51
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Khusnutdinova AN, Flick R, Popovic A, Brown G, Tchigvintsev A, Nocek B, Correia K, Joo JC, Mahadevan R, Yakunin AF. Exploring Bacterial Carboxylate Reductases for the Reduction of Bifunctional Carboxylic Acids. Biotechnol J 2017; 12. [PMID: 28762640 DOI: 10.1002/biot.201600751] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 05/31/2017] [Indexed: 11/12/2022]
Abstract
Carboxylic acid reductases (CARs) selectively reduce carboxylic acids to aldehydes using ATP and NADPH as cofactors under mild conditions. Although CARs attracts significant interest, only a few enzymes have been characterized to date, whereas the vast majority of CARs have yet to be examined. Herein the authors report that 12 bacterial CARs reduces a broad range of bifunctional carboxylic acids containing oxo-, hydroxy-, amino-, or second carboxyl groups with several enzymes showing activity toward 4-hydroxybutanoic (4-HB) and adipic acids. These CARs exhibits significant reductase activity against substrates whose second functional group is separated from the carboxylate by at least three carbons with both carboxylate groups being reduced in dicarboxylic acids. Purified CARs supplemented with cofactor regenerating systems (for ATP and NADPH), an inorganic pyrophosphatase, and an aldo-keto reductase catalyzes a high conversion (50-76%) of 4-HB to 1,4-butanediol (1,4-BDO) and adipic acid to 1,6-hexanediol (1,6-HDO). Likewise, Escherichia coli strains expressing eight different CARs efficiently reduces 4-HB to 1,4-BDO with 50-95% conversion, whereas adipic acid is reduced to a mixture of 6-hydroxyhexanoic acid (6-HHA) and 1,6-HDO. Thus, our results illustrate the broad biochemical diversity of bacterial CARs and their compatibility with other enzymes for applications in biocatalysis.
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Affiliation(s)
- Anna N Khusnutdinova
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, ON, M5S 3E5, Canada
| | - Robert Flick
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, ON, M5S 3E5, Canada
| | - Ana Popovic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, ON, M5S 3E5, Canada
| | - Greg Brown
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, ON, M5S 3E5, Canada
| | - Anatoli Tchigvintsev
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, ON, M5S 3E5, Canada
| | - Boguslaw Nocek
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Kevin Correia
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, ON, M5S 3E5, Canada
| | - Jeong C Joo
- Center for Bio-Based Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, Republic of Korea
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, ON, M5S 3E5, Canada
| | - Alexander F Yakunin
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, ON, M5S 3E5, Canada
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52
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Zhou S, Ding R, Chen J, Du G, Li H, Zhou J. Obtaining a Panel of Cascade Promoter-5'-UTR Complexes in Escherichia coli. ACS Synth Biol 2017; 6:1065-1075. [PMID: 28252945 DOI: 10.1021/acssynbio.7b00006] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A promoter is one of the most important and basic tools used to achieve diverse synthetic biology goals. Escherichia coli is one of the most commonly used model organisms in synthetic biology to produce useful target products and establish complicated regulation networks. During the fine-tuning of metabolic or regulation networks, the limited number of well-characterized inducible promoters has made implementing complicated strategies difficult. In this study, 104 native promoter-5'-UTR complexes (PUTR) from E. coli were screened and characterized based on a series of RNA-seq data. The strength of the 104 PUTRs varied from 0.007% to 4630% of that of the PBAD promoter in the transcriptional level and from 0.1% to 137% in the translational level. To further upregulate gene expression, a series of combinatorial PUTRs and cascade PUTRs were constructed by integrating strong transcriptional promoters with strong translational 5'-UTRs. Finally, two combinatorial PUTRs (PssrA-UTRrpsT and PdnaKJ-UTRrpsT) and two cascade PUTRs (PUTRssrA-PUTRinfC-rplT and PUTRalsRBACE-PUTRinfC-rplT) were identified as having the highest activity, with expression outputs of 170%, 137%, 409%, and 203% of that of the PBAD promoter, respectively. These engineered PUTRs are stable for the expression of different genes, such as the red fluorescence protein gene and the β-galactosidase gene. These results show that the PUTRs characterized and constructed in this study may be useful as a plug-and-play synthetic biology toolbox to achieve complicated metabolic engineering goals in fine-tuning metabolic networks to produce target products.
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Affiliation(s)
- Shenghu Zhou
- Key Laboratory
of Industrial Biotechnology, Ministry of Education,
School of Biotechnology, and ‡National Engineering Laboratory for Cereal Fermentation
Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Renpeng Ding
- Key Laboratory
of Industrial Biotechnology, Ministry of Education,
School of Biotechnology, and ‡National Engineering Laboratory for Cereal Fermentation
Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jian Chen
- Key Laboratory
of Industrial Biotechnology, Ministry of Education,
School of Biotechnology, and ‡National Engineering Laboratory for Cereal Fermentation
Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Guocheng Du
- Key Laboratory
of Industrial Biotechnology, Ministry of Education,
School of Biotechnology, and ‡National Engineering Laboratory for Cereal Fermentation
Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Huazhong Li
- Key Laboratory
of Industrial Biotechnology, Ministry of Education,
School of Biotechnology, and ‡National Engineering Laboratory for Cereal Fermentation
Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- Key Laboratory
of Industrial Biotechnology, Ministry of Education,
School of Biotechnology, and ‡National Engineering Laboratory for Cereal Fermentation
Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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53
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Harijan RK, Kiema TR, Syed SM, Qadir I, Mazet M, Bringaud F, Michels PAM, Wierenga RK. Crystallographic substrate binding studies of Leishmania mexicana SCP2-thiolase (type-2): unique features of oxyanion hole-1. Protein Eng Des Sel 2017; 30:225-233. [PMID: 28062645 DOI: 10.1093/protein/gzw080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/15/2016] [Indexed: 12/26/2022] Open
Abstract
C Structures of the C123A variant of the dimeric Leishmania mexicana SCP2-thiolase (type-2) (Lm-thiolase), complexed with acetyl-CoA and acetoacetyl-CoA, respectively, are reported. The catalytic site of thiolase contains two oxyanion holes, OAH1 and OAH2, which are important for catalysis. The two structures reveal for the first time the hydrogen bond interactions of the CoA-thioester oxygen atom of the substrate with the hydrogen bond donors of OAH1 of a CHH-thiolase. The amino acid sequence fingerprints ( xS, EAF, G P) of three catalytic loops identify the active site geometry of the well-studied CNH-thiolases, whereas SCP2-thiolases (type-1, type-2) are classified as CHH-thiolases, having as corresponding fingerprints xS, DCF and G P. In all thiolases, OAH2 is formed by the main chain NH groups of two catalytic loops. In the well-studied CNH-thiolases, OAH1 is formed by a water (of the Wat-Asn(NEAF) dyad) and NE2 (of the GHP-histidine). In the two described liganded Lm-thiolase structures, it is seen that in this CHH-thiolase, OAH1 is formed by NE2 of His338 (HDCF) and His388 (GHP). Analysis of the OAH1 hydrogen bond networks suggests that the GHP-histidine is doubly protonated and positively charged in these complexes, whereas the HDCF histidine is neutral and singly protonated.
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Affiliation(s)
- Rajesh K Harijan
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland.,Present address: Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Tiila-Riikka Kiema
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland
| | - Shahan M Syed
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland
| | - Imran Qadir
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland
| | - Muriel Mazet
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), UMR5536, Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076 Bordeaux, France.,Present address: Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR5234, Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076 Bordeaux, France
| | - Frédéric Bringaud
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), UMR5536, Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076 Bordeaux, France.,Present address: Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR5234, Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076 Bordeaux, France
| | - Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, The King's Buildings, The University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland
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54
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Patrikainen P, Carbonell V, Thiel K, Aro EM, Kallio P. Comparison of orthologous cyanobacterial aldehyde deformylating oxygenases in the production of volatile C3-C7 alkanes in engineered E. coli. Metab Eng Commun 2017; 5:9-18. [PMID: 29188180 PMCID: PMC5699528 DOI: 10.1016/j.meteno.2017.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/11/2017] [Accepted: 05/01/2017] [Indexed: 01/01/2023] Open
Abstract
Aldehyde deformylating oxygenase (ADO) is a unique enzyme found exclusively in photosynthetic cyanobacteria, which natively converts acyl aldehyde precursors into hydrocarbon products embedded in cellular lipid bilayers. This capacity has opened doors for potential biotechnological applications aiming at biological production of diesel-range alkanes and alkenes, which are compatible with the nonrenewable petroleum-derived end-products in current use. The development of production platforms, however, has been limited by the relative inefficiency of ADO enzyme, promoting research towards finding new strategies and information to be used for rational design of enhanced pathways for hydrocarbon over-expression. In this work we present an optimized approach to study different ADO orthologs derived from different cyanobacterial species in an in vivo set-up in Escherichia coli. The system enabled comparison of alternative ADOs for the production efficiency of short-chain volatile C3-C7 alkanes, propane, pentane and heptane, and provided insight on the differences in substrate preference, catalytic efficiency and limitations associated with the enzymes. The work concentrated on five ADO orthologs which represent the most extensively studied cyanobacterial species in the field, and revealed distinct differences between the enzymes. In most cases the ADO from Nostoc punctiforme PCC 73102 performed the best in respect to yields and initial rates for the production of the volatile hydrocarbons. At the other extreme, the system harboring the ADO form Synechococcus sp. RS9917 produced very low amounts of the short-chain alkanes, primarily due to poor accumulation of the enzyme in E. coli. The ADOs from Synechocystis sp. PCC 6803 and Prochlorococcus marinus MIT9313, and the corresponding variant A134F displayed less divergence, although variation between chain-length preferences could be observed. The results confirmed the general trend of ADOs having decreasing catalytic efficiency towards precursors of decreasing chain-length, while expanding the knowledge on the species-specific traits, which may aid future pathway design and structure-based engineering of ADO for more efficient hydrocarbon production systems. Five cyanobacterial aldehyde deformylating oxygenases were compared in E. coli. The engineered pathways produced volatile Cn-1 alkanes from supplemented fatty acids. The E. coli strains produced propane, pentane and heptane in the culture headspace. The results revealed clear differences in the catalytic performance between the ADOs.
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Affiliation(s)
- Pekka Patrikainen
- Molecular Plant Biology, Department of Biochemistry, University of Turku (Turun Yliopisto), 20014 TURUN YLIOPISTO, Finland
| | - Veronica Carbonell
- Molecular Plant Biology, Department of Biochemistry, University of Turku (Turun Yliopisto), 20014 TURUN YLIOPISTO, Finland
| | - Kati Thiel
- Molecular Plant Biology, Department of Biochemistry, University of Turku (Turun Yliopisto), 20014 TURUN YLIOPISTO, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku (Turun Yliopisto), 20014 TURUN YLIOPISTO, Finland
| | - Pauli Kallio
- Molecular Plant Biology, Department of Biochemistry, University of Turku (Turun Yliopisto), 20014 TURUN YLIOPISTO, Finland
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55
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Zargar A, Bailey CB, Haushalter RW, Eiben CB, Katz L, Keasling JD. Leveraging microbial biosynthetic pathways for the generation of 'drop-in' biofuels. Curr Opin Biotechnol 2017; 45:156-163. [PMID: 28427010 DOI: 10.1016/j.copbio.2017.03.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 02/24/2017] [Accepted: 03/03/2017] [Indexed: 01/21/2023]
Abstract
Advances in retooling microorganisms have enabled bioproduction of 'drop-in' biofuels, fuels that are compatible with existing spark-ignition, compression-ignition, and gas-turbine engines. As the majority of petroleum consumption in the United States consists of gasoline (47%), diesel fuel and heating oil (21%), and jet fuel (8%), 'drop-in' biofuels that replace these petrochemical sources are particularly attractive. In this review, we discuss the application of aldehyde decarbonylases to produce gasoline substitutes from fatty acid products, a recently crystallized reductase that could hydrogenate jet fuel precursors from terpene synthases, and the exquisite control of polyketide synthases to produce biofuels with desired physical properties (e.g., lower freezing points). With our increased understanding of biosynthetic logic of metabolic pathways, we discuss the unique advantages of fatty acid, terpene, and polyketide synthases for the production of bio-based gasoline, diesel and jet fuel.
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Affiliation(s)
- Amin Zargar
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, United States; QB3 Institute, University of California-Berkeley, 5885 Hollis Street, 4th Floor, Emeryville, CA 94608, United States
| | - Constance B Bailey
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, United States; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Robert W Haushalter
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, United States; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Christopher B Eiben
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, United States; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Leonard Katz
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, United States; QB3 Institute, University of California-Berkeley, 5885 Hollis Street, 4th Floor, Emeryville, CA 94608, United States; Synthetic Biology Engineering Research Center, University of California, Berkeley, CA 94720, United States
| | - Jay D Keasling
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, United States; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States; QB3 Institute, University of California-Berkeley, 5885 Hollis Street, 4th Floor, Emeryville, CA 94608, United States; Synthetic Biology Engineering Research Center, University of California, Berkeley, CA 94720, United States; Department of Chemical & Biomolecular Engineering, Department of Bioengineering, University of California, Berkeley, CA 94720, United States; Novo Nordisk Foundation Center for Biosustainability, Technical University Denmark, DK2970 Horsholm, Denmark.
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56
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Cheon S, Kim HM, Gustavsson M, Lee SY. Recent trends in metabolic engineering of microorganisms for the production of advanced biofuels. Curr Opin Chem Biol 2016; 35:10-21. [DOI: 10.1016/j.cbpa.2016.08.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/14/2016] [Accepted: 08/07/2016] [Indexed: 10/21/2022]
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57
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Heterologous biosynthesis and manipulation of alkanes in Escherichia coli. Metab Eng 2016; 38:19-28. [DOI: 10.1016/j.ymben.2016.06.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/12/2016] [Accepted: 06/03/2016] [Indexed: 12/26/2022]
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58
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Jiménez-Díaz L, Caballero A, Pérez-Hernández N, Segura A. Microbial alkane production for jet fuel industry: motivation, state of the art and perspectives. Microb Biotechnol 2016; 10:103-124. [PMID: 27723249 PMCID: PMC5270751 DOI: 10.1111/1751-7915.12423] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/09/2016] [Accepted: 09/15/2016] [Indexed: 11/27/2022] Open
Abstract
Bio‐jet fuel has attracted a lot of interest in recent years and has become a focus for aircraft and engine manufacturers, oil companies, governments and researchers. Given the global concern about environmental issues and the instability of oil market, bio‐jet fuel has been identified as a promising way to reduce the greenhouse gas emissions from the aviation industry, while also promoting energy security. Although a number of bio‐jet fuel sources have been approved for manufacture, their commercialization and entry into the market is still a far way away. In this review, we provide an overview of the drivers for intensified research into bio‐jet fuel technologies, the type of chemical compounds found in bio‐jet fuel preparations and the current state of related pre‐commercial technologies. The biosynthesis of hydrocarbons is one of the most promising approaches for bio‐jet fuel production, and thus we provide a detailed analysis of recent advances in the microbial biosynthesis of hydrocarbons (with a focus on alkanes). Finally, we explore the latest developments and their implications for the future of research into bio‐jet fuel technologies.
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Affiliation(s)
- Lorena Jiménez-Díaz
- Abengoa Research, Campus Palmas Altas, C/Energía Solar, 41014, Sevilla, Spain
| | - Antonio Caballero
- Abengoa Research, Campus Palmas Altas, C/Energía Solar, 41014, Sevilla, Spain
| | | | - Ana Segura
- Abengoa Research, Campus Palmas Altas, C/Energía Solar, 41014, Sevilla, Spain.,Estación Experimental del Zaidín-CSIC, C/Profesor Albareda s/n, 18008, Granada, Spain
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59
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Cordova LT, Alper HS. Central metabolic nodes for diverse biochemical production. Curr Opin Chem Biol 2016; 35:37-42. [PMID: 27607733 DOI: 10.1016/j.cbpa.2016.08.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 12/25/2022]
Abstract
Central carbon metabolism is conserved among all organisms for cellular function and energy generation. The connectivity of this metabolic map gives rises to key metabolite nodes. Five of these nodes in particular, pyruvate, citric acid, tyrosine and aspartate, acetyl-CoA, serve as critical starting points for the generation of a broad class of relevant chemical molecules with ranging applications from fuels, pharmaceuticals and polymer precursors. This review highlights recent progress in converting these metabolite nodes into valuable products. In particular, acetyl-CoA, the most well-connected node, serves as the building block for several classes of molecules including fatty acids and terpenes. Systematic metabolic engineering efforts focused on these metabolic building blocks has enabled the production of industrially-relevant, biobased compounds.
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Affiliation(s)
- Lauren T Cordova
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2500 Speedway Avenue, Austin, TX 78712, United States
| | - Hal S Alper
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2500 Speedway Avenue, Austin, TX 78712, United States; McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 E Dean Keeton St. Stop C0400, Austin, TX 78712, United States.
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60
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Production of 1-decanol by metabolically engineered Yarrowia lipolytica. Metab Eng 2016; 38:139-147. [PMID: 27471068 DOI: 10.1016/j.ymben.2016.07.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/24/2016] [Accepted: 07/25/2016] [Indexed: 12/14/2022]
Abstract
Medium-chain alcohols are used to produce solvents, surfactants, lubricants, waxes, creams, and cosmetics. In this study, we engineered the oleaginous yeast Yarrowia lipolytica to produce 1-decanol from glucose. Expression of a fatty acyl-CoA reductase from Arabidopsis thaliana in strains of Y. lipolytica previously engineered to produce medium-chain fatty acids resulted in the production of 1-decanol. However, the resulting titers were very low (<10mg/mL), most likely due to product catabolism. In addition, these strains produced small quantities of 1-hexadecanol and 1-octadecanol. Deleting the major peroxisome assembly factor Pex10 was found to significantly increase 1-decanol production, resulting in titers exceeding 500mg/L. It also increased 1-hexadecanoland and 1-octadecanol titers, though the resulting increases were less than those for 1-decanol. These results demonstrate that Y. lipolytica can potentially be used for the industrial production of 1-decanol and other fatty alcohols from simple sugars.
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61
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Metabolic engineering of Cupriavidus necator for heterotrophic and autotrophic alka(e)ne production. Metab Eng 2016; 37:92-101. [PMID: 27212691 DOI: 10.1016/j.ymben.2016.05.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 04/15/2016] [Accepted: 05/05/2016] [Indexed: 11/23/2022]
Abstract
Alkanes of defined carbon chain lengths can serve as alternatives to petroleum-based fuels. Recently, microbial pathways of alkane biosynthesis have been identified and enabled the production of alkanes in non-native producing microorganisms using metabolic engineering strategies. The chemoautotrophic bacterium Cupriavidus necator has great potential for producing chemicals from CO2: it is known to have one of the highest growth rate among natural autotrophic bacteria and under nutrient imbalance it directs most of its carbon flux to the synthesis of the acetyl-CoA derived polymer, polyhydroxybutyrate (PHB), (up to 80% of intracellular content). Alkane synthesis pathway from Synechococcus elongatus (2 genes coding an acyl-ACP reductase and an aldehyde deformylating oxygenase) was heterologously expressed in a C. necator mutant strain deficient in the PHB synthesis pathway. Under heterotrophic condition on fructose we showed that under nitrogen limitation, in presence of an organic phase (decane), the strain produced up to 670mg/L total hydrocarbons containing 435mg/l of alkanes consisting of 286mg/l of pentadecane, 131mg/l of heptadecene, 18mg/l of heptadecane, and 236mg/l of hexadecanal. We report here the highest level of alka(e)nes production by an engineered C. necator to date. We also demonstrated the first reported alka(e)nes production by a non-native alkane producer from CO2 as the sole carbon source.
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