1
|
Deedwania A, Karmakar S, Kumar V, Shefrin S, Sundar D, Srivastava P. Construction and characterization of a temperature-sensitive pRC4 replicon for Rhodococcus and Gordonia. Gene 2024; 896:147990. [PMID: 37977321 DOI: 10.1016/j.gene.2023.147990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/08/2023] [Accepted: 11/13/2023] [Indexed: 11/19/2023]
Abstract
Temperature-sensitive plasmids are useful for genome engineering and several synthetic biology applications. There are only limited reports on temperature-sensitive plasmids for Rhodococcus and none for Gordonia. Here, we report the construction of a temperature-sensitive pRC4 replicon that is functional in Rhodococcus and Gordonia. The amino acid residues were predicted for the temperature-sensitive phenotype in the pRC4 replicon using in silico methods and molecular simulation of the DNA-binding replication protein with the origin of replication. The amino acid residues were mutated, and the temperature-sensitive phenotype was validated in Gordonia sp. IITR100. Similar results were also observed in Rhodococcus erythropolis, suggesting that the temperature-sensitive phenotype was exhibited across genera.
Collapse
Affiliation(s)
- Agrima Deedwania
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110 016, India
| | - Shreyoshi Karmakar
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110 016, India
| | - Vipul Kumar
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110 016, India
| | - Seyad Shefrin
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110 016, India
| | - Durai Sundar
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110 016, India.
| | - Preeti Srivastava
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110 016, India.
| |
Collapse
|
2
|
Silva Júnior JVJ, da Silva ANMR, da Silva Santos JJ, Gil LHVG. Reverse Genetics of Dengue Virus. Methods Mol Biol 2024; 2733:231-248. [PMID: 38064036 DOI: 10.1007/978-1-0716-3533-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Dengue virus (DENV) is one of the most important and widespread arthropod-borne viruses, causing millions of infections over the years. Considering its epidemiological importance, efforts have been directed towards understanding various aspects of DENV biology, which have been facilitated by the development of different molecular strategies for engineering viral genomes, such as reverse genetics approaches. Reverse genetic systems are a powerful tool for investigating virus-host interaction, for vaccine development, and for high-throughput screening of antiviral compounds. However, stable manipulation of DENV genomes is a major molecular challenge, especially when using conventional cloning systems. To circumvent this issue, we describe a simple and efficient yeast-based reverse genetics system to recover infectious DENV clones.
Collapse
Affiliation(s)
- José Valter Joaquim Silva Júnior
- Virology Sector, Department of Preventive Veterinary Medicine, Federal University of Santa Maria, Santa Maria, RS, Brazil
- Virology Sector, Laboratory of Immunopathology Keizo Asami, Federal University of Pernambuco, Recife, PE, Brazil
| | | | | | - Laura Helena Vega Gonzales Gil
- Laboratory of Virology and Experimental Therapy, Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, PE, Brazil.
| |
Collapse
|
3
|
Millgaard M, Bidart GN, Pogrebnyakov I, Nielsen AT, Welner DH. An improved integrative GFP-based vector for genetic engineering of Parageobacillus thermoglucosidasius facilitates the identification of a key sporulation regulator. AMB Express 2023; 13:44. [PMID: 37154828 PMCID: PMC10167077 DOI: 10.1186/s13568-023-01544-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 04/05/2023] [Indexed: 05/10/2023] Open
Abstract
Parageobacillus thermoglucosidasius is a thermophilic Gram-positive bacterium, which is a promising host organism for sustainable bio-based production processes. However, to take full advantage of the potential of P. thermoglucosidasius, more efficient tools for genetic engineering are required. The present study describes an improved shuttle vector, which speeds up recombination-based genomic modification by incorporating a thermostable sfGFP variant into the vector backbone. This additional selection marker allows for easier identification of recombinants, thereby removing the need for several culturing steps. The novel GFP-based shuttle is therefore capable of facilitating faster metabolic engineering of P. thermoglucosidasius through genomic deletion, integration, or exchange. To demonstrate the efficiency of the new system, the GFP-based vector was utilised for deletion of the spo0A gene in P. thermoglucosidasius DSM2542. This gene is known to be a key regulator of sporulation in Bacillus subtilis, and it was therefore hypothesised that the deletion of spo0A in P. thermoglucosiadius would produce an analogous sporulation-inhibited phenotype. Subsequent analyses of cell morphology and culture heat resistance suggests that the P. thermoglucosidasius ∆spo0A strain is sporulation-deficient. This strain may be an excellent starting point for future cell factory engineering of P. thermoglucosidasius, as the formation of endospores is normally not a desired trait in large-scale production.
Collapse
Affiliation(s)
- Marie Millgaard
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Kemitorvet, 2800, Kgs. Lyngby, Denmark
| | - Gonzalo Nahuel Bidart
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Kemitorvet, 2800, Kgs. Lyngby, Denmark
| | - Ivan Pogrebnyakov
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Kemitorvet, 2800, Kgs. Lyngby, Denmark
| | - Alex Toftgaard Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Kemitorvet, 2800, Kgs. Lyngby, Denmark.
| | - Ditte Hededam Welner
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Kemitorvet, 2800, Kgs. Lyngby, Denmark.
| |
Collapse
|
4
|
Wang G, Christensen L, Vasquez KM. Methods to Study Z-DNA-Induced Genetic Instability. Methods Mol Biol 2023; 2651:227-240. [PMID: 36892771 DOI: 10.1007/978-1-0716-3084-6_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
Alternative DNA structures that differ from the canonical B-DNA double helix, including Z-DNA, have received much attention recently due to their impact on DNA metabolic processes, including replication, transcription, and genome maintenance. Non-B-DNA-forming sequences can also stimulate genetic instability associated with disease development and evolution. Z-DNA can stimulate different types of genetic instability events in different species, and several different assays have been established to detect Z-DNA-induced DNA strand breaks and mutagenesis in prokaryotic and eukaryotic systems. In this chapter, we will introduce some of these methods including Z-DNA-induced mutation screening and detection of Z-DNA-induced strand breaks in mammalian cells, yeast, and mammalian cell extracts. Results from these assays should provide better insight into the mechanisms of Z-DNA-related genetic instability in different eukaryotic model systems.
Collapse
Affiliation(s)
- Guliang Wang
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, Austin, TX, USA
| | - Laura Christensen
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, Austin, TX, USA
| | - Karen M Vasquez
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, Austin, TX, USA.
| |
Collapse
|
5
|
Abstract
The bacterial genus Lactobacillus comprises a vast range of strains with varying metabolic and probiotic traits, with genome editing representing an essential tool to probe genotype-phenotype relationships and enhance their beneficial properties. Currently, one of the most effective means of genome editing in bacteria couples low-efficiency recombineering with high-efficiency counterselection by nucleases from CRISPR-Cas systems. In lactobacilli, several CRISPR-based genome editing methods exist that have shown varying success in different strains. Here, we detail a fast and simple approach using two shuttle vectors encoding a recombineering template as well as the Streptococcus pyogenes Cas9, a trans-activating RNA, and a CRISPR array. We provide a step-by-step procedure for cloning the shuttle vectors, sequentially transforming the vectors into lactobacilli, screening for the desired edit, and finally clearing the shuttle vectors from the mutant strain. As CRISPR-based genome editing in bacteria can fail for various reasons, we also lay out instructions for probing mechanisms of escape. Finally, we include practical notes along the way to facilitate each stage of genome editing, and we illustrate the technique using a representative edit in a strain of Lactobacillus plantarum. Overall, this method should serve as a complete guide to performing genome editing in lactobacilli.
Collapse
Affiliation(s)
- Justin M Vento
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Chase L Beisel
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA.
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany.
- Medical Faculty, University of Würzburg, Würzburg, Germany.
| |
Collapse
|
6
|
Fink C, Angenent LT, Molitor B. An Interdomain Conjugation Protocol for Plasmid-DNA Transfer into Methanothermobacter thermautotrophicus ΔH. Methods Mol Biol 2022; 2522:119-133. [PMID: 36125746 DOI: 10.1007/978-1-0716-2445-6_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Methanogenic archaea of the order Methanobacteriales are widespread in anaerobic environments and play pivotal roles in microbial communities. The family of Methanobacteriaceae encompasses mesophilic and thermophilic hydrogenotrophic species. Mesophilic species are found in various natural and anthropogenic environments (e.g., are associated with the microbiome in animals and humans). Thermophilic species can be found in thermally active bogs and warm sulfuric springs, but also in anthropogenic environments, such as wastewater treatment plants and anaerobic digesters. Recently, genetic tools for Methanothermobacter thermautotrophicus ΔH, as the first representative of this order of methanogenic archaea, were successfully implemented. This protocol describes the methods for interdomain conjugational DNA transfer from Escherichia coli to M. thermautotrophicus ΔH with shuttle-vector plasmid DNA, which allows the genetic manipulation of this microbe, and provides a basis for the development of further genetic methods for this and potentially other representatives of Methanobacteriales.
Collapse
Affiliation(s)
- Christian Fink
- Environmental Biotechnology Group, University of Tübingen, Tübingen, Germany
| | - Largus T Angenent
- Environmental Biotechnology Group, University of Tübingen, Tübingen, Germany
- Cluster of Excellence-Controlling Microbes to Fight Infections, University of Tübingen, Tübingen, Germany
- AG Angenent, Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Bastian Molitor
- Environmental Biotechnology Group, University of Tübingen, Tübingen, Germany.
- Cluster of Excellence-Controlling Microbes to Fight Infections, University of Tübingen, Tübingen, Germany.
| |
Collapse
|
7
|
Scott KA, Williams SA, Santangelo TJ. Thermococcus kodakarensis provides a versatile hyperthermophilic archaeal platform for protein expression. Methods Enzymol 2021; 659:243-273. [PMID: 34752288 PMCID: PMC8878339 DOI: 10.1016/bs.mie.2021.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hyperthermophiles, typically defined as organisms with growth optima ≥80°C, are dominated by the Archaea. Proteins that support life at the extremes of temperatures often retain substantial biotechnological and commercial value, but the recombinant expression of individual hyperthermophilic proteins is commonly complicated in non-native mesophilic hosts due to differences in codon bias, intracellular solutes and the requirement for accessory factors that aid in folding or deposition of metal centers within archaeal proteins. The development of versatile protein expression and facilitated protein purification systems in the model, genetically tractable, hyperthermophilic marine archaeon Thermococcus kodakarensis provides an attractive platform for protein expression within the hyperthermophiles. The assortment of T. kodakarensis genetic backgrounds and compatible selection markers allow iterative genetic manipulations that facilitate protein overexpression and expedite protein purifications. Expression vectors that stably replicate both in T. kodakarensis and Escherichia coli have been validated and permit high-level ectopic gene expression from a variety of controlled and constitutive promoters. Biologically relevant protein associations can be maintained during protein purifications to identify native protein partnerships and define protein interaction networks. T. kodakarensis thus provides a versatile platform for the expression and purification of thermostable proteins.
Collapse
Affiliation(s)
- Kristin A Scott
- Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO, United States
| | - Sere A Williams
- Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO, United States
| | - Thomas J Santangelo
- Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO, United States; Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States.
| |
Collapse
|
8
|
Liu L, Chen Y, Yu S, Chen J, Zhou J. Simultaneous transformation of five vectors in Gluconobacter oxydans. Plasmid 2021; 117:102588. [PMID: 34256060 DOI: 10.1016/j.plasmid.2021.102588] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 11/19/2022]
Abstract
Gluconobacter oxydans is an obligate Gram-negative bacterium that belongs to the family Acetobacteraceae. It is one of the most frequently used microorganisms in industrial biotechnology to produce chemicals related to incomplete oxidation. However, the fine-tuning of G. oxydans is hampered by the lack of efficient genetic tools to enable sophisticated metabolic manipulations. Thus, a series of shuttle vectors for G. oxydans inspired by a series of wild-type plasmids in different G. oxydans strains were constructed. Fifteen shuttle vectors were employed to express mCherry in G. oxydans WSH-003 using the replication origin of these wild-type plasmids. Among them, the intensity of fluorescent proteins expressed by p15-K-mCherry was about 10 times that of fluorescent proteins expressed by p5-K-mCherry. Quantitative real-time polymerase chain reaction showed that the relative copy number of p15-K-mCherry reached 19 and had high stability. In contrast, some of the plasmids had a relative copy number of less than 10. The co-expression of multiple shuttle vectors revealed five shuttle vectors that could be transformed into G. oxydans WSH-003 and could express five different fluorescent proteins. The shuttle vectors will facilitate genetic operations for Gluconobacter strains to produce useful compounds more efficiently.
Collapse
Affiliation(s)
- Li Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Yue Chen
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Shiqin Yu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jian Chen
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
| |
Collapse
|
9
|
Sheridan PO, Martin JC, Scott KP. Conjugation Protocol Optimised for Roseburia inulinivorans and Eubacterium rectale. Bio Protoc 2020; 10:e3575. [PMID: 33659545 DOI: 10.21769/bioprotoc.3575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/17/2020] [Accepted: 03/11/2020] [Indexed: 11/02/2022] Open
Abstract
Roseburia and Eubacterium species of the human gut microbiota play an important role in the maintaince of human health, partly by producing butyrate, the main energy source of our colonic epithelial cells. However, our knowledge of the biochemistry and physiology of these bacteria has been limited by a lack of genetic manipulation techniques. Conjugative transposons previously introduced into Roseburia species could not be easily modified, greatly limiting their applicability as genetic modification platforms. Modular plasmid shuttle vectors have previously been developed for Clostridium species, which share a taxonomic order with Roseburia and Eubacterium, raising the possibility that these vectors could be used in these organisms. Here, we describe an optimized conjugation protocol enabling the transfer of autonomously replicating plasmids from an E. coli donor strain into Roseburia inulinivorans and Eubacterium rectale. The modular nature of the plasmids and their ability to be maintained in the recipient bacterium by autonomous replication makes them ideal for investigating heterologous gene expression, and as a platform for other genetic tools including antisense RNA silencing or mobile group II interon gene disruption strategies.
Collapse
Affiliation(s)
- Paul O Sheridan
- Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Jennifer C Martin
- Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Karen P Scott
- Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| |
Collapse
|
10
|
Togawa Y, Shiotani S, Kato Y, Ezaki K, Nunoshiba T, Hiratsu K. Development of a supF-based mutation-detection system in the extreme thermophile Thermus thermophilus HB27. Mol Genet Genomics 2019; 294:1085-1093. [PMID: 30968247 DOI: 10.1007/s00438-019-01565-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 04/03/2019] [Indexed: 01/07/2023]
Abstract
Thermus thermophilus (T. thermophilus) HB27 is an extreme thermophile that grows optimally at 65-72 °C. Heat-induced DNA lesions are expected to occur at a higher frequency in the genome of T. thermophilus than in those of mesophiles; however, the mechanisms underlying the maintenance of genome integrity at high temperatures remain poorly understood. The study of mutation spectra has become a powerful approach to understanding the molecular mechanisms responsible for DNA repair and mutagenesis in mesophilic species. Therefore, we developed a supF-based system to detect a broad spectrum of mutations in T. thermophilus. This system was validated by measuring spontaneous mutations in the wild type and a udgA, B double mutant deficient in uracil-DNA glycosylase (UDG) activity. We found that the mutation frequency of the udgA, B strain was 4.7-fold higher than that of the wild type and G:C→A:T transitions dominated, which was the most reasonable for the mutator phenotype associated with the loss of UDG function in T. thermophilus. These results show that this system allowed for the rapid analysis of mutations in T. thermophilus, and may be useful for studying the molecular mechanisms responsible for DNA repair and mutagenesis in this extreme thermophile.
Collapse
Affiliation(s)
- Yoichiro Togawa
- Department of Applied Chemistry, National Defense Academy, Hashirimizu 1-10-20, Yokosuka, Kanagawa, 239-8686, Japan
| | - Shiori Shiotani
- Department of Applied Chemistry, National Defense Academy, Hashirimizu 1-10-20, Yokosuka, Kanagawa, 239-8686, Japan
| | - Yuki Kato
- College of Liberal Arts, International Christian University, Osawa 3-10-2, Mitaka, Tokyo, 181-8585, Japan
| | - Kazune Ezaki
- College of Liberal Arts, International Christian University, Osawa 3-10-2, Mitaka, Tokyo, 181-8585, Japan
| | - Tatsuo Nunoshiba
- College of Liberal Arts, International Christian University, Osawa 3-10-2, Mitaka, Tokyo, 181-8585, Japan
| | - Keiichiro Hiratsu
- Department of Applied Chemistry, National Defense Academy, Hashirimizu 1-10-20, Yokosuka, Kanagawa, 239-8686, Japan.
| |
Collapse
|
11
|
Heinze S, Kornberger P, Grätz C, Schwarz WH, Zverlov VV, Liebl W. Transmating: conjugative transfer of a new broad host range expression vector to various Bacillus species using a single protocol. BMC Microbiol 2018; 18:56. [PMID: 29884129 PMCID: PMC5994095 DOI: 10.1186/s12866-018-1198-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/30/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The genus Bacillus includes a great variety of species with potential applications in biotechnology. While species such as B. subtilis or B. licheniformis are well-known and used to provide various products at industrial scale, other Bacillus species are less characterized and are not yet used in commercial processes. One reason for this is the fact that genetic manipulation of new isolates is usually complicated with conventional techniques which have to be adapted to each new strain. Even in well-established strains, the available transformation protocols often suffer from low efficiencies. RESULTS In this paper, we provide a new broad host range E. coli/Bacillus shuttle vector, named pBACOV (Bacillus conjugation vector), that can be efficiently transferred to various Bacillus species using a single protocol. A variant of pBACOV carrying the sfGFP gene was successfully transferred to eight different species from the genus Bacillus and to one Paenibacillus species using triparental conjugation ("transmating"). This was achieved using a single protocol and worked for nine out of eleven tested acceptor species. The transmating procedure was used to test expression of the heterologous reporter gene sfGFP under control of the PaprE-promoter from B. subtilis in several Bacillus species in parallel. Expression of sfGFP was found in eight out of nine transmates. For several of the tested species, this is the first report of a method for genetic modification and heterologous gene expression. The expression level, analyzed by measuring the relative sfGFP-fluorescence normalized to the cell density of the cultures, was highest in B. mojavensis. CONCLUSIONS The new shuttle vector pBACOV can be transferred to many different Bacillus and Paenibacillus species using a simple and efficient transmating protocol. It is a versatile tool facilitating the application of recombinant DNA technology in new as well as established strains, or selection of an ideal host for heterologous gene expression from a multitude of strains. This paves the way for the genetic modification and biotechnological exploitation of the broad diversity of species of Bacillus and related genera as well as different strains from these species.
Collapse
Affiliation(s)
- Simon Heinze
- Department of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, D-85354, Freising-Weihenstephan, Germany
| | - Petra Kornberger
- Department of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, D-85354, Freising-Weihenstephan, Germany.
| | - Christian Grätz
- Department of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, D-85354, Freising-Weihenstephan, Germany
| | - Wolfgang H Schwarz
- Department of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, D-85354, Freising-Weihenstephan, Germany
| | - Vladimir V Zverlov
- Department of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, D-85354, Freising-Weihenstephan, Germany.,Institute of Molecular Genetics, Russian Academy of Science, Kurchatov Sq. 2, 123182, Moscow, Russia
| | - Wolfgang Liebl
- Department of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, D-85354, Freising-Weihenstephan, Germany
| |
Collapse
|
12
|
Abstract
The disciplines of Borrelia (Borreliella) burgdorferi microbiology and Lyme disease pathogenesis have come to depend on the genetic manipulation of the spirochete. Generating mutants in these recalcitrant bacteria, while not straightforward, is routinely accomplished in numerous laboratories, although there are several crucial caveats to consider. This chapter describes the design of basic molecular genetic experiments as well as the detailed methodologies to prepare and transform competent cells, select for and isolate transformants, and complement or genetically restore mutants.
Collapse
Affiliation(s)
- D Scott Samuels
- Division of Biological Sciences, University of Montana, Missoula, MT, USA.
| | - Dan Drecktrah
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Laura S Hall
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| |
Collapse
|
13
|
Abstract
Functional expression of genes from metagenomic libraries is limited by various factors including inefficient transcription and/or translation of target genes as well as improper folding and assembly of the corresponding proteins caused by the lack of appropriate chaperones and cofactors. It is now well accepted that the use of different expression hosts of distinct phylogeny and physiology can dramatically increase the rate of success. In the following chapter, we therefore describe tools and protocols allowing for the comparative heterologous expression of genes in five bacterial expression hosts, namely Escherichia coli, Pseudomonas putida, Bacillus subtilis, Burkholderia glumae, and Rhodobacter capsulatus. Different broad-host-range shuttle vectors are described that allow activity-based screening of metagenomic DNA in these bacteria. Furthermore, we describe the newly developed transfer-and-expression system TREX which comprises genetic elements essential to allow for expression of large clusters of functionally coupled genes in different microbial species.
Collapse
Affiliation(s)
- Nadine Katzke
- Institute of Molecular Enzyme Technology, Forschungszentrum Jülich GmbH, Heinrich-Heine-University Düsseldorf, 52426, Jülich, Germany
| | - Andreas Knapp
- Institute of Molecular Enzyme Technology, Forschungszentrum Jülich GmbH, Heinrich-Heine-University Düsseldorf, 52426, Jülich, Germany
| | - Anita Loeschcke
- Institute of Molecular Enzyme Technology, Forschungszentrum Jülich GmbH, Heinrich-Heine-University Düsseldorf, 52426, Jülich, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Forschungszentrum Jülich GmbH, Heinrich-Heine-University Düsseldorf, 52426, Jülich, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Forschungszentrum Jülich GmbH, Heinrich-Heine-University Düsseldorf, 52426, Jülich, Germany.
| |
Collapse
|
14
|
Jang MS, Fujita A, Ikawa S, Hanawa K, Yamamura H, Tamura T, Hayakawa M, Tezuka T, Ohnishi Y. Isolation of a novel plasmid from Couchioplanes caeruleus and construction of two plasmid vectors for gene expression in Actinoplanes missouriensis. Plasmid 2014; 77:32-8. [PMID: 25500016 DOI: 10.1016/j.plasmid.2014.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/22/2014] [Accepted: 12/01/2014] [Indexed: 11/15/2022]
Abstract
To date, no plasmid vector has been developed for the rare actinomycete Actinoplanes missouriensis. Moreover, no small circular plasmid has been reported to exist in the genus Actinoplanes. Here, a novel plasmid, designated pCAZ1, was isolated from Couchioplanes caeruleus subsp. azureus via screening for small circular plasmids in Actinoplanes (57 strains) and Couchioplanes (2 strains). Nucleotide sequencing revealed that pCAZ1 is a 5845-bp circular molecule with a G + C content of 67.5%. The pCAZ1 copy number was estimated at 30 per chromosome. pCAZ1 contains seven putative open reading frames, one of which encodes a protein containing three motifs conserved among plasmid-encoded replication proteins that are involved in the rolling-circle mechanism of replication. Detection of single-stranded DNA intermediates in C. caeruleus confirmed that pCAZ1 replicates by this mechanism. The ColE1 origin from pBluescript SK(+) and the oriT sequence with the apramycin resistance gene aac(3)IV from pIJ773 were inserted together into pCAZ1, to construct the Escherichia coli-A. missouriensis shuttle vectors, pCAM1 and pCAM2, in which the foreign DNA fragment was inserted into pCAZ1 in opposite directions. pCAM1 and pCAM2 were successfully transferred to A. missouriensis through the E. coli-mediated conjugative transfer system. The copy numbers of pCAM1 and pCAM2 in A. missouriensis were estimated to be one and four per chromosome, respectively. Thus, these vectors can be used as effective genetic tools for homologous and heterologous gene expression studies in A. missouriensis.
Collapse
Affiliation(s)
- Moon-Sun Jang
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Azusa Fujita
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Satomi Ikawa
- Division of Applied Biological Sciences, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Keitaro Hanawa
- Division of Applied Biological Sciences, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Hideki Yamamura
- Division of Applied Biological Sciences, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Tomohiko Tamura
- Biological Resource Center, National Institute of Technology and Evaluation (NBRC), 2-5-8 Kazusakamatari, Kisarazu, Chiba 292-0818, Japan
| | - Masayuki Hayakawa
- Division of Applied Biological Sciences, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Takeaki Tezuka
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasuo Ohnishi
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
| |
Collapse
|
15
|
Hertel R, Volland S, Liesegang H. Conjugative reporter system for the use in Bacillus licheniformis and closely related Bacilli. Lett Appl Microbiol 2014; 60:162-167. [PMID: 25363901 DOI: 10.1111/lam.12352] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/28/2014] [Accepted: 10/28/2014] [Indexed: 01/23/2023]
Abstract
Bacillus wild-type strains are genetically difficult to manipulate, and thus, the options for rational strain investigation and design are limited. Here, we present a set of small conjugative shuttle vectors for the use in Bacillus licheniformis and related, genetically difficult accessible wild-type strains. The vector set comprises the modular general-purpose vector pV2 and its derivatives pV3SDlacZ and pV3lacZ. The pV3 vectors are designed for the investigation of transcriptional and translational activities of regulatory regions like promoters and ribosomal binding sites (RBS). The vector set has been tested for investigating gene regulation under aerobic and anaerobic conditions.
Collapse
Affiliation(s)
- R Hertel
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - S Volland
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - H Liesegang
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| |
Collapse
|
16
|
Yu Z, Jiang Q, Liu J, Guo D, Quan C, Li B, Qu L. A simplified system for generating recombinant E3-deleted canine adenovirus-2. Plasmid 2014; 77:1-6. [PMID: 25450764 DOI: 10.1016/j.plasmid.2014.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/15/2014] [Accepted: 10/27/2014] [Indexed: 11/15/2022]
Abstract
Canine adenovirus type 2 (CAV-2) has been used extensively as a vector for studying gene therapy and vaccine applications. We describe a simple strategy for generating a replication-competent recombinant CAV-2 using a backbone vector and a shuttle vector. The backbone plasmid containing the full-length CAV-2 genome was constructed by homologous recombination in Escherichia coli strain BJ5183. The shuttle plasmid, which has a deletion of 1478 bp in the nonessential E3 viral genome region, was generated by subcloning a fusion fragment containing the flanking sequences of the CAV-2 E3 region and expression cassette sequences from pcDNA3.1(+) into modified pUC18. To determine system effectiveness, a gene for enhanced green fluorescent protein (EGFP) was inserted into the shuttle plasmid and cloned into the backbone plasmid using two unique NruI and SalI sites. Transfection of Madin-Darby canine kidney (MDCK) cells with the recombinant adenovirus genome containing the EGFP expression cassette resulted in infectious viral particles. This strategy provides a solid foundation for developing candidate vaccines using CAV-2 as a delivery vector.
Collapse
Affiliation(s)
- Zuo Yu
- Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Qian Jiang
- Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jiasen Liu
- Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Dongchun Guo
- Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Chuansong Quan
- Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Botao Li
- Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Liandong Qu
- Zoonosis of Natural Foci, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China.
| |
Collapse
|
17
|
Shah N, Bandara AB, Sandal I, Inzana TJ. Natural competence in Histophilus somni strain 2336. Vet Microbiol 2014; 173:371-8. [PMID: 25218867 DOI: 10.1016/j.vetmic.2014.07.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 07/09/2014] [Accepted: 07/26/2014] [Indexed: 01/03/2023]
Abstract
Histophilus somni is an etiologic agent of shipping fever pneumonia, myocarditis, and other systemic diseases of bovines. Virulence factors that have been identified in H. somni include biofilm formation, lipooligosaccharide phase variation, immunoglobulin binding proteins, survival in phagocytic cells, and many others. However, to identify the genes responsible for virulence, an efficient mutagenesis system is needed. Mutagenesis of H. somni using allelic exchange is difficult, likely due to its tight restriction modification system. Mutagenesis by natural transformation in Haemophilus influenzae is well established and shows a strong bias for fragments containing specific uptake signal sequences (USS) within the genome. We hypothesized that natural transformation may also be possible in H. somni strain 2336 because its genome is over-represented with H. influenzae USS (5'-AAGTGCGGT-3') and contains most of the genes necessary for competence. H. somni strain 2336 was successfully transformed and mutated with genomic linear DNA from an H. somni mutant (738Δlob2a), which contains a kanamycin-resistance (Kan(R)) gene and the USS within lob2A. Although most of the competence genes found in H. influenzae were present in H. somni, comD and the 5' portion of comE were absent, which may account for the low transformation efficiency. The transformation efficiency of strain 2336 was greatest during mid-log growth phase and when cyclic adenosine monophosphate was added to the transformation medium. However, mutants were not isolated when strain 2336 was transformed with genomic DNA containing the same Kan(R) gene from H. somni luxS or uspE mutants, which lack the USS in these specific genes. Shuttle vector pNS3K was also naturally transformed into strain 2336, though at a lower efficiency. However, natural transformation with either H. somni linear DNA (2336Δlob2A) or pNS3K was unsuccessful with H. somni commensal strain 129Pt and several other disease isolates.
Collapse
|
18
|
Wang X, Chen W, Tian Y, Mao Q, Lv X, Shang M, Li X, Yu X, Huang Y. Surface display of Clonorchis sinensis enolase on Bacillus subtilis spores potentializes an oral vaccine candidate. Vaccine 2014; 32:1338-45. [PMID: 24486347 DOI: 10.1016/j.vaccine.2014.01.039] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/06/2014] [Accepted: 01/15/2014] [Indexed: 02/07/2023]
Abstract
Clonorchis sinensis (C. sinensis) infections remain the common public health problem in freshwater fish consumption areas. New effective prevention strategies are still the urgent challenges to control this kind of foodborne infectious disease. The biochemical importance and biological relevance render C. sinensis enolase (Csenolase) as a potential vaccine candidate. In the present study, we constructed Escherichia coli/Bacillus subtilis shuttle genetic engineering system and investigated the potential of Csenolase as an oral vaccine candidate for C. sinensis prevention in different immunization routes. Our results showed that, compared with control groups, both recombinant Csenolase protein and nucleic acid could induce a mixed IgG1/IgG2a immune response when administrated subcutaneously (P<0.001), intraperitoneally (P<0.01) and intramuscularly (P<0.001) with worm reduction rate of 56.29%, 15.38% and 37.42%, respectively. More importantly, Csenolase could be successfully expressed as a fusion protein (55kDa) on B. subtilis spore indicated by immunoblot and immunofluorescence assays. Killed spores triggered reactive Th1/Th2 immune response and exhibited protective efficacy against C. sinensis infection. Csenolase derived oral vaccine conferred worm reduction rate and egg reduction rate at 60.07% (P<0.001) and 80.67% (P<0.001), respectively. The shuttle genetic engineering system facilitated the development of oral vaccine with B. subtilis stably overexpressing target protein. Comparably vaccinal trails with Csenolase in different immunization routes potentialize Csenolase an oral vaccine candidate in C. sinensis prevention.
Collapse
Affiliation(s)
- Xiaoyun Wang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Wenjun Chen
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Yanli Tian
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Qiang Mao
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Xiaoli Lv
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Mei Shang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Xuerong Li
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Xinbing Yu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China.
| | - Yan Huang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China; Key Laboratory for Tropical Diseases Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China.
| |
Collapse
|
19
|
Hu Q, Miao S, Ni X, Lu F, Yu H, Xing L, Jiang P. Construction of a shuttle vector for use in Riemerella anatipestifer. J Microbiol Methods 2013; 95:262-7. [PMID: 24064367 DOI: 10.1016/j.mimet.2013.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/13/2013] [Accepted: 09/13/2013] [Indexed: 11/20/2022]
Abstract
Riemerella anatipestifer causes epizootic infectious disease in poultry and serious economic losses, especially to the duck industry. Four complete genome sequences of R. anatipestifer strains are now available. However, functional studies have been limited by the lack of an effective shuttle vector. In this study, we constructed a shuttle vector, pRES, which was able to transfer plasmid DNA between Escherichia coli and R. anatipestifer strains. The vector contains the putative replication origin from R. anatipestifer plasmid pRA7026 and a ColE1 ori for replication in R. anatipestifer and E. coli respectively. In addition, it contains oriT for transferring the vector into R. anatipestifer by conjugation, and the putative promoter of the streptothricin resistance gene of plasmid pRA0726 for heterologous gene expression in R. anatipestifer. The vector pRES will be useful in the investigation of gene function in R. anatipestifer.
Collapse
|
20
|
Xie Z, Qi F, Merritt J. Cloning-independent plasmid construction for genetic studies in streptococci. J Microbiol Methods 2013; 94:77-82. [PMID: 23673081 DOI: 10.1016/j.mimet.2013.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/05/2013] [Accepted: 05/06/2013] [Indexed: 11/29/2022]
Abstract
Shuttle plasmids are among the few routinely utilized tools in the Streptococcus mutans genetic system that still require the use of classical cloning methodologies and intermediate hosts for genetic manipulation. Accordingly, it typically requires considerably less time and effort to introduce mutations onto the S. mutans chromosome than it does to construct shuttle vectors for expressing genes in trans. Occasionally, shuttle vector constructs also exhibit toxicity in Escherichia coli, which prevents their proper assembly. To circumvent these limitations, we modified a prolonged overlap extension PCR (POE-PCR) protocol to facilitate direct plasmid assembly in S. mutans. Using solely PCR, we created the reporter vector pZX7, which contains a single minimal streptococcal replication origin and harbors a spectinomycin resistance cassette and the gusA gene encoding β-glucuronidase. We compared the efficiency of pZX7 assembly using multiple strains of S. mutans and were able to obtain from 5 × 10³ to 2 × 10⁵ CFU/μg PCR product. Likewise, we used pZX7 to further demonstrate that Streptococcus sanguinis and Streptococcus gordonii are also excellent hosts for cloning-independent plasmid assembly, which suggests that this system is likely to function in numerous other streptococci. Consequently, it should be possible to completely forgo the use of E. coli-Streptococcus shuttle vectors in many streptococcal species, thereby decreasing the time and effort required to assemble constructs and eliminating any toxicity issues associated with intermediate hosts.
Collapse
Affiliation(s)
- Zhoujie Xie
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
| | - Fengxia Qi
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States; Division of Oral Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
| | - Justin Merritt
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States; Division of Oral Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States.
| |
Collapse
|