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Yang P, Tian J, Zhang L, Zhang H, Yang G, Ren Y, Fang J, Gu Y, Jiang W. A toolbox for genetic manipulation in intestinal Clostridium symbiosum. Synth Syst Biotechnol 2024; 9:43-54. [PMID: 38234413 PMCID: PMC10793094 DOI: 10.1016/j.synbio.2023.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/08/2023] [Accepted: 12/24/2023] [Indexed: 01/19/2024] Open
Abstract
Gut microbes are closely related with human health, but remain much to learn. Clostridium symbiosum is a conditionally pathogenic human gut bacterium and regarded as a potential biomarker for early diagnosis of intestinal tumors. However, the absence of an efficient toolbox that allows diverse genetic manipulations of this bacterium limits its in-depth studies. Here, we obtained the complete genome sequence of C. symbiosum ATCC 14940, a representative strain of C. symbiosum. On this basis, we further developed a series of genetic manipulation methods for this bacterium. Firstly, following the identification of a functional replicon pBP1 in C. symbiosum ATCC 14940, a highly efficient conjugative DNA transfer method was established, enabling the rapid introduction of exogenous plasmids into cells. Next, we constructed a dual-plasmid CRISPR/Cas12a system for genome editing in this bacterium, reaching over 60 % repression for most of the chosen genes as well as efficient deletion (>90 %) of three target genes. Finally, this toolbox was used for the identification of crucial functional genes, involving growth, synthesis of important metabolites, and virulence of C. symbiosum ATCC 14940. Our work has effectively established and optimized genome editing methods in intestinal C. symbiosum, thereby providing strong support for further basic and application research in this bacterium.
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Affiliation(s)
- Pengjie Yang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinzhong Tian
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- Xianghu Laboratory, Hangzhou, 311231, China
| | - Lu Zhang
- NHC Key Laboratory of Digestive Diseases, Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai, 200001, China
| | - Hui Zhang
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Gaohua Yang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Bruna Straket 16, Gothenburg, 41345, Sweden
| | - Yimeng Ren
- NHC Key Laboratory of Digestive Diseases, Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai, 200001, China
| | - Jingyuan Fang
- NHC Key Laboratory of Digestive Diseases, Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 145 Middle Shandong Road, Shanghai, 200001, China
| | - Yang Gu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Weihong Jiang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
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2
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Boudignon E, Foulquier C, Soucaille P. Improvement of the Genome Editing Tools Based on 5FC/5FU Counter Selection in Clostridium acetobutylicum. Microorganisms 2023; 11:2696. [PMID: 38004708 PMCID: PMC10672894 DOI: 10.3390/microorganisms11112696] [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: 10/04/2023] [Revised: 10/27/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023] Open
Abstract
Several genetic tools have been developed for genome engineering in Clostridium acetobutylicum utilizing 5-fluorouracil (5FU) or 5-fluorocytosine (5FC) resistance as a selection method. In our group, a method based on the integration, by single crossing over, of a suicide plasmid (pCat-upp) followed by selection for the second crossing over using a counter-selectable marker (the upp gene and 5FU resistance) was recently developed for genome editing in C. acetobutylicum. This method allows genome modification without leaving any marker or scar in a strain of C. acetobutylicum that is ∆upp. Unfortunately, 5FU has strong mutagenic properties, inducing mutations in the strain's genome. After numerous applications of the pCat-upp/5FU system for genome modification in C. acetobutylicum, the CAB1060 mutant strain became entirely resistant to 5FU in the presence of the upp gene, resulting in failure when selecting on 5FU for the second crossing over. It was found that the potential repressor of the pyrimidine operon, PyrR, was mutated at position A115, leading to the 5FU resistance of the strain. To fix this problem, we created a corrective replicative plasmid expressing the pyrR gene, which was shown to restore the 5FU sensitivity of the strain. Furthermore, in order to avoid the occurrence of the problem observed with the CAB1060 strain, a preventive suicide plasmid, pCat-upp-pyrR*, was also developed, featuring the introduction of a synthetic codon-optimized pyrR gene, which was referred to as pyrR* with low nucleotide sequence homology to pyrR. Finally, to minimize the mutagenic effect of 5FU, we also improved the pCat-upp/5FU system by reducing the concentration of 5FU from 1 mM to 5 µM using a defined synthetic medium. The optimized system/conditions were used to successfully replace the ldh gene by the sadh-hydG operon to convert acetone into isopropanol.
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Affiliation(s)
- Eglantine Boudignon
- Toulouse Biotechnology Institute (TBI), National Institute of Applied Sciences (INSA), Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse cedex 4, France; (E.B.); (C.F.)
- Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAe), UMR 792, 24 chemin de Borde Rouge-Auzeville, 31326 Castanet-Tolosan, France
- Centre National de la Recherche Scientifique (CNRS), UMR 5504, 16 Avenue Edouard Belin, 31055 Toulouse cedex 4, France
| | - Céline Foulquier
- Toulouse Biotechnology Institute (TBI), National Institute of Applied Sciences (INSA), Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse cedex 4, France; (E.B.); (C.F.)
- Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAe), UMR 792, 24 chemin de Borde Rouge-Auzeville, 31326 Castanet-Tolosan, France
- Centre National de la Recherche Scientifique (CNRS), UMR 5504, 16 Avenue Edouard Belin, 31055 Toulouse cedex 4, France
| | - Philippe Soucaille
- Toulouse Biotechnology Institute (TBI), National Institute of Applied Sciences (INSA), Université de Toulouse, 135 Avenue de Rangueil, 31077 Toulouse cedex 4, France; (E.B.); (C.F.)
- Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAe), UMR 792, 24 chemin de Borde Rouge-Auzeville, 31326 Castanet-Tolosan, France
- Centre National de la Recherche Scientifique (CNRS), UMR 5504, 16 Avenue Edouard Belin, 31055 Toulouse cedex 4, France
- (BBSRC)/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
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3
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Kubiak AM, Claessen L, Zhang Y, Khazaie K, Bailey TS. Refined control of CRISPR-Cas9 gene editing in Clostridium sporogenes: the creation of recombinant strains for therapeutic applications. Front Immunol 2023; 14:1241632. [PMID: 37869009 PMCID: PMC10585264 DOI: 10.3389/fimmu.2023.1241632] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/01/2023] [Indexed: 10/24/2023] Open
Abstract
Despite considerable clinical success, the potential of cancer immunotherapy is restricted by a lack of tumour-targeting strategies. Treatment requires systemic delivery of cytokines or antibodies at high levels to achieve clinically effective doses at malignant sites. This is exacerbated by poor penetration of tumour tissue by therapeutic antibodies. High-grade immune-related adverse events (irAEs) occur in a significant number of patients (5-15%, cancer- and therapeutic-dependent) that can lead to lifelong issues and can exclude from treatment patients with pre-existing autoimmune diseases. Tumour-homing bacteria, genetically engineered to produce therapeutics, is one of the approaches that seeks to mitigate these drawbacks. The ability of Clostridium sporogenes to form spores that are unable to germinate in the presence of oxygen (typical of healthy tissue) offers a unique advantage over other vectors. However, the limited utility of existing gene editing tools hinders the development of therapeutic strains. To overcome the limitations of previous systems, expression of the Cas9 protein and the gRNA was controlled using tetracycline inducible promoters. Furthermore, the components of the system were divided across two plasmids, improving the efficiency of cloning and conjugation. Genome integrated therapeutic genes were assayed biochemically and in cell-based functional assays. The potency of these strains was further improved through rationally-conceived gene knock-outs. The new system was validated by demonstrating the efficient addition and deletion of large sequences from the genome. This included the creation of recombinant strains expressing two pro-inflammatory cytokines, interleukin-2 (IL-2) and granulocyte macrophage-colony stimulating factor (GM-CSF), and a pro-drug converting enzyme (PCE). A comparative, temporal in vitro analysis of the integrant strains and their plasmid-based equivalents revealed a substantial reduction of cytokine activity in chromosome-based constructs. To compensate for this loss, a 7.6 kb operon of proteolytic genes was deleted from the genome. The resultant knock-out strains showed an 8- to 10-fold increase in cytokine activity compared to parental strains.
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Affiliation(s)
- Aleksandra M. Kubiak
- Exomnis Biotech BV, Maastricht, Netherlands
- The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Reproduction, Maastricht University, Maastricht, Netherlands
| | - Luuk Claessen
- Exomnis Biotech BV, Maastricht, Netherlands
- The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Reproduction, Maastricht University, Maastricht, Netherlands
| | - Yanchao Zhang
- The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Reproduction, Maastricht University, Maastricht, Netherlands
| | - Khashayarsha Khazaie
- Department of Immunology and Cancer Biology, Mayo Clinic, Phoenix, AZ, United States
| | - Tom S. Bailey
- The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Reproduction, Maastricht University, Maastricht, Netherlands
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Zhang Y, Bailey TS, Kubiak AM, Lambin P, Theys J. Heterologous Gene Regulation in Clostridia: Rationally Designed Gene Regulation for Industrial and Medical Applications. ACS Synth Biol 2022; 11:3817-3828. [PMID: 36265075 PMCID: PMC9680021 DOI: 10.1021/acssynbio.2c00401] [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] [Indexed: 01/27/2023]
Abstract
Several species from the Clostridium genus show promise as industrial solvent producers and cancer therapeutic delivery vehicles. Previous development of shuttle plasmids and genome editing tools has aided the study of these species and enabled their exploitation in industrial and medical applications. Nevertheless, the precise control of gene expression is still hindered by the limited range of characterized promoters. To address this, libraries of promoters (native and synthetic), 5' UTRs, and alternative start codons were constructed. These constructs were tested in Escherichia coli K-12, Clostridium sporogenes NCIMB 10696, and Clostridium butyricum DSM 10702, using β-glucuronidase (gusA) as a gene reporter. Promoter activity was corroborated using a second gene reporter, nitroreductase (nmeNTR) from Neisseria meningitides. A strong correlation was observed between the two reporters. In C. sporogenes and C. butyricum, respectively, changes in GusA activity between the weakest and strongest expressing levels were 129-fold and 78-fold. Similar results were obtained with the nmeNTR. Using the GusA reporter, translation initiation from six alternative (non-AUG) start codons was measured in E. coli, C. sporogenes, and C. butyricum. Clearly, species-specific differences between clostridia and E. coli in translation initiation were observed, and the performance of the start codons was influenced by the upstream 5' UTR sequence. These results highlight a new opportunity for gene control in recombinant clostridia. To demonstrate the value of these results, expression of the sacB gene from Bacillus subtilis was optimized for use as a novel negative selection marker in C. butyricum. In summary, these results indicate improvements in the understanding of heterologous gene regulation in Clostridium species and E. coli cloning strains. This new knowledge can be utilized for rationally designed gene regulation in Clostridium-mediated industrial and medical applications, as well as fundamental research into the biology of Clostridium species.
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Affiliation(s)
- Yanchao Zhang
- The
M-Lab, Department of Precision Medicine, GROW - School of Oncology
and Reproduction, Maastricht University, 6229 ER Maastricht, The Netherlands,
| | - Tom S. Bailey
- The
M-Lab, Department of Precision Medicine, GROW - School of Oncology
and Reproduction, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Aleksandra M. Kubiak
- The
M-Lab, Department of Precision Medicine, GROW - School of Oncology
and Reproduction, Maastricht University, 6229 ER Maastricht, The Netherlands,Exomnis
Biotech BV, Oxfordlaan
55, 6229 EV Maastricht, The Netherlands
| | - Philippe Lambin
- The
M-Lab, Department of Precision Medicine, GROW - School of Oncology
and Reproduction, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Jan Theys
- The
M-Lab, Department of Precision Medicine, GROW - School of Oncology
and Reproduction, Maastricht University, 6229 ER Maastricht, The Netherlands
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5
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Lee J. Lessons from Clostridial Genetics: Toward Engineering Acetogenic Bacteria. BIOTECHNOL BIOPROC E 2021. [DOI: 10.1007/s12257-021-0062-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Anaerobic fluorescent reporters for cell identification, microbial cell biology and high-throughput screening of microbiota and genomic libraries. Curr Opin Biotechnol 2021; 71:151-163. [PMID: 34375813 DOI: 10.1016/j.copbio.2021.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/08/2021] [Indexed: 11/23/2022]
Abstract
The lack of real-time reporters in obligate anaerobes has limited studies in gene expression, promoter characterization, library screening, population dynamics, and cell biology in these organisms. While the use of enzymatic, colorimetric, and luminescent reporters has been reported, the need for reliable anaerobic fluorescent proteins is widely acknowledged. Recently, the fluorescent proteins HaloTag, SNAP-tag and FAST have been established as reliable reporters in Clostridium spp., thus suggesting that these reporters can be adopted widely for many obligate anaerobes. With a multitude of labeling options, these anaerobic fluorescent proteins hold a great potential for screening promoters, terminators, and RBS sites, tracking population dynamics in complex multi-species co-cultures, such as microbiomes, screening libraries, and in cell biology studies of protein localization and interactions using high-resolution microscopy.
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7
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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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8
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Grosse-Honebrink A, Little GT, Bean Z, Heldt D, Cornock RHM, Winzer K, Minton NP, Green E, Zhang Y. Development of Clostridium saccharoperbutylacetonicum as a Whole Cell Biocatalyst for Production of Chirally Pure ( R)-1,3-Butanediol. Front Bioeng Biotechnol 2021; 9:659895. [PMID: 34055760 PMCID: PMC8155681 DOI: 10.3389/fbioe.2021.659895] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/12/2021] [Indexed: 11/13/2022] Open
Abstract
Chirally pure (R)-1,3-butanediol ((R)-1,3-BDO) is a valuable intermediate for the production of fragrances, pheromones, insecticides and antibiotics. Biotechnological production results in superior enantiomeric excess over chemical production and is therefore the preferred production route. In this study (R)-1,3-BDO was produced in the industrially important whole cell biocatalyst Clostridium saccharoperbutylacetonicum through expression of the enantio-specific phaB gene from Cupriavidus necator. The heterologous pathway was optimised in three ways: at the transcriptional level choosing strongly expressed promoters and comparing plasmid borne with chromosomal gene expression, at the translational level by optimising the codon usage of the gene to fit the inherent codon adaptation index of C. saccharoperbutylacetonicum, and at the enzyme level by introducing point mutations which led to increased enzymatic activity. The resulting whole cell catalyst produced up to 20 mM (1.8 g/l) (R)-1,3-BDO in non-optimised batch fermentation which is a promising starting position for economical production of this chiral chemical.
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Affiliation(s)
- Alexander Grosse-Honebrink
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Gareth T Little
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Zak Bean
- CHAIN Biotechnology Ltd., MediCity, Nottingham, United Kingdom
| | - Dana Heldt
- CHAIN Biotechnology Ltd., MediCity, Nottingham, United Kingdom
| | - Ruth H M Cornock
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Klaus Winzer
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Nigel P Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Edward Green
- CHAIN Biotechnology Ltd., MediCity, Nottingham, United Kingdom
| | - Ying Zhang
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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Riley LA, Guss AM. Approaches to genetic tool development for rapid domestication of non-model microorganisms. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:30. [PMID: 33494801 PMCID: PMC7830746 DOI: 10.1186/s13068-020-01872-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/30/2020] [Indexed: 05/04/2023]
Abstract
Non-model microorganisms often possess complex phenotypes that could be important for the future of biofuel and chemical production. They have received significant interest the last several years, but advancement is still slow due to the lack of a robust genetic toolbox in most organisms. Typically, "domestication" of a new non-model microorganism has been done on an ad hoc basis, and historically, it can take years to develop transformation and basic genetic tools. Here, we review the barriers and solutions to rapid development of genetic transformation tools in new hosts, with a major focus on Restriction-Modification systems, which are a well-known and significant barrier to efficient transformation. We further explore the tools and approaches used for efficient gene deletion, DNA insertion, and heterologous gene expression. Finally, more advanced and high-throughput tools are now being developed in diverse non-model microbes, paving the way for rapid and multiplexed genome engineering for biotechnology.
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Affiliation(s)
- Lauren A Riley
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Bredesen Center, University of Tennessee, Knoxville, TN, 37996, USA
| | - Adam M Guss
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
- Bredesen Center, University of Tennessee, Knoxville, TN, 37996, USA.
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10
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Han S, Kim Y, Karanjikar M, San KY, Bennett GN. Genetic sensor-regulators functional in Clostridia. J Ind Microbiol Biotechnol 2020; 47:609-620. [DOI: 10.1007/s10295-020-02303-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/18/2020] [Indexed: 11/30/2022]
Abstract
Abstract
This study addressed the functionality of genetic circuits carrying natural regulatory elements of Clostridium acetobutylicum ATCC 824 in the presence of the respective inducer molecules. Specifically, promoters and their regulators involved in diverse carbon source utilization were characterized using mCherryOpt or beta-galactosidase as a reporter. Consequently, most of the genetic circuits tested in this study were functional in Clostridium acetobutylicum ATCC 824 in the presence of an inducer, leading to the expression of reporter proteins. These genetic sensor-regulators were found to be transferable to another Clostridium species, such as Clostridium beijerinckii NCIMB 8052. The gradual expression of reporter protein was observed as a function of the carbohydrates of interest. A xylose-inducible promoter allows a titratable and robust expression of a reporter protein with stringency and efficacy. This xylose-inducible circuit was seen to enable induction of the expression of reporter proteins in the presence of actual sugar mixtures incorporated in woody hydrolysate wherein glucose and xylose are present as predominant carbon sources.
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Affiliation(s)
- SongI Han
- grid.21940.3e 0000 0004 1936 8278 Department of Bioengineering Rice University 77005 Houston TX USA
| | - Younghwan Kim
- grid.427405.0 Technology Holding LLC 84119 West Valley City UT USA
| | | | - Ka-Yiu San
- grid.21940.3e 0000 0004 1936 8278 Department of Bioengineering Rice University 77005 Houston TX USA
- grid.21940.3e 0000 0004 1936 8278 Department of Chemical and Biomolecular Engineering Rice University 77005 Houston TX USA
| | - George N Bennett
- grid.21940.3e 0000 0004 1936 8278 Department of Chemical and Biomolecular Engineering Rice University 77005 Houston TX USA
- grid.21940.3e 0000 0004 1936 8278 Department of BioSciences Rice University 77005 Houston TX USA
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Zhao R, Liu Y, Zhang H, Chai C, Wang J, Jiang W, Gu Y. CRISPR-Cas12a-Mediated Gene Deletion and Regulation in Clostridium ljungdahlii and Its Application in Carbon Flux Redirection in Synthesis Gas Fermentation. ACS Synth Biol 2019; 8:2270-2279. [PMID: 31526005 DOI: 10.1021/acssynbio.9b00033] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Uncovering the full potential of gas-fermenting Clostridia, attractive autotrophic bacteria capable of using synthesis gases (CO-CO2-H2) to produce a range of chemicals and fuels, for industrial applications relies on having efficient molecular tools for genetic modifications. Although the CRISPR-Cas9-mediated genome editing system has been developed in Clostridia, its use is limited owing to low GC content (approx. 30%) in these anaerobes. Therefore, the effector protein Cas12a, which recognizes T-rich instead of G-rich protospacer-adjacent motifs (PAMs), has evident advantages over Cas9 in CRISPR genome editing in Clostridia. Here, we developed the CRISPR-Cas12a system for efficient gene deletion and regulation in the gas-fermenting Clostridium ljungdahlii species. On the basis of screening for the most suitable Cas12a and significantly improved electrotransformation efficiency that bypassed poor repair efficiency of the Cas12a-caused DNA double-strand break (DSB) in C. ljungdahlii, efficient deletion (80-100%) of four genes (pyrE, pta, adhE1, and ctf) was achieved by using the CRISPR-FnCas12a system. Furthermore, a DNase-deactivated FnCas12a (ddCas12a) was adopted to construct a CRISPRi system to downregulate targeted genes, reaching over 80% repression for most of the chosen binding sites. This CRISPRi system was also used in a butyric acid-producing C. ljungdahlii strain to redirect carbon flux, leading to 20-40% reductions in ethanol titer that were accompanied by increased butyric acid titer. These results demonstrate the high efficiency of the CRISPR-FnCas12a system for genome engineering in C. ljungdahlii, which effectively expands the existing CRISPR-Cas toolbox in gas-fermenting Clostridium species and may play important roles in genetic manipulations where CRISPR-Cas9 is incompetent.
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Affiliation(s)
- Ran Zhao
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- School of Life Sciences, Henan University, Kaifeng 475001, China
| | - Yanqiang Liu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Huan Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Changsheng Chai
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jin Wang
- College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Weihong Jiang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yang Gu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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12
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A Strongly Fluorescing Anaerobic Reporter and Protein-Tagging System for Clostridium Organisms Based on the Fluorescence-Activating and Absorption-Shifting Tag Protein (FAST). Appl Environ Microbiol 2019; 85:AEM.00622-19. [PMID: 31076434 DOI: 10.1128/aem.00622-19] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/07/2019] [Indexed: 01/03/2023] Open
Abstract
Visualizing protein localization and characterizing gene expression activity in live Clostridium cells is limited for lack of a real-time, highly fluorescent, oxygen-independent reporter system. Enzymatic reporter systems have been used successfully for many years with Clostridium spp.; however, these assays do not allow for real-time analysis of gene expression activity with flow cytometry or for visualizing protein localization through fusion proteins. Commonly used fluorescent reporter proteins require oxygen for chromophore maturation and cannot be used for most strictly anaerobic Clostridium organisms. Here we show that the fluorescence-activating and absorption-shifting tag protein (FAST), when associated with the fluorogenic ligand 4-hydroxy-3-methylbenzylidene-rhodanine (HMBR; now commercially available) and other commercially available ligands, is highly fluorescent in Clostridium acetobutylicum under anaerobic conditions. Using flow cytometry and a fluorescence microplate reader, we demonstrated FAST as a reporter system by employing the promoters of the C. acetobutylicum thiolase (thl), acetoacetate decarboxylase (adc), and phosphotransbutyrylase (ptb) metabolic genes, as well as a mutant Pthl and modified ribosome binding site (RBS) versions of Padc and Pptb Flow cytometry-based sorting was efficient and fast in sorting FAST-expressing cells, and positively and negatively sorted cells could be effectively recultured. FAST was also used to tag and examine protein localization of the predicted cell division FtsZ partner protein, ZapA, to visualize the divisome localization in live C. acetobutylicum cells. Our findings suggest that FAST can be used to further investigate Clostridium divisomes and more broadly the localization and expression levels of other proteins in Clostridium organisms, thus enabling cell biology studies with these organisms.IMPORTANCE FAST in association with the fluorogenic ligand HMBR is characterized as a successful, highly fluorescent reporter system in C. acetobutylicum FAST can be used to distinguish between promoters in live cells using flow cytometry or a fluorescence microplate reader and can be used to tag and examine protein localization in live, anaerobically grown cells. Given that FAST is highly fluorescent under anaerobic conditions, it can be used in several applications of this and likely many Clostridium organisms and other strict anaerobes, including studies involving cell sorting, sporulation dynamics, and population characterization in pure as well as mixed cultures, such as those in various native or synthetic microbiomes and syntrophic cultures.
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Agu CV, Ujor V, Ezeji TC. Metabolic engineering of Clostridium beijerinckii to improve glycerol metabolism and furfural tolerance. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:50. [PMID: 30899330 PMCID: PMC6408787 DOI: 10.1186/s13068-019-1388-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 02/25/2019] [Indexed: 05/12/2023]
Abstract
BACKGROUND Inefficient utilization of glycerol by Clostridium beijerinckii (Cb) is a major impediment to adopting glycerol metabolism as a strategy for increasing NAD(P)H regeneration, which would in turn, alleviate the toxicity of lignocellulose-derived microbial inhibitory compounds (LDMICs, e.g., furfural), and improve the fermentation of lignocellulosic biomass hydrolysates (LBH) to butanol. To address this problem, we employed a metabolic engineering strategy to enhance glycerol utilization by Cb. RESULTS By overexpressing two glycerol dehydrogenase (Gldh) genes (dhaD1 and gldA1) from the glycerol hyper-utilizing Clostridium pasteurianum (Cp) as a fused protein in Cb, we achieved approximately 43% increase in glycerol consumption, when compared to the plasmid control. Further, Cb_dhaD1 + gldA1 achieved a 59% increase in growth, while butanol and acetone-butanol-ethanol (ABE) concentrations and productivities increased 14.0%, 17.3%, and 55.6%, respectively, relative to the control. Co-expression of dhaD1 + gldA1 and gldA1 + dihydroxyacetone kinase (dhaK) resulted in significant payoffs in cell growth and ABE production compared to expression of one Gldh. In the presence of 4-6 g/L furfural, increased glycerol consumption by the dhaD1 + gldA1 strain increased cell growth (> 50%), the rate of furfural detoxification (up to 68%), and ABE production (up to 40%), relative to the plasmid control. Likewise, over-expression of [(dhaD1 + gldA1) dhaK] improved butanol and ABE production by 70% and 50%, respectively, in the presence of 5 and 6 g/L furfural relative to the plasmid control. CONCLUSIONS Overexpression of Cp gldhs and dhaK in Cb significantly enhanced glycerol utilization, ABE production, and furfural tolerance by Cb. Future research will address the inability of recombinant Cb to metabolize glycerol as a sole substrate.
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Affiliation(s)
- Chidozie Victor Agu
- Department of Animal Sciences and Ohio State Agricultural Research and Development Center (OARDC), The Ohio State University, 305 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH 44691 USA
- INanoBio Inc., 320 Logue Ave., Suite 212, Mountain View, CA 94043 USA
| | - Victor Ujor
- Bioenergy and Biological Waste Management Program, Agricultural Technical Institute, The Ohio State University, 1328 Dover Road, Wooster, OH 44691 USA
| | - Thaddeus Chukwuemeka Ezeji
- Department of Animal Sciences and Ohio State Agricultural Research and Development Center (OARDC), The Ohio State University, 305 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH 44691 USA
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14
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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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15
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Toth M, Stewart NK, Smith C, Vakulenko SB. Intrinsic Class D β-Lactamases of Clostridium difficile. mBio 2018; 9:e01803-18. [PMID: 30563905 PMCID: PMC6299217 DOI: 10.1128/mbio.01803-18] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/15/2018] [Indexed: 12/14/2022] Open
Abstract
Clostridium difficile is the causative agent of the deadly C. difficile infection. Resistance of the pathogen to β-lactam antibiotics plays a major role in the development of the disease, but the mechanism of resistance is currently unknown. We discovered that C. difficile encodes class D β-lactamases, i.e., CDDs, which are intrinsic to this species. We studied two CDD enzymes, CDD-1 and CDD-2, and showed that they display broad-spectrum, high catalytic efficiency against various β-lactam antibiotics, including penicillins and expanded-spectrum cephalosporins. We demonstrated that the cdd genes are poorly expressed under the control of their own promoters and contribute only partially to the observed resistance to β-lactams. However, when the cdd1 gene was expressed under the control of efficient promoters in the antibiotic-sensitive Clostridium cochlearium strain, it produced high-level resistance to β-lactams. Taken together, the results determined in this work demonstrate the existence in C. difficile of intrinsic class D β-lactamases which constitute a reservoir of highly potent enzymes capable of conferring broad-spectrum, clinically relevant levels of resistance to β-lactam antibiotics. This discovery is a significant contribution to elucidation of the mechanism(s) of resistance of the clinically important pathogen C. difficile to β-lactam antibiotics.IMPORTANCEC. difficile is a spore-forming anaerobic bacterium which causes infection of the large intestine with high mortality rates. The C. difficile infection is difficult to prevent and treat, as the pathogen is resistant to many antimicrobial agents. Prolonged use of β-lactam antibiotics for treatment of various infectious diseases triggers the infection, as these drugs suppress the abundance of protective gut bacteria, allowing the resistant C. difficile bacteria to multiply. While resistance of C. difficile to β-lactam antibiotics plays the major role in the development of the disease, the mechanism of resistance is unknown. The significance of our research is in the discovery in C. difficile of β-lactamases, enzymes that destroy β-lactam antibiotics. These findings ultimately can help to combat deadly C. difficile infections.
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Affiliation(s)
- Marta Toth
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Nichole K Stewart
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Clyde Smith
- Stanford Synchrotron Radiation Lightsource, Stanford University, Menlo Park, California, USA
| | - Sergei B Vakulenko
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
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16
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Freed E, Fenster J, Smolinski SL, Walker J, Henard CA, Gill R, Eckert CA. Building a genome engineering toolbox in nonmodel prokaryotic microbes. Biotechnol Bioeng 2018; 115:2120-2138. [PMID: 29750332 DOI: 10.1002/bit.26727] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/02/2018] [Accepted: 03/10/2018] [Indexed: 12/26/2022]
Abstract
The realization of a sustainable bioeconomy requires our ability to understand and engineer complex design principles for the development of platform organisms capable of efficient conversion of cheap and sustainable feedstocks (e.g., sunlight, CO2 , and nonfood biomass) into biofuels and bioproducts at sufficient titers and costs. For model microbes, such as Escherichia coli, advances in DNA reading and writing technologies are driving the adoption of new paradigms for engineering biological systems. Unfortunately, microbes with properties of interest for the utilization of cheap and renewable feedstocks, such as photosynthesis, autotrophic growth, and cellulose degradation, have very few, if any, genetic tools for metabolic engineering. Therefore, it is important to develop "design rules" for building a genetic toolbox for novel microbes. Here, we present an overview of our current understanding of these rules for the genetic manipulation of prokaryotic microbes and the available genetic tools to expand our ability to genetically engineer nonmodel systems.
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Affiliation(s)
- Emily Freed
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
| | - Jacob Fenster
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO.,Chemical and Biological Engineering, University of Colorado, Boulder, CO
| | | | - Julie Walker
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
| | - Calvin A Henard
- National Renewable Energy Laboratory, National Bioenergy Center, Golden, CO
| | - Ryan Gill
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO.,Chemical and Biological Engineering, University of Colorado, Boulder, CO
| | - Carrie A Eckert
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
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17
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Gyulev IS, Willson BJ, Hennessy RC, Krabben P, Jenkinson ER, Thomas GH. Part by Part: Synthetic Biology Parts Used in Solventogenic Clostridia. ACS Synth Biol 2018; 7:311-327. [PMID: 29186949 DOI: 10.1021/acssynbio.7b00327] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The solventogenic Clostridia are of interest to the chemical industry because of their natural ability to produce chemicals such as butanol, acetone and ethanol from diverse feedstocks. Their use as whole cell factories presents multiple metabolic engineering targets that could lead to improved sustainability and profitability of Clostridium industrial processes. However, engineering efforts have been held back by the scarcity of genetic and synthetic biology tools. Over the past decade, genetic tools to enable transformation and chromosomal modifications have been developed, but the lack of a broad palette of synthetic biology parts remains one of the last obstacles to the rapid engineered improvement of these species for bioproduction. We have systematically reviewed existing parts that have been used in the modification of solventogenic Clostridia, revealing a narrow range of empirically chosen and nonengineered parts that are in current use. The analysis uncovers elements, such as promoters, transcriptional terminators and ribosome binding sites where increased fundamental knowledge is needed for their reliable use in different applications. Together, the review provides the most comprehensive list of parts used and also presents areas where an improved toolbox is needed for full exploitation of these industrially important bacteria.
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Affiliation(s)
- Ivan S. Gyulev
- Department
of Biology, University of York, Wentworth Way, York YO10 5DD, United Kingdom
| | - Benjamin J. Willson
- Department
of Biology, University of York, Wentworth Way, York YO10 5DD, United Kingdom
| | - Rosanna C. Hennessy
- Department
of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, 1871, Denmark
| | - Preben Krabben
- Green Biologics Limited, Milton Park, Abingdon, Oxfordshire OX14 4RU, United Kingdom
| | | | - Gavin H. Thomas
- Department
of Biology, University of York, Wentworth Way, York YO10 5DD, United Kingdom
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18
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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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19
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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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20
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Seo SO, Lu T, Jin YS, Blaschek HP. Development of an oxygen-independent flavin mononucleotide-based fluorescent reporter system in Clostridium beijerinckii and its potential applications. J Biotechnol 2017; 265:119-126. [PMID: 29158189 DOI: 10.1016/j.jbiotec.2017.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 12/21/2022]
Abstract
Clostridium beijerinckii is a predominant solventogenic clostridia with great attraction for renewable liquid biofuel and biochemical production. Metabolic engineering and synthetic biology can be employed to engineer the strain toward desirable phenotypes. However, current limited information such as promoter strength and gene regulation may hinder the efficient engineering of the strain. To investigate genetic information and complex cellular bioprocesses of C. beijerinckii, an in vivo fluorescence reporter system can be employed. In general, green fluorescence protein (GFP) and relative analogs have been widely used as real-time reporters. However, GFP-family proteins require molecular oxygen for fluorescence maturation. Considering the strict anaerobic growth requirement of the clostridia, an oxygen-independent fluorescence reporter such as a flavin mononucleotide-based fluorescent protein (FbFP) can be used as an alternative fluorescence reporter. In this study, we synthesized and expressed the codon-optimized FbFP gene for C. beijerinckii (CbFbFP) based on the nucleotide sequence of Bacillus subtilis YtvA variant EcFbFP in C. beijerinckii NCIMB 8052 wild-type. Protein expression and in vivo fluorescence of CbFbFP in C. beijeirnckii were confirmed under anaerobic growth conditions. Through fluorescence-activated cell sorting (FACS), we isolated the bright cells from the heterogenous population of C. beijerinckii cells expressing CbFbFP. Several mutations were found in the isolated plasmid which may be responsible for the high-level expression of CbFbFP in C. beijerinckii. The mutant plasmid and CbFbFP reporter were further utilized for strain selection, real-time fluorescence measurement, population analysis, and metabolic engineering in this study.
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Affiliation(s)
- Seung-Oh Seo
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ting Lu
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Bioengineering and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yong-Su Jin
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Hans P Blaschek
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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21
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Application of β-glucuronidase (GusA) as an effective reporter for extremely acidophilic Acidithiobacillus ferrooxidans. Appl Microbiol Biotechnol 2017; 101:3283-3294. [DOI: 10.1007/s00253-017-8116-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 12/20/2016] [Accepted: 12/29/2016] [Indexed: 10/20/2022]
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22
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Huang H, Chai C, Li N, Rowe P, Minton NP, Yang S, Jiang W, Gu Y. CRISPR/Cas9-Based Efficient Genome Editing in Clostridium ljungdahlii, an Autotrophic Gas-Fermenting Bacterium. ACS Synth Biol 2016; 5:1355-1361. [PMID: 27276212 DOI: 10.1021/acssynbio.6b00044] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acetogenic bacteria have the potential to convert single carbon gases (CO and CO2) into a range of bulk chemicals and fuels. Realization of their full potential is being impeded by the absence of effective genetic tools for high throughput genome modification. Here we report the development of a highly efficient CRISPR/Cas9 system for rapid genome editing of Clostridium ljungdahlii, a paradigm for the commercial production of ethanol from synthesis gas. Following the experimental selection of two promoters (Pthl and ParaE) for expression of cas9 and the requisite single guide RNA (sgRNA), the efficiency of system was tested by making precise deletions of four genes, pta, adhE1, ctf and pyrE. Deletion efficiencies were 100%, >75%, 100% and >50%, respectively. The system overcomes the deficiencies of currently available tools (more rapid, no added antibiotic resistance gene, scarless and minimal polar effects) and will find utility in other acetogens, including the pathogen Clostridium difficile.
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Affiliation(s)
- He Huang
- 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
| | - Ning Li
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai 200032, China
| | - Pete Rowe
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham , Nottingham, NG7 2RD, U.K
| | - Nigel P Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham , Nottingham, NG7 2RD, U.K
| | - 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
| | - 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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23
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Cho C, Lee SY. Efficient gene knockdown inClostridium acetobutylicumby synthetic small regulatory RNAs. Biotechnol Bioeng 2016; 114:374-383. [DOI: 10.1002/bit.26077] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 07/19/2016] [Accepted: 08/07/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Changhee Cho
- Metabolic and Biomolecular Engineering National Research Laboratory; Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Center for Systems and Synthetic Biotechnology, Institute for the BioCentury, KAIST; Daejeon 34141 Republic of Korea
| | - Sang Yup Lee
- Metabolic and Biomolecular Engineering National Research Laboratory; Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Center for Systems and Synthetic Biotechnology, Institute for the BioCentury, KAIST; Daejeon 34141 Republic of Korea
- BioProcess Engineering Research Center; KAIST; Daejeon Republic of Korea
- BioInformatics Research Center; KAIST; Daejeon Republic of Korea
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24
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Lee J, Jang YS, Papoutsakis ET, Lee SY. Stable and enhanced gene expression in Clostridium acetobutylicum using synthetic untranslated regions with a stem-loop. J Biotechnol 2016; 230:40-3. [DOI: 10.1016/j.jbiotec.2016.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 04/02/2016] [Accepted: 05/13/2016] [Indexed: 10/21/2022]
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25
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Liew F, Martin ME, Tappel RC, Heijstra BD, Mihalcea C, Köpke M. Gas Fermentation-A Flexible Platform for Commercial Scale Production of Low-Carbon-Fuels and Chemicals from Waste and Renewable Feedstocks. Front Microbiol 2016; 7:694. [PMID: 27242719 PMCID: PMC4862988 DOI: 10.3389/fmicb.2016.00694] [Citation(s) in RCA: 206] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 04/26/2016] [Indexed: 12/13/2022] Open
Abstract
There is an immediate need to drastically reduce the emissions associated with global fossil fuel consumption in order to limit climate change. However, carbon-based materials, chemicals, and transportation fuels are predominantly made from fossil sources and currently there is no alternative source available to adequately displace them. Gas-fermenting microorganisms that fix carbon dioxide (CO2) and carbon monoxide (CO) can break this dependence as they are capable of converting gaseous carbon to fuels and chemicals. As such, the technology can utilize a wide range of feedstocks including gasified organic matter of any sort (e.g., municipal solid waste, industrial waste, biomass, and agricultural waste residues) or industrial off-gases (e.g., from steel mills or processing plants). Gas fermentation has matured to the point that large-scale production of ethanol from gas has been demonstrated by two companies. This review gives an overview of the gas fermentation process, focusing specifically on anaerobic acetogens. Applications of synthetic biology and coupling gas fermentation to additional processes are discussed in detail. Both of these strategies, demonstrated at bench-scale, have abundant potential to rapidly expand the commercial product spectrum of gas fermentation and further improve efficiencies and yields.
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Oh YH, Eom GT, Kang KH, Joo JC, Jang YA, Choi JW, Song BK, Lee SH, Park SJ. Construction of heterologous gene expression cassettes for the development of recombinant Clostridium beijerinckii. Bioprocess Biosyst Eng 2016; 39:555-63. [DOI: 10.1007/s00449-016-1537-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 01/05/2016] [Indexed: 02/08/2023]
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Teng L, Wang K, Xu J, Xu C. Flavin mononucleotide (FMN)-based fluorescent protein (FbFP) as reporter for promoter screening in Clostridium cellulolyticum. J Microbiol Methods 2015; 119:37-43. [PMID: 26427827 DOI: 10.1016/j.mimet.2015.09.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/28/2015] [Accepted: 09/28/2015] [Indexed: 12/13/2022]
Abstract
Conventional methods for screening promoters in anaerobic bacteria are generally based on detection of enzymatic reactions and thus usually complicated or strain specific. Therefore a more efficient and universal method will be valuable. Here, using cellulolytic bacteria Clostridium cellulolyticum H10 as a model, we employed an oxygen-independent flavin-based fluorescent protein (FbFP) derived from Pseudomonas putida as a quantitative reporter for the screening of promoter via monitoring fluorescence intensity. The stability and reliability of FbFP fluorescence were proven by the high correlation (R(2)=0.87) between fluorescence intensity and abundance of FbFP. Moreover, two endogenous promoters with exceptional performance were identified and characterized, including a constitutive promoter p3398 and an inducible promoter p1133. Compared to the existing reporter systems widely used in clostridia, this FbFP-based method is more rapid, intuitive and versatile, and the endogenous promoters reported here should enrich the synthetic biology toolbox for this and related organisms.
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Affiliation(s)
- Lin Teng
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kun Wang
- Key Laboratory of Horticulture Science for Southern Mountainous Region, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400716, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China.
| | - Chenggang Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China.
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Cuív PÓ, Smith WJ, Pottenger S, Burman S, Shanahan ER, Morrison M. Isolation of Genetically Tractable Most-Wanted Bacteria by Metaparental Mating. Sci Rep 2015; 5:13282. [PMID: 26293474 PMCID: PMC4642544 DOI: 10.1038/srep13282] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 07/16/2015] [Indexed: 01/03/2023] Open
Abstract
Metagenomics has rapidly advanced our inventory and appreciation of the genetic potential inherent to the gut microbiome. However it is widely accepted that two key constraints to further genetic dissection of the gut microbiota and host-microbe interactions have been our inability to recover new isolates from the human gut, and the paucity of genetically tractable gut microbes. To address this challenge we developed a modular RP4 mobilisable recombinant vector system and an approach termed metaparental mating to support the rapid and directed isolation of genetically tractable fastidious gut bacteria. Using this approach we isolated transconjugants affiliated with Clostridium cluster IV (Faecalibacterium and Oscillibacter spp.), Clostridium cluster XI (Anaerococcus) and Clostridium XIVa (Blautia spp.) and group 2 ruminococci amongst others, and demonstrated that the recombinant vectors were stably maintained in their recipient hosts. By a similar approach we constructed fluorescently labelled bacterial transconjugants affiliated with Clostridium cluster IV (including Flavonifractor and Pseudoflavonifractor spp.), Clostridium XIVa (Blautia spp.) and Clostridium cluster XVIII (Clostridium ramosum) that expressed a flavin mononucleotide-based reporter gene (evoglow-C-Bs2). Our approach will advance the integration of bacterial genetics with metagenomics and realize new directions to support a more mechanistic dissection of host-microbe associations relevant to human health and disease.
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Affiliation(s)
- Páraic Ó Cuív
- CSIRO Preventative Health Flagship Research Program, Queensland, Australia.,The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Queensland, Australia
| | - Wendy J Smith
- CSIRO Preventative Health Flagship Research Program, Queensland, Australia
| | - Sian Pottenger
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Queensland, Australia
| | - Sriti Burman
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Queensland, Australia
| | - Erin R Shanahan
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Queensland, Australia.,Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Queensland, Australia
| | - Mark Morrison
- CSIRO Preventative Health Flagship Research Program, Queensland, Australia.,The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Queensland, Australia
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Köhler KAK, Rühl J, Blank LM, Schmid A. Integration of biocatalyst and process engineering for sustainable and efficientn-butanol production. Eng Life Sci 2015. [DOI: 10.1002/elsc.201400041] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
| | - Jana Rühl
- Laboratory of Chemical Biotechnology; TU Dortmund University; Dortmund Germany
| | - Lars M. Blank
- Institute of Applied Microbiology (iAMB); Aachen Biology and Biotechnology (ABBt); RWTH Aachen University; Aachen Germany
| | - Andreas Schmid
- Department Solar Materials; Helmholtz Centre for Environmental Research (UFZ); Leipzig Germany
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Zhang J, Liu YJ, Cui GZ, Cui Q. A novel arabinose-inducible genetic operation system developed for Clostridium cellulolyticum. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:36. [PMID: 25763107 PMCID: PMC4355141 DOI: 10.1186/s13068-015-0214-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 01/29/2015] [Indexed: 05/07/2023]
Abstract
BACKGROUND Clostridium cellulolyticum and other cellulolytic Clostridium strains are natural producers of lignocellulosic biofuels and chemicals via the consolidated bioprocessing (CBP) route, and systems metabolic engineering is indispensable to meet the cost-efficient demands of industry. Several genetic tools have been developed for Clostridium strains, and an efficient and stringent inducible genetic operation system is still required for the precise regulation of the target gene function. RESULTS Here, we provide a stringent arabinose-inducible genetic operation (ARAi) system for C. cellulolyticum, including an effective gene expression platform with an oxygen-independent fluorescent reporter, a sensitive MazF-based counterselection genetic marker, and a precise gene knock-out method based on an inducible ClosTron system. A novel arabinose-inducible promoter derived from Clostridium acetobutylicum is employed in the ARAi system to control the expression of the target gene, and the gene expression can be up-regulated over 800-fold with highly induced stringency. The inducible ClosTron method of the ARAi system decreases the off-target frequency from 100% to 0, which shows the precise gene targeting in C. cellulolyticum. The inducible effect of the ARAi system is specific to a universal carbon source L-arabinose, implying that the system could be used widely for clostridial strains with various natural substrates. CONCLUSIONS The inducible genetic operation system ARAi developed in this study, containing both controllable gene expression and disruption tools, has the highest inducing activity and stringency in Clostridium by far. Thus, the ARAi system will greatly support the efficient metabolic engineering of C. cellulolyticum and other mesophilic Clostridium strains for lignocellulose bioconversion.
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Affiliation(s)
- Jie Zhang
- />Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
- />Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
- />University of Chinese Academy of Sciences, Chinese Academy of Sciences, 19, Yuquan Road, Beijing, 100049 People’s Republic of China
| | - Ya-Jun Liu
- />Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
- />Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
| | - Gu-Zhen Cui
- />Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
- />Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
| | - Qiu Cui
- />Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
- />Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
- />Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189, Songling Road, Qingdao, 266101 People’s Republic of China
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Daniell J, Nagaraju S, Burton F, Köpke M, Simpson SD. Low-Carbon Fuel and Chemical Production by Anaerobic Gas Fermentation. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 156:293-321. [PMID: 26957126 DOI: 10.1007/10_2015_5005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
World energy demand is expected to increase by up to 40% by 2035. Over this period, the global population is also expected to increase by a billion people. A challenge facing the global community is not only to increase the supply of fuel, but also to minimize fossil carbon emissions to safeguard the environment, at the same time as ensuring that food production and supply is not detrimentally impacted. Gas fermentation is a rapidly maturing technology which allows low carbon fuel and commodity chemical synthesis. Unlike traditional biofuel technologies, gas fermentation avoids the use of sugars, relying instead on gas streams rich in carbon monoxide and/or hydrogen and carbon dioxide as sources of carbon and energy for product synthesis by specialized bacteria collectively known as acetogens. Thus, gas fermentation enables access to a diverse array of novel, large volume, and globally available feedstocks including industrial waste gases and syngas produced, for example, via the gasification of municipal waste and biomass. Through the efforts of academic labs and early stage ventures, process scale-up challenges have been surmounted through the development of specialized bioreactors. Furthermore, tools for the genetic improvement of the acetogenic bacteria have been reported, paving the way for the production of a spectrum of ever-more valuable products via this process. As a result of these developments, interest in gas fermentation among both researchers and legislators has grown significantly in the past 5 years to the point that this approach is now considered amongst the mainstream of emerging technology solutions for near-term low-carbon fuel and chemical synthesis.
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Affiliation(s)
- James Daniell
- LanzaTech Inc., 8045 Lamon Ave, Suite 400, Skokie, IL, 60077, USA.,School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Shilpa Nagaraju
- LanzaTech Inc., 8045 Lamon Ave, Suite 400, Skokie, IL, 60077, USA
| | - Freya Burton
- LanzaTech Inc., 8045 Lamon Ave, Suite 400, Skokie, IL, 60077, USA
| | - Michael Köpke
- LanzaTech Inc., 8045 Lamon Ave, Suite 400, Skokie, IL, 60077, USA
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Lütke-Eversloh T. Application of new metabolic engineering tools for Clostridium acetobutylicum. Appl Microbiol Biotechnol 2014; 98:5823-37. [DOI: 10.1007/s00253-014-5785-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/22/2014] [Accepted: 04/23/2014] [Indexed: 01/30/2023]
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Pyne ME, Bruder M, Moo-Young M, Chung DA, Chou CP. Technical guide for genetic advancement of underdeveloped and intractable Clostridium. Biotechnol Adv 2014; 32:623-41. [DOI: 10.1016/j.biotechadv.2014.04.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/10/2014] [Accepted: 04/15/2014] [Indexed: 02/04/2023]
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Lactose-inducible system for metabolic engineering of Clostridium ljungdahlii. Appl Environ Microbiol 2014; 80:2410-6. [PMID: 24509933 DOI: 10.1128/aem.03666-13] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The development of tools for genetic manipulation of Clostridium ljungdahlii has increased its attractiveness as a chassis for autotrophic production of organic commodities and biofuels from syngas and microbial electrosynthesis and established it as a model organism for the study of the basic physiology of acetogenesis. In an attempt to expand the genetic toolbox for C. ljungdahlii, the possibility of adapting a lactose-inducible system for gene expression, previously reported for Clostridium perfringens, was investigated. The plasmid pAH2, originally developed for C. perfringens with a gusA reporter gene, functioned as an effective lactose-inducible system in C. ljungdahlii. Lactose induction of C. ljungdahlii containing pB1, in which the gene for the aldehyde/alcohol dehydrogenase AdhE1 was downstream of the lactose-inducible promoter, increased expression of adhE1 30-fold over the wild-type level, increasing ethanol production 1.5-fold, with a corresponding decrease in acetate production. Lactose-inducible expression of adhE1 in a strain in which adhE1 and the adhE1 homolog adhE2 had been deleted from the chromosome restored ethanol production to levels comparable to those in the wild-type strain. Inducing expression of adhE2 similarly failed to restore ethanol production, suggesting that adhE1 is the homolog responsible for ethanol production. Lactose-inducible expression of the four heterologous genes necessary to convert acetyl coenzyme A (acetyl-CoA) to acetone diverted ca. 60% of carbon flow to acetone production during growth on fructose, and 25% of carbon flow went to acetone when carbon monoxide was the electron donor. These studies demonstrate that the lactose-inducible system described here will be useful for redirecting carbon and electron flow for the biosynthesis of products more valuable than acetate. Furthermore, this tool should aid in optimizing microbial electrosynthesis and for basic studies on the physiology of acetogenesis.
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Dusséaux S, Croux C, Soucaille P, Meynial-Salles I. Metabolic engineering of Clostridium acetobutylicum ATCC 824 for the high-yield production of a biofuel composed of an isopropanol/butanol/ethanol mixture. Metab Eng 2013; 18:1-8. [PMID: 23541907 DOI: 10.1016/j.ymben.2013.03.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 03/18/2013] [Indexed: 01/16/2023]
Abstract
Clostridium acetobutylicum was metabolically engineered to produce a biofuel consisting of an isopropanol/butanol/ethanol mixture. For this purpose, different synthetic isopropanol operons were constructed and introduced on plasmids in a butyrate minus mutant strain (C. acetobutylicum ATCC 824 Δcac15ΔuppΔbuk). The best strain expressing the isopropanol operon from the thl promoter was selected from batch experiments at pH 5. By further optimizing the pH of the culture, a biofuel mixture with almost no by-products was produced at a titer, a yield and productivity never reached before, opening the opportunities to develop an industrial process for alternative biofuels with Clostridial species. Furthermore, by performing in vivo and in vitro flux analysis of the synthetic isopropanol pathway, this flux was identified to be limited by the [acetate](int) and the high Km of CoA-transferase for acetate. Decreasing the Km of this enzyme using a protein engineering approach would be a good target for improving isopropanol production and avoiding acetate accumulation in the culture medium.
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Affiliation(s)
- Simon Dusséaux
- INSA, UPS, INP, LISBP, Université de Toulouse, 135 Avenue de Rangueil, F-31077 Toulouse, France
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Xiao H, Li Z, Jiang Y, Yang Y, Jiang W, Gu Y, Yang S. Metabolic engineering of D-xylose pathway in Clostridium beijerinckii to optimize solvent production from xylose mother liquid. Metab Eng 2012; 14:569-78. [PMID: 22677452 DOI: 10.1016/j.ymben.2012.05.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 04/29/2012] [Accepted: 05/22/2012] [Indexed: 11/18/2022]
Abstract
Clostridium beijerinckii is an attractive butanol-producing microbe for its advantage in co-fermenting hexose and pentose sugars. However, this Clostridium strain exhibits undesired efficiency in utilizing D-xylose, one of the major building blocks contained in lignocellulosic materials. Here, we reported a useful metabolic engineering strategy to improve D-xylose consumption by C. beijerinckii. Gene cbei2385, encoding a putative D-xylose repressor XylR, was first disrupted in the C. beijerinckii NCIMB 8052, resulting in a significant increase in D-xylose consumption. A D-xylose proton-symporter (encoded by gene cbei0109) was identified and then overexpressed to further optimize D-xylose utilization, yielding an engineered strain 8052xylR-xylT(ptb) (xylR inactivation plus xylT overexpression driven by ptb promoter). We investigated the strain 8052xylR-xylT(ptb) in fermenting xylose mother liquid, an abundant by-product from industrial-scale xylose preparation from corncob and rich in D-xylose, finally achieving a 35% higher Acetone, Butanol and Ethanol (ABE) solvent titer (16.91 g/L) and a 38% higher yield (0.29 g/g) over those of the wild-type strain. The strategy used in this study enables C. beijerinckii more suitable for butanol production from lignocellulosic materials.
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Affiliation(s)
- Han Xiao
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
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Tracy BP, Jones SW, Fast AG, Indurthi DC, Papoutsakis ET. Clostridia: the importance of their exceptional substrate and metabolite diversity for biofuel and biorefinery applications. Curr Opin Biotechnol 2012; 23:364-81. [DOI: 10.1016/j.copbio.2011.10.008] [Citation(s) in RCA: 313] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 10/06/2011] [Accepted: 10/20/2011] [Indexed: 12/19/2022]
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Dong H, Tao W, Zhang Y, Li Y. Development of an anhydrotetracycline-inducible gene expression system for solvent-producing Clostridium acetobutylicum: A useful tool for strain engineering. Metab Eng 2012; 14:59-67. [DOI: 10.1016/j.ymben.2011.10.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Revised: 09/23/2011] [Accepted: 10/21/2011] [Indexed: 12/14/2022]
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The issue of secretion in heterologous expression of Clostridium cellulolyticum cellulase-encoding genes in Clostridium acetobutylicum ATCC 824. Appl Environ Microbiol 2011; 77:2831-8. [PMID: 21378034 DOI: 10.1128/aem.03012-10] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The genes encoding the cellulases Cel5A, Cel8C, Cel9E, Cel48F, Cel9G, and Cel9M from Clostridium cellulolyticum were cloned in the C. acetobutylicum expression vector pSOS952 under the control of a Gram-positive constitutive promoter. The DNA encoding the native leader peptide of the heterologous cellulases was maintained. The transformation of the solventogenic bacterium with the corresponding vectors generated clones in the cases of Cel5A, Cel8C, and Cel9M. Analyses of the recombinant strains indicated that the three cellulases are secreted in an active form to the medium. A large fraction of the secreted cellulases, however, lost the C-terminal dockerin module. In contrast, with the plasmids pSOS952-cel9E, pSOS952-cel48F, and pSOS952-cel9G no colonies were obtained, suggesting that the expression of these genes has an inhibitory effect on growth. The deletion of the DNA encoding the leader peptide of Cel48F in pSOS952-cel48F, however, generated strains of C. acetobutylicum in which mature Cel48F accumulates in the cytoplasm. Thus, the growth inhibition observed when the wild-type cel48F gene is expressed seems related to the secretion of the cellulase. The weakening of the promoter, the coexpression of miniscaffoldin-encoding genes, or the replacement of the native signal sequence of Cel48F by that of secreted heterologous or endogenous proteins failed to generate strains secreting Cel48F. Taken together, our data suggest that a specific chaperone(s) involved in the secretion of the key family 48 cellulase, and probably Cel9G and Cel9E, is missing or insufficiently synthesized in C. acetobutylicum.
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Krätzer C, Welte C, Dörner K, Friedrich T, Deppenmeier U. Methanoferrodoxin represents a new class of superoxide reductase containing an iron-sulfur cluster. FEBS J 2010; 278:442-51. [PMID: 21138528 DOI: 10.1111/j.1742-4658.2010.07964.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Protein MM0632 from the methanogenic archaeon Methanosarcina mazei showed strong superoxide reductase activity and rapidly decomposed superoxide radicals to peroxides. The superoxide reductase activity of the heterologously produced enzyme was determined by a cytochrome c assay and in a test system with NADPH, ferredoxin:NADP(+) reductase, and rubredoxin. Furthermore, EPR spectroscopy showed that MM0632 is the first superoxide reductase that possesses an iron-sulfur cluster instead of a second mononuclear iron center. We propose the name methanoferrodoxin for this new class of superoxide reductase with an [Fe(NHis)(4)(SCys)] site as the catalytic center and a [4Fe-4S] cluster as second prosthetic group that is probably involved in electron transfer to the catalytic center. Methanosarcina mazei grows only under anaerobic conditions, but is one of the most aerotolerant methanogens. It is tempting to speculate that methanoferrodoxin contributes to the protection of cells from oxygen radicals formed by flavoproteins during periodic exposure to oxygen in natural environments.
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Affiliation(s)
- Christian Krätzer
- Institut für Mikrobiologie und Biotechnologie, Universität Bonn, Germany
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Construction and characterization of a lactose-inducible promoter system for controlled gene expression in Clostridium perfringens. Appl Environ Microbiol 2010; 77:471-8. [PMID: 21097603 DOI: 10.1128/aem.01536-10] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [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 which causes many diseases in humans and animals. While some genetic tools exist for working with C. perfringens, a tightly regulated, inducible promoter system is currently lacking. Therefore, we constructed a plasmid-based promoter system that provided regulated expression when lactose was added. This plasmid (pKRAH1) is an Escherichia coli-C. perfringens shuttle vector containing the gene encoding a transcriptional regulator, BgaR, and a divergent promoter upstream of gene bgaL (bgaR-P(bgaL)). To measure transcription at the bgaL promoter in pKRAH1, the E. coli reporter gene gusA, encoding β-glucuronidase, was placed downstream of the P(bgaL) promoter to make plasmid pAH2. When transformed into three strains of C. perfringens, pAH2 exhibited lactose-inducible expression. C. perfringens strain 13, a commonly studied strain, has endogenous β-glucuronidase activity. We mutated gene bglR, encoding a putative β-glucuronidase, and observed an 89% decrease in endogenous activity with no lactose. This combination of a system for regulated gene expression and a mutant of strain 13 with low β-glucuronidase activity are useful tools for studying gene regulation and protein expression in an important pathogenic bacterium. We used this system to express the yfp-pilB gene, comprised of a yellow fluorescent protein (YFP)-encoding gene fused to an assembly ATPase gene involved in type IV pilus-dependent gliding motility in C. perfringens. Expression in the wild-type strain showed that YFP-PilB localized mostly to the poles of cells, but in a pilC mutant it localized throughout the cell, demonstrating that the membrane protein PilC is required for polar localization of PilB.
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Zheng YN, Li LZ, Xian M, Ma YJ, Yang JM, Xu X, He DZ. Problems with the microbial production of butanol. J Ind Microbiol Biotechnol 2009; 36:1127-38. [PMID: 19562394 DOI: 10.1007/s10295-009-0609-9] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Accepted: 06/04/2009] [Indexed: 10/20/2022]
Abstract
With the incessant fluctuations in oil prices and increasing stress from environmental pollution, renewed attention is being paid to the microbial production of biofuels from renewable sources. As a gasoline substitute, butanol has advantages over traditional fuel ethanol in terms of energy density and hygroscopicity. A variety of cheap substrates have been successfully applied in the production of biobutanol, highlighting the commercial potential of biobutanol development. In this review, in order to better understand the process of acetone-butanol-ethanol production, traditional clostridia fermentation is discussed. Sporulation is probably induced by solvent formation, and the molecular mechanism leading to the initiation of sporulation and solventogenesis is also investigated. Different strategies are employed in the metabolic engineering of clostridia that aim to enhancing solvent production, improve selectivity for butanol production, and increase the tolerance of clostridia to solvents. However, it will be hard to make breakthroughs in the metabolic engineering of clostridia for butanol production without gaining a deeper understanding of the genetic background of clostridia and developing more efficient genetic tools for clostridia. Therefore, increasing attention has been paid to the metabolic engineering of E. coli for butanol production. The importation and expression of a non-clostridial butanol-producing pathway in E. coli is probably the most promising strategy for butanol biosynthesis. Due to the lower butanol titers in the fermentation broth, simultaneous fermentation and product removal techniques have been developed to reduce the cost of butanol recovery. Gas stripping is the best technique for butanol recovery found so far.
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Affiliation(s)
- Yan-Ning Zheng
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266071 Qingdao, China.
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Heap JT, Pennington OJ, Cartman ST, Minton NP. A modular system for Clostridium shuttle plasmids. J Microbiol Methods 2009; 78:79-85. [PMID: 19445976 DOI: 10.1016/j.mimet.2009.05.004] [Citation(s) in RCA: 344] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 05/07/2009] [Accepted: 05/08/2009] [Indexed: 10/20/2022]
Abstract
Despite their medical and industrial importance, our basic understanding of the biology of the genus Clostridium is rudimentary in comparison to their aerobic counterparts in the genus Bacillus. A major contributing factor has been the comparative lack of sophistication in the gene tools available to the clostridial molecular biologist, which are immature, and in clear need of development. The transfer and maintenance of recombinant, replicative plasmids into various species of Clostridium has been reported, and several elements suitable as shuttle plasmid components are known. However, these components have to-date only been available in disparate plasmid contexts, and their use has not been broadly explored. Here we describe the specification, design and construction of a standardized modular system for Clostridium-Escherichia coli shuttle plasmids. Existing replicons and selectable markers were incorporated, along with a novel clostridial replicon. The properties of these components were compared, and the data allow researchers to identify combinations of components potentially suitable for particular hosts and applications. The system has been extensively tested in our laboratory, where it is utilized in all ongoing recombinant work. We propose that adoption of this modular system as a standard would be of substantial benefit to the Clostridium research community, whom we invite to use and contribute to the system.
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Affiliation(s)
- John T Heap
- BBSRC Sustainable BioEnergy Centre, School of Molecular Medical Sciences, Centre for Biomolecular Sciences, The University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
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Lee SY, Park JH, Jang SH, Nielsen LK, Kim J, Jung KS. Fermentative butanol production by clostridia. Biotechnol Bioeng 2008; 101:209-28. [DOI: 10.1002/bit.22003] [Citation(s) in RCA: 773] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Papoutsakis ET. Engineering solventogenic clostridia. Curr Opin Biotechnol 2008; 19:420-9. [PMID: 18760360 DOI: 10.1016/j.copbio.2008.08.003] [Citation(s) in RCA: 229] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 07/23/2008] [Accepted: 08/01/2008] [Indexed: 01/28/2023]
Abstract
Solventogenic clostridia are strictly anaerobic, endospore forming bacteria that produce a large array of primary metabolites, like butanol, by anaerobically degrading simple and complex carbohydrates, including cellulose and hemicellulose. Two genomes have been sequenced and some genetic tools have been developed, but more are now urgently needed. Genomic tools for designing, and assessing the impact of, genetic modifications are well developed. Early efforts to metabolically engineer these organisms suggest that they are promising organisms for biorefinery applications. Pathway engineering efforts have resulted in interesting strains, but global engineering of their transcriptional machinery has produced better outcomes. Future efforts are expected to undertake the development of complex multigenic phenotypes, such as aerotolerance, solvent tolerance, high-cell density fermentations, abolished sporulation without impacting product formation, and genetic stability for continuous bioprocessing.
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Affiliation(s)
- Eleftherios T Papoutsakis
- Department of Chemical Engineering, University of Delaware, 15 Innovation Way, Newark, DE 19711, USA.
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Heap JT, Pennington OJ, Cartman ST, Carter GP, Minton NP. The ClosTron: a universal gene knock-out system for the genus Clostridium. J Microbiol Methods 2007; 70:452-64. [PMID: 17658189 DOI: 10.1016/j.mimet.2007.05.021] [Citation(s) in RCA: 503] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Accepted: 05/30/2007] [Indexed: 11/22/2022]
Abstract
Progress in exploiting clostridial genome information has been severely impeded by a general lack of effective methods for the directed inactivation of specific genes. Those few mutants that have been generated have been almost exclusively derived by single crossover integration of a replication-deficient or defective plasmid by homologous recombination. The mutants created are therefore unstable. Here we have adapted a mutagenesis system based on the mobile group II intron from the ltrB gene of Lactococcus lactis (Ll.ltrB) to function in clostridial hosts. Integrants are readily selected on the basis of acquisition of resistance to erythromycin, and are generated from start to finish in as little as 10 to 14 days. Unlike single crossover plasmid integrants, the mutants are extremely stable. The system has been used to make 6 mutants of Clostridium acetobutylicum and 5 of Clostridium difficile, exceeding the number of published mutants ever generated in these species. Genes have also been inactivated for the first time in Clostridium botulinum and Clostridium sporogenes, suggesting the system will be universally applicable to the genus. The procedure is highly efficient and reproducible, and should revolutionize functional genomic studies in clostridia.
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Affiliation(s)
- John T Heap
- Institute of Infection, Immunity and Inflammation, School of Molecular Medical Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
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Nakayama S, Irie R, Kosaka T, Matsuura K, Yoshino S, Furukawa K. New host-vector system in solvent-producing Clostridium saccharoperbutylacetonicum strain N1-4. J GEN APPL MICROBIOL 2007; 53:53-6. [PMID: 17429161 DOI: 10.2323/jgam.53.53] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Shunichi Nakayama
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
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