nitrogen fixation for desired purposes.IMPORTANCEAll life on Earth requires nitrogen to survive. About 78% of the atmosphere alone is nitrogen, yet humans cannot use it directly. Instead, we obtain the nitrogen we need for our survival through the food we eat. For more than 100 years, a substantial portion of agricultural productivity has relied on industrial methods for nitrogen fertilizer synthesis, which consumes significant amounts of nonrenewable energy resources and exacerbates environmental degradation and human-induced climate change. Promising alternatives to these industrial methods rely on engineering the only biological pathway for generating bioaccessible nitrogen: microbial nitrogen fixation. Bioengineering strategies require an extensive understanding of underlying genetics in nitrogen-fixing microbes, but genetic tools for this critical goal remain lacking. The CRISPRi gene silencing system that we report, developed in the broadly utilized nitrogen-fixing bacterial model, Azotobacter vinelandii, is an important step toward elucidating the complexity of nitrogen fixation genetics and enabling their manipulation.
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Affiliation(s)
- Steven J. Russell
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Amanda K. Garcia
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Betül Kaçar
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Banta AB, Myers KS, Ward RD, Cuellar RA, Place M, Freeh CC, Bacon EE, Peters JM. A Targeted Genome-scale Overexpression Platform for Proteobacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.01.582922. [PMID: 38496613 PMCID: PMC10942329 DOI: 10.1101/2024.03.01.582922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Targeted, genome-scale gene perturbation screens using Clustered Regularly Interspaced Short Palindromic Repeats interference (CRISPRi) and activation (CRISPRa) have revolutionized eukaryotic genetics, advancing medical, industrial, and basic research. Although CRISPRi knockdowns have been broadly applied in bacteria, options for genome-scale overexpression face key limitations. Here, we develop a facile approach for genome-scale gene overexpression in bacteria we call, "CRISPRtOE" (CRISPR transposition and OverExpression). We create a platform for comprehensive gene targeting using CRISPR-associated transposition (CAST) and show that transposition occurs at a higher frequency in non-transcribed DNA. We then demonstrate that CRISPRtOE can upregulate gene expression in Proteobacteria with medical and industrial relevance by integrating synthetic promoters of varying strength upstream of target genes. Finally, we employ CRISPRtOE screening at the genome-scale in Escherichia coli, recovering known antibiotic targets and genes with unexplored roles in antibiotic function. We envision that CRISPRtOE will be a valuable overexpression tool for antibiotic mode of action, industrial strain optimization, and gene function discovery in bacteria.
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Affiliation(s)
- Amy B Banta
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Kevin S Myers
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Ryan D Ward
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Rodrigo A Cuellar
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Michael Place
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Claire C Freeh
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - Emily E Bacon
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Jason M Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA
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Geyman L, Tanner M, Rosario-Melendez N, Peters J, Mandel MJ, van Kessel JC. Mobile-CRISPRi as a powerful tool for modulating Vibrio gene expression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.17.575898. [PMID: 38293084 PMCID: PMC10827217 DOI: 10.1101/2024.01.17.575898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
CRISPRi (Clustered Regularly Interspaced Palindromic Repeats interference) is a gene knockdown method that uses a deactivated Cas9 protein (dCas9) that binds a specific gene target locus dictated by an encoded guide RNA (sgRNA) to block transcription. Mobile-CRISPRi is a suite of modular vectors that enable CRISPRi knockdowns in diverse bacteria by integrating IPTG-inducible dcas9 and sgRNA genes into the genome using Tn 7 transposition. Here, we show that the Mobile-CRISPRi system functions robustly and specifically in multiple Vibrio species: Vibrio cholerae, Vibrio fischeri, Vibrio vulnificus, Vibrio parahaemolyticus , and Vibrio campbellii . We demonstrate efficacy by targeting both essential and non-essential genes that function to produce defined, measurable phenotypes: bioluminescence, quorum sensing, cell division, and growth arrest. We anticipate that Mobile-CRISPRi will be used in Vibrio species to systematically probe gene function and essentiality in various behaviors and native environments.
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Yu MA, Banta AB, Ward RD, Prasad NK, Kwon MS, Rosenberg OS, Peters JM. Investigating Pseudomonas aeruginosa Gene Function During Pathogenesis Using Mobile-CRISPRi. Methods Mol Biol 2024; 2721:13-32. [PMID: 37819512 DOI: 10.1007/978-1-0716-3473-8_2] [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: 10/13/2023]
Abstract
CRISPR interference (CRISPRi) is a robust gene silencing technique that is ideal for targeting essential and conditionally essential (CE) genes. CRISPRi is especially valuable for investigating gene function in pathogens such as P. aeruginosa where essential and CE genes underlie clinically important phenotypes such as antibiotic susceptibility and virulence. To facilitate the use of CRISPRi in diverse bacteria-including P. aeruginosa-we developed a suite of modular, mobilizable, and integrating vectors we call, "Mobile-CRISPRi." We further optimized Mobile-CRISPRi for use in P. aeruginosa mouse models of acute lung infection by expressing the CRISPRi machinery at low levels constitutively, enabling partial knockdown of essential and CE genes without the need for an exogenous inducer. Here, we describe protocols for creating Mobile-CRISPRi knockdown strains and testing their phenotypes in a mouse pneumonia model of P. aeruginosa infection. In addition, we provide comprehensive guide RNA designs to target genes in common laboratory strains of P. aeruginosa and other Pseudomonas species.
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Affiliation(s)
- Michelle A Yu
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Amy B Banta
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Ryan D Ward
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Neha K Prasad
- Chan Zuckerberg Biohub, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Michael S Kwon
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Oren S Rosenberg
- Chan Zuckerberg Biohub, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - Jason M Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA.
- Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA.
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Enright AL, Banta AB, Ward RD, Rivera Vazquez J, Felczak MM, Wolfe MB, TerAvest MA, Amador-Noguez D, Peters JM. The genetics of aerotolerant growth in an alphaproteobacterium with a naturally reduced genome. mBio 2023; 14:e0148723. [PMID: 37905909 PMCID: PMC10746277 DOI: 10.1128/mbio.01487-23] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 09/25/2023] [Indexed: 11/02/2023] Open
Abstract
IMPORTANCE The inherent complexity of biological systems is a major barrier to our understanding of cellular physiology. Bacteria with markedly fewer genes than their close relatives, or reduced genome bacteria, are promising biological models with less complexity. Reduced genome bacteria can also have superior properties for industrial use, provided the reduction does not overly restrict strain robustness. Naturally reduced genome bacteria, such as the alphaproteobacterium Zymomonas mobilis, have fewer genes but remain environmentally robust. In this study, we show that Z. mobilis is a simplified genetic model for Alphaproteobacteria, a class with important impacts on the environment, human health, and industry. We also identify genes that are only required in the absence of atmospheric oxygen, uncovering players that maintain and utilize the cellular energy state. Our findings have broad implications for the genetics of Alphaproteobacteria and industrial use of Z. mobilis to create biofuels and bioproducts.
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Affiliation(s)
- Amy L. Enright
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Amy B. Banta
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ryan D. Ward
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Julio Rivera Vazquez
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Magdalena M. Felczak
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Michael B. Wolfe
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Michaela A. TerAvest
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Daniel Amador-Noguez
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jason M. Peters
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Huang Y, Chen M, Hu G, Wu B, He M. Elimination of editing plasmid mediated by theophylline riboswitch in Zymomonas mobilis. Appl Microbiol Biotechnol 2023; 107:7151-7163. [PMID: 37728624 DOI: 10.1007/s00253-023-12783-y] [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: 05/15/2023] [Revised: 08/23/2023] [Accepted: 09/07/2023] [Indexed: 09/21/2023]
Abstract
Zymomonas mobilis is regarded as a potential chassis for the production of platform chemicals. Genome editing using the CRISPR-Cas system could meet the need for gene modification in metabolic engineering. However, the low curing efficiency of CRISPR editing plasmid is a common bottleneck in Z. mobilis. In this study, we utilized a theophylline-dependent riboswitch to regulate the expression of the replicase gene of the editing plasmid, thereby promoting the elimination of exogeneous plasmid. The riboswitch D (RSD) with rigorous regulatory ability was identified as the optimal candidate by comparing the transformation efficiency of four theophylline riboswitch-based backbone editing plasmids, and the optimal theophylline concentration for inducing RSD was determined to be 2 mM. A highly effective method for eliminating the editing plasmid, cells with RSD-based editing plasmid which were cultured in liquid and solid RM media in alternating passages at 37 °C without shaking, was established by testing the curing efficiency of backbone editing plasmids pMini and pMini-RSD in RM medium with or without theophylline at 30 °C or 37 °C. Finally, the RSD-based editing plasmid was applied to genome editing, resulting in an increase of more than 10% in plasmid elimination efficiency compared to that of pMini-based editing plasmid. KEY POINTS: • An effective strategy for curing CRISPR editing plasmid has been established in Z. mobilis. • Elimination efficiency of the CRISPR editing plasmid was enhanced by 10% to 20% under the regulation of theophylline-dependent riboswitch RSD.
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Affiliation(s)
- Yuhuan Huang
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041, China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081, China
| | - Mao Chen
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041, China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081, China
| | - Guoquan Hu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041, China
| | - Bo Wu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041, China.
| | - Mingxiong He
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041, China.
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Li Q, Gao R, Li Y, Fan B, Ma C, He YC. Improved biotransformation of lignin-valorized vanillin into vanillylamine in a sustainable bioreaction medium. BIORESOURCE TECHNOLOGY 2023; 384:129292. [PMID: 37295479 DOI: 10.1016/j.biortech.2023.129292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/06/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023]
Abstract
Lignin is a critical biopolymer for creating a large number of highly valuable biobased compounds. Vanillin, one of lignin-derived aromatics, can be used to synthesize vanillylamine that is a key fine chemical and pharmaceutical intermediate. To produce vanillylamine, a productive whole-cell-catalyzed biotransformation of vanillin was developed in deep eutectic solvent - surfactant - H2O media. One newly created recombinant E. coli 30CA cells expressing ω-transaminase and L-alanine dehydrogenase was employed to transform 50 mM and 60 mM vanillin into vanillylamine in the yield of 82.2% and 8.5% under 40 °C, respectively. The biotransamination efficiency was enhanced by introducing surfactant PEG-2000 (40 mM) and deep eutectic solvent ChCl:LA (5.0 wt%, pH 8.0), and the highest vanillylamine yield reached 90.0% from 60 mM vanillin. Building an effective bioprocess was utilized for transamination of lignin-derived vanillin to vanillylamine with newly created bacteria in an eco-friendly medium, which had potential application for valorization of lignin to value-added compounds.
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Affiliation(s)
- Qi Li
- School of Pharmacy, National-Local Joint Engineering Research Center of Biomass Refining and High-Quality Utilization, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Lifes, Hubei University, Wuhan 430062, Hubei Province, PR China
| | - Ruiying Gao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Lifes, Hubei University, Wuhan 430062, Hubei Province, PR China
| | - Yucheng Li
- School of Pharmacy, National-Local Joint Engineering Research Center of Biomass Refining and High-Quality Utilization, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China
| | - Bo Fan
- School of Pharmacy, National-Local Joint Engineering Research Center of Biomass Refining and High-Quality Utilization, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China
| | - Cuiluan Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Lifes, Hubei University, Wuhan 430062, Hubei Province, PR China
| | - Yu-Cai He
- School of Pharmacy, National-Local Joint Engineering Research Center of Biomass Refining and High-Quality Utilization, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China; State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Lifes, Hubei University, Wuhan 430062, Hubei Province, PR China; State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
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11
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Hall AN, Hall BW, Kinney KJ, Olsen GG, Banta AB, Noguera DR, Donohue TJ, Peters JM. Tools for Genetic Engineering and Gene Expression Control in Novosphingobium aromaticivorans and Rhodobacter sphaeroides. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.25.554875. [PMID: 37662258 PMCID: PMC10473679 DOI: 10.1101/2023.08.25.554875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Alphaproteobacteria have a variety of cellular and metabolic features that provide important insights into biological systems and enable biotechnologies. For example, some species are capable of converting plant biomass into valuable biofuels and bioproducts have the potential to form the backbone of the sustainable bioeconomy. Among the Alphaproteobacteria, Novosphingobium aromaticivorans, Rhodobacter sphaeroides, and Zymomonas mobilis, show particular promise as organisms that can be engineered to convert extracted plant lignin or sugars into bioproducts and biofuels. Genetic manipulation of these bacteria is needed to introduce engineered pathways and modulate expression of native genes with the goal of enhancing bioproduct output. Although recent work has expanded the genetic toolkit for Z. mobilis, N. aromaticivorans and R. sphaeroides still need facile, reliable approaches to deliver genetic payloads to the genome and to control gene expression. Here, we expand the platform of genetic tools for N. aromaticivorans and R. sphaeroides to address these issues. We demonstrate that Tn7 transposition is an effective approach for introducing engineered DNA into the chromosome of N. aromaticivorans and R. sphaeroides. We screen a synthetic promoter library to identify inducible promoters with strong, regulated activity in both organisms. Combining Tn7 integration with promoters from our library, we establish CRISPR interference systems for N. aromaticivorans and R. sphaeroides that can target essential genes and modulate engineered pathways. We anticipate that these systems will greatly facilitate both genetic engineering and gene function discovery efforts in these industrially important species and other Alphaproteobacteria.
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Affiliation(s)
- Ashley N. Hall
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Benjamin W. Hall
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kyle J. Kinney
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Gabby G. Olsen
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Amy B. Banta
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Daniel R. Noguera
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Timothy J. Donohue
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jason M. Peters
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, USA
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12
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Huang J, Wang X, Chen X, Li H, Chen Y, Hu Z, Yang S. Adaptive Laboratory Evolution and Metabolic Engineering of Zymomonas mobilis for Bioethanol Production Using Molasses. ACS Synth Biol 2023; 12:1297-1307. [PMID: 37036829 DOI: 10.1021/acssynbio.3c00056] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
Molasses with abundant sugars is widely used for bioethanol production. Although the ethanologenic bacterium Zymomonas mobilis can use glucose, fructose, and sucrose for ethanol production, levan production from sucrose reduces the ethanol yield of molasses fermentation. To increase ethanol production from sucrose-rich molasses, Z. mobilis was adapted in molasses, sucrose, and fructose in parallel. Adaptation in fructose is the most effective route to generate an evolved strain F74 with improved molasses utilization, which is majorly due to a G99S mutation in Glf for enhanced fructose import. Subsequent sacB deletion and sacC overexpression in F74 to divert sucrose metabolism from levan production to ethanol production further enhanced ethanol productivity 28.6% to 1.35 g/L/h. The efficient utilization of molasses by diverting sucrose metabolic flux through adaptation and genome engineering not only generated an excellent ethanol producer using molasses but also provided the strategy for developing microbial cell factories.
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Affiliation(s)
- Ju Huang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Xia Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Xiangyu Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Han Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Yunhao Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Zhousheng Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, and School of Life Sciences, Hubei University, Wuhan 430062, China
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13
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Zhang K, Zhang W, Qin M, Li Y, Wang H. Characterization and Application of the Sugar Transporter Zmo0293 from Zymomonas mobilis. Int J Mol Sci 2023; 24:ijms24065888. [PMID: 36982961 PMCID: PMC10055971 DOI: 10.3390/ijms24065888] [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: 02/03/2023] [Revised: 03/15/2023] [Accepted: 03/19/2023] [Indexed: 03/30/2023] Open
Abstract
Zymomonas mobilis is a natural ethanologen with many desirable characteristics, which makes it an ideal industrial microbial biocatalyst for the commercial production of desirable bioproducts. Sugar transporters are responsible for the import of substrate sugars and the conversion of ethanol and other products. Glucose-facilitated diffusion protein Glf is responsible for facilitating the diffusion of glucose uptake in Z. mobilis. However, another sugar transporter-encoded gene, ZMO0293, is poorly characterized. We employed gene deletion and heterologous expression mediated by the CRISPR/Cas method to investigate the role of ZMO0293. The results showed that deletion of the ZMO0293 gene slowed growth and reduced ethanol production and the activities of key enzymes involved in glucose metabolism in the presence of high concentrations of glucose. Moreover, ZMO0293 deletion caused different transcriptional changes in some genes of the Entner Doudoroff (ED) pathway in the ZM4-ΔZM0293 strain but not in ZM4 cells. The integrated expression of ZMO0293 restored the growth of the glucose uptake-defective strain Escherichia coli BL21(DE3)-ΔptsG. This study reveals the function of the ZMO0293 gene in Z. mobilis in response to high concentrations of glucose and provides a new biological part for synthetic biology.
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Affiliation(s)
- Kun Zhang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Wenwen Zhang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Mengxing Qin
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Yi Li
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Hailei Wang
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
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14
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Tang Y, Wang F, Wang Y, Wang Y, Liu Y, Chen Z, Li W, Yang S, Ma L. In vitro characterization of a pAgo nuclease TtdAgo from Thermococcus thioreducens and evaluation of its effect in vivo. Front Bioeng Biotechnol 2023; 11:1142637. [PMID: 36937752 PMCID: PMC10017986 DOI: 10.3389/fbioe.2023.1142637] [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: 01/11/2023] [Accepted: 02/06/2023] [Indexed: 03/06/2023] Open
Abstract
In spite of the development of genome-editing tools using CRISPR-Cas systems, highly efficient and effective genome-editing tools are still needed that use novel programmable nucleases such as Argonaute (Ago) proteins to accelerate the construction of microbial cell factories. In this study, a prokaryotic Ago (pAgo) from a hyperthermophilic archaeon Thermococcus thioreducens (TtdAgo) was characterized in vitro. Our results showed that TtdAgo has a typical DNA-guided DNA endonuclease activity, and the efficiency and accuracy of cleavage are modulated by temperature, divalent ions, and the phosphorylation and length of gDNAs and their complementarity to the DNA targets. TtdAgo can utilize 5'-phosphorylated (5'-P) or 5'- hydroxylated (5'-OH) DNA guides to cleave single-stranded DNA (ssDNA) at temperatures ranging from 30°C to 95°C in the presence of Mn2+ or Mg2+ and displayed no obvious preference for the 5'-end-nucleotide of the guide. In addition, single-nucleotide mismatches had little effects on cleavage efficiency, except for mismatches at position 4 or 8 that dramatically reduced target cleavage. Moreover, TtdAgo performed programmable cleavage of double-stranded DNA at 75°C. We further introduced TtdAgo into an industrial ethanologenic bacterium Zymomonas mobilis to evaluate its effect in vivo. Our preliminary results indicated that TtdAgo showed cell toxicity toward Z. mobilis, resulting in a reduced growth rate and final biomass. In conclusion, we characterized TtdAgo in vitro and investigated its effect on Z. mobilis in this study, which lays a foundation to develop Ago-based genome-editing tools for recalcitrant industrial microorganisms in the future.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Lixin Ma
- *Correspondence: Shihui Yang, ; Lixin Ma,
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15
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Behrendt G, Frohwitter J, Vlachonikolou M, Klamt S, Bettenbrock K. Zymo-Parts: A Golden Gate Modular Cloning Toolbox for Heterologous Gene Expression in Zymomonas mobilis. ACS Synth Biol 2022; 11:3855-3864. [PMID: 36346889 PMCID: PMC9680023 DOI: 10.1021/acssynbio.2c00428] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Zymomonas mobilis is a microorganism with extremely high sugar consumption and ethanol production rates and is generally considered to hold great potential for biotechnological applications. However, its genetic engineering is still difficult, hampering the efficient construction of genetically modified strains. In this work, we present Zymo-Parts, a modular toolbox based on Golden-Gate cloning offering a collection of promoters (including native, inducible, and synthetic constitutive promoters of varying strength), an array of terminators and several synthetic ribosomal binding sites and reporter genes. All these parts can be combined in an efficient and flexible way to achieve a desired level of gene expression, either from plasmids or via genome integration. Use of the GoldenBraid-based system also enables an assembly of operons consisting of up to five genes. We present the basic structure of the Zymo-Parts cloning system, characterize several constitutive and inducible promoters, and exemplify the construction of an operon and of chromosomal integration of a reporter gene. Finally, we demonstrate the power and utility of the Zymo-Parts toolbox for metabolic engineering applications by overexpressing a heterologous gene encoding for the lactate dehydrogenase of Escherichia coli to achieve different levels of lactate production in Z. mobilis.
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16
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Roba A, Carlier E, Godessart P, Naili C, De Bolle X. A histidine auxotroph mutant is defective for cell separation and allows the identification of crucial factors for cell division in Brucella abortus. Mol Microbiol 2022; 118:145-154. [PMID: 35748337 DOI: 10.1111/mmi.14956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 11/29/2022]
Abstract
The pathogenic bacterium Brucella abortus invades and multiplies inside host cells. To grow inside host cells, B. abortus requires a functional histidine biosynthesis pathway. Here, we show that a B. abortus histidine auxotroph mutant also displays an unexpected chaining phenotype. The intensity of this phenotype varies according to the culture medium and is exacerbated inside host cells. Chains of bacteria consist of contiguous peptidoglycan, and likely result from the defective cleavage of peptidoglycan at septa. Genetic suppression of the chaining phenotype unearthed two essential genes with a role in B. abortus cell division, dipM and cdlP. Loss of function of dipM and cdlP generates swelling at the division site. While DipM is strictly localized at the division site, CdlP is localized at the growth pole and the division site. Altogether, the unexpected chaining phenotype of a hisB mutant allowed the discovery of new crucial actors in cell division in B. abortus.
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Affiliation(s)
- Agnès Roba
- Research Unit in Biology of Microorganisms, Narilis, University of Namur, Namur, Belgium
| | - Elodie Carlier
- Research Unit in Biology of Microorganisms, Narilis, University of Namur, Namur, Belgium
| | - Pierre Godessart
- Research Unit in Biology of Microorganisms, Narilis, University of Namur, Namur, Belgium
| | - Cerine Naili
- Research Unit in Biology of Microorganisms, Narilis, University of Namur, Namur, Belgium
| | - Xavier De Bolle
- Research Unit in Biology of Microorganisms, Narilis, University of Namur, Namur, Belgium
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17
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Call SN, Andrews LB. CRISPR-Based Approaches for Gene Regulation in Non-Model Bacteria. Front Genome Ed 2022; 4:892304. [PMID: 35813973 PMCID: PMC9260158 DOI: 10.3389/fgeed.2022.892304] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/11/2022] [Indexed: 01/08/2023] Open
Abstract
CRISPR interference (CRISPRi) and CRISPR activation (CRISPRa) have become ubiquitous approaches to control gene expression in bacteria due to their simple design and effectiveness. By regulating transcription of a target gene(s), CRISPRi/a can dynamically engineer cellular metabolism, implement transcriptional regulation circuitry, or elucidate genotype-phenotype relationships from smaller targeted libraries up to whole genome-wide libraries. While CRISPRi/a has been primarily established in the model bacteria Escherichia coli and Bacillus subtilis, a growing numbering of studies have demonstrated the extension of these tools to other species of bacteria (here broadly referred to as non-model bacteria). In this mini-review, we discuss the challenges that contribute to the slower creation of CRISPRi/a tools in diverse, non-model bacteria and summarize the current state of these approaches across bacterial phyla. We find that despite the potential difficulties in establishing novel CRISPRi/a in non-model microbes, over 190 recent examples across eight bacterial phyla have been reported in the literature. Most studies have focused on tool development or used these CRISPRi/a approaches to interrogate gene function, with fewer examples applying CRISPRi/a gene regulation for metabolic engineering or high-throughput screens and selections. To date, most CRISPRi/a reports have been developed for common strains of non-model bacterial species, suggesting barriers remain to establish these genetic tools in undomesticated bacteria. More efficient and generalizable methods will help realize the immense potential of programmable CRISPR-based transcriptional control in diverse bacteria.
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Affiliation(s)
- Stephanie N. Call
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, United States
| | - Lauren B. Andrews
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, United States
- Biotechnology Training Program, University of Massachusetts Amherst, Amherst, MA, United States
- Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, MA, United States
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18
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Balagurunathan B, Ling H, Choi WJ, Chang MW. Potential use of microbial engineering in single-cell protein production. Curr Opin Biotechnol 2022; 76:102740. [PMID: 35660478 DOI: 10.1016/j.copbio.2022.102740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 04/08/2022] [Accepted: 04/28/2022] [Indexed: 12/16/2022]
Abstract
Single-cell proteins (SCPs) have been widely used in human food and animal feed applications, still, there are challenges in their production and commercialization. Recently, advances in microbial synthetic biology, genomic engineering, and biofoundry technologies have offered capabilities to effectively and rapidly engineer microorganisms for improving the productivity, nutritional, and functional quality of SCPs. In this review, we discuss various synthetic biology, genomic engineering, and biofoundry tools that can be harnessed for SCP production and genetic modification. We also describe the current and potential applications of genetic modification in producing intermediate feedstocks, as well as biomass-based and multifunctional SCPs. Finally, we discuss the technological and policy-control related challenges encountered when deploying genetic modification in SCP production for animal feed and human food applications.
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Affiliation(s)
- Balaji Balagurunathan
- Singapore Institute of Food and Biotechnology Innovation, Agency for Science, Technology and Research (A⁎STAR) 1, Pesek Road, Jurong Island, 627833, Singapore.
| | - Hua Ling
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; Wilmar-NUS Corporate Laboratory (WIL@NUS), National University of Singapore, 14 Medical Drive, Singapore 117599, Singapore.
| | - Won Jae Choi
- Singapore Institute of Food and Biotechnology Innovation, Agency for Science, Technology and Research (A⁎STAR) 1, Pesek Road, Jurong Island, 627833, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research in Singapore (A⁎STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Singapore; Singapore Institute of Technology, 10 Dover Dr, Singapore 138683, Singapore
| | - Matthew Wook Chang
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; Wilmar-NUS Corporate Laboratory (WIL@NUS), National University of Singapore, 14 Medical Drive, Singapore 117599, Singapore.
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19
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Schwarz TS, Schreiber SS, Marchfelder A. CRISPR Interference as a Tool to Repress Gene Expression in Haloferax volcanii. Methods Mol Biol 2022; 2522:57-85. [PMID: 36125743 DOI: 10.1007/978-1-0716-2445-6_4] [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: 06/15/2023]
Abstract
To date, a plethora of tools for molecular biology have been developed on the basis of the CRISPR-Cas system. Almost all use the class 2 systems since here the setup is the simplest with only one protein and one guide RNA, allowing for easy transfer to and expression in other organisms. However, the CRISPR-Cas components harnessed for applications are derived from mesophilic bacteria and are not optimal for use in extremophilic archaea.Here, we describe the application of an endogenous CRISPR-Cas system as a tool for silencing gene expression in a halophilic archaeon. Haloferax volcanii has a CRISPR-Cas system of subtype I-B, which can be easily used to repress the transcription of endogenous genes, allowing to study the effects of their depletion. This article gives a step-by-step introduction on how to use the implemented system for any gene of interest in Haloferax volcanii. The concept of CRISPRi described here for Haloferax can be transferred to any other archaeon, that is genetically tractable and has an endogenous CRISPR-Cas I systems.
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20
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Braga A, Gomes D, Rainha J, Amorim C, Cardoso BB, Gudiña EJ, Silvério SC, Rodrigues JL, Rodrigues LR. Zymomonas mobilis as an emerging biotechnological chassis for the production of industrially relevant compounds. BIORESOUR BIOPROCESS 2021; 8:128. [PMID: 38650193 PMCID: PMC10992037 DOI: 10.1186/s40643-021-00483-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/06/2021] [Indexed: 11/10/2022] Open
Abstract
Zymomonas mobilis is a well-recognized ethanologenic bacterium with outstanding characteristics which make it a promising platform for the biotechnological production of relevant building blocks and fine chemicals compounds. In the last years, research has been focused on the physiological, genetic, and metabolic engineering strategies aiming at expanding Z. mobilis ability to metabolize lignocellulosic substrates toward biofuel production. With the expansion of the Z. mobilis molecular and computational modeling toolbox, the potential of this bacterium as a cell factory has been thoroughly explored. The number of genomic, transcriptomic, proteomic, and fluxomic data that is becoming available for this bacterium has increased. For this reason, in the forthcoming years, systems biology is expected to continue driving the improvement of Z. mobilis for current and emergent biotechnological applications. While the existing molecular toolbox allowed the creation of stable Z. mobilis strains with improved traits for pinpointed biotechnological applications, the development of new and more flexible tools is crucial to boost the engineering capabilities of this bacterium. Novel genetic toolkits based on the CRISPR-Cas9 system and recombineering have been recently used for the metabolic engineering of Z. mobilis. However, they are mostly at the proof-of-concept stage and need to be further improved.
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Affiliation(s)
- Adelaide Braga
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Daniela Gomes
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - João Rainha
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Cláudia Amorim
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Beatriz B Cardoso
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Eduardo J Gudiña
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Sara C Silvério
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Joana L Rodrigues
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Lígia R Rodrigues
- CEB-Centre of Biological Engineering, Universidade Do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
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21
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Sui X, Wang X, Liu T, Ye Q, Wu B, Hu G, Yang S, He M, Peng N. Endogenous CRISPR-assisted microhomology-mediated end joining enables rapid genome editing in Zymomonas mobilis. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:208. [PMID: 34689795 PMCID: PMC8543907 DOI: 10.1186/s13068-021-02056-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Zymomonas mobilis is a natural ethanologen with many desirable characteristics, making it an ideal platform for future biorefineries. Recently, an endogenous CRISPR-based genome editing tool has been developed for this species. However, a simple and high-efficient genome editing method is still required. RESULTS We developed a novel gene deletion tool based on the endogenous subtype I-F CRISPR-Cas system and the microhomology-mediated end joining (MMEJ) pathway. This tool only requires a self-interference plasmid carrying the mini-CRISPR (Repeat-Spacer-Repeat) expression cassette, where the spacer matches the target DNA. Transformation of the self-interference plasmid leads to target DNA damage and subsequently triggers the endogenous MMEJ pathway to repair the damaged DNA, leaving deletions normally smaller than 500 bp. Importantly, the MMEJ repair efficiency was increased by introducing mutations at the second repeat of the mini-CRISPR cassette expressing the guide RNA. Several genes have been successfully deleted via this method, and the phenotype of a σ28 deletion mutant generated in this study was characterized. Moreover, large fragment deletions were obtained by transformation of the self-interference plasmids expressing two guide RNAs in tandem. CONCLUSIONS Here, we report the establishment of an efficient gene deletion tool based on the endogenous subtype I-F CRISPR-Cas system and the MMEJ pathway in Zymomonas mobilis. We achieved single gene deletion and large-fragment knockout using this tool. In addition, we further promoted the editing efficiency by modifying the guide RNA expression cassette and selecting lower GC% target sites. Our study has provided an effective method for genetic manipulation in Z. mobilis.
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Affiliation(s)
- Xin Sui
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Xiaojie Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Tao Liu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Qing Ye
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Bo Wu
- Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Chengdu, 610041, Sichuan, People's Republic of China
| | - Guoquan Hu
- Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Chengdu, 610041, Sichuan, People's Republic of China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Engineering Research Center for Bio-Enzyme Catalysis, Environmental Microbial Technology Center of Hubei Province, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, School of Life Sciences, Hubei University, Wuhan, 430062, People's Republic of China
| | - Mingxiong He
- Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Chengdu, 610041, Sichuan, People's Republic of China.
| | - Nan Peng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China.
- Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biomass Energy Technology Research Centre, Biogas Institute of Ministry of Agriculture, Chengdu, 610041, Sichuan, People's Republic of China.
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Fuchino K, Wasser D, Soppa J. Genome Copy Number Quantification Revealed That the Ethanologenic Alpha-Proteobacterium Zymomonas mobilis Is Polyploid. Front Microbiol 2021; 12:705895. [PMID: 34408736 PMCID: PMC8365228 DOI: 10.3389/fmicb.2021.705895] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/07/2021] [Indexed: 11/20/2022] Open
Abstract
The alpha-proteobacterium Zymomonas mobilis is a promising biofuel producer, based on its native metabolism that efficiently converts sugars to ethanol. Therefore, it has a high potential for industrial-scale biofuel production. Two previous studies suggested that Z. mobilis strain Zm4 might not be monoploid. However, a systematic analysis of the genome copy number is still missing, in spite of the high potential importance of Z. mobilis. To get a deep insight into the ploidy level of Z. mobilis and its regulation, the genome copy numbers of three strains were quantified. The analyses revealed that, during anaerobic growth, the lab strain Zm6, the Zm6 type strain obtained from DSMZ (German Collection of Microorganisms), and the lab strain Zm4, have copy numbers of 18.9, 22.3 and 16.2, respectively, of an origin-adjacent region. The copy numbers of a terminus-adjacent region were somewhat lower with 9.3, 15.8, and 12.9, respectively. The values were similar throughout the growth curves, and they were only slightly downregulated in late stationary phase. During aerobic growth, the copy numbers of the lab strain Zm6 were much higher with around 40 origin-adjacent copies and 17 terminus-adjacent copies. However, the cells were larger during aerobic growth, and the copy numbers per μm3 cell volume were rather similar. Taken together, this first systematic analysis revealed that Z. mobilis is polyploid under regular laboratory growth conditions. The copy number is constant during growth, in contrast to many other polyploid bacteria. This knowledge should be considered in further engineering of the strain for industrial applications.
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Affiliation(s)
- Katsuya Fuchino
- Institute for Molecular Biosciences, Goethe-University, Frankfurt, Germany.,Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, Trondheim, Norway
| | - Daniel Wasser
- Institute for Molecular Biosciences, Goethe-University, Frankfurt, Germany
| | - Jörg Soppa
- Institute for Molecular Biosciences, Goethe-University, Frankfurt, Germany
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Banta AB, Ward RD, Tran JS, Bacon EE, Peters JM. Programmable Gene Knockdown in Diverse Bacteria Using Mobile-CRISPRi. ACTA ACUST UNITED AC 2020; 59:e130. [PMID: 33332762 PMCID: PMC7809906 DOI: 10.1002/cpmc.130] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Facile bacterial genome sequencing has unlocked a veritable treasure trove of novel genes awaiting functional exploration. To make the most of this opportunity requires powerful genetic tools that can target all genes in diverse bacteria. CRISPR interference (CRISPRi) is a programmable gene‐knockdown tool that uses an RNA‐protein complex comprised of a single guide RNA (sgRNA) and a catalytically inactive Cas9 nuclease (dCas9) to sterically block transcription of target genes. We previously developed a suite of modular CRISPRi systems that transfer by conjugation and integrate into the genomes of diverse bacteria, which we call Mobile‐CRISPRi. Here, we provide detailed protocols for the modification and transfer of Mobile‐CRISPRi vectors for the purpose of knocking down target genes in bacteria of interest. We further discuss strategies for optimizing Mobile‐CRISPRi knockdown, transfer, and integration. We cover the following basic protocols: sgRNA design, cloning new sgRNA spacers into Mobile‐CRISPRi vectors, Tn7 transfer of Mobile‐CRISPRi to Gram‐negative bacteria, and ICEBs1 transfer of Mobile‐CRISPRi to Bacillales. © 2020 The Authors. Basic Protocol 1: sgRNA design Basic Protocol 2: Cloning of new sgRNA spacers into Mobile‐CRISPRi vectors Basic Protocol 3: Tn7 transfer of Mobile‐CRISPRi to Gram‐negative bacteria Basic Protocol 4: ICEBs1 transfer of Mobile‐CRISPRi to Bacillales Support Protocol 1: Quantification of CRISPRi repression using fluorescent reporters Support Protocol 2: Testing for gene essentiality using CRISPRi spot assays on plates Support Protocol 3: Transformation of E. coli by electroporation Support Protocol 4: Transformation of CaCl2‐competent E. coli
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Affiliation(s)
- Amy B Banta
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin.,Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin
| | - Ryan D Ward
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin.,Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jennifer S Tran
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin
| | - Emily E Bacon
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jason M Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin.,Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin.,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin.,Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin
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24
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Todor H, Silvis MR, Osadnik H, Gross CA. Bacterial CRISPR screens for gene function. Curr Opin Microbiol 2020; 59:102-109. [PMID: 33285498 DOI: 10.1016/j.mib.2020.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 12/16/2022]
Abstract
In this review we describe the application of CRISPR tools for functional genomics screens in bacteria, with a focus on the use of interference (CRISPRi) approaches. We review recent developments in CRISPRi titration, which has enabled essential gene functional screens, and genome-scale pooled CRISPRi screens. We summarize progress toward enabling CRISPRi screens in non-model and pathogenic bacteria, including the development of new dCas9 variants. Taking into account the current state of the field, we provide a forward-looking analysis of CRISPRi strategies for determining gene function in bacteria.
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Affiliation(s)
- Horia Todor
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Melanie R Silvis
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Hendrik Osadnik
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Carol A Gross
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute of Quantitative Biology, University of California, San Francisco, San Francisco 94158 CA, USA.
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