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Kong F, Blot C, Liu K, Kim M, Li-Beisson Y. Advances in algal lipid metabolism and their use to improve oil content. Curr Opin Biotechnol 2024; 87:103130. [PMID: 38579630 DOI: 10.1016/j.copbio.2024.103130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/07/2024]
Abstract
Microalgae are eukaryotic photosynthetic micro-organisms that convert CO2 into carbohydrates, lipids, and other valuable metabolites. They are considered promising chassis for the production of various bioproducts, including fatty acid-derived biofuels. However, algae-based biofuels are not yet commercially available, mainly because of their low yields and high production cost. Optimizing strains to improve lipid productivity using the principles of synthetic biology should help move forward. This necessitates developments in the following areas: (1) identification of molecular bricks (enzymes, transcription factors, regulatory proteins etc.); (2) development of genetic tools; and (3) availability of high-throughput phenotyping methods. Here, we highlight the most recent developments in some of these areas and provide examples of the use of genome editing tools to improve oil content.
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Affiliation(s)
- Fantao Kong
- MOE Key Laboratory of Bio-Intelligent Manufacturing, School of Bioengineering, Dalian University of Technology, Dalian 116024, Liaoning, China.
| | - Carla Blot
- Aix Marseille Univ, CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint Paul-Lez-Durance 13108, France
| | - Keqing Liu
- MOE Key Laboratory of Bio-Intelligent Manufacturing, School of Bioengineering, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Minjae Kim
- Aix Marseille Univ, CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint Paul-Lez-Durance 13108, France
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint Paul-Lez-Durance 13108, France
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Milito A, Alzuria D, Aschern M, McQuillan JL, Yang JS. Rational Design and Screening of Synthetic Promoters in Chlamydomonas reinhardtii. Methods Mol Biol 2024; 2844:69-83. [PMID: 39068332 DOI: 10.1007/978-1-0716-4063-0_4] [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] [Indexed: 07/30/2024]
Abstract
Synthetic promoters are powerful tools to boost the biotechnological potential of microalgae as eco-sustainable industrial hosts. The increasing availability of transcriptome data on microalgae in a variety of environmental conditions allows to identify cis-regulatory elements (CREs) that are responsible for the transcriptional output. Furthermore, advanced cloning technologies, such as golden gate-based MoClo toolkits, enable the creation of modular constructs for testing multiple promoters and a range of reporter systems in a convenient manner. In this chapter, we will describe how to introduce in silico-identified CREs into promoter sequences, and how to clone the modified promoters into MoClo compatible vectors. We will then describe how these promoters can be evaluated and screened for transgene expression in an established microalgal model for genetic perturbation, i.e., Chlamydomonas reinhardtii.
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Affiliation(s)
- Alfonsina Milito
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Barcelona, Spain
| | - David Alzuria
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Barcelona, Spain
| | - Moritz Aschern
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Barcelona, Spain
| | - Josie L McQuillan
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Barcelona, Spain
| | - Jae-Seong Yang
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Barcelona, Spain.
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Kreis E, König K, Misir M, Niemeyer J, Sommer F, Schroda M. TurboID reveals the proxiomes of Chlamydomonas proteins involved in thylakoid biogenesis and stress response. PLANT PHYSIOLOGY 2023; 193:1772-1796. [PMID: 37310689 PMCID: PMC10602608 DOI: 10.1093/plphys/kiad335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/24/2023] [Accepted: 05/04/2023] [Indexed: 06/14/2023]
Abstract
In Chlamydomonas (Chlamydomonas reinhardtii), the VESICLE-INDUCING PROTEIN IN PLASTIDS 1 and 2 (VIPP1 and VIPP2) play roles in the sensing and coping with membrane stress and in thylakoid membrane biogenesis. To gain more insight into these processes, we aimed to identify proteins interacting with VIPP1/2 in the chloroplast and chose proximity labeling (PL) for this purpose. We used the transient interaction between the nucleotide exchange factor CHLOROPLAST GRPE HOMOLOG 1 (CGE1) and the stromal HEAT SHOCK PROTEIN 70B (HSP70B) as test system. While PL with APEX2 and BioID proved to be inefficient, TurboID resulted in substantial biotinylation in vivo. TurboID-mediated PL with VIPP1/2 as baits under ambient and H2O2 stress conditions confirmed known interactions of VIPP1 with VIPP2, HSP70B, and the CHLOROPLAST DNAJ HOMOLOG 2 (CDJ2). Proteins identified in the VIPP1/2 proxiomes can be grouped into proteins involved in the biogenesis of thylakoid membrane complexes and the regulation of photosynthetic electron transport, including PROTON GRADIENT REGULATION 5-LIKE 1 (PGRL1). A third group comprises 11 proteins of unknown function whose genes are upregulated under chloroplast stress conditions. We named them VIPP PROXIMITY LABELING (VPL). In reciprocal experiments, we confirmed VIPP1 in the proxiomes of VPL2 and PGRL1. Our results demonstrate the robustness of TurboID-mediated PL for studying protein interaction networks in the chloroplast of Chlamydomonas and pave the way for analyzing functions of VIPPs in thylakoid biogenesis and stress responses.
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Affiliation(s)
- Elena Kreis
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Katharina König
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Melissa Misir
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Justus Niemeyer
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Frederik Sommer
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Michael Schroda
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
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Findinier J, Grossman AR. Chlamydomonas: Fast tracking from genomics. JOURNAL OF PHYCOLOGY 2023; 59:644-652. [PMID: 37417760 DOI: 10.1111/jpy.13356] [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: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 07/08/2023]
Abstract
Elucidating biological processes has relied on the establishment of model organisms, many of which offer advantageous features such as rapid axenic growth, extensive knowledge of their physiological features and gene content, and the ease with which they can be genetically manipulated. The unicellular green alga Chlamydomonas reinhardtii has been an exemplary model that has enabled many scientific breakthroughs over the decades, especially in the fields of photosynthesis, cilia function and biogenesis, and the acclimation of photosynthetic organisms to their environment. Here, we discuss recent molecular/technological advances that have been applied to C. reinhardtii and how they have further fostered its development as a "flagship" algal system. We also explore the future promise of this alga in leveraging advances in the fields of genomics, proteomics, imaging, and synthetic biology for addressing critical future biological issues.
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Affiliation(s)
- Justin Findinier
- The Carnegie Institution for Science, Biosphere Science and Engineering, Stanford, California, USA
| | - Arthur R Grossman
- The Carnegie Institution for Science, Biosphere Science and Engineering, Stanford, California, USA
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Perozeni F, Baier T. Current Nuclear Engineering Strategies in the Green Microalga Chlamydomonas reinhardtii. Life (Basel) 2023; 13:1566. [PMID: 37511941 PMCID: PMC10381326 DOI: 10.3390/life13071566] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/07/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
The green model microalga Chlamydomonas reinhardtii recently emerged as a sustainable production chassis for the efficient biosynthesis of recombinant proteins and high-value metabolites. Its capacity for scalable, rapid and light-driven growth in minimal salt solutions, its simplicity for genetic manipulation and its "Generally Recognized As Safe" (GRAS) status are key features for its application in industrial biotechnology. Although nuclear transformation has typically resulted in limited transgene expression levels, recent developments now allow the design of powerful and innovative bioproduction concepts. In this review, we summarize the main obstacles to genetic engineering in C. reinhardtii and describe all essential aspects in sequence adaption and vector design to enable sufficient transgene expression from the nuclear genome. Several biotechnological examples of successful engineering serve as blueprints for the future establishment of C. reinhardtii as a green cell factory.
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Affiliation(s)
- Federico Perozeni
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | - Thomas Baier
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
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Niemeyer J, Fischer L, Aylward FO, Schroda M. Analysis of Viral Promoters for Transgene Expression and of the Effect of 5'-UTRs on Alternative Translational Start Sites in Chlamydomonas. Genes (Basel) 2023; 14:genes14040948. [PMID: 37107706 PMCID: PMC10138193 DOI: 10.3390/genes14040948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/15/2023] [Accepted: 04/19/2023] [Indexed: 04/29/2023] Open
Abstract
Microalgae biotechnology has the potential to produce high quality bioproducts in a sustainable manner. Here, Chlamydomonas reinhardtii has shown great potential as a host for biotechnological exploitation. However, low expression of nuclear transgenes is still a problem and needs to be optimized. In many model organisms, viral promoters are used to drive transgene expression at high levels. However, no viruses are known to infect Chlamydomonas, and known viral promoters are not functional. Recently, two different lineages of giant viruses were identified in the genomes of Chlamydomonas reinhardtii field isolates. In this work, we tested six potentially strong promoters from these viral genomes for their ability to drive transgene expression in Chlamydomonas. We used ble, NanoLUC, and mCherry as reporter genes, and three native benchmark promoters as controls. None of the viral promoters drove expression of any reporter gene beyond background. During our study, we found that mCherry variants are produced by alternative in-frame translational start sites in Chlamydomonas. We show that this problem can be overcome by mutating the responsible methionine codons to codons for leucine and by using the 5'-UTR of βTUB2 instead of the 5'-UTRs of PSAD or RBCS2. Apparently, the βTUB2 5'-UTR promotes the use of the first start codon. This could be mediated by the formation of a stem-loop between sequences of the βTUB2 5'-UTR and sequences downstream of the first AUG in the mCherry reporter, potentially increasing the dwell time of the scanning 40S subunit on the first AUG and thus decreasing the probability of leaky scanning.
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Affiliation(s)
- Justus Niemeyer
- Molecular Biotechnology & Systems Biology, RPTU Kaiserslautern-Landau, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany
| | - Laura Fischer
- Molecular Biotechnology & Systems Biology, RPTU Kaiserslautern-Landau, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany
| | | | - Michael Schroda
- Molecular Biotechnology & Systems Biology, RPTU Kaiserslautern-Landau, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany
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Schroda M, Remacle C. Molecular Advancements Establishing Chlamydomonas as a Host for Biotechnological Exploitation. FRONTIERS IN PLANT SCIENCE 2022; 13:911483. [PMID: 35845675 PMCID: PMC9277225 DOI: 10.3389/fpls.2022.911483] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 06/07/2022] [Indexed: 05/13/2023]
Abstract
Chlamydomonas reinhardtii is emerging as a production platform for biotechnological purposes thanks to recent achievements, which we briefly summarize in this review. Firstly, robust nuclear transgene expression is now possible because several impressive improvements have been made in recent years. Strains allowing efficient and stable nuclear transgene expression are available and were recently made more amenable to rational biotechnological approaches by enabling genetic crosses and identifying their causative mutation. The MoClo synthetic biology strategy, based on Golden Gate cloning, was developed for Chlamydomonas and includes a growing toolkit of more than 100 genetic parts that can be robustly and rapidly assembled in a predefined order. This allows for rapid iterative cycles of transgene design, building, testing, and learning. Another major advancement came from various findings improving transgene design and expression such as the systematic addition of introns into codon-optimized coding sequences. Lastly, the CRISPR/Cas9 technology for genome editing has undergone several improvements since its first successful report in 2016, which opens the possibility of optimizing biosynthetic pathways by switching off competing ones. We provide a few examples demonstrating that all these recent developments firmly establish Chlamydomonas as a chassis for synthetic biology and allow the rewiring of its metabolism to new capabilities.
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Affiliation(s)
- Michael Schroda
- Molecular Biotechnology and Systems Biology, TU Kaiserslautern, Kaiserslautern, Germany
| | - Claire Remacle
- Genetics and Physiology of Microalgae, InBios/Phytosystems Research Unit, University of Liege, Liege, Belgium
- *Correspondence: Claire Remacle,
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