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Metabolic model guided strain design of cyanobacteria. Curr Opin Biotechnol 2019; 64:17-23. [PMID: 31585306 DOI: 10.1016/j.copbio.2019.08.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 08/23/2019] [Accepted: 08/25/2019] [Indexed: 12/11/2022]
Abstract
Cyanobacteria are oxygenic photoautotrophs that serve as potential platforms for the production of biochemicals from cheap and renewable raw materials - sunlight, water, and carbon dioxide. Systems level analysis of the metabolic network of these organisms could enable the successful engineering of these organisms for the enhanced production of target chemicals. Metabolic modeling techniques including both stoichiometric and kinetic modeling with a genome-wide coverage enable a global assessment of metabolic capabilities. Recent studies guided by such modeling techniques have engineered strains for the enhanced production of valuable chemicals such as ethanol, n-butanol, 1,3-propanediol, glycerol, limonene, and isoprene from CO2.
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Vijay D, Akhtar MK, Hess WR. Genetic and metabolic advances in the engineering of cyanobacteria. Curr Opin Biotechnol 2019; 59:150-156. [DOI: 10.1016/j.copbio.2019.05.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 05/16/2019] [Accepted: 05/22/2019] [Indexed: 11/28/2022]
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Santos-Merino M, Singh AK, Ducat DC. New Applications of Synthetic Biology Tools for Cyanobacterial Metabolic Engineering. Front Bioeng Biotechnol 2019; 7:33. [PMID: 30873404 PMCID: PMC6400836 DOI: 10.3389/fbioe.2019.00033] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/05/2019] [Indexed: 01/25/2023] Open
Abstract
Cyanobacteria are promising microorganisms for sustainable biotechnologies, yet unlocking their potential requires radical re-engineering and application of cutting-edge synthetic biology techniques. In recent years, the available devices and strategies for modifying cyanobacteria have been increasing, including advances in the design of genetic promoters, ribosome binding sites, riboswitches, reporter proteins, modular vector systems, and markerless selection systems. Because of these new toolkits, cyanobacteria have been successfully engineered to express heterologous pathways for the production of a wide variety of valuable compounds. Cyanobacterial strains with the potential to be used in real-world applications will require the refinement of genetic circuits used to express the heterologous pathways and development of accurate models that predict how these pathways can be best integrated into the larger cellular metabolic network. Herein, we review advances that have been made to translate synthetic biology tools into cyanobacterial model organisms and summarize experimental and in silico strategies that have been employed to increase their bioproduction potential. Despite the advances in synthetic biology and metabolic engineering during the last years, it is clear that still further improvements are required if cyanobacteria are to be competitive with heterotrophic microorganisms for the bioproduction of added-value compounds.
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Affiliation(s)
- María Santos-Merino
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - Amit K. Singh
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - Daniel C. Ducat
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
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Chen H, Li T, Wang Q. Ten years of algal biofuel and bioproducts: gains and pains. PLANTA 2019; 249:195-219. [PMID: 30603791 DOI: 10.1007/s00425-018-3066-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 12/10/2018] [Indexed: 05/09/2023]
Abstract
It has been proposed that future efforts should focus on basic studies, biotechnology studies and synthetic biology studies related to algal biofuels and various high-value bioproducts for the economically viable production of algal biof uels. In recognition of diminishing fossil fuel reserves and the worsening environment, microalgal biofuel has been proposed as a renewable energy source with great potential. Algal biofuel thus became one of the hottest topics in renewable energy research in the new century, especially over the past decade. Between 2007 and 2017, research related to microalgal biofuels experienced a dramatic, three-stage development, rising, growing exponentially, and then declining rapidly due to overheating of the subject. However, biofuel-driven algal biotechnology and bioproducts research has been thriving since 2010. To clarify the gains (and pains) of the past decade and detail prospects for the future, this review summarizes the extensive scientific progress and substantial technical advances in algal biofuel over the past decade, covering basic biology, applied research, as well as the production of value-added natural products. Even after 10 years of hard work and billions of dollars in investments, its unacceptably high cost remains the ultimate bottleneck for the industrialization of algal biofuel. To maximize the total research benefits, both economically and socially, it has been proposed that future efforts should focus on basic studies to characterize oilgae, on biotechnology studies into various high-value bioproducts. Moreover, the development of synthetic biology provides new possibilities for the economically viable production of biofuels via the directional manufacture of microalgal bioproducts in algal cell factories.
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Affiliation(s)
- Hui Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 7 South Donghu Rd., Wuhan, 430072, Hubei Province, China
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, Hubei, 430072, China
| | - Tianpei Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 7 South Donghu Rd., Wuhan, 430072, Hubei Province, China
- University of the Chinese Academy of Sciences, Beijing, 100039, China
| | - Qiang Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 7 South Donghu Rd., Wuhan, 430072, Hubei Province, China.
- University of the Chinese Academy of Sciences, Beijing, 100039, China.
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Lin PC, Pakrasi HB. Engineering cyanobacteria for production of terpenoids. PLANTA 2019; 249:145-154. [PMID: 30465115 DOI: 10.1007/s00425-018-3047-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/14/2018] [Indexed: 05/08/2023]
Abstract
This review summarizes recent advances in cyanobacterial terpenoid production. The challenges and opportunities of improving terpenoid production by cyanobacteria are discussed. Terpenoids are a diverse group of natural products with a variety of commercial applications. With recent advances in synthetic biology and metabolic engineering, microbial terpenoid synthesis is being viewed as a feasible approach for industrial production. Among different microbial hosts, cyanobacteria have the potential of sustainable production of terpenoids using light and CO2. Terpene synthases and the precursor pathways have been expressed in cyanobacteria for enhanced production of various terpene hydrocarbons, including isoprene, limonene, β-phellandrene, and farnesene. However, the productivities need to be further improved for commercial production. Many barriers remain to be overcome in order to efficiently convert CO2 to terpenoids. In this review, we will summarize recent efforts on photosynthetic production of terpenoids and discuss the challenges and opportunities of engineering cyanobacteria for terpenoid bioproduction.
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Affiliation(s)
- Po-Cheng Lin
- Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Himadri B Pakrasi
- Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO, 63130, USA.
- Department of Biology, Washington University, St. Louis, MO, 63130, USA.
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Tetali SD. Terpenes and isoprenoids: a wealth of compounds for global use. PLANTA 2019; 249:1-8. [PMID: 30467631 DOI: 10.1007/s00425-018-3056-x] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/17/2018] [Indexed: 05/07/2023]
Abstract
Role of terpenes and isoprenoids has been pivotal in the survival and evolution of higher plants in various ecoregions. These products find application in the pharmaceutical, flavor fragrance, and biofuel industries. Fitness of plants in a wide range of environmental conditions entailed (i) evolution of secondary metabolic pathways enabling utilization of photosynthate for the synthesis of a variety of biomolecules, thereby facilitating diverse eco-interactive functions, and (ii) evolution of structural features for the sequestration of such compounds away from the mainstream primary metabolism to prevent autotoxicity. This review summarizes features and applications of terpene and isoprenoid compounds, comprising the largest class of secondary metabolites. Many of these terpene and isoprenoid biomolecules happen to be high-value bioproducts. They are essential components of all living organisms that are chemically highly variant. They are constituents of primary (quinones, chlorophylls, carotenoids, steroids) as well as secondary metabolism compounds with roles in signal transduction, reproduction, communication, climatic acclimation, defense mechanisms and more. They comprise single to several hundreds of repetitive five-carbon units of isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP). In plants, there are two pathways that lead to the synthesis of terpene and isoprenoid precursors, the cytosolic mevalonic acid (MVA) pathway and the plastidic methylerythritol phosphate (MEP) pathway. The diversity of terpenoids can be attributed to differential enzyme and substrate specificities and to secondary modifications acquired by terpene synthases. The biological role of secondary metabolites has been recognized as pivotal in the survival and evolution of higher plants. Terpenes and isoprenoids find application in pharmaceutical, nutraceutical, synthetic chemistry, flavor fragrance, and possibly biofuel industries.
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Affiliation(s)
- Sarada D Tetali
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, C. R. Prof. CR Rao Rd., CUC, Gachibowli, Hyderabad, 500046, Telangana, India.
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Vavitsas K, Fabris M, Vickers CE. Terpenoid Metabolic Engineering in Photosynthetic Microorganisms. Genes (Basel) 2018; 9:E520. [PMID: 30360565 PMCID: PMC6266707 DOI: 10.3390/genes9110520] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/17/2018] [Accepted: 10/17/2018] [Indexed: 12/13/2022] Open
Abstract
Terpenoids are a group of natural products that have a variety of roles, both essential and non-essential, in metabolism and in biotic and abiotic interactions, as well as commercial applications such as pharmaceuticals, food additives, and chemical feedstocks. Economic viability for commercial applications is commonly not achievable by using natural source organisms or chemical synthesis. Engineered bio-production in suitable heterologous hosts is often required to achieve commercial viability. However, our poor understanding of regulatory mechanisms and other biochemical processes makes obtaining efficient conversion yields from feedstocks challenging. Moreover, production from carbon dioxide via photosynthesis would significantly increase the environmental and potentially the economic credentials of these processes by disintermediating biomass feedstocks. In this paper, we briefly review terpenoid metabolism, outline some recent advances in terpenoid metabolic engineering, and discuss why photosynthetic unicellular organisms-such as algae and cyanobacteria-might be preferred production platforms for the expression of some of the more challenging terpenoid pathways.
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Affiliation(s)
- Konstantinos Vavitsas
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.
- CSIRO Synthetic Biology Future Science Platform, GPO Box 2583, Brisbane, QLD 4001, Australia.
| | - Michele Fabris
- Climate Change Cluster, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia.
- CSIRO Synthetic Biology Future Science Platform, GPO Box 2583, Brisbane, QLD 4001, Australia.
| | - Claudia E Vickers
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.
- CSIRO Synthetic Biology Future Science Platform, GPO Box 2583, Brisbane, QLD 4001, Australia.
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