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Kohman RE, Kunjapur AM, Hysolli E, Wang Y, Church GM. Vom Design der Moleküle des Lebens zum Design von Leben: Zukünftige Anwendungen von DNA-Technologien. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201707976] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Richie E. Kohman
- Wyss Institute for Biologically Inspired Engineering; Harvard University; Boston MA 02115 USA
| | | | - Eriona Hysolli
- Department of Genetics; Harvard Medical School; Boston MA 02115 USA
| | - Yu Wang
- Department of Genetics; Harvard Medical School; Boston MA 02115 USA
- Wyss Institute for Biologically Inspired Engineering; Harvard University; Boston MA 02115 USA
| | - George M. Church
- Department of Genetics; Harvard Medical School; Boston MA 02115 USA
- Wyss Institute for Biologically Inspired Engineering; Harvard University; Boston MA 02115 USA
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Moreb EA, Hoover B, Yaseen A, Valyasevi N, Roecker Z, Menacho-Melgar R, Lynch MD. Managing the SOS Response for Enhanced CRISPR-Cas-Based Recombineering in E. coli through Transient Inhibition of Host RecA Activity. ACS Synth Biol 2017; 6:2209-2218. [PMID: 28915012 DOI: 10.1021/acssynbio.7b00174] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Phage-derived "recombineering" methods are utilized for bacterial genome editing. Recombineering results in a heterogeneous population of modified and unmodified chromosomes, and therefore selection methods, such as CRISPR-Cas9, are required to select for edited clones. Cells can evade CRISPR-Cas-induced cell death through recA-mediated induction of the SOS response. The SOS response increases RecA dependent repair as well as mutation rates through induction of the umuDC error prone polymerase. As a result, CRISPR-Cas selection is more efficient in recA mutants. We report an approach to inhibiting the SOS response and RecA activity through the expression of a mutant dominant negative form of RecA, which incorporates into wild type RecA filaments and inhibits activity. Using a plasmid-based system in which Cas9 and recA mutants are coexpressed, we can achieve increased efficiency and consistency of CRISPR-Cas9-mediated selection and recombineering in E. coli, while reducing the induction of the SOS response. To date, this approach has been shown to be independent of recA genotype and host strain lineage. Using this system, we demonstrate increased CRISPR-Cas selection efficacy with over 10 000 guides covering the E. coli chromosome. The use of dominant negative RecA or homologues may be of broad use in bacterial CRISPR-Cas-based genome editing where the SOS pathways are present.
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Affiliation(s)
- Eirik Adim Moreb
- Department of Biomedical
Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Benjamin Hoover
- Department of Biomedical
Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Adam Yaseen
- Department of Biomedical
Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Nisakorn Valyasevi
- Department of Biomedical
Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Zoe Roecker
- Department of Biomedical
Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Romel Menacho-Melgar
- Department of Biomedical
Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Michael D. Lynch
- Department of Biomedical
Engineering, Duke University, Durham, North Carolina 27708, United States
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Wei Y, Deng P, Mohsin A, Yang Y, Zhou H, Guo M, Fang H. An electroporation-free method based on Red recombineering for markerless deletion and genomic replacement in the Escherichia coli DH1 genome. PLoS One 2017; 12:e0186891. [PMID: 29065183 PMCID: PMC5655456 DOI: 10.1371/journal.pone.0186891] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 10/09/2017] [Indexed: 11/24/2022] Open
Abstract
The λ-Red recombination system is a popular method for gene editing. However, its applications are limited due to restricted electroporation of DNA fragments. Here, we present an electroporation-free λ-Red recombination method in which target DNA fragments are excised by I-CreI endonuclease in vivo from the landing pad plasmid. Subsequently, the I-SceI endonuclease-cutting chromosome and DNA double-strand break repair were required. Markerless deletion and genomic replacement were successfully accomplished by this novel approach. Eight nonessential regions of 2.4–104.4 kb in the Escherichia coli DH1 genome were deleted separately with selection efficiencies of 5.3–100%. Additionally, the recombination efficiencies were 2.5–45%, representing an order of magnitude improvement over the electroporation method. For example, for genomic replacement, lycopene expression flux (3.5 kb) was efficiently and precisely integrated into the chromosome, accompanied by replacement of nonessential regions separately into four differently oriented loci. The lycopene production level varied approximately by 5- and 10-fold, corresponding to the integrated position and expression direction, respectively, in the E. coli chromosome.
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Affiliation(s)
- Yanlong Wei
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Pingping Deng
- Institute of Health Sciences, Anhui University, Economic and Technology Development Zone, Hefei, Anhui, China
| | - Ali Mohsin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Yan Yang
- Luoyang Vocational & Technical College, Luoyang, Henan, China
- Institute of Biotechnology, Academy of Military Medical Sciences, Beijing, China
| | - Huayan Zhou
- Institute of Biotechnology, Academy of Military Medical Sciences, Beijing, China
| | - Meijin Guo
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- * E-mail: (MG); (HF)
| | - Hongqing Fang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Institute of Health Sciences, Anhui University, Economic and Technology Development Zone, Hefei, Anhui, China
- Institute of Biotechnology, Academy of Military Medical Sciences, Beijing, China
- * E-mail: (MG); (HF)
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Ryu YS, Chandran SP, Kim K, Lee SK. Oligo- and dsDNA-mediated genome editing using a tetA dual selection system in Escherichia coli. PLoS One 2017; 12:e0181501. [PMID: 28719630 PMCID: PMC5515457 DOI: 10.1371/journal.pone.0181501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 07/03/2017] [Indexed: 12/26/2022] Open
Abstract
The ability to precisely and seamlessly modify a target genome is needed for metabolic engineering and synthetic biology techniques aimed at creating potent biosystems. Herein, we report on a promising method in Escherichia coli that relies on the insertion of an optimized tetA dual selection cassette followed by replacement of the same cassette with short, single-stranded DNA (oligos) or long, double-stranded DNA and the isolation of recombinant strains by negative selection using NiCl2. This method could be rapidly and successfully used for genome engineering, including deletions, insertions, replacements, and point mutations, without inactivation of the methyl-directed mismatch repair (MMR) system and plasmid cloning. The method we describe here facilitates positive genome-edited recombinants with selection efficiencies ranging from 57 to 92%. Using our method, we increased lycopene production (3.4-fold) by replacing the ribosome binding site (RBS) of the rate-limiting gene (dxs) in the 1-deoxy-D-xylulose-5-phosphate (DXP) biosynthesis pathway with a strong RBS. Thus, this method could be used to achieve scarless, proficient, and targeted genome editing for engineering E. coli strains.
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Affiliation(s)
- Young Shin Ryu
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Sathesh-Prabu Chandran
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Kyungchul Kim
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Sung Kuk Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
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Kim Y, de la Torre A, Leal AA, Finkelstein IJ. Efficient modification of λ-DNA substrates for single-molecule studies. Sci Rep 2017; 7:2071. [PMID: 28522818 PMCID: PMC5437064 DOI: 10.1038/s41598-017-01984-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 04/05/2017] [Indexed: 01/15/2023] Open
Abstract
Single-molecule studies of protein-nucleic acid interactions frequently require site-specific modification of long DNA substrates. The bacteriophage λ is a convenient source of high quality long (48.5 kb) DNA. However, introducing specific sequences, tertiary structures, and chemical modifications into λ-DNA remains technically challenging. Most current approaches rely on multi-step ligations with low yields and incomplete products. Here, we describe a molecular toolkit for rapid preparation of modified λ-DNA. A set of PCR cassettes facilitates the introduction of recombinant DNA sequences into the λ-phage genome with 90-100% yield. Extrahelical structures and chemical modifications can be inserted at user-defined sites via an improved nicking enzyme-based strategy. As a proof-of-principle, we explore the interactions of S. cerevisiae Proliferating Cell Nuclear Antigen (yPCNA) with modified DNA sequences and structures incorporated within λ-DNA. Our results demonstrate that S. cerevisiae Replication Factor C (yRFC) can load yPCNA onto 5'-ssDNA flaps, (CAG)13 triplet repeats, and homoduplex DNA. However, yPCNA remains trapped on the (CAG)13 structure, confirming a proposed mechanism for triplet repeat expansion. We anticipate that this molecular toolbox will be broadly useful for other studies that require site-specific modification of long DNA substrates.
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Affiliation(s)
- Yoori Kim
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, 78712, USA
| | - Armando de la Torre
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, 78712, USA
| | - Andrew A Leal
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, 78712, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, 78712, USA.
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, 78712, USA.
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Hoffmann S, Schmidt C, Walter S, Bender JK, Gerlach RG. Scarless deletion of up to seven methyl-accepting chemotaxis genes with an optimized method highlights key function of CheM in Salmonella Typhimurium. PLoS One 2017; 12:e0172630. [PMID: 28212413 PMCID: PMC5315404 DOI: 10.1371/journal.pone.0172630] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/07/2017] [Indexed: 11/19/2022] Open
Abstract
Site-directed scarless mutagenesis is an essential tool of modern pathogenesis research. We describe an optimized two-step protocol for genome editing in Salmonella enterica serovar Typhimurium to enable multiple sequential mutagenesis steps in a single strain. The system is based on the λ Red recombinase-catalyzed integration of a selectable antibiotics resistance marker followed by replacement of this cassette. Markerless mutants are selected by expressing the meganuclease I-SceI which induces double-strand breaks in bacteria still harboring the resistance locus. Our new dual-functional plasmid pWRG730 allows for heat-inducible expression of the λ Red recombinase and tet-inducible production of I-SceI. Methyl-accepting chemotaxis proteins (MCP) are transmembrane chemoreceptors for a vast set of environmental signals including amino acids, sugars, ions and oxygen. Based on the sensory input of MCPs, chemotaxis is a key component for Salmonella virulence. To determine the contribution of individual MCPs we sequentially deleted seven MCP genes. The individual mutations were validated by PCR and genetic integrity of the final seven MCP mutant WRG279 was confirmed by whole genome sequencing. The successive MCP mutants were functionally tested in a HeLa cell infection model which revealed increased invasion rates for non-chemotactic mutants and strains lacking the MCP CheM (Tar). The phenotype of WRG279 was reversed with plasmid-based expression of CheM. The complemented WRG279 mutant showed also partially restored chemotaxis in swarming assays on semi-solid agar. Our optimized scarless deletion protocol enables efficient and precise manipulation of the Salmonella genome. As demonstrated with whole genome sequencing, multiple subsequent mutagenesis steps can be realized without the introduction of unwanted mutations. The sequential deletion of seven MCP genes revealed a significant role of CheM for the interaction of S. Typhimurium with host cells which might give new insights into mechanisms of Salmonella host cell sensing.
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Affiliation(s)
| | | | - Steffi Walter
- Project Group 5, Robert Koch Institute, Wernigerode, Germany
| | - Jennifer K. Bender
- Division of Nosocomial Pathogens and Antibiotic Resistances, Department of Infectious Diseases, Robert Koch Institute, Wernigerode, Germany
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Winkler JD, Halweg-Edwards AL, Gill RT. Quantifying complexity in metabolic engineering using the LASER database. Metab Eng Commun 2016; 3:227-233. [PMID: 29468127 PMCID: PMC5779719 DOI: 10.1016/j.meteno.2016.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/04/2016] [Indexed: 11/26/2022] Open
Abstract
We previously introduced the LASER database (Learning Assisted Strain EngineeRing, https://bitbucket.org/jdwinkler/laser_release) (Winkler et al. 2015) to serve as a platform for understanding past and present metabolic engineering practices. Over the past year, LASER has been expanded by 50% to include over 600 engineered strains from 450 papers, including their growth conditions, genetic modifications, and other information in an easily searchable format. Here, we present the results of our efforts to use LASER as a means for defining the complexity of a metabolic engineering "design". We evaluate two complexity metrics based on the concepts of construction difficulty and novelty. No correlation is observed between expected product yield and complexity, allowing minimization of complexity without a performance trade-off. We envision the use of such complexity metrics to filter and prioritize designs prior to implementation of metabolic engineering efforts, thereby potentially reducing the time, labor, and expenses of large-scale projects. Possible future developments based on an expanding LASER database are then discussed.
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Affiliation(s)
| | | | - Ryan T. Gill
- Department of Chemical and Biological Engineering, University of Colorado-Boulder, Jennie Smoly Caruthers Biotechnology Building, Research Park, Boulder, CO 80303, USA
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58
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A CRISPR-Cas9 Assisted Non-Homologous End-Joining Strategy for One-step Engineering of Bacterial Genome. Sci Rep 2016; 6:37895. [PMID: 27883076 PMCID: PMC5121644 DOI: 10.1038/srep37895] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/01/2016] [Indexed: 11/08/2022] Open
Abstract
Homologous recombination-mediated genome engineering has been broadly applied in prokaryotes with high efficiency and accuracy. However, this method is limited in realizing larger-scale genome editing with numerous genes or large DNA fragments because of the relatively complicated procedure for DNA editing template construction. Here, we describe a CRISPR-Cas9 assisted non-homologous end-joining (CA-NHEJ) strategy for the rapid and efficient inactivation of bacterial gene (s) in a homologous recombination-independent manner and without the use of selective marker. Our study show that CA-NHEJ can be used to delete large chromosomal DNA fragments in a single step that does not require homologous DNA template. It is thus a novel and powerful tool for bacterial genomes reducing and possesses the potential for accelerating the genome evolution.
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Krishnamurthy M, Moore RT, Rajamani S, Panchal RG. Bacterial genome engineering and synthetic biology: combating pathogens. BMC Microbiol 2016; 16:258. [PMID: 27814687 PMCID: PMC5097395 DOI: 10.1186/s12866-016-0876-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 10/28/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The emergence and prevalence of multidrug resistant (MDR) pathogenic bacteria poses a serious threat to human and animal health globally. Nosocomial infections and common ailments such as pneumonia, wound, urinary tract, and bloodstream infections are becoming more challenging to treat due to the rapid spread of MDR pathogenic bacteria. According to recent reports by the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC), there is an unprecedented increase in the occurrence of MDR infections worldwide. The rise in these infections has generated an economic strain worldwide, prompting the WHO to endorse a global action plan to improve awareness and understanding of antimicrobial resistance. This health crisis necessitates an immediate action to target the underlying mechanisms of drug resistance in bacteria. RESEARCH The advent of new bacterial genome engineering and synthetic biology (SB) tools is providing promising diagnostic and treatment plans to monitor and treat widespread recalcitrant bacterial infections. Key advances in genetic engineering approaches can successfully aid in targeting and editing pathogenic bacterial genomes for understanding and mitigating drug resistance mechanisms. In this review, we discuss the application of specific genome engineering and SB methods such as recombineering, clustered regularly interspaced short palindromic repeats (CRISPR), and bacterial cell-cell signaling mechanisms for pathogen targeting. The utility of these tools in developing antibacterial strategies such as novel antibiotic production, phage therapy, diagnostics and vaccine production to name a few, are also highlighted. CONCLUSIONS The prevalent use of antibiotics and the spread of MDR bacteria raise the prospect of a post-antibiotic era, which underscores the need for developing novel therapeutics to target MDR pathogens. The development of enabling SB technologies offers promising solutions to deliver safe and effective antibacterial therapies.
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Affiliation(s)
- Malathy Krishnamurthy
- Department of Target Discovery and Experimental Microbiology, Division of Molecular and Translational Sciences, U. S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702 USA
| | - Richard T. Moore
- Department of Target Discovery and Experimental Microbiology, Division of Molecular and Translational Sciences, U. S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702 USA
| | - Sathish Rajamani
- Department of Target Discovery and Experimental Microbiology, Division of Molecular and Translational Sciences, U. S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702 USA
| | - Rekha G. Panchal
- Department of Target Discovery and Experimental Microbiology, Division of Molecular and Translational Sciences, U. S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD 21702 USA
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60
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Zhang MM, Wang Y, Ang EL, Zhao H. Engineering microbial hosts for production of bacterial natural products. Nat Prod Rep 2016; 33:963-87. [PMID: 27072804 PMCID: PMC4963277 DOI: 10.1039/c6np00017g] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Covering up to end 2015Microbial fermentation provides an attractive alternative to chemical synthesis for the production of structurally complex natural products. In most cases, however, production titers are low and need to be improved for compound characterization and/or commercial production. Owing to advances in functional genomics and genetic engineering technologies, microbial hosts can be engineered to overproduce a desired natural product, greatly accelerating the traditionally time-consuming strain improvement process. This review covers recent developments and challenges in the engineering of native and heterologous microbial hosts for the production of bacterial natural products, focusing on the genetic tools and strategies for strain improvement. Special emphasis is placed on bioactive secondary metabolites from actinomycetes. The considerations for the choice of host systems will also be discussed in this review.
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Affiliation(s)
- Mingzi M Zhang
- Metabolic Engineering Research Laboratory, Science and Engineering Institutes, Agency for Science, Technology and Research, Singapore
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61
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Meng J, Wang B, Liu D, Chen T, Wang Z, Zhao X. High-yield anaerobic succinate production by strategically regulating multiple metabolic pathways based on stoichiometric maximum in Escherichia coli. Microb Cell Fact 2016; 15:141. [PMID: 27520031 PMCID: PMC4983090 DOI: 10.1186/s12934-016-0536-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 08/02/2016] [Indexed: 12/03/2022] Open
Abstract
Background Succinate has been identified by the U.S. Department of Energy as one of the top 12 building block chemicals, which can be used as a specialty chemical in the agricultural, food, and pharmaceutical industries. Escherichia coli are now one of the most important succinate producing candidates. However, the stoichiometric maximum succinate yield under anaerobic conditions through the reductive branch of the TCA cycle is restricted by NADH supply in E. coli. Results In the present work, we report a rational approach to increase succinate yield by regulating NADH supply via pentose phosphate (PP) pathway and enhancing flux towards succinate. The deregulated genes zwf243 (encoding glucose-6-phosphate dehydrogenase) and gnd361 (encoding 6-phosphogluconate dehydrogenase) involved in NADPH generation from Corynebacterium glutamicum were firstly introduced into E. coli for succinate production. Co-expression of beneficial mutated dehydrogenases, which removed feedback inhibition in the oxidative part of the PP pathway, increased succinate yield from 1.01 to 1.16 mol/mol glucose. Three critical genes, pgl (encoding 6-phosphogluconolactonase), tktA (encoding transketolase) and talB (encoding transaldolase) were then overexpressed to redirect more carbon flux towards PP pathway and further improved succinate yield to 1.21 mol/mol glucose. Furthermore, introducing Actinobacillus succinogenes pepck (encoding phosphoenolpyruvate carboxykinase) together with overexpressing sthA (encoding soluble transhydrogenase), further increased succinate yield to 1.31 mol/mol glucose. In addition, removing byproduct formation through inactivating acetate formation genes ackA-pta and heterogenously expressing pyc (encoding pyruvate carboxylase) from C. glutamicum led to improved succinate yield to 1.4 mol/mol glucose. Finally, synchronously overexpressing dcuB and dcuC encoding succinate exporters enhanced succinate yield to 1.54 mol/mol glucose, representing 52 % increase relative to the parent strain and amounting to 90 % of the strain-specific stoichiometric maximum (1.714 mol/mol glucose). Conclusions It’s the first time to rationally regulate pentose phosphate pathway to improve NADH supply for succinate synthesis in E. coli. 90 % of stoichiometric maximum succinate yield was achieved by combining further flux increase towards succinate and engineering its export. Regulation of NADH supply via PP pathway is therefore recommended for the production of products that are NADH-demanding in E. coli. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0536-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jiao Meng
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, People's Republic of China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Baiyun Wang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, People's Republic of China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Dingyu Liu
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, People's Republic of China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Tao Chen
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, People's Republic of China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China.,Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei University of Technology, Wuhan, 430068, People's Republic of China
| | - Zhiwen Wang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China.
| | - Xueming Zhao
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, People's Republic of China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
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Mougiakos I, Bosma EF, de Vos WM, van Kranenburg R, van der Oost J. Next Generation Prokaryotic Engineering: The CRISPR-Cas Toolkit. Trends Biotechnol 2016; 34:575-587. [DOI: 10.1016/j.tibtech.2016.02.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 01/10/2023]
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63
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Itan Y. Evolutionary Genomics. Evol Bioinform Online 2016; 11:53-5. [PMID: 27127402 PMCID: PMC4841156 DOI: 10.4137/ebo.s39729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This supplement is intended to focus on evolutionary genomics. Evolutionary Bioinformatics aims to provide researchers working in this complex, quickly developing field with online, open access to highly relevant scholarly articles by leading international researchers. In a field where the literature is ever-expanding, researchers increasingly need access to up-to-date, high quality scholarly articles on areas of specific contemporary interest. This supplement aims to address this by presenting high-quality articles that allow readers to distinguish the signal from the noise. The editor in chief hopes that through this effort, practitioners and researchers will be aided in finding answers to some of the most complex and pressing issues of our time.
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Affiliation(s)
- Yuval Itan
- Human Genetics of Infectious Diseases, The Rockefeller University, New York, NY, USA
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64
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Liu R, Bassalo MC, Zeitoun RI, Gill RT. Genome scale engineering techniques for metabolic engineering. Metab Eng 2015; 32:143-154. [PMID: 26453944 DOI: 10.1016/j.ymben.2015.09.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 08/15/2015] [Accepted: 09/02/2015] [Indexed: 12/18/2022]
Abstract
Metabolic engineering has expanded from a focus on designs requiring a small number of genetic modifications to increasingly complex designs driven by advances in genome-scale engineering technologies. Metabolic engineering has been generally defined by the use of iterative cycles of rational genome modifications, strain analysis and characterization, and a synthesis step that fuels additional hypothesis generation. This cycle mirrors the Design-Build-Test-Learn cycle followed throughout various engineering fields that has recently become a defining aspect of synthetic biology. This review will attempt to summarize recent genome-scale design, build, test, and learn technologies and relate their use to a range of metabolic engineering applications.
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Affiliation(s)
- Rongming Liu
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, United States.
| | - Marcelo C Bassalo
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309, United States.
| | - Ramsey I Zeitoun
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, United States.
| | - Ryan T Gill
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, United States.
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Bao Z, Cobb RE, Zhao H. Accelerated genome engineering through multiplexing. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2015; 8:5-21. [PMID: 26394307 DOI: 10.1002/wsbm.1319] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 08/19/2015] [Accepted: 08/19/2015] [Indexed: 12/27/2022]
Abstract
Throughout the biological sciences, the past 15 years have seen a push toward the analysis and engineering of biological systems at the organism level. Given the complexity of even the simplest organisms, though, to elicit a phenotype of interest often requires genotypic manipulation of several loci. By traditional means, sequential editing of genomic targets requires a significant investment of time and labor, as the desired editing event typically occurs at a very low frequency against an overwhelming unedited background. In recent years, the development of a suite of new techniques has greatly increased editing efficiency, opening up the possibility for multiple editing events to occur in parallel. Termed as multiplexed genome engineering, this approach to genome editing has greatly expanded the scope of possible genome manipulations in diverse hosts, ranging from bacteria to human cells. The enabling technologies for multiplexed genome engineering include oligonucleotide-based and nuclease-based methodologies, and their application has led to the great breadth of successful examples described in this review. While many technical challenges remain, there also exists a multiplicity of opportunities in this rapidly expanding field.
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Affiliation(s)
- Zehua Bao
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ryan E Cobb
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Huimin Zhao
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemistry, Department of Bioengineering, and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Winkler JD, Erickson K, Choudhury A, Halweg-Edwards AL, Gill RT. Complex systems in metabolic engineering. Curr Opin Biotechnol 2015; 36:107-14. [PMID: 26319897 DOI: 10.1016/j.copbio.2015.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 01/11/2023]
Abstract
Metabolic engineers manipulate intricate biological networks to build efficient biological machines. The inherent complexity of this task, derived from the extensive and often unknown interconnectivity between and within these networks, often prevents researchers from achieving desired performance. Other fields have developed methods to tackle the issue of complexity for their unique subset of engineering problems, but to date, there has not been extensive and comprehensive examination of how metabolic engineers use existing tools to ameliorate this effect on their own research projects. In this review, we examine how complexity affects engineering at the protein, pathway, and genome levels within an organism, and the tools for handling these issues to achieve high-performing strain designs. Quantitative complexity metrics and their applications to metabolic engineering versus traditional engineering fields are also discussed. We conclude by predicting how metabolic engineering practices may advance in light of an explicit consideration of design complexity.
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Affiliation(s)
- James D Winkler
- Department of Chemical and Biological Engineering, University of Colorado-Boulder, Jennie Smoly Caruthers Biotechnology Building, Research Park, Boulder, CO 80303, USA
| | - Keesha Erickson
- Department of Chemical and Biological Engineering, University of Colorado-Boulder, Jennie Smoly Caruthers Biotechnology Building, Research Park, Boulder, CO 80303, USA
| | - Alaksh Choudhury
- Department of Chemical and Biological Engineering, University of Colorado-Boulder, Jennie Smoly Caruthers Biotechnology Building, Research Park, Boulder, CO 80303, USA
| | - Andrea L Halweg-Edwards
- Department of Chemical and Biological Engineering, University of Colorado-Boulder, Jennie Smoly Caruthers Biotechnology Building, Research Park, Boulder, CO 80303, USA
| | - Ryan T Gill
- Department of Chemical and Biological Engineering, University of Colorado-Boulder, Jennie Smoly Caruthers Biotechnology Building, Research Park, Boulder, CO 80303, USA.
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Abstract
Next-generation DNA sequencing has revealed the complete genome sequences of numerous organisms, establishing a fundamental and growing understanding of genetic variation and phenotypic diversity. Engineering at the gene, network and whole-genome scale aims to introduce targeted genetic changes both to explore emergent phenotypes and to introduce new functionalities. Expansion of these approaches into massively parallel platforms establishes the ability to generate targeted genome modifications, elucidating causal links between genotype and phenotype, as well as the ability to design and reprogramme organisms. In this Review, we explore techniques and applications in genome engineering, outlining key advances and defining challenges.
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