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Delarouzée A, Lopes Ferreira N, Baum C, Wasels F. Gene essentiality in the solventogenic Clostridium acetobutylicum DSM 792. Appl Environ Microbiol 2024; 90:e0028224. [PMID: 38864631 PMCID: PMC11267918 DOI: 10.1128/aem.00282-24] [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: 02/15/2024] [Accepted: 05/20/2024] [Indexed: 06/13/2024] Open
Abstract
Clostridium acetobutylicum is a solventogenic, anaerobic, gram-positive bacterium that is commonly considered the model organism for studying acetone-butanol-ethanol fermentation. The need to produce these chemicals sustainably and with a minimal impact on the environment has revived the interest in research on this bacterium. The recent development of efficient genetic tools allows to better understand the physiology of this micro-organism, aiming at improving its fermentation capacities. Knowledge about gene essentiality would guide the future genetic editing strategies and support the understanding of crucial cellular functions in this bacterium. In this work, we applied a transposon insertion site sequencing method to generate large mutant libraries containing millions of independent mutants that allowed us to identify a core group of 418 essential genes needed for in vitro development. Future research on this significant biocatalyst will be guided by the data provided in this work, which will serve as a valuable resource for the community. IMPORTANCE Clostridium acetobutylicum is a leading candidate to synthesize valuable compounds like three and four carbons alcohols. Its ability to convert carbohydrates into a mixture of acetone, butanol, and ethanol as well as other chemicals of interest upon genetic engineering makes it an advantageous organism for the valorization of lignocellulose-derived sugar mixtures. Since, genetic optimization depends on the fundamental insights supplied by accurate gene function assignment, gene essentiality analysis is of great interest as it can shed light on the function of many genes whose functions are still to be confirmed. The data obtained in this study will be of great value for the research community aiming to develop C. acetobutylicum as a platform organism for the production of chemicals of interest.
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Affiliation(s)
| | | | - Chloé Baum
- Institut Pasteur, Université Paris Cité, Plate-forme Technologique Biomics, Paris, France
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2
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Tripathi S, Voogdt CGP, Bassler SO, Anderson M, Huang PH, Sakenova N, Capraz T, Jain S, Koumoutsi A, Bravo AM, Trotter V, Zimmerman M, Sonnenburg JL, Buie C, Typas A, Deutschbauer AM, Shiver AL, Huang KC. Randomly barcoded transposon mutant libraries for gut commensals I: Strategies for efficient library construction. Cell Rep 2024; 43:113517. [PMID: 38142397 DOI: 10.1016/j.celrep.2023.113517] [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: 07/27/2023] [Revised: 10/22/2023] [Accepted: 11/14/2023] [Indexed: 12/26/2023] Open
Abstract
Randomly barcoded transposon mutant libraries are powerful tools for studying gene function and organization, assessing gene essentiality and pathways, discovering potential therapeutic targets, and understanding the physiology of gut bacteria and their interactions with the host. However, construction of high-quality libraries with uniform representation can be challenging. In this review, we survey various strategies for barcoded library construction, including transposition systems, methods of transposon delivery, optimal library size, and transconjugant selection schemes. We discuss the advantages and limitations of each approach, as well as factors to consider when selecting a strategy. In addition, we highlight experimental and computational advances in arraying condensed libraries from mutant pools. We focus on examples of successful library construction in gut bacteria and their application to gene function studies and drug discovery. Given the need for understanding gene function and organization in gut bacteria, we provide a comprehensive guide for researchers to construct randomly barcoded transposon mutant libraries.
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Affiliation(s)
- Surya Tripathi
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Carlos Geert Pieter Voogdt
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Stefan Oliver Bassler
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, Grabengasse 1, 69117 Heidelberg, Germany
| | - Mary Anderson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Po-Hsun Huang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nazgul Sakenova
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Tümay Capraz
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sunit Jain
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Alexandra Koumoutsi
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Afonso Martins Bravo
- Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Valentine Trotter
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Michael Zimmerman
- Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Justin L Sonnenburg
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Cullen Buie
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Athanasios Typas
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany.
| | - Adam M Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Anthony L Shiver
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
| | - Kerwyn Casey Huang
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
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3
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Tan Y, Liang J, Lai M, Wan S, Luo X, Li F. Advances in synthetic biology toolboxes paving the way for mechanistic understanding and strain engineering of gut commensal Bacteroides spp. and Clostridium spp. Biotechnol Adv 2023; 69:108272. [PMID: 37844770 DOI: 10.1016/j.biotechadv.2023.108272] [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: 08/13/2023] [Revised: 10/10/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
The gut microbiota plays a significant role in influencing human immunity, metabolism, development, and behavior by producing a wide range of metabolites. While there is accumulating data on several microbiota-derived small molecules that contribute to host health and disease, our knowledge regarding the molecular mechanisms underlying metabolite-mediated microbe-host interactions remains limited. This is primarily due to the lack of efficient genetic tools for most commensal bacteria, especially those belonging to the dominant phyla Bacteroides spp. and Clostridium spp., which hinders the application of synthetic biology to these gut commensal bacteria. In this review, we provide an overview of recent advances in synthetic biology tools developed for the two dominant genera, as well as their applications in deciphering the mechanisms of microbe-host interactions mediated by microbiota-derived small molecules. We also discuss the potential biomedical applications of engineering commensal bacteria using these toolboxes. Finally, we share our perspective on the future development of synthetic biology tools for a better understanding of small molecule-mediated microbe-host interactions and their engineering for biomedical purposes.
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Affiliation(s)
- Yang Tan
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao C1 Refinery Engineering Research Center, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; Shandong Energy Institute, Qingdao 266101, China; Qingdao New Energy Shandong Laboratory, Qingdao 266101, China.
| | - Jing Liang
- Center for Synthetic Biochemistry, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Mingchi Lai
- College of Life Sciences, Qingdao Agricultural University, Qingdao 266109, China
| | - Sai Wan
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao C1 Refinery Engineering Research Center, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; Shandong Energy Institute, Qingdao 266101, China; Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Xiaozhou Luo
- Center for Synthetic Biochemistry, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Fuli Li
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao C1 Refinery Engineering Research Center, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; Shandong Energy Institute, Qingdao 266101, China; Qingdao New Energy Shandong Laboratory, Qingdao 266101, China.
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4
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Alenezi T, Fu Y, Alrubaye B, Alanazi T, Almansour A, Wang H, Sun X. Potent Bile Acid Microbial Metabolites Modulate Clostridium perfringens Virulence. Pathogens 2023; 12:1202. [PMID: 37887718 PMCID: PMC10610205 DOI: 10.3390/pathogens12101202] [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: 08/24/2023] [Revised: 09/19/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
Clostridium perfringens is a versatile pathogen, inducing diseases in the skin, intestine (such as chicken necrotic enteritis (NE)), and other organs. The classical sign of NE is the foul smell gas in the ballooned small intestine. We hypothesized that deoxycholic acid (DCA) reduced NE by inhibiting C. perfringens virulence signaling pathways. To evaluate the hypothesis, C. perfringens strains CP1 and wild-type (WT) HN13 and its mutants were cultured with different bile acids, including DCA and isoallolithocholic acid (isoalloLCA). Growth, hydrogen sulfide (H2S) production, and virulence gene expression were measured. Notably, isoalloLCA was more potent in reducing growth, H2S production, and virulence gene expression in CP1 and WT HN13 compared to DCA, while other bile acids were less potent compared to DCA. Interestingly, there was a slightly different impact between DCA and isoalloLCA on the growth, H2S production, and virulence gene expression in the three HN13 mutants, suggesting possibly different signaling pathways modulated by the two bile acids. In conclusion, DCA and isoalloLCA reduced C. perfringens virulence by transcriptionally modulating the pathogen signaling pathways. The findings could be used to design new strategies to prevent and treat C. perfringens-induced diseases.
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Affiliation(s)
- Tahrir Alenezi
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA; (T.A.); (Y.F.); (B.A.); (T.A.); (A.A.); (H.W.)
- Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA
- College of Medical Applied Sciences, The Northern Border University, Arar 91431, Saudi Arabia
| | - Ying Fu
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA; (T.A.); (Y.F.); (B.A.); (T.A.); (A.A.); (H.W.)
| | - Bilal Alrubaye
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA; (T.A.); (Y.F.); (B.A.); (T.A.); (A.A.); (H.W.)
| | - Thamer Alanazi
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA; (T.A.); (Y.F.); (B.A.); (T.A.); (A.A.); (H.W.)
- Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Ayidh Almansour
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA; (T.A.); (Y.F.); (B.A.); (T.A.); (A.A.); (H.W.)
- Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Hong Wang
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA; (T.A.); (Y.F.); (B.A.); (T.A.); (A.A.); (H.W.)
- Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Xiaolun Sun
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA; (T.A.); (Y.F.); (B.A.); (T.A.); (A.A.); (H.W.)
- Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA
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Bailey TS, Hittmeyer P, Zhang Y, Kubiak AM. Streamlined assembly of cloning and genome editing vectors for genus Clostridium. iScience 2023; 26:107484. [PMID: 37599836 PMCID: PMC10432817 DOI: 10.1016/j.isci.2023.107484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 03/27/2023] [Accepted: 07/24/2023] [Indexed: 08/22/2023] Open
Abstract
Reported herein is a new set of vectors designed to streamline molecular cloning and genome editing by exploiting modern cloning methods. The new vectors build on the existing pMTL8000 vectors that have been a staple of Clostridium research for more than a decade. The introduction of two pairs of type IIS restriction sites flanking an insulated multiple cloning site in both a cloning vector and a CRISPR-Cas9 gene editing vector enables plasmid construction in a "one-pot" reaction, avoiding the more laborious steps of conventional cloning. A synthetic lacZα expression cassette introduced between the cloning sites enables visual detection of background colonies. In addition, distinct selection markers on each vector permit selection of the desired clones according to antibiotic resistance. An example of strain development using the new vectors is demonstrated.
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Affiliation(s)
- Tom S. Bailey
- GROW - School for Oncology and Reproduction, Faculty of Health and Medical Life Sciences, Maastricht University, Maastricht, Limburg, the Netherlands
| | - Philip Hittmeyer
- GROW - School for Oncology and Reproduction, Faculty of Health and Medical Life Sciences, Maastricht University, Maastricht, Limburg, the Netherlands
| | - Yanchao Zhang
- GROW - School for Oncology and Reproduction, Faculty of Health and Medical Life Sciences, Maastricht University, Maastricht, Limburg, the Netherlands
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Bortolucci J, Guazzaroni ME, Schoch T, Dürre P, Reginatto V. Enhancing 1,3-Propanediol Productivity in the Non-Model Chassis Clostridium beijerinckii through Genetic Manipulation. Microorganisms 2023; 11:1855. [PMID: 37513028 PMCID: PMC10383064 DOI: 10.3390/microorganisms11071855] [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: 06/16/2023] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
Biotechnological processes at biorefineries are considered one of the most attractive alternatives for valorizing biomasses by converting them into bioproducts, biofuels, and bioenergy. For example, biodiesel can be obtained from oils and grease but generates glycerol as a byproduct. Glycerol recycling has been studied in several bioprocesses, with one of them being its conversion to 1,3-propanediol (1,3-PDO) by Clostridium. Clostridium beijerinckii is particularly interesting because it can produce a range of industrially relevant chemicals, including solvents and organic acids, and it is non-pathogenic. However, while Clostridium species have many potential advantages as chassis for synthetic biology applications, there are significant limitations when considering their use, such as their limited genetic tools, slow growth rate, and oxygen sensitivity. In this work, we carried out the overexpression of the genes involved in the synthesis of 1,3-PDO in C. beijerinckii Br21, which allowed us to increase the 1,3-PDO productivity in this strain. Thus, this study contributed to a better understanding of the metabolic pathways of glycerol conversion to 1,3-PDO by a C. beijerinckii isolate. Also, it made it possible to establish a transformation method of a modular vector in this strain, therefore expanding the limited genetic tools available for this bacterium, which is highly relevant in biotechnological applications.
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Affiliation(s)
- Jonatã Bortolucci
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto 14040-030, SP, Brazil
| | - María-Eugenia Guazzaroni
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto 14040-030, SP, Brazil
| | - Teresa Schoch
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee, 11, D-89081 Ulm, Germany
| | - Peter Dürre
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee, 11, D-89081 Ulm, Germany
| | - Valeria Reginatto
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto 14040-030, SP, Brazil
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7
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Ronish LA, Sidner B, Yu Y, Piepenbrink KH. Recognition of extracellular DNA by type IV pili promotes biofilm formation by Clostridioides difficile. J Biol Chem 2022; 298:102449. [PMID: 36064001 PMCID: PMC9556784 DOI: 10.1016/j.jbc.2022.102449] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/15/2022] Open
Abstract
Clostridioides difficile is a Gram-positive bacillus, which is a frequent cause of gastrointestinal infections triggered by the depletion of the gut microbiome. Because of the frequent recurrence of these infections after antibiotic treatment, mechanisms of C. difficile persistence and recurrence, including biofilm formation, are of increasing interest. Previously, our group and others found that type IV pili, filamentous helical appendages polymerized from protein subunits, promoted microcolony and biofilm formation in C. difficile. In Gram-negative bacteria, the ability of type IV pili to mediate bacterial self-association has been explained through interactions between the pili of adjacent cells, but type IV pili from several Gram-negative species are also required for natural competence through DNA uptake. Here, we report the ability of two C. difficile pilin subunits, PilJ and PilW, to bind to DNA in vitro, as well as the defects in biofilm formation in the pilJ and pilW gene-interruption mutants. Additionally, we have resolved the X-ray crystal structure of PilW, which we use to model possible structural mechanisms for the formation of C. difficile biofilm through interactions between type IV pili and the DNA of the extracellular matrix. Taken together, our results provide further insight into the relationship between type IV pilus function and biofilm formation in C. difficile and, more broadly, suggest that DNA recognition by type IV pili and related structures may have functional importance beyond DNA uptake for natural competence.
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Affiliation(s)
- Leslie A Ronish
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Ben Sidner
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Yafan Yu
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Kurt H Piepenbrink
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Nebraska Food for Health Center, University of Nebraska-Lincoln, Lincoln, Nebraska, USA; Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.
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8
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Mechanical limitation of bacterial motility mediated by growing cell chains. Biophys J 2022; 121:2461-2473. [PMID: 35591787 DOI: 10.1016/j.bpj.2022.05.012] [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: 01/05/2022] [Revised: 04/20/2022] [Accepted: 05/12/2022] [Indexed: 11/23/2022] Open
Abstract
Contrasting most known bacterial motility mechanisms, a bacterial sliding motility discovered in at least two Gram-positive bacterial families does not depend on designated motors. Instead, the cells maintain end-to-end connections following cell divisions to form long chains and exploit cell growth and division to push the cells forward. To investigate the dynamics of this motility mechanism, we constructed a mechanical model that depicts the interplay of the forces acting on and between the cells comprising the chain. Due to the exponential growth of individual cells, the tips of the chains can, in principle, accelerate to speeds faster than any known single-cell motility mechanism can achieve. However, analysis of the mechanical model shows that the exponential acceleration comes at the cost of an exponential buildup in mechanical stress in the chain, making overly long chains prone to breakage. Additionally, the mechanical model reveals that the dynamics of the chain expansion hinges on a single non-dimensional parameter. Perturbation analysis of the mechanical model further predicts the critical stress leading to chain breakage and its dependence on the non-dimensional parameter. Finally, we developed a simplistic population expansion model that uses the predicted breaking behavior to estimate the physical limit of chain-mediated population expansion. Predictions from the models provide critical insights into how this motility depends on key physical properties of the cell and the substrate. Overall, our models present a generically applicable theoretical framework for cell chain-mediated bacterial sliding motility and provide guidance for future experimental studies on such motility.
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Joseph RC, Kelley SQ, Kim NM, Sandoval NR. Metabolic Engineering and the Synthetic Biology Toolbox for
Clostridium. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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10
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Jackson DR, Cassilly CD, Plichta DR, Vlamakis H, Liu H, Melville SB, Xavier RJ, Clardy J. Plasmalogen Biosynthesis by Anaerobic Bacteria: Identification of a Two-Gene Operon Responsible for Plasmalogen Production in Clostridium perfringens. ACS Chem Biol 2021; 16:6-13. [PMID: 33350306 PMCID: PMC7812594 DOI: 10.1021/acschembio.0c00673] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
![]()
Plasmalogens are vinyl ether-containing
lipids produced by mammals
and bacteria. The aerobic biosynthetic pathway in eukaryotes and bacteria
is known, but the anaerobic pathway has remained a mystery. Here,
we describe a two-gene operon (plasmalogen synthase, pls) responsible for plasmalogen production in the anaerobic bacterium Clostridium perfringens. While aerobic plasmalogen biosynthesis
involves an oxidative conversion of an ether to a vinyl ether, anaerobic
plasmalogen biosynthesis uses the reductive conversion of an ester
to an aldehyde equivalent. Heterologous expression of the C. perfringens pls operon in E. coli conferred
the ability to produce plasmalogens. The pls operon
is predicted to encode a multidomain complex similar to benzoyl-CoA
reductase/hydroxylacyl-CoA dehydratase (BCR/HAD) enzymes. Versions
of this operon can be found in a wide range of obligate and facultative
anaerobic bacteria, including many human gut microbes.
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Affiliation(s)
- David R. Jackson
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston Massachusetts 02115, United States
| | - Chelsi D. Cassilly
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston Massachusetts 02115, United States
| | - Damian R. Plichta
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Hera Vlamakis
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Hualan Liu
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Stephen B. Melville
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Ramnik J. Xavier
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston Massachusetts 02115, United States
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Kazi MI, Schargel RD, Boll JM. Generating Transposon Insertion Libraries in Gram-Negative Bacteria for High-Throughput Sequencing. J Vis Exp 2020. [PMID: 32716393 DOI: 10.3791/61612] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Transposon sequencing (Tn-seq) is a powerful method that combines transposon mutagenesis and massive parallel sequencing to identify genes and pathways that contribute to bacterial fitness under a wide range of environmental conditions. Tn-seq applications are extensive and have not only enabled examination of genotype-phenotype relationships at an organism level but also at the population, community and systems levels. Gram-negative bacteria are highly associated with antimicrobial resistance phenotypes, which has increased incidents of antibiotic treatment failure. Antimicrobial resistance is defined as bacterial growth in the presence of otherwise lethal antibiotics. The "last-line" antimicrobial colistin is used to treat Gram-negative bacterial infections. However, several Gram-negative pathogens, including Acinetobacter baumannii can develop colistin resistance through a range of molecular mechanisms, some of which were characterized using Tn-seq. Furthermore, signal transduction pathways that regulate colistin resistance vary within Gram-negative bacteria. Here we propose an efficient method of transposon mutagenesis in A. baumannii that streamlines generation of a saturating transposon insertion library and amplicon library construction by eliminating the need for restriction enzymes, adapter ligation, and gel purification. The methods described herein will enable in-depth analysis of molecular determinants that contribute to A. baumannii fitness when challenged with colistin. The protocol is also applicable to other Gram-negative ESKAPE pathogens, which are primarily associated with drug resistant hospital-acquired infections.
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Affiliation(s)
- Misha I Kazi
- Department of Biology, University of Texas at Arlington
| | | | - Joseph M Boll
- Department of Biology, University of Texas at Arlington;
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12
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Wenzel CQ, Mills DC, Dobruchowska JM, Vlach J, Nothaft H, Nation P, Azadi P, Melville SB, Carlson RW, Feldman MF, Szymanski CM. An atypical lipoteichoic acid from Clostridium perfringens elicits a broadly cross-reactive and protective immune response. J Biol Chem 2020; 295:9513-9530. [PMID: 32424044 DOI: 10.1074/jbc.ra119.009978] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 05/02/2020] [Indexed: 12/14/2022] Open
Abstract
Clostridium perfringens is a leading cause of food-poisoning and causes avian necrotic enteritis, posing a significant problem to both the poultry industry and human health. No effective vaccine against C. perfringens is currently available. Using an antiserum screen of mutants generated from a C. perfringens transposon-mutant library, here we identified an immunoreactive antigen that was lost in a putative glycosyltransferase mutant, suggesting that this antigen is likely a glycoconjugate. Following injection of formalin-fixed whole cells of C. perfringens HN13 (a laboratory strain) and JGS4143 (chicken isolate) intramuscularly into chickens, the HN13-derived antiserum was cross-reactive in immunoblots with all tested 32 field isolates, whereas only 5 of 32 isolates were recognized by JGS4143-derived antiserum. The immunoreactive antigens from both HN13 and JGS4143 were isolated, and structural analysis by MALDI-TOF-MS, GC-MS, and 2D NMR revealed that both were atypical lipoteichoic acids (LTAs) with poly-(β1→4)-ManNAc backbones substituted with phosphoethanolamine. However, although the ManNAc residues in JGS4143 LTA were phosphoethanolamine-modified, a few of these residues were instead modified with phosphoglycerol in the HN13 LTA. The JGS4143 LTA also had a terminal ribose and ManNAc instead of ManN in the core region, suggesting that these differences may contribute to the broadly cross-reactive response elicited by HN13. In a passive-protection chicken experiment, oral challenge with C. perfringens JGS4143 lead to 22% survival, whereas co-gavage with JGS4143 and α-HN13 antiserum resulted in 89% survival. This serum also induced bacterial killing in opsonophagocytosis assays, suggesting that HN13 LTA is an attractive target for future vaccine-development studies.
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Affiliation(s)
- Cory Q Wenzel
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,VaxAlta Inc., Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Dominic C Mills
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | | | - Jiri Vlach
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Harald Nothaft
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,VaxAlta Inc., Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Patrick Nation
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Stephen B Melville
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Russell W Carlson
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Mario F Feldman
- VaxAlta Inc., Edmonton, Alberta, Canada.,Department of Molecular Microbiology, Washington University of Medicine, St. Louis, Missouri, USA
| | - Christine M Szymanski
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada .,VaxAlta Inc., Edmonton, Alberta, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.,Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
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13
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Abstract
Since Barbara McClintock’s groundbreaking discovery of mobile DNA sequences some 70 years ago, transposable elements have come to be recognized as important mutagenic agents impacting genome composition, genome evolution, and human health. Transposable elements are a major constituent of prokaryotic and eukaryotic genomes, and the transposition mechanisms enabling transposon proliferation over evolutionary time remain engaging topics for study, suggesting complex interactions with the host, both antagonistic and mutualistic. The impact of transposition is profound, as over 100 human heritable diseases have been attributed to transposon insertions. Transposition can be highly mutagenic, perturbing genome integrity and gene expression in a wide range of organisms. This mutagenic potential has been exploited in the laboratory, where transposons have long been utilized for phenotypic screening and the generation of defined mutant libraries. More recently, barcoding applications and methods for RNA-directed transposition are being used towards new phenotypic screens and studies relevant for gene therapy. Thus, transposable elements are significant in affecting biology both
in vivo and in the laboratory, and this review will survey advances in understanding the biological role of transposons and relevant laboratory applications of these powerful molecular tools.
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Affiliation(s)
- Anuj Kumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.,Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, USA
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14
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Garrett EM, Sekulovic O, Wetzel D, Jones JB, Edwards AN, Vargas-Cuebas G, McBride SM, Tamayo R. Phase variation of a signal transduction system controls Clostridioides difficile colony morphology, motility, and virulence. PLoS Biol 2019; 17:e3000379. [PMID: 31658249 PMCID: PMC6837544 DOI: 10.1371/journal.pbio.3000379] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 11/07/2019] [Accepted: 10/15/2019] [Indexed: 12/20/2022] Open
Abstract
Recent work has revealed that Clostridioides difficile, a major cause of nosocomial diarrheal disease, exhibits phenotypic heterogeneity within a clonal population as a result of phase variation. Many C. difficile strains representing multiple ribotypes develop two colony morphotypes, termed rough and smooth, but the biological implications of this phenomenon have not been explored. Here, we examine the molecular basis and physiological relevance of the distinct colony morphotypes produced by this bacterium. We show that C. difficile reversibly differentiates into rough and smooth colony morphologies and that bacteria derived from the isolates display discrete motility behaviors. We identified an atypical phase-variable signal transduction system consisting of a histidine kinase and two response regulators, named herein colony morphology regulators RST (CmrRST), which mediates the switch in colony morphology and motility behaviors. The CmrRST-regulated surface motility is independent of flagella and type IV pili, suggesting a novel mechanism of cell migration in C. difficile. Microscopic analysis of cell and colony structure indicates that CmrRST promotes the formation of elongated bacteria arranged in bundled chains, which may contribute to bacterial migration on surfaces. In a hamster model of acute C. difficile disease, the CmrRST system is required for disease development. Furthermore, we provide evidence that CmrRST phase varies during infection, suggesting that the intestinal environment impacts the proportion of CmrRST-expressing C. difficile. Our findings indicate that C. difficile employs phase variation of the CmrRST signal transduction system to generate phenotypic heterogeneity during infection, with concomitant effects on bacterial physiology and pathogenesis.
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Affiliation(s)
- Elizabeth M. Garrett
- Department of Microbiology and Immunology, University of North Carolina Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Ognjen Sekulovic
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Daniela Wetzel
- Department of Microbiology and Immunology, Emory University, Rollins Research Center, Atlanta, Georgia, United States of America
| | - Joshua B. Jones
- Department of Microbiology and Immunology, Emory University, Rollins Research Center, Atlanta, Georgia, United States of America
| | - Adrianne N. Edwards
- Department of Microbiology and Immunology, Emory University, Rollins Research Center, Atlanta, Georgia, United States of America
| | - Germán Vargas-Cuebas
- Department of Microbiology and Immunology, Emory University, Rollins Research Center, Atlanta, Georgia, United States of America
| | - Shonna M. McBride
- Department of Microbiology and Immunology, Emory University, Rollins Research Center, Atlanta, Georgia, United States of America
| | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina Chapel Hill, Chapel Hill, North Carolina, United States of America
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15
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Kuehne SA, Rood JI, Lyras D. Clostridial Genetics: Genetic Manipulation of the Pathogenic Clostridia. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0040-2018. [PMID: 31172914 PMCID: PMC11315012 DOI: 10.1128/microbiolspec.gpp3-0040-2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Indexed: 02/07/2023] Open
Abstract
The past 10 years have been revolutionary for clostridial genetics. The rise of next-generation sequencing led to the availability of annotated whole-genome sequences of the important pathogenic clostridia: Clostridium perfringens, Clostridioides (Clostridium) difficile, and Clostridium botulinum, but also Paeniclostridium (Clostridium) sordellii and Clostridium tetani. These sequences were a prerequisite for the development of functional, sophisticated genetic tools for the pathogenic clostridia. A breakthrough came in the early 2000s with the development of TargeTron-based technologies specific for the clostridia, such as ClosTron, an insertional gene inactivation tool. The following years saw a plethora of new technologies being developed, mostly for C. difficile, but also for other members of the genus, including C. perfringens. A range of tools is now available, allowing researchers to precisely delete genes, change single nucleotides in the genome, complement deletions, integrate novel DNA into genomes, or overexpress genes. There are tools for forward genetics, including an inducible transposon mutagenesis system for C. difficile. As the latest addition to the tool kit, clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 technologies have also been adopted for the construction of single and multiple gene deletions in C. difficile. This article summarizes the key genetic technologies available to manipulate, study, and understand the pathogenic clostridia.
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Affiliation(s)
- S A Kuehne
- School of Dentistry and Institute for Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - J I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia 3800
| | - D Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia 3800
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16
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Bouillaut L, Dubois T, Francis MB, Daou N, Monot M, Sorg JA, Sonenshein AL, Dupuy B. Role of the global regulator Rex in control of NAD + -regeneration in Clostridioides (Clostridium) difficile. Mol Microbiol 2019; 111:1671-1688. [PMID: 30882947 DOI: 10.1111/mmi.14245] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2019] [Indexed: 12/31/2022]
Abstract
For the human pathogen Clostridioides (also known as Clostridium) difficile, the ability to adapt to nutrient availability is critical for its proliferation and production of toxins during infection. Synthesis of the toxins is regulated by the availability of certain carbon sources, fermentation products and amino acids (e.g. proline, cysteine, isoleucine, leucine and valine). The effect of proline is attributable at least in part to its role as an inducer and substrate of D-proline reductase (PR), a Stickland reaction that regenerates NAD+ from NADH. Many Clostridium spp. use Stickland metabolism (co-fermentation of pairs of amino acids) to generate ATP and NAD+ . Synthesis of PR is activated by PrdR, a proline-responsive regulatory protein. Here we report that PrdR, in the presence of proline, represses other NAD+ -generating pathways, such as the glycine reductase and succinate-acetyl CoA utilization pathways leading to butyrate production, but does so indirectly by affecting the activity of Rex, a global redox-sensing regulator that responds to the NAD+ /NADH ratio. Our results indicate that PR activity is the favored mechanism for NAD+ regeneration and that both Rex and PrdR influence toxin production. Using the hamster model of C. difficile infection, we revealed the importance of PrdR-regulated Stickland metabolism in the virulence of C. difficile.
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Affiliation(s)
- Laurent Bouillaut
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111
| | - Thomas Dubois
- Pathogenesis of Bacterial Anaerobes Laboratory, Institut Pasteur, 75724, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Michael B Francis
- Department of Biology, Texas A&M University, College Station, TX, 77843
| | - Nadine Daou
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111
| | - Marc Monot
- Pathogenesis of Bacterial Anaerobes Laboratory, Institut Pasteur, 75724, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Joseph A Sorg
- Department of Biology, Texas A&M University, College Station, TX, 77843
| | - Abraham L Sonenshein
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111
| | - Bruno Dupuy
- Pathogenesis of Bacterial Anaerobes Laboratory, Institut Pasteur, 75724, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
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17
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Philipps G, de Vries S, Jennewein S. Development of a metabolic pathway transfer and genomic integration system for the syngas-fermenting bacterium Clostridium ljungdahlii. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:112. [PMID: 31086564 PMCID: PMC6507227 DOI: 10.1186/s13068-019-1448-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 04/22/2019] [Indexed: 05/15/2023]
Abstract
BACKGROUND Clostridium spp. can synthesize valuable chemicals and fuels by utilizing diverse waste-stream substrates, including starchy biomass, lignocellulose, and industrial waste gases. However, metabolic engineering in Clostridium spp. is challenging due to the low efficiency of gene transfer and genomic integration of entire biosynthetic pathways. RESULTS We have developed a reliable gene transfer and genomic integration system for the syngas-fermenting bacterium Clostridium ljungdahlii based on the conjugal transfer of donor plasmids containing large transgene cassettes (> 5 kb) followed by the inducible activation of Himar1 transposase to promote integration. We established a conjugation protocol for the efficient generation of transconjugants using the Gram-positive origins of replication repL and repH. We also investigated the impact of DNA methylation on conjugation efficiency by testing donor constructs with all possible combinations of Dam and Dcm methylation patterns, and used bisulfite conversion and PacBio sequencing to determine the DNA methylation profile of the C. ljungdahlii genome, resulting in the detection of four sequence motifs with N6-methyladenosine. As proof of concept, we demonstrated the transfer and genomic integration of a heterologous acetone biosynthesis pathway using a Himar1 transposase system regulated by a xylose-inducible promoter. The functionality of the integrated pathway was confirmed by detecting enzyme proteotypic peptides and the formation of acetone and isopropanol by C. ljungdahlii cultures utilizing syngas as a carbon and energy source. CONCLUSIONS The developed multi-gene delivery system offers a versatile tool to integrate and stably express large biosynthetic pathways in the industrial promising syngas-fermenting microorganism C. ljungdahlii. The simple transfer and stable integration of large gene clusters (like entire biosynthetic pathways) is expanding the range of possible fermentation products of heterologously expressing recombinant strains. We also believe that the developed gene delivery system can be adapted to other clostridial strains as well.
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Affiliation(s)
- Gabriele Philipps
- Department for Industrial Biotechnology, Fraunhofer IME, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstr. 6, 52074 Aachen, Germany
| | - Sebastian de Vries
- Department for Industrial Biotechnology, Fraunhofer IME, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstr. 6, 52074 Aachen, Germany
- Present Address: Department of Intensive Care Medicine, University Hospital, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany
| | - Stefan Jennewein
- Department for Industrial Biotechnology, Fraunhofer IME, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstr. 6, 52074 Aachen, Germany
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18
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Schlechter RO, Jun H, Bernach M, Oso S, Boyd E, Muñoz-Lintz DA, Dobson RCJ, Remus DM, Remus-Emsermann MNP. Chromatic Bacteria - A Broad Host-Range Plasmid and Chromosomal Insertion Toolbox for Fluorescent Protein Expression in Bacteria. Front Microbiol 2018; 9:3052. [PMID: 30631309 PMCID: PMC6315172 DOI: 10.3389/fmicb.2018.03052] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 11/27/2018] [Indexed: 12/26/2022] Open
Abstract
Differential fluorescent labeling of bacteria has become instrumental for many aspects of microbiological research, such as the study of biofilm formation, bacterial individuality, evolution, and bacterial behavior in complex environments. We designed a variety of plasmids, each bearing one of eight unique, constitutively expressed fluorescent protein genes in conjunction with one of four different antibiotic resistance combinations. The fluorophores mTagBFP2, mTurquoise2, sGFP2, mClover3, sYFP2, mOrange2, mScarlet-I, and mCardinal, encoding for blue, cyan, green, green-yellow, yellow, orange, red, and far-red fluorescent proteins, respectively, were combined with selectable markers conferring tetracycline, gentamicin, kanamycin, and/or chloramphenicol resistance. These constructs were cloned into three different plasmid backbones: a broad host-range plasmid, a Tn5 transposon delivery plasmid, and a Tn7 transposon delivery plasmid. The utility of the plasmids and transposons was tested in bacteria from the phyla Actinobacteria, Proteobacteria, and Bacteroidetes. We were able to tag representatives from the phylum Proteobacteria at least via our Tn5 transposon delivery system. The present study enables labeling bacteria with a set of plasmids available to the community. One potential application of fluorescently-tagged bacterial species is the study of bacteria-bacteria, bacteria-host, and bacteria-environment interactions.
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Affiliation(s)
- Rudolf O. Schlechter
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
| | - Hyunwoo Jun
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Michał Bernach
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
| | - Simisola Oso
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Erica Boyd
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Dian A. Muñoz-Lintz
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Renwick C. J. Dobson
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
- Bio21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Daniela M. Remus
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
- Protein Science & Engineering, Callaghan Innovation, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Mitja N. P. Remus-Emsermann
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand
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19
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A Transposon Mutagenesis System for Bifidobacterium longum subsp. longum Based on an IS 3 Family Insertion Sequence, IS Blo11. Appl Environ Microbiol 2018; 84:AEM.00824-18. [PMID: 29934330 DOI: 10.1128/aem.00824-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 06/16/2018] [Indexed: 12/29/2022] Open
Abstract
Bifidobacteria are a major component of the intestinal microbiota in humans, particularly breast-fed infants. Therefore, elucidation of the mechanisms by which these bacteria colonize the intestine is desired. One approach is transposon mutagenesis, a technique currently attracting much attention because, in combination with next-generation sequencing, it enables exhaustive identification of genes that contribute to microbial fitness. We now describe a transposon mutagenesis system for Bifidobacterium longum subsp. longum 105-A (JCM 31944) based on ISBlo11, a native IS3 family insertion sequence. To build this system, xylose-inducible or constitutive bifidobacterial promoters were tested to drive the expression of full-length or a truncated form at the N terminus of the ISBlo11 transposase. An artificial transposon plasmid, pBFS12, in which ISBlo11 terminal inverted repeats are separated by a 3-bp spacer, was also constructed to mimic the transposition intermediate of IS3 elements. The introduction of this plasmid into a strain expressing transposase resulted in the insertion of the plasmid with an efficiency of >103 CFU/μg DNA. The plasmid targets random 3- to 4-bp sequences, but with a preference for noncoding regions. This mutagenesis system also worked at least in B. longum NCC2705. Characterization of a transposon insertion mutant revealed that a putative α-glucosidase mediates palatinose and trehalose assimilation, demonstrating the suitability of transposon mutagenesis for loss-of-function analysis. We anticipate that this approach will accelerate functional genomic studies of B. longum subsp. longumIMPORTANCE Several hundred species of bacteria colonize the mammalian intestine. However, the genes that enable such bacteria to colonize and thrive in the intestine remain largely unexplored. Transposon mutagenesis, combined with next-generation sequencing, is a promising tool to comprehensively identify these genes but has so far been applied only to a small number of intestinal bacterial species. In this study, a transposon mutagenesis system was established for Bifidobacterium longum subsp. longum, a representative health-promoting Bifidobacterium species. The system enables the identification of genes that promote colonization and survival in the intestine and should help illuminate the physiology of this species.
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20
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Mattingly AE, Weaver AA, Dimkovikj A, Shrout JD. Assessing Travel Conditions: Environmental and Host Influences On Bacterial Surface Motility. J Bacteriol 2018; 200:e00014-18. [PMID: 29555698 PMCID: PMC5952383 DOI: 10.1128/jb.00014-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The degree to which surface motile bacteria explore their surroundings is influenced by aspects of their local environment. Accordingly, regulation of surface motility is controlled by numerous chemical, physical, and biological stimuli. Discernment of such regulation due to these multiple cues is a formidable challenge. Additionally inherent ambiguity and variability from the assays used to assess surface motility can be an obstacle to clear delineation of regulated surface motility behavior. Numerous studies have reported single environmental determinants of microbial motility and lifestyle behavior but the translation of these data to understand surface motility and bacterial colonization of human host or environmental surfaces is unclear. Here, we describe the current state of the field and our understanding of exogenous factors that influence bacterial surface motility.
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Affiliation(s)
- Anne E. Mattingly
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Abigail A. Weaver
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Aleksandar Dimkovikj
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Joshua D. Shrout
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
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21
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Joseph RC, Kim NM, Sandoval NR. Recent Developments of the Synthetic Biology Toolkit for Clostridium. Front Microbiol 2018; 9:154. [PMID: 29483900 PMCID: PMC5816073 DOI: 10.3389/fmicb.2018.00154] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 01/23/2018] [Indexed: 12/15/2022] Open
Abstract
The Clostridium genus is a large, diverse group consisting of Gram-positive, spore-forming, obligate anaerobic firmicutes. Among this group are historically notorious pathogens as well as several industrially relevant species with the ability to produce chemical commodities, particularly biofuels, from renewable biomass. Additionally, other species are studied for their potential use as therapeutics. Although metabolic engineering and synthetic biology have been instrumental in improving product tolerance, titer, yields, and feed stock consumption capabilities in several organisms, low transformation efficiencies and lack of synthetic biology tools and genetic parts make metabolic engineering within the Clostridium genus difficult. Progress has recently been made to overcome challenges associated with engineering various Clostridium spp. For example, developments in CRISPR tools in multiple species and strains allow greater capability to produce edits with greater precision, faster, and with higher efficiencies. In this mini-review, we will highlight these recent advances and compare them to established methods for genetic engineering in Clostridium. In addition, we discuss the current state and development of Clostridium-based promoters (constitutive and inducible) and reporters. Future progress in this area will enable more rapid development of strain engineering, which would allow for the industrial exploitation of Clostridium for several applications including bioproduction of several commodity products.
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Affiliation(s)
- Rochelle C. Joseph
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA, United States
| | - Nancy M. Kim
- Interdisciplinary Bioinnovation PhD Program, Tulane University, New Orleans, LA, United States
| | - Nicholas R. Sandoval
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA, United States
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22
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Magic Pools: Parallel Assessment of Transposon Delivery Vectors in Bacteria. mSystems 2018; 3:mSystems00143-17. [PMID: 29359196 PMCID: PMC5768790 DOI: 10.1128/msystems.00143-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 12/11/2017] [Indexed: 12/14/2022] Open
Abstract
Molecular genetics is indispensable for interrogating the physiology of bacteria. However, the development of a functional genetic system for any given bacterium can be time-consuming. Here, we present a streamlined approach for identifying an effective transposon mutagenesis system for a new bacterium. Our strategy first involves the construction of hundreds of different transposon vector variants, which we term a “magic pool.” The efficacy of each vector in a magic pool is monitored in parallel using a unique DNA barcode that is introduced into each vector design. Using archived DNA “parts,” we next reassemble an effective vector for making a whole-genome transposon mutant library that is suitable for large-scale interrogation of gene function using competitive growth assays. Here, we demonstrate the utility of the magic pool system to make mutant libraries in five genera of bacteria. Transposon mutagenesis coupled to next-generation sequencing (TnSeq) is a powerful approach for discovering the functions of bacterial genes. However, the development of a suitable TnSeq strategy for a given bacterium can be costly and time-consuming. To meet this challenge, we describe a part-based strategy for constructing libraries of hundreds of transposon delivery vectors, which we term “magic pools.” Within a magic pool, each transposon vector has a different combination of upstream sequences (promoters and ribosome binding sites) and antibiotic resistance markers as well as a random DNA barcode sequence, which allows the tracking of each vector during mutagenesis experiments. To identify an efficient vector for a given bacterium, we mutagenize it with a magic pool and sequence the resulting insertions; we then use this efficient vector to generate a large mutant library. We used the magic pool strategy to construct transposon mutant libraries in five genera of bacteria, including three genera of the phylum Bacteroidetes. IMPORTANCE Molecular genetics is indispensable for interrogating the physiology of bacteria. However, the development of a functional genetic system for any given bacterium can be time-consuming. Here, we present a streamlined approach for identifying an effective transposon mutagenesis system for a new bacterium. Our strategy first involves the construction of hundreds of different transposon vector variants, which we term a “magic pool.” The efficacy of each vector in a magic pool is monitored in parallel using a unique DNA barcode that is introduced into each vector design. Using archived DNA “parts,” we next reassemble an effective vector for making a whole-genome transposon mutant library that is suitable for large-scale interrogation of gene function using competitive growth assays. Here, we demonstrate the utility of the magic pool system to make mutant libraries in five genera of bacteria.
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23
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Joseph RC, Kim NM, Sandoval NR. Recent Developments of the Synthetic Biology Toolkit for Clostridium. Front Microbiol 2018. [PMID: 29483900 DOI: 10.3389/fmicb.2018.00154/full] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
The Clostridium genus is a large, diverse group consisting of Gram-positive, spore-forming, obligate anaerobic firmicutes. Among this group are historically notorious pathogens as well as several industrially relevant species with the ability to produce chemical commodities, particularly biofuels, from renewable biomass. Additionally, other species are studied for their potential use as therapeutics. Although metabolic engineering and synthetic biology have been instrumental in improving product tolerance, titer, yields, and feed stock consumption capabilities in several organisms, low transformation efficiencies and lack of synthetic biology tools and genetic parts make metabolic engineering within the Clostridium genus difficult. Progress has recently been made to overcome challenges associated with engineering various Clostridium spp. For example, developments in CRISPR tools in multiple species and strains allow greater capability to produce edits with greater precision, faster, and with higher efficiencies. In this mini-review, we will highlight these recent advances and compare them to established methods for genetic engineering in Clostridium. In addition, we discuss the current state and development of Clostridium-based promoters (constitutive and inducible) and reporters. Future progress in this area will enable more rapid development of strain engineering, which would allow for the industrial exploitation of Clostridium for several applications including bioproduction of several commodity products.
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Affiliation(s)
- Rochelle C Joseph
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA, United States
| | - Nancy M Kim
- Interdisciplinary Bioinnovation PhD Program, Tulane University, New Orleans, LA, United States
| | - Nicholas R Sandoval
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA, United States
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Li C, Lillehoj HS, Gadde UD, Ritter D, Oh S. Characterization ofClostridium perfringensStrains Isolated from Healthy and Necrotic Enteritis-Afflicted Broiler Chickens. Avian Dis 2017; 61:178-185. [DOI: 10.1637/11507-093016-reg.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Charles Li
- Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service–U.S. Department of Agriculture, 10300 Baltimore Avenue, Beltsville, MD 20705
| | - Hyun S. Lillehoj
- Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service–U.S. Department of Agriculture, 10300 Baltimore Avenue, Beltsville, MD 20705
| | - Ujvala Deepthi Gadde
- Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service–U.S. Department of Agriculture, 10300 Baltimore Avenue, Beltsville, MD 20705
| | - Don Ritter
- Mountaire Farms, 29005 John J. Williams Highway, Millsboro, DE 19966
| | - SungTaek Oh
- Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service–U.S. Department of Agriculture, 10300 Baltimore Avenue, Beltsville, MD 20705
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Cyclic Di-GMP Binding by an Assembly ATPase (PilB2) and Control of Type IV Pilin Polymerization in the Gram-Positive Pathogen Clostridium perfringens. J Bacteriol 2017; 199:JB.00034-17. [PMID: 28242722 DOI: 10.1128/jb.00034-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 02/18/2017] [Indexed: 11/20/2022] Open
Abstract
The Gram-positive pathogen Clostridium perfringens possesses type IV pili (TFP), which are extracellular fibers that are polymerized from a pool of pilin monomers in the cytoplasmic membrane. Two proteins that are essential for pilus functions are an assembly ATPase (PilB) and an inner membrane core protein (PilC). Two homologues each of PilB and PilC are present in C. perfringens, called PilB1/PilB2 and PilC1/PilC2, respectively, along with four pilin proteins, PilA1 to PilA4. The gene encoding PilA2, which is considered the major pilin based on previous studies, is immediately downstream of the pilB2 and pilC2 genes. Purified PilB2 had ATPase activity, bound zinc, formed hexamers even in the absence of ATP, and bound the second messenger molecule cyclic di-GMP (c-di-GMP). Circular dichroism spectroscopy of purified PilC2 indicated that it retained its predicted degree of alpha-helical secondary structure. Even though no direct interactions between PilB2 and PilC2 could be detected in vivo or in vitro even in the presence of c-di-GMP, high levels of expression of a diguanylate cyclase from C. perfringens (CPE1788) stimulated polymerization of PilA2 in a PilB2- and PilC2-dependent manner. These results suggest that PilB2 activity is controlled by c-di-GMP levels in vivo but that PilB2-PilC2 interactions are either transitory or of low affinity, in contrast to results reported previously from in vivo studies of the PilB1/PilC1 pair in which PilC1 was needed for polar localization of PilB1. This is the first biochemical characterization of a c-di-GMP-dependent assembly ATPase from a Gram-positive bacterium.IMPORTANCE Type IV pili (TFP) are protein fibers involved in important bacterial functions, including motility, adherence to surfaces and host cells, and natural transformation. All clostridia whose genomes have been sequenced show evidence of the presence of TFP. The genetically tractable species Clostridium perfringens was used to study proteins involved in polymerizing the pilin, PilA2, into a pilus. The assembly ATPase PilB2 and its cognate membrane protein partner, PilC2, were purified. PilB2 bound the intracellular signal molecule c-di-GMP. Increased levels of intracellular c-di-GMP led to increased polymerization of PilA2, indicating that Gram-positive bacteria use this molecule to regulate pilus synthesis. These findings provide valuable information for understanding how pathogenic clostridia regulate TFP to cause human diseases.
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Bengelsdorf FR, Poehlein A, Flitsch SK, Linder S, Schiel-Bengelsdorf B, Stegmann BA, Krabben P, Green E, Zhang Y, Minton N, Dürre P. Host Organisms: Clostridium acetobutylicum/ Clostridium beijerinckiiand Related Organisms. Ind Biotechnol (New Rochelle N Y) 2016. [DOI: 10.1002/9783527807796.ch9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Frank R. Bengelsdorf
- Universität Ulm; Institut für Mikrobiologie und Biotechnologie; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Anja Poehlein
- Georg-August University; Genomic and Applied Microbiology and Göttingen Genomics Laboratory; Göttingen, Grisebachstr. 8 37077 Göttingen Germany
| | - Stefanie K. Flitsch
- Universität Ulm; Institut für Mikrobiologie und Biotechnologie; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Sonja Linder
- Universität Ulm; Institut für Mikrobiologie und Biotechnologie; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Bettina Schiel-Bengelsdorf
- Universität Ulm; Institut für Mikrobiologie und Biotechnologie; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Benjamin A. Stegmann
- Universität Ulm; Institut für Mikrobiologie und Biotechnologie; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Preben Krabben
- Green Biologics Limited; 45A Western Avenue, Milton Park Abingdon Oxfordshire OX14 4RU UK
| | - Edward Green
- CHAIN Biotechnology Limited; Imperial College Incubator, Imperial College London; Level 1 Bessemer Building London SW7 2AZ UK
| | - Ying Zhang
- University of Nottingham; BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences; University Park Nottingham NG7 2RD UK
| | - Nigel Minton
- University of Nottingham; BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences; University Park Nottingham NG7 2RD UK
| | - Peter Dürre
- Universität Ulm; Institut für Mikrobiologie und Biotechnologie; Albert-Einstein-Allee 11 89081 Ulm Germany
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Zhang Y, Xu S, Chai C, Yang S, Jiang W, Minton NP, Gu Y. Development of an inducible transposon system for efficient random mutagenesis in Clostridium acetobutylicum. FEMS Microbiol Lett 2016; 363:fnw065. [PMID: 27001972 PMCID: PMC4941238 DOI: 10.1093/femsle/fnw065] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2016] [Indexed: 01/05/2023] Open
Abstract
Clostridium acetobutylicum is an industrially important Gram-positive organism, which is capable of producing economically important chemicals in the ABE (Acetone, Butanol and Ethanol) fermentation process. Renewed interests in the ABE process necessitate the availability of additional genetics tools to facilitate the derivation of a greater understanding of the underlying metabolic and regulatory control processes in operation through forward genetic strategies. In this study, a xylose inducible, mariner-based, transposon system was developed and shown to allow high-efficient random mutagenesis in the model strain ATCC 824. Of the thiamphenicol resistant colonies obtained, 91.9% were shown to be due to successful transposition of the catP-based mini-transposon element. Phenotypic screening of 200 transposon clones revealed a sporulation-defective clone with an insertion in spo0A, thereby demonstrating that this inducible transposon system can be used for forward genetic studies in C. acetobutylicum. A useful method for forward genetic studies in Clostridium acetobutylicum.
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Affiliation(s)
- Ying Zhang
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Shu Xu
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Changsheng Chai
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Sheng Yang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China Jiangsu National Synergetic Innovation Center for Advanced Materials, SICAM, 200 North Zhongshan Road, Nanjing 210009, China
| | - Weihong Jiang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China Jiangsu National Synergetic Innovation Center for Advanced Materials, SICAM, 200 North Zhongshan Road, Nanjing 210009, China
| | - Nigel P Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Yang Gu
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, China
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Zhang Y, Grosse-Honebrink A, Minton NP. A universal mariner transposon system for forward genetic studies in the genus Clostridium. PLoS One 2015; 10:e0122411. [PMID: 25836262 PMCID: PMC4383383 DOI: 10.1371/journal.pone.0122411] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 02/20/2015] [Indexed: 01/11/2023] Open
Abstract
DNA transposons represent an essential tool in the armoury of the molecular microbiologist. We previously developed a catP-based mini transposon system for Clostridium difficile in which the expression of the transposase gene was dependent on a sigma factor unique to C. difficile, TcdR. Here we have shown that the host range of the transposon is easily extended through the rapid chromosomal insertion of the tcdR gene at the pyrE locus of the intended clostridial target using Allele-Coupled Exchange (ACE). To increase the effectiveness of the system, a novel replicon conditional for plasmid maintenance was developed, which no longer supports the effective retention of the transposon delivery vehicle in the presence of the inducer isopropyl β-D-1-thiogalactopyranoside (IPTG). As a consequence, those thiamphenicol resistant colonies that arise in clostridial recipients, following plating on agar medium supplemented with IPTG, are almost exclusively due to insertion of the mini transposon into the genome. The system has been exemplified in both Clostridium acetobutylicum and Clostridium sporogenes, where transposon insertion has been shown to be entirely random. Moreover, appropriate screening of both libraries resulted in the isolation of auxotrophic mutants as well as cells deficient in spore formation/germination. This strategy is capable of being implemented in any Clostridium species.
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Affiliation(s)
- Ying Zhang
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail: (YZ); (NPM)
| | - Alexander Grosse-Honebrink
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Nigel P. Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail: (YZ); (NPM)
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Latif H, Zeidan AA, Nielsen AT, Zengler K. Trash to treasure: production of biofuels and commodity chemicals via syngas fermenting microorganisms. Curr Opin Biotechnol 2014; 27:79-87. [DOI: 10.1016/j.copbio.2013.12.001] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 11/27/2013] [Accepted: 12/02/2013] [Indexed: 01/01/2023]
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Hypermotility in Clostridium perfringens strain SM101 is due to spontaneous mutations in genes linked to cell division. J Bacteriol 2014; 196:2405-12. [PMID: 24748614 DOI: 10.1128/jb.01614-14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridium perfringens is a Gram-positive anaerobic pathogen of humans and animals. Although they lack flagella, C. perfringens bacteria can still migrate across surfaces using a type of gliding motility that involves the formation of filaments of bacteria lined up in an end-to-end conformation. In strain SM101, hypermotile variants are often found arising from the edges of colonies on agar plates. Hypermotile cells are longer than wild-type cells, and video microscopy of their gliding motility suggests that they form long, thin filaments that move rapidly away from a colony, analogously to swarmer cells in bacteria with flagella. To identify the cause(s) of the hypermotility phenotype, the genome sequences of normal strains and their direct hypermotile derivatives were determined and compared. Strains SM124 and SM127, hypermotile derivatives of strains SM101 and SM102, respectively, contained 10 and 6 single nucleotide polymorphisms (SNPs) relative to their parent strains. While SNPs were located in different genes in the two sets of strains, one feature in common was mutations in cell division genes, an ftsI homolog in strain SM124 (CPR_1831) and a minE homolog in strain SM127 (CPR_2104). Complementation of these mutations with wild-type copies of each gene restored the normal motility phenotype. A model explaining the principles underlying the hypermotility phenotype is presented.
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Abstract
Type IV pili (T4P) are surface-exposed fibers that mediate many functions in bacteria, including locomotion, adherence to host cells, DNA uptake (competence), and protein secretion and that can act as nanowires carrying electric current. T4P are composed of a polymerized protein, pilin, and their assembly apparatuses share protein homologs with type II secretion systems in eubacteria and the flagella of archaea. T4P are found throughout Gram-negative bacterial families and have been studied most extensively in certain model Gram-negative species. Recently, it was discovered that T4P systems are also widespread among Gram-positive species, in particular the clostridia. Since Gram-positive and Gram-negative bacteria have many differences in cell wall architecture and other features, it is remarkable how similar the T4P core proteins are between these organisms, yet there are many key and interesting differences to be found as well. In this review, we compare the two T4P systems and identify and discuss the features they have in common and where they differ to provide a very broad-based view of T4P systems across all eubacterial species.
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Identification of a proton-chloride antiporter (EriC) by Himar1 transposon mutagenesis in Lactobacillus reuteri and its role in histamine production. Antonie van Leeuwenhoek 2014; 105:579-92. [PMID: 24488273 DOI: 10.1007/s10482-014-0113-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 01/01/2014] [Indexed: 12/21/2022]
Abstract
The gut microbiome may modulate intestinal immunity by luminal conversion of dietary amino acids to biologically active signals. The model probiotic organism Lactobacillus reuteri ATCC PTA 6475 is indigenous to the human microbiome, and converts the amino acid L-histidine to the biogenic amine, histamine. Histamine suppresses tumor necrosis factor (TNF) production by human myeloid cells and is a product of L-histidine decarboxylation, which is a proton-facilitated reaction. A transposon mutagenesis strategy was developed based on a single-plasmid nisin-inducible Himar1 transposase/transposon delivery system for L. reuteri. A highly conserved proton-chloride antiporter gene (eriC), a gene widely present in the gut microbiome was discovered by Himar1 transposon (Tn)-mutagenesis presented in this study. Genetic inactivation of eriC by transposon insertion and genetic recombineering resulted in reduced ability of L. reuteri to inhibit TNF production by activated human myeloid cells, diminished histamine production by the bacteria and downregulated expression of histidine decarboxylase cluster genes compared to those of WT 6475. EriC belongs to a large family of ion transporters that includes chloride channels and proton-chloride antiporters and may facilitate the availability of protons for the decarboxylation reaction, resulting in histamine production by L. reuteri. This report leverages the tools of bacterial genetics for probiotic gene discovery. The findings highlight the widely conserved nature of ion transporters in bacteria and how ion transporters are coupled with amino acid decarboxylation and contribute to microbiome-mediated immunomodulation.
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Ruiz L, Motherway MO, Lanigan N, van Sinderen D. Transposon mutagenesis in Bifidobacterium breve: construction and characterization of a Tn5 transposon mutant library for Bifidobacterium breve UCC2003. PLoS One 2013; 8:e64699. [PMID: 23737995 PMCID: PMC3667832 DOI: 10.1371/journal.pone.0064699] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 04/17/2013] [Indexed: 01/20/2023] Open
Abstract
Bifidobacteria are claimed to contribute positively to human health through a range of beneficial or probiotic activities, including amelioration of gastrointestinal and metabolic disorders, and therefore this particular group of gastrointestinal commensals has enjoyed increasing industrial and scientific attention in recent years. However, the molecular mechanisms underlying these probiotic mechanisms are still largely unknown, mainly due to the fact that molecular tools for bifidobacteria are rather poorly developed, with many strains lacking genetic accessibility. In this work, we describe the generation of transposon insertion mutants in two bifidobacterial strains, B. breve UCC2003 and B. breve NCFB2258. We also report the creation of the first transposon mutant library in a bifidobacterial strain, employing B. breve UCC2003 and a Tn5-based transposome strategy. The library was found to be composed of clones containing single transposon insertions which appear to be randomly distributed along the genome. The usefulness of the library to perform phenotypic screenings was confirmed through identification and analysis of mutants defective in D-galactose, D-lactose or pullulan utilization abilities.
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Affiliation(s)
- Lorena Ruiz
- Department of Microbiology and Alimentary Pharmabiotic Centre, National University of Ireland, Cork, Ireland
| | - Mary O’Connell Motherway
- Department of Microbiology and Alimentary Pharmabiotic Centre, National University of Ireland, Cork, Ireland
| | - Noreen Lanigan
- Department of Microbiology and Alimentary Pharmabiotic Centre, National University of Ireland, Cork, Ireland
| | - Douwe van Sinderen
- Department of Microbiology and Alimentary Pharmabiotic Centre, National University of Ireland, Cork, Ireland
- * E-mail:
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