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Optimization of hydrogenobyrinic acid biosynthesis in Escherichia coli using multi-level metabolic engineering strategies. Microb Cell Fact 2020; 19:118. [PMID: 32487216 PMCID: PMC7268678 DOI: 10.1186/s12934-020-01377-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/25/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Hydrogenobyrinic acid is a key intermediate of the de-novo aerobic biosynthesis pathway of vitamin B12. The introduction of a heterologous de novo vitamin B12 biosynthesis pathway in Escherichia coli offers an alternative approach for its production. Although E. coli avoids major limitations that currently faced by industrial producers of vitamin B12, such as long growth cycles, the insufficient supply of hydrogenobyrinic acid restricts industrial vitamin B12 production. RESULTS By designing combinatorial ribosomal binding site libraries of the hemABCD genes in vivo, we found that their optimal relative translational initiation rates are 10:1:1:5. The transcriptional coordination of the uroporphyrinogen III biosynthetic module was realized by promoter engineering of the hemABCD operon. Knockdown of competitive heme and siroheme biosynthesis pathways by RBS engineering enhanced the hydrogenobyrinic acid titer to 20.54 and 15.85 mg L-1, respectively. Combined fine-tuning of the heme and siroheme biosynthetic pathways enhanced the hydrogenobyrinic acid titer to 22.57 mg L-1, representing a remarkable increase of 1356.13% compared with the original strain FH215-HBA. CONCLUSIONS Through multi-level metabolic engineering strategies, we achieved the metabolic balance of the uroporphyrinogen III biosynthesis pathway, eliminated toxicity due to by-product accumulation, and finally achieved a high HBA titer of 22.57 mg L-1 in E. coli. This lays the foundation for high-yield production of vitamin B12 in E. coli and will hopefully accelerate its industrial production.
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2
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Mie Y, Yasutake Y, Takayama H, Tamura T. Electrochemically boosted cytochrome P450 reaction that efficiently produces 25-hydroxyvitamin D3. J Catal 2020. [DOI: 10.1016/j.jcat.2020.02.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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3
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Ullah E, Yosafshahi M, Hassoun S. Towards scaling elementary flux mode computation. Brief Bioinform 2019; 21:1875-1885. [PMID: 31745550 DOI: 10.1093/bib/bbz094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 01/05/2023] Open
Abstract
While elementary flux mode (EFM) analysis is now recognized as a cornerstone computational technique for cellular pathway analysis and engineering, EFM application to genome-scale models remains computationally prohibitive. This article provides a review of aspects of EFM computation that elucidates bottlenecks in scaling EFM computation. First, algorithms for computing EFMs are reviewed. Next, the impact of redundant constraints, sensitivity to constraint ordering and network compression are evaluated. Then, the advantages and limitations of recent parallelization and GPU-based efforts are highlighted. The article then reviews alternative pathway analysis approaches that aim to reduce the EFM solution space. Despite advances in EFM computation, our review concludes that continued scaling of EFM computation is necessary to apply EFM to genome-scale models. Further, our review concludes that pathway analysis methods that target specific pathway properties can provide powerful alternatives to EFM analysis.
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Affiliation(s)
- Ehsan Ullah
- Qatar Computing Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Mona Yosafshahi
- Qatar Computing Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Soha Hassoun
- Department of Computer Science, Tufts University, Medford MA 02155, USA
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4
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Wu Z, Zhao D, Li S, Wang J, Bi C, Zhang X. Combinatorial modulation of initial codons for improved zeaxanthin synthetic pathway efficiency in Escherichia coli. Microbiologyopen 2019; 8:e930. [PMID: 31532062 PMCID: PMC6925171 DOI: 10.1002/mbo3.930] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 11/09/2022] Open
Abstract
A balanced and optimized metabolic pathway is the basis for efficient production of a target metabolite. Traditional strategies mostly involve the manipulation of promoters or ribosome-binding sites, which can encompass long sequences and can be complex to operate. In this work, we found that by changing only the three nucleotides of the initiation codons, expression libraries of reporter proteins RFP, GFP, and lacZ with a large dynamic range and evenly distributed expression levels could be established in Escherichia coli (E. coli). Thus, a novel strategy that uses combinatorial modulation of initial codons (CMIC) was developed for metabolic pathway optimization and applied to the three genes crtZ, crtY, and crtI of the zeaxanthin synthesis pathway in E. coli. The initial codons of these genes were changed to random nucleotides NNN, and the gene cassettes were assembled into vectors via an optimized strategy based on type II restriction enzymes. With minimal labor time, a combinatorial library was obtained containing strains with various zeaxanthin production levels, including a strain with a titer of 6.33 mg/L and specific production value of 1.24 mg/g DCW-a striking 10-fold improvement over the starting strain. The results demonstrated that CMIC was a feasible technique for conveniently optimizing metabolic pathways. To our best knowledge, this is the first metabolic engineering strategy that relies on manipulating the initiation codons for pathway optimization in E. coli.
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Affiliation(s)
- Zaiqiang Wu
- Center for Molecular Metabolism, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Dongdong Zhao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Park, Tianjin, 300308, China
| | - Siwei Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Park, Tianjin, 300308, China
| | - Junsong Wang
- Center for Molecular Metabolism, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Changhao Bi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Park, Tianjin, 300308, China
| | - Xueli Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Ave, Tianjin Airport Economic Park, Tianjin, 300308, China
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5
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Amin SA, Endalur Gopinarayanan V, Nair NU, Hassoun S. Establishing synthesis pathway-host compatibility via enzyme solubility. Biotechnol Bioeng 2019; 116:1405-1416. [PMID: 30802311 DOI: 10.1002/bit.26959] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 12/18/2018] [Accepted: 02/21/2019] [Indexed: 12/12/2022]
Abstract
Current pathway synthesis tools identify possible pathways that can be added to a host to produce the desired target molecule through the exploration of abstract metabolic and reaction network space. However, not many of these tools explore gene-level information required to physically realize the identified synthesis pathways, and none explore enzyme-host compatibility. Developing tools that address this disconnect between abstract reactions/metabolic design space and physical genetic sequence design space will enable expedited experimental efforts that avoid exploring unprofitable synthesis pathways. This work describes a workflow, termed Probabilistic Pathway Assembly with Solubility Confidence Scores (ProPASS), which links synthesis pathway construction with the exploration of the physical design space as imposed by the availability of enzymes with predicted characterized activities within the host. Predicted protein solubility propensity scores are used as a confidence level to quantify the compatibility of each pathway enzyme with the host Escherichia coli (E. coli). This study also presents a database, termed Protein Solubility Database (ProSol DB), which provides solubility confidence scores in E. coli for 240,016 characterized enzymes obtained from UniProtKB/Swiss-Prot. The utility of ProPASS is demonstrated by generating genetic implementations of heterologous synthesis pathways in E. coli that target several commercially useful biomolecules.
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Affiliation(s)
- Sara A Amin
- Department of Computer Science, Tufts University, Medford, Massachusetts
| | | | - Nikhil U Nair
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts
| | - Soha Hassoun
- Department of Computer Science, Tufts University, Medford, Massachusetts.,Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts
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6
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de Carvalho CCCR. Whole cell biocatalysts: essential workers from Nature to the industry. Microb Biotechnol 2017; 10:250-263. [PMID: 27145540 PMCID: PMC5328830 DOI: 10.1111/1751-7915.12363] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/28/2016] [Accepted: 03/31/2016] [Indexed: 11/30/2022] Open
Abstract
Microorganisms have been exposed to a myriad of substrates and environmental conditions throughout evolution resulting in countless metabolites and enzymatic activities. Although mankind have been using these properties for centuries, we have only recently learned to control their production, to develop new biocatalysts with high stability and productivity and to improve their yields under new operational conditions. However, microbial cells still provide the best known environment for enzymes, preventing conformational changes in the protein structure in non-conventional medium and under harsh reaction conditions, while being able to efficiently regenerate necessary cofactors and to carry out cascades of reactions. Besides, a still unknown microbe is probably already producing a compound that will cure cancer, Alzeihmer's disease or kill the most resistant pathogen. In this review, the latest developments in screening desirable activities and improving production yields are discussed.
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Affiliation(s)
- Carla C. C. R. de Carvalho
- iBB‐Institute for Bioengineering and BiosciencesDepartment of BioengineeringInstituto Superior TécnicoUniversidade de LisboaAv. Rovisco PaisLisbon1049‐001Portugal
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7
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Bution ML, Molina G, Abrahão MR, Pastore GM. Genetic and metabolic engineering of microorganisms for the development of new flavor compounds from terpenic substrates. Crit Rev Biotechnol 2014; 35:313-25. [DOI: 10.3109/07388551.2013.855161] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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8
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Ióca LP, Allard PM, Berlinck RGS. Thinking big about small beings – the (yet) underdeveloped microbial natural products chemistry in Brazil. Nat Prod Rep 2014; 31:646-75. [DOI: 10.1039/c3np70112c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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The Biotechnological Potential of Corynebacterium glutamicum, from Umami to Chemurgy. CORYNEBACTERIUM GLUTAMICUM 2013. [DOI: 10.1007/978-3-642-29857-8_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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10
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Li S, Anand K, Tran H, Yu F, Finefield JM, Sunderhaus JD, McAfoos TJ, Tsukamoto S, Williams RM, Sherman DH. Comparative analysis of the biosynthetic systems for fungal bicyclo[2.2.2]diazaoctane indole alkaloids: the (+)/(-)-notoamide, paraherquamide and malbrancheamide pathways. MEDCHEMCOMM 2012; 3:987-996. [PMID: 23213353 PMCID: PMC3511817 DOI: 10.1039/c2md20029e] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The biosynthesis of fungal bicyclo[2.2.2]diazaoctane indole alkaloids with a wide spectrum of biological activities have attracted increasing interest. Their intriguing mode of assembly has long been proposed to feature a non-ribosomal peptide synthetase, a presumed intramolecular Diels-Alderase, a variant number of prenyltransferases, and a series of oxidases responsible for the diverse tailoring modifications of their cyclodipeptide-based structural core. Until recently, the details of these biosynthetic pathways have remained largely unknown due to lack of information on the fungal derived biosynthetic gene clusters. Herein, we report a comparative analysis of four natural product metabolic systems of a select group of bicyclo[2.2.2]diazaoctane indole alkaloids including (+)/(-)-notoamide, paraherquamide and malbrancheamide, in which we propose an enzyme for each step in the biosynthetic pathway based on deep annotation and on-going biochemical studies.
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Affiliation(s)
- Shengying Li
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Krithika Anand
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Hong Tran
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Fengan Yu
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | - James D. Sunderhaus
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Timothy J. McAfoos
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Sachiko Tsukamoto
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan
| | - Robert M. Williams
- University of Colorado Cancer Center, Aurora, Colorado 80045, USA
- Departments of Medicinal Chemistry, Microbiology & Immunology, and Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - David H. Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA
- Departments of Medicinal Chemistry, Microbiology & Immunology, and Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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11
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Marques MP, Walshe K, Doyle S, Fernandes P, de Carvalho CC. Anchoring high-throughput screening methods to scale-up bioproduction of siderophores. Process Biochem 2012. [DOI: 10.1016/j.procbio.2011.11.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Probabilistic pathway construction. Metab Eng 2011; 13:435-44. [DOI: 10.1016/j.ymben.2011.01.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 01/13/2011] [Accepted: 01/25/2011] [Indexed: 02/07/2023]
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13
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Belen’kii L, Gramenitskaya V, Evdokimenkova Y. The Literature of Heterocyclic Chemistry, Part X, 2005–2007. ADVANCES IN HETEROCYCLIC CHEMISTRY 2011. [DOI: 10.1016/b978-0-12-385464-3.00001-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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14
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Ondari ME, Walker KD. The Taxol Pathway 10-O-Acetyltransferase Shows Regioselective Promiscuity with the Oxetane Hydroxyl of 4-Deacetyltaxanes. J Am Chem Soc 2008; 130:17187-94. [DOI: 10.1021/ja8067534] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mark E. Ondari
- Departments of Chemistry and Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Kevin D. Walker
- Departments of Chemistry and Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan 48824
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15
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Albermann C, Ghanegaonkar S, Lemuth K, Vallon T, Reuss M, Armbruster W, Sprenger GA. Biosynthesis of the Vitamin E Compound δ-Tocotrienol in RecombinantEscherichia coliCells. Chembiochem 2008; 9:2524-33. [DOI: 10.1002/cbic.200800242] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Biosynthesis of ubiquinone compounds with conjugated prenyl side chains. Appl Environ Microbiol 2008; 74:6908-17. [PMID: 18820051 DOI: 10.1128/aem.01495-08] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enzymatic steps from two different biosynthetic pathways were combined in Escherichia coli, directing the synthesis of a new class of biomolecules--ubiquinones with prenyl side chains containing conjugated double bonds. This was achieved by the activity of a C(30) carotenoid desaturase, CrtN, from Staphylococcus aureus, which exhibited an inherent flexibility in substrate recognition compared to other carotenoid desaturases. By utilizing the known plasticity of E. coli's native ubiquinone biosynthesis pathway and the unusual activity of CrtN, modified ubiquinone structures with prenyl side chains containing conjugated double bonds were generated. The side chains of the new structures were confirmed to have different degrees of desaturation by mass spectrometry and nuclear magnetic resonance analysis. In vivo (14)C labeling and in vitro activity studies showed that CrtN desaturates octaprenyl diphosphates but not the ubiquinone compounds directly. Antioxidant properties of conjugated side chain ubiquinones were analyzed in an in vitro beta-carotene-linoleate model system and were found to be higher than the corresponding unmodified ubiquinones. These results demonstrate that by combining pathway steps from different branches of biosynthetic networks, classes of compounds not observed in nature can be synthesized and structural motifs that are functionally important can be combined or enhanced.
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17
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De novo biosynthetic pathways: rational design of microbial chemical factories. Curr Opin Biotechnol 2008; 19:468-74. [PMID: 18725289 DOI: 10.1016/j.copbio.2008.07.009] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 07/25/2008] [Accepted: 07/29/2008] [Indexed: 12/18/2022]
Abstract
Increasing interest in the production of organic compounds from non-petroleum-derived feedstocks, especially biomass, is a significant driver for the construction of new recombinant microorganisms for this purpose. As a discipline, Metabolic Engineering has provided a framework for the development of such systems. Efforts have traditionally been focused, first, on the optimization of natural producers, later progressing towards re-construction of natural pathways in heterologous hosts. To maximize the potential of microbes for biosynthetic purposes, new tools and methodologies within Metabolic Engineering are needed for the proposition and construction of de novo designed pathways. This review will focus on recent advances towards the design and assembly of biosynthetic pathways, and provide a Synthetic Biology perspective for the construction of microbial chemical factories.
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18
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Ajikumar PK, Tyo K, Carlsen S, Mucha O, Phon TH, Stephanopoulos G. Terpenoids: Opportunities for Biosynthesis of Natural Product Drugs Using Engineered Microorganisms. Mol Pharm 2008; 5:167-90. [DOI: 10.1021/mp700151b] [Citation(s) in RCA: 311] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Parayil Kumaran Ajikumar
- Department of Chemical Engineering, Room 56-469, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and Chemical and Pharmaceutical Engineering, Singapore−MIT Alliance, 4 Engineering Drive 3, Singapore 117 576
| | - Keith Tyo
- Department of Chemical Engineering, Room 56-469, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and Chemical and Pharmaceutical Engineering, Singapore−MIT Alliance, 4 Engineering Drive 3, Singapore 117 576
| | - Simon Carlsen
- Department of Chemical Engineering, Room 56-469, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and Chemical and Pharmaceutical Engineering, Singapore−MIT Alliance, 4 Engineering Drive 3, Singapore 117 576
| | - Oliver Mucha
- Department of Chemical Engineering, Room 56-469, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and Chemical and Pharmaceutical Engineering, Singapore−MIT Alliance, 4 Engineering Drive 3, Singapore 117 576
| | - Too Heng Phon
- Department of Chemical Engineering, Room 56-469, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and Chemical and Pharmaceutical Engineering, Singapore−MIT Alliance, 4 Engineering Drive 3, Singapore 117 576
| | - Gregory Stephanopoulos
- Department of Chemical Engineering, Room 56-469, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and Chemical and Pharmaceutical Engineering, Singapore−MIT Alliance, 4 Engineering Drive 3, Singapore 117 576
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19
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Application of functional genomics to pathway optimization for increased isoprenoid production. Appl Environ Microbiol 2008; 74:3229-41. [PMID: 18344344 DOI: 10.1128/aem.02750-07] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Producing complex chemicals using synthetic metabolic pathways in microbial hosts can have many advantages over chemical synthesis but is often complicated by deleterious interactions between pathway intermediates and the host cell metabolism. With the maturation of functional genomic analysis, it is now technically feasible to identify modes of toxicity associated with the accumulation of foreign molecules in the engineered bacterium. Previously, Escherichia coli was engineered to produce large quantities of isoprenoids by creating a mevalonate-based isopentenyl pyrophosphate biosynthetic pathway (V. J. J. Martin et al., Nat. Biotechnol. 21:796-802, 2003). The engineered E. coli strain produced high levels of isoprenoids, but further optimization led to an imbalance in carbon flux and the accumulation of the pathway intermediate 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA), which proved to be cytotoxic to E. coli. Using both DNA microarray analysis and targeted metabolite profiling, we have studied E. coli strains inhibited by the intracellular accumulation of HMG-CoA. Our results indicate that HMG-CoA inhibits fatty acid biosynthesis in the microbial host, leading to generalized membrane stress. The cytotoxic effects of HMG-CoA accumulation can be counteracted by the addition of palmitic acid (16:0) and, to a lesser extent, oleic acid (cis-Delta(9)-18:1) in the growth medium. This work demonstrates the utility of using transcriptomic and metabolomic methods to optimize synthetic biological systems.
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20
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Klein-Marcuschamer D, Ajikumar PK, Stephanopoulos G. Engineering microbial cell factories for biosynthesis of isoprenoid molecules: beyond lycopene. Trends Biotechnol 2007; 25:417-24. [PMID: 17681626 DOI: 10.1016/j.tibtech.2007.07.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 05/24/2007] [Accepted: 07/20/2007] [Indexed: 11/23/2022]
Abstract
The isoprenoid superfamily of compounds holds great potential for delivering commercial therapeutics, neutraceuticals and fine chemicals. As such, it has attracted widespread attention and prompted research aimed at metabolic engineering of the pathway for isoprenoid overproduction. The carotenoids in particular, because of their convenient colorimetric screening properties, have facilitated the investigation of new tools for pathway optimization. Because all isoprenoids share common metabolic precursors, genetic platforms resulting from work with carotenoids can be applied to the biosynthesis of other valuable products. In this review we summarize the many tools and methods that have been developed for isoprenoid pathway engineering, and the potential of these technologies for producing other molecules of this family, especially terpenoids.
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21
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Pitera DJ, Paddon CJ, Newman JD, Keasling JD. Balancing a heterologous mevalonate pathway for improved isoprenoid production in Escherichia coli. Metab Eng 2007; 9:193-207. [PMID: 17239639 DOI: 10.1016/j.ymben.2006.11.002] [Citation(s) in RCA: 307] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Revised: 10/25/2006] [Accepted: 11/13/2006] [Indexed: 11/25/2022]
Abstract
Engineering biosynthetic pathways in microbes for the production of complex chemicals and pharmaceuticals is an attractive alternative to chemical synthesis. However, in transferring large pathways to alternate hosts and manipulating expression levels, the native regulation of carbon flux through the pathway may be lost leading to imbalances in the pathways. Previously, Escherichia coli was engineered to produce large quantities of isoprenoids by creating a mevalonate-based isopentenyl pyrophosphate biosynthetic pathway [Martin, V.J., Pitera, D.J., Withers, S.T., Newman, J.D., Keasling, J.D., 2003. Engineering a mevalonate pathway in Escherichia coli for production of terpenoids. Nat. Biotechnol. 21, 796-802]. The strain produces high levels of isoprenoids, but upon further investigation we discovered that the accumulation of pathway intermediates limited flux and that high-level expression of the mevalonate pathway enzymes inhibited cell growth. Gene titration studies and metabolite profiling using liquid chromatography-mass spectrometry linked the growth inhibition phenotype with the accumulation of the pathway intermediate 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA). Such an accumulation implies that the activity of HMG-CoA reductase was insufficient to balance flux in the engineered pathway. By modulating HMG-CoA reductase production, we eliminated the pathway bottleneck and increased mevalonate production. These results demonstrate that balancing carbon flux through the heterologous pathway is a key determinant in optimizing isoprenoid biosynthesis in microbial hosts.
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Affiliation(s)
- Douglas J Pitera
- Department of Chemical Engineering, University of California, Berkeley, CA 94720-1462, USA
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22
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Newman JD, Marshall J, Chang M, Nowroozi F, Paradise E, Pitera D, Newman KL, Keasling JD. High-level production of amorpha-4,11-diene in a two-phase partitioning bioreactor of metabolically engineered Escherichia coli. Biotechnol Bioeng 2006; 95:684-91. [PMID: 16878333 DOI: 10.1002/bit.21017] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Reconstructing synthetic metabolic pathways in microbes holds great promise for the production of pharmaceuticals in large-scale fermentations. By recreating biosynthetic pathways in bacteria, complex molecules traditionally harvested from scarce natural resources can be produced in microbial cultures. Here we report on a strain of Escherichia coli containing a heterologous, nine-gene biosynthetic pathway for the production of the terpene amorpha-4,11-diene, a precursor to the anti-malarial drug artemisinin. Previous reports have underestimated the productivity of this strain due to the volatility of amorphadiene. Here we show that amorphadiene evaporates from a fermentor with a half-life of about 50 min. Using a condenser, we take advantage of this volatility by trapping the amorphadiene in the off-gas. Amorphadiene was positively identified using nuclear magnetic resonance spectroscopy and determined to be 89% pure as collected. We captured amorphadiene as it was produced in situ by employing a two-phase partitioning bioreactor with a dodecane organic phase. Using a previously characterized caryophyllene standard to calibrate amorphadiene production and capture, the concentration of amorphadiene produced was determined to be 0.5 g/L of culture medium. A standard of amorphadiene collected from the off-gas showed that the caryophyllene standard overestimated amorphadiene production by approximately 30%.
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Affiliation(s)
- Jack D Newman
- Department of Chemical Engineering, University of California, Berkeley, California, USA
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Loncaric C, Merriweather E, Walker KD. Profiling a Taxol pathway 10beta-acetyltransferase: assessment of the specificity and the production of baccatin III by in vivo acetylation in E. coli. ACTA ACUST UNITED AC 2006; 13:309-17. [PMID: 16638536 DOI: 10.1016/j.chembiol.2006.01.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 12/22/2005] [Accepted: 01/18/2006] [Indexed: 11/30/2022]
Abstract
The 10beta-acetyltransferase on the biosynthetic pathway of the antineoplastic drug Taxol catalyzes the regiospecific transfer of the acetyl group of acetyl-coenzyme A (CoA) to 10-deacetylbaccatin III. We demonstrate that in addition to acetyl group transfer, the overexpressed enzyme also catalyzes the exchange of propionyl and n-butyryl from the corresponding CoA thioester to the hydroxyl group at C10 of the cosubstrate. Also, in vivo studies revealed that E. coli, producing endogenous acetyl-CoA and overexpressing the recombinant acetyltransferase, can convert exogenously supplied 10-deacetylbaccatin III to baccatin III. Potentially, this heterologous in vivo production method in bacteria could be optimized to couple various unnatural acyl-CoA analogs to myriad amino and/or hydroxyl acceptors by acyltransferase catalysis; conceivably, this process could facilitate the preparation of second-generation Taxols.
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Affiliation(s)
- Catherine Loncaric
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
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Chemler JA, Yan Y, Koffas MAG. Biosynthesis of isoprenoids, polyunsaturated fatty acids and flavonoids in Saccharomyces cerevisiae. Microb Cell Fact 2006; 5:20. [PMID: 16719921 PMCID: PMC1533850 DOI: 10.1186/1475-2859-5-20] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 05/23/2006] [Indexed: 11/10/2022] Open
Abstract
Industrial biotechnology employs the controlled use of microorganisms for the production of synthetic chemicals or simple biomass that can further be used in a diverse array of applications that span the pharmaceutical, chemical and nutraceutical industries. Recent advances in metagenomics and in the incorporation of entire biosynthetic pathways into Saccharomyces cerevisiae have greatly expanded both the fitness and the repertoire of biochemicals that can be synthesized from this popular microorganism. Further, the availability of the S. cerevisiae entire genome sequence allows the application of systems biology approaches for improving its enormous biosynthetic potential. In this review, we will describe some of the efforts on using S. cerevisiae as a cell factory for the biosynthesis of high-value natural products that belong to the families of isoprenoids, flavonoids and long chain polyunsaturated fatty acids. As natural products are increasingly becoming the center of attention of the pharmaceutical and nutraceutical industries, the use of S. cerevisiae for their production is only expected to expand in the future, further allowing the biosynthesis of novel molecular structures with unique properties.
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Affiliation(s)
- Joseph A Chemler
- Department of Chemical and Biological Engineering, State University of New York at Buffalo, Buffalo, NY 14260-4200, USA
| | - Yajun Yan
- Department of Chemical and Biological Engineering, State University of New York at Buffalo, Buffalo, NY 14260-4200, USA
| | - Mattheos AG Koffas
- Department of Chemical and Biological Engineering, State University of New York at Buffalo, Buffalo, NY 14260-4200, USA
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25
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Silver LL. Does the cell wall of bacteria remain a viable source of targets for novel antibiotics? Biochem Pharmacol 2005; 71:996-1005. [PMID: 16290173 DOI: 10.1016/j.bcp.2005.10.029] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2005] [Revised: 10/13/2005] [Accepted: 10/17/2005] [Indexed: 11/19/2022]
Abstract
Whether the bacterial cell wall remains a viable source of novel antibacterials is addressed here by reviewing screen and design strategies for discovery of antibacterials with a focus on their output. Inhibitors for which antibacterial activity has been shown to be due to specific inhibition of a reaction (antibacterially validated inhibitors) are known for 8 of the 14 conserved essential steps of the pathway. Antibacterially validated enzyme inhibitors exist for six of these steps. The possible obstacles to finding validated inhibitors of the remaining enzymes are discussed and some strategies are suggested.
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Affiliation(s)
- Lynn L Silver
- LL Silver Consulting (LLC), 3403 Park Place, Springfield, NJ 07081, USA.
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