1
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Einhaus A, Baier T, Kruse O. Molecular design of microalgae as sustainable cell factories. Trends Biotechnol 2024; 42:728-738. [PMID: 38092627 DOI: 10.1016/j.tibtech.2023.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 06/09/2024]
Abstract
Microalgae are regarded as sustainable and potent chassis for biotechnology. Their capacity for efficient photosynthesis fuels dynamic growth independent from organic carbon sources and converts atmospheric CO2 directly into various valuable hydrocarbon-based metabolites. However, approaches to gene expression and metabolic regulation have been inferior to those in more established heterotrophs (e.g., prokaryotes or yeast) since the genetic tools and insights in expression regulation have been distinctly less advanced. In recent years, however, these tools and their efficiency have dramatically improved. Various examples have demonstrated new trends in microalgal biotechnology and the potential of microalgae for the transition towards a sustainable bioeconomy.
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Affiliation(s)
- Alexander Einhaus
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Thomas Baier
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Olaf Kruse
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.
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2
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Canini D, Ceschi E, Perozeni F. Toward the Exploitation of Sustainable Green Factory: Biotechnology Use of Nannochloropsis spp. BIOLOGY 2024; 13:292. [PMID: 38785776 PMCID: PMC11117969 DOI: 10.3390/biology13050292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024]
Abstract
Securing food, energy, and raw materials for a growing population is one of the most significant challenges of our century. Algae play a central role as an alternative to plants. Wastewater and flue gas can secure nutrients and CO2 for carbon fixation. Unfortunately, algae domestication is necessary to enhance biomass production and reduce cultivation costs. Nannochloropsis spp. have increased in popularity among microalgae due to their ability to accumulate high amounts of lipids, including PUFAs. Recently, the interest in the use of Nannochloropsis spp. as a green bio-factory for producing high-value products increased proportionally to the advances of synthetic biology and genetic tools in these species. In this review, we summarized the state of the art of current nuclear genetic manipulation techniques and a few examples of their application. The industrial use of Nannochloropsis spp. has not been feasible yet, but genetic tools can finally lead to exploiting this full-of-potential microalga.
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Affiliation(s)
| | | | - Federico Perozeni
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (D.C.); (E.C.)
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3
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Ye Y, Liu M, Yu L, Sun H, Liu J. Nannochloropsis as an Emerging Algal Chassis for Light-Driven Synthesis of Lipids and High-Value Products. Mar Drugs 2024; 22:54. [PMID: 38393025 PMCID: PMC10890015 DOI: 10.3390/md22020054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 01/14/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024] Open
Abstract
In light of the escalating global energy crisis, microalgae have emerged as highly promising producers of biofuel and high-value products. Among these microalgae, Nannochloropsis has received significant attention due to its capacity to generate not only triacylglycerol (TAG) but also eicosapentaenoic acid (EPA) and valuable carotenoids. Recent advancements in genetic tools and the field of synthetic biology have revolutionized Nannochloropsis into a powerful biofactory. This comprehensive review provides an initial overview of the current state of cultivation and utilization of the Nannochloropsis genus. Subsequently, our review examines the metabolic pathways governing lipids and carotenoids, emphasizing strategies to enhance oil production and optimize carbon flux redirection toward target products. Additionally, we summarize the utilization of advanced genetic manipulation techniques in Nannochloropsis. Together, the insights presented in this review highlight the immense potential of Nannochloropsis as a valuable model for biofuels and synthetic biology. By effectively integrating genetic tools and metabolic engineering, the realization of this potential becomes increasingly feasible.
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Affiliation(s)
- Ying Ye
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China; (Y.Y.); (M.L.); (L.Y.)
| | - Meijing Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China; (Y.Y.); (M.L.); (L.Y.)
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Center for Algae Innovation & Engineering Research, School of Resources and Environment, Nanchang University, Nanchang 330031, China
| | - Lihua Yu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China; (Y.Y.); (M.L.); (L.Y.)
| | - Han Sun
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Jin Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China; (Y.Y.); (M.L.); (L.Y.)
- Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Center for Algae Innovation & Engineering Research, School of Resources and Environment, Nanchang University, Nanchang 330031, China
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4
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Shitanaka T, Fujioka H, Khan M, Kaur M, Du ZY, Khanal SK. Recent advances in microalgal production, harvesting, prediction, optimization, and control strategies. BIORESOURCE TECHNOLOGY 2024; 391:129924. [PMID: 37925082 DOI: 10.1016/j.biortech.2023.129924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 11/06/2023]
Abstract
The market value of microalgae has grown exponentially over the past two decades, due to their use in the pharmaceutical, nutraceutical, cosmetic, and aquatic/animal feed industries. In particular, high-value products such as omega-3 fatty acids, proteins, and pigments derived from microalgae have high demand. However, the supply of these high-value microalgal bioproducts is hampered by several critical factors, including low biomass and bioproduct yields, inefficiencies in monitoring microalgal growth, and costly harvesting methods. To overcome these constraints, strategies such as synthetic biology, bubble generation, photobioreactor designs, electro-/magnetic-/bioflocculation, and artificial intelligence integration in microalgal production are being explored. These strategies have significant promise in improving the production of microalgae, which will further boost market availability of algal-derived bioproducts. This review focuses on the recent advances in these technologies. Furthermore, this review aims to provide a critical analysis of the challenges in existing algae bioprocessing methods, and highlights future research directions.
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Affiliation(s)
- Ty Shitanaka
- Department of Molecular Biosciences & Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States
| | - Haylee Fujioka
- Department of Molecular Biosciences & Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States
| | - Muzammil Khan
- Department of Civil and Environmental Engineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States
| | - Manpreet Kaur
- Department of Molecular Biosciences & Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States
| | - Zhi-Yan Du
- Department of Molecular Biosciences & Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States.
| | - Samir Kumar Khanal
- Department of Molecular Biosciences & Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States; Department of Civil and Environmental Engineering, University of Hawai'i at Mānoa, Honolulu, HI 96822, United States.
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5
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Guo L, Yang G. Pioneering DNA assembling techniques and their applications in eukaryotic microalgae. Biotechnol Adv 2024; 70:108301. [PMID: 38101551 DOI: 10.1016/j.biotechadv.2023.108301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/12/2023] [Accepted: 12/08/2023] [Indexed: 12/17/2023]
Abstract
Assembling DNA fragments is a fundamental manipulation of cloning microalgal genes and carrying out microalgal synthetic biological studies. From the earliest DNA recombination to current trait and metabolic pathway engineering, we are always accompanied by homology-based DNA assembling. The improvement and modification of pioneering DNA assembling techniques and the combinational applications of the available assembling techniques have diversified and complicated the literature environment and aggravated our identification of the core and pioneering methodologies. Identifying the core assembling methodologies and using them appropriately and flourishing them even are important for researchers. A group of microalgae have been evolving as the models for both industrial applications and biological studies. DNA assembling requires researchers to know the methods available and their improvements and evolvements. In this review, we summarized the pioneering (core; leading) DNA assembling techniques developed previously, extended these techniques to their modifications, improvements and their combinations, and highlighted their applications in eukaryotic microalgae. We predicted that the gene(s) will be assembled into a functional cluster (e.g., those involving in a metabolic pathway, and stacked on normal microalgal chromosomes, their artificial episomes and looming artificial chromosomes. It should be particularly pointed out that the techniques mentioned in this review are classified according to the strategy used to assemble the final construct.
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Affiliation(s)
- Li Guo
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Guanpin Yang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China; Institutes of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China; MoE Laboratory of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China; Key Laboratory of Marine Genetics and Breeding of Ministry of Education, Ocean University of China, Qingdao 266003, China.
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6
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Du Z, Bhat WW, Poliner E, Johnson S, Bertucci C, Farre E, Hamberger B. Engineering Nannochloropsis oceanica for the production of diterpenoid compounds. MLIFE 2023; 2:428-437. [PMID: 38818264 PMCID: PMC10989085 DOI: 10.1002/mlf2.12097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 08/24/2023] [Accepted: 10/04/2023] [Indexed: 06/01/2024]
Abstract
Photosynthetic microalgae like Nannochloropsis hold enormous potential as sustainable, light-driven biofactories for the production of high-value natural products such as terpenoids. Nannochloropsis oceanica is distinguished as a particularly robust host with extensive genomic and transgenic resources available. Its capacity to grow in wastewater, brackish, and sea waters, coupled with advances in microalgal metabolic engineering, genome editing, and synthetic biology, provides an excellent opportunity. In the present work, we demonstrate how N. oceanica can be engineered to produce the diterpene casbene-an important intermediate in the biosynthesis of pharmacologically relevant macrocyclic diterpenoids. Casbene accumulated after stably expressing and targeting the casbene synthase from Daphne genkwa (DgTPS1) to the algal chloroplast. The engineered strains yielded production titers of up to 0.12 mg g-1 total dry cell weight (DCW) casbene. Heterologous overexpression and chloroplast targeting of two upstream rate-limiting enzymes in the 2-C-methyl- d-erythritol 4-phosphate pathway, Coleus forskohlii 1-deoxy- d-xylulose-5-phosphate synthase and geranylgeranyl diphosphate synthase genes, further enhanced the yield of casbene to a titer up to 1.80 mg g-1 DCW. The results presented here form a basis for further development and production of complex plant diterpenoids in microalgae.
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Affiliation(s)
- Zhi‐Yan Du
- Department of Molecular Biosciences and BioengineeringUniversity of Hawaii at ManoaHonoluluHawaiiUSA
| | - Wajid W. Bhat
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Eric Poliner
- Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Sean Johnson
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Present address:
New England Biolabs Inc.240 County RoadIpswich01938MAUSA
| | - Conor Bertucci
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Eva Farre
- Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Bjoern Hamberger
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
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7
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Patwari P, Pruckner F, Fabris M. Biosensors in microalgae: A roadmap for new opportunities in synthetic biology and biotechnology. Biotechnol Adv 2023; 68:108221. [PMID: 37495181 DOI: 10.1016/j.biotechadv.2023.108221] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 06/22/2023] [Accepted: 07/22/2023] [Indexed: 07/28/2023]
Abstract
Biosensors are powerful tools to investigate, phenotype, improve and prototype microbial strains, both in fundamental research and in industrial contexts. Genetic and biotechnological developments now allow the implementation of synthetic biology approaches to novel different classes of microbial hosts, for example photosynthetic microalgae, which offer unique opportunities. To date, biosensors have not yet been implemented in phototrophic eukaryotic microorganisms, leaving great potential for novel biological and technological advancements untapped. Here, starting from selected biosensor technologies that have successfully been implemented in heterotrophic organisms, we project and define a roadmap on how these could be applied to microalgae research. We highlight novel opportunities for the development of new biosensors, identify critical challenges, and finally provide a perspective on the impact of their eventual implementation to tackle research questions and bioengineering strategies. From studying metabolism at the single-cell level to genome-wide screen approaches, and assisted laboratory evolution experiments, biosensors will greatly impact the pace of progress in understanding and engineering microalgal metabolism. We envision how this could further advance the possibilities for unraveling their ecological role, evolutionary history and accelerate their domestication, to further drive them as resource-efficient production hosts.
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Affiliation(s)
- Payal Patwari
- SDU Biotechnology, Faculty of Engineering, University of Southern Denmark, Odense M DK-5230, Denmark
| | - Florian Pruckner
- SDU Biotechnology, Faculty of Engineering, University of Southern Denmark, Odense M DK-5230, Denmark
| | - Michele Fabris
- SDU Biotechnology, Faculty of Engineering, University of Southern Denmark, Odense M DK-5230, Denmark.
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8
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Patel VK, Das A, Kumari R, Kajla S. Recent progress and challenges in CRISPR-Cas9 engineered algae and cyanobacteria. ALGAL RES 2023. [DOI: 10.1016/j.algal.2023.103068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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9
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Xu Y. Biochemistry and Biotechnology of Lipid Accumulation in the Microalga Nannochloropsis oceanica. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:11500-11509. [PMID: 36083864 DOI: 10.1021/acs.jafc.2c05309] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Oils are among the most important agricultural commodities and have wide applications in food/nutrition, biofuels, and oleochemicals. The oleaginous microalga Nannochloropsis oceanica can produce large amounts of oils and the high-value ω-3 eicosapentaenoic acid, which represents a promising resource for oil production targeting biodiesel, nutraceutical, and aquaculture industries. In recent years, with the availability of omics databases and the development of genetic tools, N. oceanica has been extensively investigated as a model photosynthetic organism for studying lipid metabolism and as a green cellular factory to produce lipids for industrial applications. This review summarizes the current knowledge on the lipid composition and biosynthetic pathways of N. oceanica and reviews the recent advances in metabolic engineering of lipid production in this microalga.
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Affiliation(s)
- Yang Xu
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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10
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Rout SS, de Grahl I, Yu X, Reumann S. Production of a viral surface protein in Nannochloropsis oceanica for fish vaccination against infectious pancreatic necrosis virus. Appl Microbiol Biotechnol 2022; 106:6535-6549. [PMID: 36069927 PMCID: PMC9449291 DOI: 10.1007/s00253-022-12106-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/24/2022] [Accepted: 07/27/2022] [Indexed: 11/15/2022]
Abstract
Abstract Nannochloropsis oceanica is a unicellular oleaginous microalga of emerging biotechnological interest with a sequenced, annotated genome, available transcriptomic and proteomic data, and well-established basic molecular tools for genetic engineering. To establish N. oceanica as a eukaryotic host for recombinant protein synthesis and develop molecular technology for vaccine production, we chose the viral surface protein 2 (VP2) of a pathogenic fish virus that causes infectious pancreatic necrosis as a model vaccine. Upon stable nuclear transformation of N. oceanica strain CCMP1779 with the codon-optimized VP2 gene, a Venus reporter fusion served to evaluate the strength of different endogenous promoters in transformant populations by qPCR and flow cytometry. The highest VP2 yields were achieved for the elongation factor promoter, with enhancer effects by its N-terminal leader sequence. Individual transformants differed in their production capability of reporter-free VP2 by orders of magnitude. When subjecting the best candidates to kinetic analyses of growth and VP2 production in photobioreactors, recombinant protein integrity was maintained until the early stationary growth phase, and a high yield of 4.4% VP2 of total soluble protein was achieved. The maximum yield correlated with multiple integrations of the expression vector into the nuclear genome. The results demonstrate that N. oceanica was successfully engineered to constitute a robust platform for high-level production of a model subunit vaccine. The molecular methodology established here can likely be adapted in a straightforward manner to the production of further vaccines in the same host, allowing their distribution to fish, vertebrates, or humans via a microalgae-containing diet. Key points • We engineered N. oceanica for recombinant protein production. • The antigenic surface protein 2 of IPN virus could indeed be expressed in the host. • A high yield of 4.4% VP2 of total soluble protein was achieved in N. oceanica. Supplementary Information The online version contains supplementary material available at 10.1007/s00253-022-12106-7.
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Affiliation(s)
- Sweta Suman Rout
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Imke de Grahl
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Xiaohong Yu
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany.,Zybio Inc, Chongqing Municipality, 400084, China
| | - Sigrun Reumann
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany.
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11
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Liu M, Ding W, Yu L, Shi Y, Liu J. Functional characterization of carotenogenic genes provides implications into carotenoid biosynthesis and engineering in the marine alga Nannochloropsis oceanica. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Poliner E, Busch AWU, Newton L, Kim YU, Clark R, Gonzalez-Martinez SC, Jeong BR, Montgomery BL, Farré EM. Aureochromes maintain polyunsaturated fatty acid content in Nannochloropsis oceanica. PLANT PHYSIOLOGY 2022; 189:906-921. [PMID: 35166829 PMCID: PMC9157131 DOI: 10.1093/plphys/kiac052] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/12/2022] [Indexed: 05/05/2023]
Abstract
Nannochloropsis oceanica, like other stramenopile microalgae, is rich in long-chain polyunsaturated fatty acids (LC-PUFAs) such as eicosapentaenoic acid (EPA). We observed that fatty acid desaturases (FADs) involved in LC-PUFA biosynthesis were among the strongest blue light-induced genes in N. oceanica CCMP1779. Blue light was also necessary for maintaining LC-PUFA levels in CCMP1779 cells, and growth under red light led to a reduction in EPA content. Aureochromes are stramenopile-specific proteins that contain a light-oxygen-voltage (LOV)-sensing domain that associates with a flavin mononucleotide and is able to sense blue light. These proteins also contain a basic leucine zipper DNA-binding motif and can act as blue light-regulated transcription factors by associating with an E-box like motif, which we found enriched in the promoters of blue light-induced genes. We demonstrated that, in vitro, two CCMP1779 aureochromes were able to absorb blue light. Moreover, the loss or reduction of the expression of any of the three aureochrome genes led to a decrease in the blue light-specific induction of several FADs in CCMP1779. EPA content was also significantly reduced in NoAUREO2 and NoAUREO4 mutants. Taken together, our results indicate that aureochromes mediate blue light-dependent regulation of LC-PUFA content in N. oceanica CCMP1779 cells.
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Affiliation(s)
- Eric Poliner
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan, USA
| | - Andrea W U Busch
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Linsey Newton
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
| | - Young Uk Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Rachel Clark
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
| | | | - Byeong-Ryool Jeong
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandon Key Laboratory of Energy Genetics, Shandong Institute of Energy Research, Qingdao Institute of BioEnergy and Bioprocess Technology (QiBEBT), Chinese Academy of Sciences, Qingdao, Shandong 266101, China
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Beronda L Montgomery
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Eva M Farré
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
- Author for correspondence: (E.M.F.)
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Ranjbar S, Malcata FX. Is Genetic Engineering a Route to Enhance Microalgae-Mediated Bioremediation of Heavy Metal-Containing Effluents? Molecules 2022; 27:1473. [PMID: 35268582 PMCID: PMC8911655 DOI: 10.3390/molecules27051473] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/19/2022] Open
Abstract
Contamination of the biosphere by heavy metals has been rising, due to accelerated anthropogenic activities, and is nowadays, a matter of serious global concern. Removal of such inorganic pollutants from aquatic environments via biological processes has earned great popularity, for its cost-effectiveness and high efficiency, compared to conventional physicochemical methods. Among candidate organisms, microalgae offer several competitive advantages; phycoremediation has even been claimed as the next generation of wastewater treatment technologies. Furthermore, integration of microalgae-mediated wastewater treatment and bioenergy production adds favorably to the economic feasibility of the former process-with energy security coming along with environmental sustainability. However, poor biomass productivity under abiotic stress conditions has hindered the large-scale deployment of microalgae. Recent advances encompassing molecular tools for genome editing, together with the advent of multiomics technologies and computational approaches, have permitted the design of tailor-made microalgal cell factories, which encompass multiple beneficial traits, while circumventing those associated with the bioaccumulation of unfavorable chemicals. Previous studies unfolded several routes through which genetic engineering-mediated improvements appear feasible (encompassing sequestration/uptake capacity and specificity for heavy metals); they can be categorized as metal transportation, chelation, or biotransformation, with regulation of metal- and oxidative stress response, as well as cell surface engineering playing a crucial role therein. This review covers the state-of-the-art metal stress mitigation mechanisms prevalent in microalgae, and discusses putative and tested metabolic engineering approaches, aimed at further improvement of those biological processes. Finally, current research gaps and future prospects arising from use of transgenic microalgae for heavy metal phycoremediation are reviewed.
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Affiliation(s)
- Saeed Ranjbar
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal;
- Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal
| | - Francisco Xavier Malcata
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal;
- Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal
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14
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Naduthodi MIS, Südfeld C, Avitzigiannis EK, Trevisan N, van Lith E, Alcaide Sancho J, D’Adamo S, Barbosa M, van der Oost J. Comprehensive Genome Engineering Toolbox for Microalgae Nannochloropsis oceanica Based on CRISPR-Cas Systems. ACS Synth Biol 2021; 10:3369-3378. [PMID: 34793143 PMCID: PMC8689688 DOI: 10.1021/acssynbio.1c00329] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Microalgae can produce
industrially relevant metabolites using
atmospheric CO2 and sunlight as carbon and energy sources,
respectively. Developing molecular tools for high-throughput genome
engineering could accelerate the generation of tailored strains with
improved traits. To this end, we developed a genome editing strategy
based on Cas12a ribonucleoproteins (RNPs) and homology-directed repair
(HDR) to generate scarless and markerless mutants of the microalga Nannochloropsis oceanica. We also developed an episomal
plasmid-based Cas12a system for efficiently introducing indels at
the target site. Additionally, we exploited the ability of Cas12a
to process an associated CRISPR array to perform multiplexed genome
engineering. We efficiently targeted three sites in the host genome
in a single transformation, thereby making a major step toward high-throughput
genome engineering in microalgae. Furthermore, a CRISPR interference
(CRISPRi) tool based on Cas9 and Cas12a was developed for effective
downregulation of target genes. We observed up to 85% reduction in
the transcript levels upon performing CRISPRi with dCas9 in N. oceanica. Overall, these developments substantially
accelerate genome engineering efforts in N. oceanica and potentially provide a general toolbox for improving other microalgal
strains.
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Affiliation(s)
- Mihris Ibnu Saleem Naduthodi
- Laboratory of Microbiology, Wageningen University, Wageningen 6708 WE, The Netherlands
- Bioprocess Engineering, Wageningen University, Wageningen 6708 PB, The Netherlands
| | - Christian Südfeld
- Bioprocess Engineering, Wageningen University, Wageningen 6708 PB, The Netherlands
| | | | - Nicola Trevisan
- Bioprocess Engineering, Wageningen University, Wageningen 6708 PB, The Netherlands
| | - Eduard van Lith
- Laboratory of Microbiology, Wageningen University, Wageningen 6708 WE, The Netherlands
| | - Javier Alcaide Sancho
- Laboratory of Microbiology, Wageningen University, Wageningen 6708 WE, The Netherlands
| | - Sarah D’Adamo
- Bioprocess Engineering, Wageningen University, Wageningen 6708 PB, The Netherlands
| | - Maria Barbosa
- Bioprocess Engineering, Wageningen University, Wageningen 6708 PB, The Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University, Wageningen 6708 WE, The Netherlands
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15
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Metabolic engineering of the oleaginous alga Nannochloropsis for enriching eicosapentaenoic acid in triacylglycerol by combined pulling and pushing strategies. Metab Eng 2021; 69:163-174. [PMID: 34864212 DOI: 10.1016/j.ymben.2021.11.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 11/20/2021] [Accepted: 11/30/2021] [Indexed: 11/23/2022]
Abstract
The marine alga Nannochloropsis oceanica has been considered as a promising photosynthetic cell factory for synthesizing eicosapentaenoic acid (EPA), yet the accumulation of EPA in triacylglycerol (TAG) is restricted to an extreme low level. Poor channeling of EPA to TAG was observed in N. oceanica under TAG induction conditions, likely due to the weak activity of endogenous diacylglycerol acyltransferases (DGATs) on EPA-CoA. Screening over thirty algal DGATs revealed potent enzymes acting on EPA-CoA. Whilst overexpressing endogenous DGATs had no or slight effect on EPA abundance in TAG, introducing selected DGATs with strong activity on EPA-CoA, particularly the Chlamydomonas-derived CrDGTT1, which resided at the outermost membrane of the chloroplast and provided a strong pulling power to divert EPA to TAG for storage and protection, led to drastic increases in EPA abundance in TAG and TAG-derived EPA level in N. oceanica. They were further promoted by additional overexpression of an elongase gene involved in EPA biosynthesis, reaching 5.9- and 12.3-fold greater than the control strain, respectively. Our results together demonstrate the concept of applying combined pulling and pushing strategies to enrich EPA in algal TAG and provide clues for the enrichment of other desired fatty acids in TAG as well.
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16
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Yang HP, Wenzel M, Hauser DA, Nelson JM, Xu X, Eliáš M, Li FW. Monodopsis and Vischeria Genomes Shed New Light on the Biology of Eustigmatophyte Algae. Genome Biol Evol 2021; 13:6402010. [PMID: 34665222 PMCID: PMC8570151 DOI: 10.1093/gbe/evab233] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2021] [Indexed: 11/12/2022] Open
Abstract
Members of eustigmatophyte algae, especially Nannochloropsis and Microchloropsis, have been tapped for biofuel production owing to their exceptionally high lipid content. Although extensive genomic, transcriptomic, and synthetic biology toolkits have been made available for Nannochloropsis and Microchloropsis, very little is known about other eustigmatophytes. Here we present three near-chromosomal and gapless genome assemblies of Monodopsis strains C73 and C141 (60 Mb) and Vischeria strain C74 (106 Mb), which are the sister groups to Nannochloropsis and Microchloropsis in the order Eustigmatales. These genomes contain unusually high percentages of simple repeats, ranging from 12% to 21% of the total assembly size. Unlike Nannochloropsis and Microchloropsis, long interspersed nuclear element repeats are abundant in Monodopsis and Vischeria and might constitute the centromeric regions. We found that both mevalonate and nonmevalonate pathways for terpenoid biosynthesis are present in Monodopsis and Vischeria, which is different from Nannochloropsis and Microchloropsis that have only the latter. Our analysis further revealed extensive spliced leader trans-splicing in Monodopsis and Vischeria at 36-61% of genes. Altogether, the high-quality genomes of Monodopsis and Vischeria not only serve as the much-needed outgroups to advance Nannochloropsis and Microchloropsis research, but also shed new light on the biology and evolution of eustigmatophyte algae.
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Affiliation(s)
| | - Marius Wenzel
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | | | | | - Xia Xu
- Boyce Thompson Institute, Ithaca, New York, USA
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Fay-Wei Li
- Boyce Thompson Institute, Ithaca, New York, USA.,Plant Biology Section, Cornell University, USA
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17
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Vavitsas K, Kugler A, Satta A, Hatzinikolaou DG, Lindblad P, Fewer DP, Lindberg P, Toivari M, Stensjö K. Doing synthetic biology with photosynthetic microorganisms. PHYSIOLOGIA PLANTARUM 2021; 173:624-638. [PMID: 33963557 DOI: 10.1111/ppl.13455] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/22/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
The use of photosynthetic microbes as synthetic biology hosts for the sustainable production of commodity chemicals and even fuels has received increasing attention over the last decade. The number of studies published, tools implemented, and resources made available for microalgae have increased beyond expectations during the last few years. However, the tools available for genetic engineering in these organisms still lag those available for the more commonly used heterotrophic host organisms. In this mini-review, we provide an overview of the photosynthetic microbes most commonly used in synthetic biology studies, namely cyanobacteria, chlorophytes, eustigmatophytes and diatoms. We provide basic information on the techniques and tools available for each model group of organisms, we outline the state-of-the-art, and we list the synthetic biology tools that have been successfully used. We specifically focus on the latest CRISPR developments, as we believe that precision editing and advanced genetic engineering tools will be pivotal to the advancement of the field. Finally, we discuss the relative strengths and weaknesses of each group of organisms and examine the challenges that need to be overcome to achieve their synthetic biology potential.
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Affiliation(s)
- Konstantinos Vavitsas
- Enzyme and Microbial Biotechnology Unit, Department of Biology, National and Kapodistrian University of Athens, Zografou Campus, Athens, Greece
| | - Amit Kugler
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Alessandro Satta
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
- CSIRO Synthetic Biology Future Science Platform, Brisbane, Australia
| | - Dimitris G Hatzinikolaou
- Enzyme and Microbial Biotechnology Unit, Department of Biology, National and Kapodistrian University of Athens, Zografou Campus, Athens, Greece
| | - Peter Lindblad
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - David P Fewer
- Department of Microbiology, University of Helsinki, Helsinki, Finland
| | - Pia Lindberg
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Mervi Toivari
- VTT, Technical Research Centre of Finland Ltd, Espoo, Finland
| | - Karin Stensjö
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
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18
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Shi Y, Liu M, Pan Y, Hu H, Liu J. Δ6 Fatty Acid Elongase is Involved in Eicosapentaenoic Acid Biosynthesis Via the ω6 Pathway in the Marine Alga Nannochloropsis oceanica. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:9837-9848. [PMID: 34414763 DOI: 10.1021/acs.jafc.1c04192] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nannochloropsis oceanica represents a promising sunlight-driven alga for producing eicosapentaenoic acid (EPA, 20:5Δ5,8,11,14,17), a value-added very long-chain polyunsaturated fatty acid (VLC-PUFA). Here, we unraveled the function and roles of a Δ6 fatty acid elongase (NoΔ6-FAE) in N. oceanica. Heterologous expression of NoΔ6-FAE in yeast confirmed its function in elongating C18 Δ6-PUFAs rather than others. Subcellular localization experiments suggested that NoΔ6-FAE resides in the chloroplast endoplasmic reticulum. NoΔ6-FAE knockdown attenuated C20:3Δ8,11,14, C20:4Δ5,8,11,14, and EPA yet enhanced C18:3Δ6,9,12, leading to overall decreases in total fatty acids, triacylglycerol, diacylglycerol, free fatty acids, and polar membrane lipids. In contrast, NoΔ6-FAE overexpression in N. oceanica caused nearly opposite phenotypes. Moreover, N. oceanica lacked detectable C18:3Δ9,12,15, C18:4Δ6,9,12,15, and C20:4Δ8,11,14,17 even under NoΔ6-FAE knockdown or overexpression. Our results reveal the involvement of NoΔ6-FAE in EPA biosynthesis via the ω6 pathway in N. oceanica and highlight the potential of manipulating NoΔ6-FAE for improved lipid production.
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Affiliation(s)
- Ying Shi
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Meijing Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Yufang Pan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Hanhua Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Jin Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
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19
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de Grahl I, Reumann S. Stramenopile microalgae as "green biofactories" for recombinant protein production. World J Microbiol Biotechnol 2021; 37:163. [PMID: 34453200 PMCID: PMC8397651 DOI: 10.1007/s11274-021-03126-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/06/2021] [Indexed: 12/23/2022]
Abstract
Photoautotrophic microalgae have become intriguing hosts for recombinant protein production because they offer important advantages of both prokaryotic and eukaryotic expression systems. Advanced molecular tools have recently been established for the biotechnologically relevant group of stramenopile microalgae, particularly for several Nannochloropsis species and diatoms. Strategies for the selection of powerful genetic elements and for optimization of protein production have been reported. Much needed high-throughput techniques required for straight-forward identification and selection of the best expression constructs and transformants have become available and are discussed. The first recombinant proteins have already been produced successfully in stramenopile microalgae and include not only several subunit vaccines but also one antimicrobial peptide, a fish growth hormone, and an antibody. These research results offer interesting future applications in aquaculture and as biopharmaceuticals. In this review we highlight recent progress in genetic technology development for recombinant protein production in the most relevant Nannochloropsis species and diatoms. Diverse realistic biotechnological applications of these proteins are emphasized that have the potential to establish stramenopile algae as sustainable green factories for an economically competitive production of high-value biomolecules.
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Affiliation(s)
- Imke de Grahl
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany.
| | - Sigrun Reumann
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
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20
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Gutiérrez S, Lauersen KJ. Gene Delivery Technologies with Applications in Microalgal Genetic Engineering. BIOLOGY 2021; 10:265. [PMID: 33810286 PMCID: PMC8067306 DOI: 10.3390/biology10040265] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 12/28/2022]
Abstract
Microalgae and cyanobacteria are photosynthetic microbes that can be grown with the simple inputs of water, carbon dioxide, (sun)light, and trace elements. Their engineering holds the promise of tailored bio-molecule production using sustainable, environmentally friendly waste carbon inputs. Although algal engineering examples are beginning to show maturity, severe limitations remain in the transformation of multigene expression cassettes into model species and DNA delivery into non-model hosts. This review highlights common and emerging DNA delivery methods used for other organisms that may find future applications in algal engineering.
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Affiliation(s)
| | - Kyle J. Lauersen
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia;
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21
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22
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Synthetic Biology Approaches To Enhance Microalgal Productivity. Trends Biotechnol 2021; 39:1019-1036. [PMID: 33541719 DOI: 10.1016/j.tibtech.2020.12.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022]
Abstract
The major bottleneck in commercializing biofuels and other commodities produced by microalgae is the high cost associated with phototrophic cultivation. Improving microalgal productivities could be a solution to this problem. Synthetic biology methods have recently been used to engineer the downstream production pathways in several microalgal strains. However, engineering upstream photosynthetic and carbon fixation metabolism to enhance growth, productivity, and yield has barely been explored in microalgae. We describe strategies to improve the generation of reducing power from light, as well as to improve the assimilation of CO2 by either the native Calvin cycle or synthetic alternatives. Overall, we are optimistic that recent technological advances will prompt long-awaited breakthroughs in microalgal research.
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23
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Young R, Haines M, Storch M, Freemont PS. Combinatorial metabolic pathway assembly approaches and toolkits for modular assembly. Metab Eng 2020; 63:81-101. [PMID: 33301873 DOI: 10.1016/j.ymben.2020.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 11/16/2020] [Accepted: 12/03/2020] [Indexed: 12/18/2022]
Abstract
Synthetic Biology is a rapidly growing interdisciplinary field that is primarily built upon foundational advances in molecular biology combined with engineering design principles such as modularity and interoperability. The field considers living systems as programmable at the genetic level and has been defined by the development of new platform technologies and methodological advances. A key concept driving the field is the Design-Build-Test-Learn cycle which provides a systematic framework for building new biological systems. One major application area for synthetic biology is biosynthetic pathway engineering that requires the modular assembly of different genetic regulatory elements and biosynthetic enzymes. In this review we provide an overview of modular DNA assembly and describe and compare the plethora of in vitro and in vivo assembly methods for combinatorial pathway engineering. Considerations for part design and methods for enzyme balancing are also presented, and we briefly discuss alternatives to intracellular pathway assembly including microbial consortia and cell-free systems for biosynthesis. Finally, we describe computational tools and automation for pathway design and assembly and argue that a deeper understanding of the many different variables of genetic design, pathway regulation and cellular metabolism will allow more predictive pathway design and engineering.
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Affiliation(s)
- Rosanna Young
- Department of Infectious Disease, Sir Alexander Fleming Building, South Kensington Campus, Imperial College London, SW7 2AZ, UK
| | - Matthew Haines
- Department of Infectious Disease, Sir Alexander Fleming Building, South Kensington Campus, Imperial College London, SW7 2AZ, UK
| | - Marko Storch
- Department of Infectious Disease, Sir Alexander Fleming Building, South Kensington Campus, Imperial College London, SW7 2AZ, UK; London Biofoundry, Imperial College Translation & Innovation Hub, London, W12 0BZ, UK
| | - Paul S Freemont
- Department of Infectious Disease, Sir Alexander Fleming Building, South Kensington Campus, Imperial College London, SW7 2AZ, UK; London Biofoundry, Imperial College Translation & Innovation Hub, London, W12 0BZ, UK; UK DRI Care Research and Technology Centre, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.
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24
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de Grahl I, Rout SS, Maple-Grødem J, Reumann S. Development of a constitutive and an auto-inducible high-yield expression system for recombinant protein production in the microalga Nannochloropsis oceanica. Appl Microbiol Biotechnol 2020; 104:8747-8760. [PMID: 32902683 PMCID: PMC7502441 DOI: 10.1007/s00253-020-10789-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/10/2020] [Accepted: 07/19/2020] [Indexed: 01/28/2023]
Abstract
Photoautotrophic microalgae offer a great potential as novel hosts for efficient recombinant protein production. Nannochloropsis oceanica produces an extraordinarily high content of polyunsaturated fatty acids, and its robust growth characteristics, published genome sequence and efficient nuclear transformation make N. oceanica a promising candidate for biotechnological applications. To establish a robust and flexible system for recombinant protein production, we cloned six endogenous, potentially constitutive or inducible promoters from N. oceanica strain CCMP1779 and investigated their strength using monomeric Venus as reporter gene. Microscopic pre-screening of individual transformants revealed that the promoters of elongation factor (EF), tubulin (TUB) and nitrate reductase (NR) enabled high reporter gene expression. Comparative quantitative analyses of transformant populations by flow cytometry and qRT-PCR demonstrated the highest Venus expression from the EF promoter and the NR promoter if extended by an N-terminal 14-amino acid leader sequence. The kinetics of reporter gene expression were analysed during photobioreactor cultivation, achieving Venus yields of 0.3% (for EF) and 4.9% (for NR::LS) of total soluble protein. Since inducible expression systems enable the production of toxic proteins, we developed an auto-induction medium for the NR promoter transformants. By switching the N source from ammonium to nitrate in the presence of low ammonium concentrations, the starting point of Venus induction could be fine-tuned and shifted towards exponential growth phase while maintaining high recombinant protein yields. Taken together, we demonstrate that a model recombinant protein can be produced robustly and at very high levels in N. oceanica not only under constitutive but also under auto-inducible cultivation conditions. KEY POINTS: • Nannochloropsis oceanica might serve as host for recombinant protein production. • Comparative promoter strength analyses were conducted for twelve different constructs. • Robust high-yield recombinant protein production was achieved under constitutive conditions. • The nitrate reductase promoter enabled protein production under auto-induction conditions.
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Affiliation(s)
- Imke de Grahl
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, D-22609, Hamburg, Germany
| | - Sweta Suman Rout
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, D-22609, Hamburg, Germany
| | - Jodi Maple-Grødem
- The Norwegian Centre for Movement Disorders, Stavanger University Hospital, N-4021, Stavanger, Norway.,Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, N-4036, Stavanger, Norway
| | - Sigrun Reumann
- Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, Universität Hamburg, Ohnhorststr. 18, D-22609, Hamburg, Germany.
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25
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Wu T, Fu Y, Shi Y, Li Y, Kou Y, Mao X, Liu J. Functional Characterization of Long-Chain Acyl-CoA Synthetase Gene Family from the Oleaginous Alga Chromochloris zofingiensis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:4473-4484. [PMID: 32208653 DOI: 10.1021/acs.jafc.0c01284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Long-chain acyl-coenzyme A (CoA) synthetase (LACS) catalyzes the formation of acyl-CoAs from free fatty acids, which is pivotal for lipid metabolism. Here, we confirmed the presence of six CzLACS genes in Chromochloris zofingiensis. Functional complementation and in vitro enzymatic assay indicated that CzLACS2 through CzLACS5 rather than CzLACS1 or CzLACS6 are bona fide LACS enzymes and they have overlapping yet distinct substrate preference. The results of the subcellular colocalization experiment and different expression patterns under three triacylglycerol (TAG)-inducing conditions showed that CzLACS2 through CzLACS4 reside at endoplasmic reticulum (ER) and are involved in TAG biosynthesis, while CzLACS5 resides in peroxisome and participates in fatty acid β-oxidation. The yeast one-hybrid assay using a library of 50 transcription factors (TFs) constructed in our study identified 12 TFs potentially involved in regulating the expression of CzLACSs. Moreover, heterologous expression of CzLACSs demonstrated their engineering potential for modulating TAG synthesis in yeast and algal cells.
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Affiliation(s)
- Tao Wu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
- BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Yunlei Fu
- BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Ying Shi
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Yuelian Li
- BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Yaping Kou
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Xuemei Mao
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
- BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Jin Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
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