1
|
Zhao J, Ge Y, Liu K, Yamaoka Y, Zhang D, Chi Z, Akkaya M, Kong F. Overexpression of a MYB1 Transcription Factor Enhances Triacylglycerol and Starch Accumulation and Biomass Production in the Green Microalga Chlamydomonas reinhardtii. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:17833-17841. [PMID: 37934701 DOI: 10.1021/acs.jafc.3c05290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Microalgae are promising platforms for biofuel production. Transcription factors (TFs) are emerging as key regulators of lipid metabolism for biofuel production in microalgae. We previously identified a novel TF MYB1, which mediates lipid accumulation in the green microalga Chlamydomonas under nitrogen depletion. However, the function of MYB1 on lipid metabolism in microalgae under standard growth conditions remains poorly understood. Here, we examined the effects of MYB1 overexpression (MYB1-OE) on lipid metabolism and physiological changes in Chlamydomonas. Under standard growth conditions, MYB1-OE transformants accumulated 1.9 to 3.2-fold more triacylglycerols (TAGs) than that in the parental line (PL), and total fatty acids (FAs) also significantly increased. Moreover, saturated FA (C16:0) was enriched in TAGs and total FAs in MYB1-OE transformants. Notably, starch and protein content and biomass production also significantly increased in MYB1-OE transformants compared with that in PL. Furthermore, RT-qPCR results showed that the expressions of key genes involved in TAG, FA, and starch biosynthesis were upregulated. In addition, MYB1-OE transformants showed higher biomass production without a compromised cell growth rate and photosynthetic activity. Overall, our results indicate that MYB1 overexpression not only enhanced lipid content but also improved starch and protein content and biomass production under standard growth conditions. TF MYB1 engineering is a promising genetic engineering tool for biofuel production in microalgae.
Collapse
Affiliation(s)
- Jilong Zhao
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Yunlong Ge
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Keqing Liu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Yasuyo Yamaoka
- Division of Biotechnology, The Catholic University of Korea, Bucheon 14662, Korea
| | - Di Zhang
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Zhanyou Chi
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Mahinur Akkaya
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| | - Fantao Kong
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Kong F, Li M, Liu K, Ge Y, Yamasaki T, Beyly-Adriano A, Ohama T, Li-Beisson Y. Efficient approaches for nuclear transgene stacking in the unicellular green microalga Chlamydomonas reinhardtii. ALGAL RES 2023. [DOI: 10.1016/j.algal.2023.103048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
|
4
|
Co-Expression of Lipid Transporters Simultaneously Enhances Oil and Starch Accumulation in the Green Microalga Chlamydomonas reinhardtii under Nitrogen Starvation. Metabolites 2023; 13:metabo13010115. [PMID: 36677040 PMCID: PMC9866645 DOI: 10.3390/metabo13010115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/31/2022] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
Lipid transporters synergistically contribute to oil accumulation under normal conditions in microalgae; however, their effects on lipid metabolism under stress conditions are unknown. Here, we examined the effect of the co-expression of lipid transporters, fatty acid transporters, (FAX1 and FAX2) and ABC transporter (ABCA2) on lipid metabolism and physiological changes in the green microalga Chlamydomonas under nitrogen (N) starvation. The results showed that the TAG content in FAX1-FAX2-ABCA2 over-expressor (OE) was 2.4-fold greater than in the parental line. Notably, in FAX1-FAX2-ABCA2-OE, the major membrane lipids and the starch and cellular biomass content also significantly increased compared with the control lines. Moreover, the expression levels of genes directly involved in TAG, fatty acid, and starch biosynthesis were upregulated. FAX1-FAX2-ABCA2-OE showed altered photosynthesis activity and increased ROS levels during nitrogen (N) deprivation. Our results indicated that FAX1-FAX2-ABCA2 overexpression not only enhanced cellular lipids but also improved starch and biomass contents under N starvation through modulation of lipid and starch metabolism and changes in photosynthesis activity. The strategy developed here could also be applied to other microalgae to produce FA-derived energy-rich and value-added compounds.
Collapse
|
5
|
Pervaiz R, Khan MA, Raza FA, Ahmad S, Zafar AU, Ahmed N, Akram M. Expression of a mosquito larvicidal gene in chloroplast and nuclear compartments of Chlamydomonas reinhardtii. J Biotechnol 2022; 360:182-191. [PMID: 36368638 DOI: 10.1016/j.jbiotec.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 11/09/2022]
Abstract
As a part of the search for environment-friendly biocontrol of mosquito-borne diseases, mosquito larvicidal potential of Bacillus thuringiensis subsp. jegathesan (Btj) Cry toxins is explored for toxins with increased toxicity. Safe delivery of the Cry toxins to mosquito larvae in aquatic habitats is a major concern. This is because in water bodies Bacillus thuringiensis (Bt) protein formulations degrade by sunlight, can sink down and get adsorbed by the silt. So, because of its short persistence the toxin requires repeated applications at the given site. Therefore, an upcoming approach is incorporating the Bt toxins in Chlamydomonas reinhardtii (C. reinhardtii) because it is a food of mosquito larvae in water and its molecular toolkit is well investigated for foreign gene expression. The present work aimed to compare the feasibility of C. reinhardtii chloroplast and nuclear compartments for stable expression of Cry11Ba toxin as this is the most toxic Btj protein to date, lethal to different mosquito species. With chloroplast expression of cry11Ba gene we were able to generate marker-free C. reinhardtii strain stably expressing Cry11Ba protein and demonstrating mortality against Aedes aegypti larvae. Moreover, for nuclear expression linking the cry11Ba gene to zeocin via foot and mouth disease virus (FMDV) 2A peptide resulted in the selection of transformants with increased cry11Ba mRNA expression levels by semi-quantitative reverse transcriptase PCR. Obtained results lay a foundation for the C. reinhardtii chloroplast expression system to be used for genetic engineering with Bt toxins which possess enhanced toxicity.
Collapse
Affiliation(s)
- Rabbia Pervaiz
- Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Road, Thokar Niaz Baig Sector-1, Lahore 53700, Pakistan.
| | - Mohsin Ahmad Khan
- Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Road, Thokar Niaz Baig Sector-1, Lahore 53700, Pakistan
| | - Faiz Ahmed Raza
- Health Research Institute, National Institute of Health (HRI-NIH), Research Centre, King Edward Medical University, Lahore 54000, Pakistan
| | - Sohail Ahmad
- Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Road, Thokar Niaz Baig Sector-1, Lahore 53700, Pakistan
| | - Ahmad Usman Zafar
- Qarshi University, 8-Km Thokar Niaz Baig, Canal Bank Road, Opposite Izmir Town, Lahore 54000, Pakistan
| | - Nadeem Ahmed
- Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Road, Thokar Niaz Baig Sector-1, Lahore 53700, Pakistan
| | - Maham Akram
- Centre of Excellence in Molecular Biology, University of the Punjab, 87-West Canal Road, Thokar Niaz Baig Sector-1, Lahore 53700, Pakistan
| |
Collapse
|
6
|
Enhanced accumulation of oil through co-expression of fatty acid and ABC transporters in Chlamydomonas under standard growth conditions. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:54. [PMID: 35596223 PMCID: PMC9123788 DOI: 10.1186/s13068-022-02154-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 05/07/2022] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Chloroplast and endoplasmic reticulum (ER)-localized fatty acid (FA) transporters have been reported to play important roles in oil (mainly triacylglycerols, TAG) biosynthesis. However, whether these FA transporters synergistically contribute to lipid accumulation, and their effect on lipid metabolism in microalgae are unknown.
Results
Here, we co-overexpressed two chloroplast-localized FA exporters (FAX1 and FAX2) and one ER-localized FA transporter (ABCA2) in Chlamydomonas. Under standard growth conditions, FAX1/FAX2/ABCA2 over-expression lines (OE) accumulated up to twofold more TAG than the parental strain UVM4, and the total amounts of major polyunsaturated FAs (PUFA) in TAG increased by 4.7-fold. In parallel, the total FA contents and major membrane lipids in FAX1/FAX2/ABCA2-OE also significantly increased compared with those in the control lines. Additionally, the total accumulation contribution ratio of PUFA, to total FA and TAG synthesis in FAX1/FAX2/ABCA2-OE, was 54% and 40% higher than that in UVM4, respectively. Consistently, the expression levels of genes directly involved in TAG synthesis, such as type-II diacylglycerol acyltransferases (DGTT1, DGTT3 and DGTT5), and phospholipid:diacylglycerol acyltransferase 1 (PDAT1), significantly increased, and the expression of PGD1 (MGDG-specific lipase) was upregulated in FAX1/FAX2/ABCA2-OE compared to UVM4.
Conclusion
These results indicate that the increased expression of FAX1/FAX2/ABCA2 has an additive effect on enhancing TAG, total FA and membrane lipid accumulation and accelerates the PUFA remobilization from membrane lipids to TAG by fine-tuning the key genes involved in lipid metabolism under standard growth conditions. Overall, FAX1/FAX2/ABCA2-OE shows better traits for lipid accumulation than the parental line and previously reported individual FA transporter-OE. Our study provides a potential useful strategy to increase the production of FA-derived energy-rich and value-added compounds in microalgae.
Collapse
|
7
|
Kselíková V, Singh A, Bialevich V, Čížková M, Bišová K. Improving microalgae for biotechnology - From genetics to synthetic biology - Moving forward but not there yet. Biotechnol Adv 2021; 58:107885. [PMID: 34906670 DOI: 10.1016/j.biotechadv.2021.107885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/28/2021] [Accepted: 12/07/2021] [Indexed: 12/28/2022]
Abstract
Microalgae are a diverse group of photosynthetic organisms that can be exploited for the production of different compounds, ranging from crude biomass and biofuels to high value-added biochemicals and synthetic proteins. Traditionally, algal biotechnology relies on bioprospecting to identify new highly productive strains and more recently, on forward genetics to further enhance productivity. However, it has become clear that further improvements in algal productivity for biotechnology is impossible without combining traditional tools with the arising molecular genetics toolkit. We review recent advantages in developing high throughput screening methods, preparing genome-wide mutant libraries, and establishing genome editing techniques. We discuss how algae can be improved in terms of photosynthetic efficiency, biofuel and high value-added compound production. Finally, we critically evaluate developments over recent years and explore future potential in the field.
Collapse
Affiliation(s)
- Veronika Kselíková
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic; Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Anjali Singh
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Vitali Bialevich
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Mária Čížková
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Kateřina Bišová
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic.
| |
Collapse
|
8
|
Nouemssi SB, Ghribi M, Beauchemin R, Meddeb-Mouelhi F, Germain H, Desgagné-Penix I. Rapid and Efficient Colony-PCR for High Throughput Screening of Genetically Transformed Chlamydomonas reinhardtii. Life (Basel) 2020; 10:E186. [PMID: 32927613 PMCID: PMC7554959 DOI: 10.3390/life10090186] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/29/2020] [Accepted: 09/08/2020] [Indexed: 01/07/2023] Open
Abstract
Microalgae biotechnologies are rapidly developing into new commercial settings. Several high value products already exist on the market, and biotechnological development is focused on genetic engineering of microalgae to open up future economic opportunities for food, fuel and pharmacological production. Colony-polymerase chain reaction (colony-PCR or cPCR) is a critical method for screening genetically transformed microalgae cells. However, the ability to rapidly screen thousands of transformants using the current colony-PCR method, becomes a very laborious and time-consuming process. Herein, the non-homologous transformation of Chlamydomonas reinhardtii using the electroporation and glass beads methods generated more than seven thousand transformants. In order to manage this impressive number of clones efficiently, we developed a high-throughput screening (HTS) cPCR method to rapidly maximize the detection and selection of positively transformed clones. For this, we optimized the Chlamydomonas transformed cell layout on the culture media to improve genomic DNA extraction and cPCR in 96-well plate. The application of this optimized HTS cPCR method offers a rapid, less expensive and reliable method for the detection and selection of microalgae transformants. Our method, which saves up to 80% of the experimental time, holds promise for evaluating genetically transformed cells and selection for microalgae-based biotechnological applications such as synthetic biology and metabolic engineering.
Collapse
Affiliation(s)
- Serge Basile Nouemssi
- Department of Chemistry, Biochemistry and Physics, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada; (S.B.N.); (M.G.); (R.B.); (F.M.-M.); (H.G.)
| | - Manel Ghribi
- Department of Chemistry, Biochemistry and Physics, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada; (S.B.N.); (M.G.); (R.B.); (F.M.-M.); (H.G.)
| | - Rémy Beauchemin
- Department of Chemistry, Biochemistry and Physics, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada; (S.B.N.); (M.G.); (R.B.); (F.M.-M.); (H.G.)
| | - Fatma Meddeb-Mouelhi
- Department of Chemistry, Biochemistry and Physics, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada; (S.B.N.); (M.G.); (R.B.); (F.M.-M.); (H.G.)
- Groupe de Recherche en Biologie Végétale, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada
| | - Hugo Germain
- Department of Chemistry, Biochemistry and Physics, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada; (S.B.N.); (M.G.); (R.B.); (F.M.-M.); (H.G.)
- Groupe de Recherche en Biologie Végétale, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada
| | - Isabel Desgagné-Penix
- Department of Chemistry, Biochemistry and Physics, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada; (S.B.N.); (M.G.); (R.B.); (F.M.-M.); (H.G.)
- Groupe de Recherche en Biologie Végétale, Université du Québec à Trois-Rivières, 3351, boul. des Forges, C.P. 500, Trois-Rivières, QC G9A 5H7, Canada
| |
Collapse
|
9
|
Achievements and challenges of genetic engineering of the model green alga Chlamydomonas reinhardtii. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101986] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
10
|
Effect of biphasic temperature regime on therapeutic recombinant protein production in the green alga Chlamydomonas reinhardtii. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
11
|
Metabolic engineering of ketocarotenoids biosynthetic pathway in Chlamydomonas reinhardtii strain CC-4102. Sci Rep 2020; 10:10688. [PMID: 32612116 PMCID: PMC7329852 DOI: 10.1038/s41598-020-67756-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 05/29/2020] [Indexed: 11/23/2022] Open
Abstract
In Chlamydomonas reinhardtii, ketocarotenoid biosynthesis is limited to the diploid zygospore stage. In this study, we attempted to engineer the ketocarotenoid pathway into Chlamydomonas haploid vegetative green cells by overexpressing the key enzyme ß-carotene ketolase (CrBKT). We chose strain CC-4102 for the approach; competitive pathways, α-carotene biosynthesis and xanthophyll cycle are silenced in this strain. Driven by the strong constitutive HSP70/RBCS2 promoter CrBKT overexpression resulted in the production of canthaxanthin, the ketolation product from ß-carotene as well as a drastic reduction in the chlorophyll concentration. Intriguingly, these phenotypes could only be detected from lines transformed and grown heterotrophically in the dark. Once exposed to light, these transformants lost the aforementioned phenotypes as well as their antibiotic resistance. This phenomenon is in agreement with the fact that we were unable to recover any canthaxanthin-producing line among light-selected transformants.
Collapse
|
12
|
Molina-Márquez A, Vila M, Rengel R, Fernández E, García-Maroto F, Vigara J, León R. Validation of a New Multicistronic Plasmid for the Efficient and Stable Expression of Transgenes in Microalgae. Int J Mol Sci 2020; 21:E718. [PMID: 31979077 PMCID: PMC7037629 DOI: 10.3390/ijms21030718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 11/16/2022] Open
Abstract
Low stability of transgenes and high variability of their expression levels among the obtained transformants are still pending challenges in the nuclear genetic transformation of microalgae. We have generated a new multicistronic microalgal expression plasmid, called Phyco69, to make easier the large phenotypic screening usually necessary for the selection of high-expression stable clones. This plasmid contains a polylinker region (PLK) where any gene of interest (GOI) can be inserted and get linked, through a short viral self-cleaving peptide to the amino terminus of the aminoglycoside 3'-phosphotransferase (APHVIII) from Streptomyces rimosus, which confers resistance to the antibiotic paromomycin. The plasmid has been validated by expressing a second antibiotic resistance marker, the ShBLE gene, which confers resistance to phleomycin. It has been shown, by RT-PCR and by phenotypic studies, that the fusion of the GOI to the selective marker gene APHVIII provides a simple method to screen and select the transformants with the highest level of expression of both the APHVIII gene and the GOI among the obtained transformants. Immunodetection studies have shown that the multicistronic transcript generated from Phyco69 is correctly processed, producing independent gene products from a common promoter.
Collapse
Affiliation(s)
- Ana Molina-Márquez
- Laboratory of Biochemistry. Faculty of Experimental Sciences. Marine International Campus of Excellence and RENSMA. University of Huelva, 21071 Huelva, Spain; (M.V.); (R.R.); (J.V.); (R.L.)
| | - Marta Vila
- Laboratory of Biochemistry. Faculty of Experimental Sciences. Marine International Campus of Excellence and RENSMA. University of Huelva, 21071 Huelva, Spain; (M.V.); (R.R.); (J.V.); (R.L.)
| | - Rocío Rengel
- Laboratory of Biochemistry. Faculty of Experimental Sciences. Marine International Campus of Excellence and RENSMA. University of Huelva, 21071 Huelva, Spain; (M.V.); (R.R.); (J.V.); (R.L.)
| | - Emilio Fernández
- Department of Biochemistry and Molecular Biology. University of Córdoba, 14071 Córdoba, Spain;
| | - Federico García-Maroto
- Laboratory of Biotechnology of Natural Products, Agro-feed International Excellence campus, University of Almería, 04071 Almería, Spain;
| | - Javier Vigara
- Laboratory of Biochemistry. Faculty of Experimental Sciences. Marine International Campus of Excellence and RENSMA. University of Huelva, 21071 Huelva, Spain; (M.V.); (R.R.); (J.V.); (R.L.)
| | - Rosa León
- Laboratory of Biochemistry. Faculty of Experimental Sciences. Marine International Campus of Excellence and RENSMA. University of Huelva, 21071 Huelva, Spain; (M.V.); (R.R.); (J.V.); (R.L.)
| |
Collapse
|
13
|
Good News for Nuclear Transgene Expression in Chlamydomonas. Cells 2019; 8:cells8121534. [PMID: 31795196 PMCID: PMC6952782 DOI: 10.3390/cells8121534] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 11/13/2019] [Accepted: 11/25/2019] [Indexed: 12/20/2022] Open
Abstract
Chlamydomonas reinhardtii is a well-established model system for basic research questions ranging from photosynthesis and organelle biogenesis, to the biology of cilia and basal bodies, to channelrhodopsins and photoreceptors. More recently, Chlamydomonas has also been recognized as a suitable host for the production of high-value chemicals and high-value recombinant proteins. However, basic and applied research have suffered from the inefficient expression of nuclear transgenes. The combined efforts of the Chlamydomonas community over the past decades have provided insights into the mechanisms underlying this phenomenon and have resulted in mutant strains defective in some silencing mechanisms. Moreover, many insights have been gained into the parameters that affect nuclear transgene expression, like promoters, introns, codon usage, or terminators. Here I critically review these insights and try to integrate them into design suggestions for the construction of nuclear transgenes that are to be expressed at high levels.
Collapse
|
14
|
Kong F, Yamaoka Y, Ohama T, Lee Y, Li-Beisson Y. Molecular Genetic Tools and Emerging Synthetic Biology Strategies to Increase Cellular Oil Content in Chlamydomonas reinhardtii. PLANT & CELL PHYSIOLOGY 2019; 60:1184-1196. [PMID: 30715500 DOI: 10.1093/pcp/pcz022] [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: 11/13/2018] [Accepted: 01/18/2019] [Indexed: 05/26/2023]
Abstract
Microalgae constitute a highly diverse group of eukaryotic and photosynthetic microorganisms that have developed extremely efficient systems for harvesting and transforming solar energy into energy-rich molecules such as lipids. Although microalgae are considered to be one of the most promising platforms for the sustainable production of liquid oil, the oil content of these organisms is naturally low, and algal oil production is currently not economically viable. Chlamydomonas reinhardtii (Chlamydomonas) is an established algal model due to its fast growth, high transformation efficiency, and well-understood physiology and to the availability of detailed genome information and versatile molecular tools for this organism. In this review, we summarize recent advances in the development of genetic manipulation tools for Chlamydomonas, from gene delivery methods to state-of-the-art genome-editing technologies and fluorescent dye-based high-throughput mutant screening approaches. Furthermore, we discuss practical strategies and toolkits that enhance transgene expression, such as choice of expression vector and background strain. We then provide examples of how advanced genetic tools have been used to increase oil content in Chlamydomonas. Collectively, the current literature indicates that microalgal oil content can be increased by overexpressing key enzymes that catalyze lipid biosynthesis, blocking lipid degradation, silencing metabolic pathways that compete with lipid biosynthesis and modulating redox state. The tools and knowledge generated through metabolic engineering studies should pave the way for developing a synthetic biological approach to enhance lipid productivity in microalgae.
Collapse
Affiliation(s)
- Fantao Kong
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China
| | - Yasuyo Yamaoka
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
| | - Takeshi Ohama
- School of Environmental Science and Engineering, Kochi University of Technology (KUT), Tosayamada, Kochi, Japan
| | - Youngsook Lee
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea
| | - Yonghua Li-Beisson
- Aix-Marseille Univ., CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F, France
| |
Collapse
|
15
|
Suttangkakul A, Sirikhachornkit A, Juntawong P, Puangtame W, Chomtong T, Srifa S, Sathitnaitham S, Dumrongthawatchai W, Jariyachawalid K, Vuttipongchaikij S. Evaluation of strategies for improving the transgene expression in an oleaginous microalga Scenedesmus acutus. BMC Biotechnol 2019; 19:4. [PMID: 30630453 PMCID: PMC6327543 DOI: 10.1186/s12896-018-0497-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 12/25/2018] [Indexed: 01/04/2023] Open
Abstract
Background Genetic transformation of microalgae has been hampered by inefficient transgene expression, limiting the progress of microalgal biotechnology. Many vector tools and strategies have been developed in recent years to improve transgene expression in the model microalga Chlamydomonas, but these were hardly applied to other microalgae. In this work, naturally-isolated oleaginous microalgae were accessed for genetic transformation, and various expression systems were evaluated in a selected microalga to circumvent inefficient transgene expression. Results Initially, a strain of Scenedesmus acutus was selected from the oleaginous microalgal collection based on its highest transformation rate and transgene stability. This strain, which had very low or no GFP reporter expression, was first tested to improve transgene expression by using intron-containing constructs and the transcript fusion using ble::E2A. The intron-containing constructs yielded 2.5–7.5% of transformants with 2–4-fold fluorescence signals, while the majority of the transformants of the transcript fusion had the fluorescence signals up to 10-fold. Subsequently, three UV-induced S. acutus mutants were isolated with moderate increases in the level and frequency of transgene expression (2–3-fold and 10–12%, respectively). Finally, a transcript fusion system was developed using psy white mutants with an expression vector containing PSY::E2A for complementation and light selection. Transformants with green colonies were selected under light exposure, and the transgene expression was detected at protein levels. Although the improvement using PSY::E2A was only minor (1–2-fold increase and ~ 7% of transformants), this system provides an alternative selectable marker that is compatible with large-scale culture. Conclusions Here, the overall improvement of transgene expression using the Chlamydomonas tools was moderate. The most effective tool so far is the transcript fusion using ble::E2A system. This work demonstrates that, so far, genetic engineering of non-model microalgae is still a challenging task. Further development of tools and strategies for transgene expression in microalgae are critically needed. Electronic supplementary material The online version of this article (10.1186/s12896-018-0497-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Anongpat Suttangkakul
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand.,Center of Advanced studies for Tropical Natural Resources, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand
| | - Anchalee Sirikhachornkit
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand.,Center of Advanced studies for Tropical Natural Resources, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand
| | - Piyada Juntawong
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand.,Center of Advanced studies for Tropical Natural Resources, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand
| | - Wilasinee Puangtame
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand
| | - Thitikorn Chomtong
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand
| | - Suchada Srifa
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand
| | - Sukhita Sathitnaitham
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand
| | - Wasawat Dumrongthawatchai
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand
| | - Kanidtha Jariyachawalid
- PTT Research and Technology Institute, PTT Public Company Limited, Ayuthaya, 13170, Thailand
| | - Supachai Vuttipongchaikij
- Special Research Unit in Microalgal Molecular Genetics and Functional Genomics (MMGFG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand. .,Center of Advanced studies for Tropical Natural Resources, Kasetsart University, 50 Ngam Wong Wan road, Chatuchak, Bangkok, 10900, Thailand.
| |
Collapse
|
16
|
Baier T, Wichmann J, Kruse O, Lauersen KJ. Intron-containing algal transgenes mediate efficient recombinant gene expression in the green microalga Chlamydomonas reinhardtii. Nucleic Acids Res 2018; 46:6909-6919. [PMID: 30053227 PMCID: PMC6061784 DOI: 10.1093/nar/gky532] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/16/2018] [Accepted: 06/08/2018] [Indexed: 12/27/2022] Open
Abstract
Among green freshwater microalgae, Chlamydomonas reinhardtii has the most comprehensive and developed molecular toolkit, however, advanced genetic and metabolic engineering driven from the nuclear genome is generally hindered by inherently low transgene expression levels. Progressive strain development and synthetic promoters have improved the capacity of transgene expression; however, the responsible regulatory mechanisms are still not fully understood. Here, we elucidate the sequence specific dynamics of native regulatory element insertion into nuclear transgenes. Systematic insertions of the first intron of the ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit 2 (rbcS2i1) throughout codon-optimized coding sequences (CDS) generates optimized algal transgenes which express reliably in C. reinhardtii. The optimal rbcS2i1 insertion site for efficient splicing was systematically determined and improved gene expression rates were shown using a codon-optimized sesquiterpene synthase CDS. Sequential insertions of rbcS2i1 were found to have a step-wise additive effect on all levels of transgene expression, which is likely correlated to a synergy of transcriptional machinery recruitment and mimicking the short average exon lengths natively found in the C. reinhardtii genome. We further demonstrate the value of this optimization with five representative transgene examples and provide guidelines for the design of any desired sequence with this strategy.
Collapse
MESH Headings
- Abies/enzymology
- Abies/genetics
- Chlamydomonas reinhardtii/genetics
- Codon/genetics
- DNA, Plant/genetics
- DNA, Recombinant/genetics
- Gene Expression Regulation, Plant
- Genes, Plant
- Genes, Synthetic
- Introns
- Isomerases/biosynthesis
- Isomerases/genetics
- Mutagenesis, Insertional
- Plant Proteins/biosynthesis
- Plant Proteins/genetics
- Pogostemon/enzymology
- Pogostemon/genetics
- Protein Engineering
- RNA Splicing
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Recombinant Proteins/biosynthesis
- Ribulose-Bisphosphate Carboxylase/genetics
- Transgenes
Collapse
Affiliation(s)
- Thomas Baier
- Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universitätsstrasse 27, 33615 Bielefeld, Germany
| | - Julian Wichmann
- Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universitätsstrasse 27, 33615 Bielefeld, Germany
| | - Olaf Kruse
- Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universitätsstrasse 27, 33615 Bielefeld, Germany
| | - Kyle J Lauersen
- Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universitätsstrasse 27, 33615 Bielefeld, Germany
| |
Collapse
|
17
|
Comparison of secretory signal peptides for heterologous protein expression in microalgae: Expanding the secretion portfolio for Chlamydomonas reinhardtii. PLoS One 2018; 13:e0192433. [PMID: 29408937 PMCID: PMC5800701 DOI: 10.1371/journal.pone.0192433] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 01/22/2018] [Indexed: 12/22/2022] Open
Abstract
Efficient protein secretion is a desirable trait for any recombinant protein expression system, together with simple, low-cost, and defined media, such as the typical media used for photosynthetic cultures of microalgae. However, low titers of secreted heterologous proteins are usually obtained, even with the most extensively studied microalga Chlamydomonas reinhardtii, preventing their industrial application. In this study, we aimed to expand and evaluate secretory signal peptides (SP) for heterologous protein secretion in C. reinhardtii by comparing previously described SP with untested sequences. We compared the SPs from arylsulfatase 1 and carbonic anhydrase 1, with those of untried SPs from binding protein 1, an ice-binding protein, and six sequences identified in silico. We identified over 2000 unique SPs using the SignalP 4.0 software. mCherry fluorescence was used to compare the protein secretion of up to 96 colonies for each construct, non-secretion construct, and parental wild-type cc1690 cells. Supernatant fluorescence varied according to the SP used, with a 10-fold difference observed between the highest and lowest secretors. Moreover, two SPs identified in silico secreted the highest amount of mCherry. Our results demonstrate that the SP should be carefully selected and that efficient sequences can be coded in the C. reinhardtii genome. The SPs described here expand the portfolio available for research on heterologous protein secretion and for biomanufacturing applications.
Collapse
|
18
|
Kong F, Li-Beisson Y. Identification of Insertion Site by RESDA-PCR in Chlamydomonas Mutants Generated by AphVIII Random Insertional Mutagenesis. Bio Protoc 2018; 8:e2718. [PMID: 34179256 DOI: 10.21769/bioprotoc.2718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/16/2018] [Accepted: 01/18/2018] [Indexed: 11/02/2022] Open
Abstract
Chlamydomonas reinhardtii is frequently used as a model organism to study fundamental processes in photosynthesis, metabolism, and flagellar biology. Versatile tool boxes have been developed for this alga ( Fuhrmann et al., 1999 ; Schroda et al., 2000 ; Schroda, 2006). Among them, forward genetic approach has been intensively used, mostly because of the high efficiency in the generation of hundreds of thousands of mutants by random insertional mutagenesis and the haploid nature therefore phenotypic analysis can be done in the first generation ( Cagnon et al., 2013 ; Tunçay et al., 2013 ). A major bottleneck in the application of high throughput methods in a forward genetic approach is the identification of the genetic lesion(s) responsible for the observed phenotype. In this protocol, we describe in detail an improved version of the restriction enzyme site-directed amplification PCR (RESDA-PCR) originally reported in (González- Ballester et al., 2005 ). The improvement includes optimization of primer combination, the choice of DNA polymerase, optimization of PCR cycle parameters, and application of direct sequencing of the PCR products. These modifications make it easier to get specific PCR products as well as speeding up subcloning steps to obtain sequencing data faster.
Collapse
Affiliation(s)
- Fantao Kong
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et Biotechnologie, CEA Cadarache, Saint-Paul-lez-Durance, France.,Centre National de la Recherche Scientifique, UMR7265, Saint-Paul-lez-Durance, France.,Aix-Marseille Université, UMR7265, Marseille, France
| | - Yonghua Li-Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et Biotechnologie, CEA Cadarache, Saint-Paul-lez-Durance, France.,Centre National de la Recherche Scientifique, UMR7265, Saint-Paul-lez-Durance, France.,Aix-Marseille Université, UMR7265, Marseille, France
| |
Collapse
|
19
|
Uchida H, Kato K, Suzuki K, Yokota A, Kawano S, Matsunaga S, Okada S. Algal Genes Encoding Enzymes for Photosynthesis and Hydrocarbon Biosynthesis as Candidates for Genetic Engineering. CYTOLOGIA 2018. [DOI: 10.1508/cytologia.83.7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Hidenobu Uchida
- Graduate School of Agricultural and Life Sciences, The University of Tokyo
| | - Ko Kato
- Graduate School of Biological Sciences, Nara Institute of Science and Technology
| | - Kensaku Suzuki
- Tohoku Agricultural Research Center, National Agriculture and Food Research Organization
| | - Akiho Yokota
- Graduate School of Biological Sciences, Nara Institute of Science and Technology
| | - Shigeyuki Kawano
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo
| | - Shigeki Matsunaga
- Graduate School of Agricultural and Life Sciences, The University of Tokyo
| | - Shigeru Okada
- Graduate School of Agricultural and Life Sciences, The University of Tokyo
| |
Collapse
|
20
|
Ramos‐Martinez EM, Fimognari L, Sakuragi Y. High-yield secretion of recombinant proteins from the microalga Chlamydomonas reinhardtii. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:1214-1224. [PMID: 28207991 PMCID: PMC5552477 DOI: 10.1111/pbi.12710] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 02/07/2017] [Accepted: 02/12/2017] [Indexed: 05/11/2023]
Abstract
Microalga-based biomanufacturing of recombinant proteins is attracting growing attention due to its advantages in safety, metabolic diversity, scalability and sustainability. Secretion of recombinant proteins can accelerate the use of microalgal platforms by allowing post-translational modifications and easy recovery of products from the culture media. However, currently, the yields of secreted recombinant proteins are low, which hampers the commercial application of this strategy. This study aimed at expanding the genetic tools for enhancing secretion of recombinant proteins in Chlamydomonas reinhardtii, a widely used green microalga as a model organism and a potential industrial biotechnology platform. We demonstrated that the putative signal sequence from C. reinhardtii gametolysin can assist the secretion of the yellow fluorescent protein Venus into the culture media. To increase the secretion yields, Venus was C-terminally fused with synthetic glycomodules comprised of tandem serine (Ser) and proline (Pro) repeats of 10 and 20 units [hereafter (SP)n , wherein n = 10 or 20]. The yields of the (SP)n -fused Venus were higher than Venus without the glycomodule by up to 12-fold, with the maximum yield of 15 mg/L. Moreover, the presence of the glycomodules conferred an enhanced proteolytic protein stability. The Venus-(SP)n proteins were shown to be glycosylated, and a treatment of the cells with brefeldin A led to a suggestion that glycosylation of the (SP)n glycomodules starts in the endoplasmic reticulum (ER). Taken together, the results demonstrate the utility of the gametolysin signal sequence and (SP)n glycomodule to promote a more efficient biomanufacturing of microalgae-based recombinant proteins.
Collapse
Affiliation(s)
- Erick Miguel Ramos‐Martinez
- Department of Plant and Environmental SciencesCopenhagen Plant Science CentreUniversity of CopenhagenFrederiksberg C, CopenhagenDenmark
| | - Lorenzo Fimognari
- Department of Plant and Environmental SciencesCopenhagen Plant Science CentreUniversity of CopenhagenFrederiksberg C, CopenhagenDenmark
| | - Yumiko Sakuragi
- Department of Plant and Environmental SciencesCopenhagen Plant Science CentreUniversity of CopenhagenFrederiksberg C, CopenhagenDenmark
| |
Collapse
|
21
|
Shrestha RP, Hildebrand M. Development of a silicon limitation inducible expression system for recombinant protein production in the centric diatoms Thalassiosira pseudonana and Cyclotella cryptica. Microb Cell Fact 2017; 16:145. [PMID: 28818078 PMCID: PMC5561644 DOI: 10.1186/s12934-017-0760-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/10/2017] [Indexed: 01/03/2023] Open
Abstract
Background An inducible promoter for recombinant protein expression provides substantial benefits because under induction conditions cellular energy and metabolic capability can be directed into protein synthesis. The most widely used inducible promoter for diatoms is for nitrate reductase, however, nitrogen metabolism is tied into diverse aspects of cellular function, and the induction response is not necessarily robust. Silicon limitation offers a means to eliminate energy and metabolic flux into cell division processes, with little other detrimental effect on cellular function, and a protein expression system that works under those conditions could be advantageous. Results In this study, we evaluate a number of promoters for recombinant protein expression induced by silicon limitation and repressed by the presence of silicon in the diatoms Thalassiosira pseudonana and Cyclotella cryptica. In addition to silicon limitation, we describe additional strategies to elevate recombinant protein expression level, including inclusion of the 5′ fragment of the coding region of the native gene and reducing carbon flow into ancillary processes of pigment synthesis and formation of photosynthetic storage products. We achieved yields of eGFP to 1.8% of total soluble protein in C. cryptica, which is about 3.6-fold higher than that obtained with chloroplast expression and ninefold higher than nuclear expression in another well-established algal system. Conclusions Our studies demonstrate that the combination of inducible promoter and other strategies can result in robust expression of recombinant protein in a nuclear-based expression system in diatoms under silicon limited conditions, separating the protein expression regime from growth processes and improving overall recombinant protein yields. Electronic supplementary material The online version of this article (doi:10.1186/s12934-017-0760-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Roshan P Shrestha
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Mark Hildebrand
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
| |
Collapse
|
22
|
Kong F, Liang Y, Légeret B, Beyly-Adriano A, Blangy S, Haslam RP, Napier JA, Beisson F, Peltier G, Li-Beisson Y. Chlamydomonas carries out fatty acid β-oxidation in ancestral peroxisomes using a bona fide acyl-CoA oxidase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:358-371. [PMID: 28142200 DOI: 10.1111/tpj.13498] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 01/25/2017] [Accepted: 01/27/2017] [Indexed: 05/03/2023]
Abstract
Peroxisomes are thought to have played a key role in the evolution of metabolic networks of photosynthetic organisms by connecting oxidative and biosynthetic routes operating in different compartments. While the various oxidative pathways operating in the peroxisomes of higher plants are fairly well characterized, the reactions present in the primitive peroxisomes (microbodies) of algae are poorly understood. Screening of a Chlamydomonas insertional mutant library identified a strain strongly impaired in oil remobilization and defective in Cre05.g232002 (CrACX2), a gene encoding a member of the acyl-CoA oxidase/dehydrogenase superfamily. The purified recombinant CrACX2 expressed in Escherichia coli catalyzed the oxidation of fatty acyl-CoAs into trans-2-enoyl-CoA and produced H2 O2 . This result demonstrated that CrACX2 is a genuine acyl-CoA oxidase, which is responsible for the first step of the peroxisomal fatty acid (FA) β-oxidation spiral. A fluorescent protein-tagging study pointed to a peroxisomal location of CrACX2. The importance of peroxisomal FA β-oxidation in algal physiology was shown by the impact of the mutation on FA turnover during day/night cycles. Moreover, under nitrogen depletion the mutant accumulated 20% more oil than the wild type, illustrating the potential of β-oxidation mutants for algal biotechnology. This study provides experimental evidence that a plant-type FA β-oxidation involving H2 O2 -producing acyl-CoA oxidation activity has already evolved in the microbodies of the unicellular green alga Chlamydomonas reinhardtii.
Collapse
Affiliation(s)
- Fantao Kong
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Yuanxue Liang
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Bertrand Légeret
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Audrey Beyly-Adriano
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Stéphanie Blangy
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Richard P Haslam
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK
| | - Johnathan A Napier
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK
| | - Fred Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Gilles Peltier
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Yonghua Li-Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| |
Collapse
|
23
|
A novel bicistronic expression system composed of the intraflagellar transport protein gene ift25 and FMDV 2A sequence directs robust nuclear gene expression in Chlamydomonas reinhardtii. Appl Microbiol Biotechnol 2017; 101:4227-4245. [DOI: 10.1007/s00253-017-8177-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 10/20/2022]
|
24
|
Robust Transgene Expression from Bicistronic mRNA in the Green Alga Chlamydomonas reinhardtii. G3-GENES GENOMES GENETICS 2016; 6:4115-4125. [PMID: 27770025 PMCID: PMC5144980 DOI: 10.1534/g3.116.033035] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The unicellular green alga Chlamydomonas reinhardtii is a model organism that provides an opportunity to understand the evolution and functional biology of the lineage that includes the land plants, as well as aspects of the fundamental core biology conserved throughout the eukaryotic phylogeny. Although many tools are available to facilitate genetic, molecular biological, biochemical, and cell biological studies in Chlamydomonas, expression of unselected transgenes of interest (GOIs) has been challenging. In most methods used previously, the GOI and a selectable marker are expressed from two separate mRNAs, so that their concomitant expression is not guaranteed. In this study, we developed constructs that allow expression of an upstream GOI and downstream selectable marker from a single bicistronic mRNA. Although this approach in other systems has typically required a translation-enhancing element such as an internal ribosome entry site for the downstream marker, we found that a short stretch of unstructured junction sequence was sufficient to obtain adequate expression of the downstream gene, presumably through post-termination reinitiation. With this system, we obtained robust expression of both endogenous and heterologous GOIs, including fluorescent proteins and tagged fusion proteins, in the vast majority of transformants, thus eliminating the need for tedious secondary screening for GOI-expressing transformants. This improved efficiency should greatly facilitate a variety of genetic and cell-biological studies in Chlamydomonas and also enable new applications such as expression-based screens and large-scale production of foreign proteins.
Collapse
|
25
|
Kurniasih SD, Yamasaki T, Kong F, Okada S, Widyaningrum D, Ohama T. UV-mediated Chlamydomonas mutants with enhanced nuclear transgene expression by disruption of DNA methylation-dependent and independent silencing systems. PLANT MOLECULAR BIOLOGY 2016; 92:629-641. [PMID: 27761764 DOI: 10.1007/s11103-016-0529-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 08/10/2016] [Indexed: 06/06/2023]
Abstract
In this investigation, we succeeded to generate Chlamydomonas mutants that bear dramatically enhanced ability for transgene expression. To yield these mutants, we utilized DNA methyltransferase deficient strain. These mutants must be useful as a plant cell factory. Chlamydomonas reinhardtii (hereafter Chlamydomonas) is a green freshwater microalga. It is a promising cell factory for the production of recombinant proteins because it rapidly grows in simple salt-based media. However, expression of transgenes integrated into the nuclear genome of Chlamydomonas is very poor, probably because of severe transcriptional silencing irrespective of the genomic position. In this study, we generated Chlamydomonas mutants by ultraviolet (UV)-mediated mutagenesis of maintenance-type DNA methyltransferase gene (MET1)-null mutants to overcome this disadvantage. We obtained several mutants with an enhanced ability to overexpress various transgenes irrespective of their integrated genomic positions. In addition, transformation efficiencies were significantly elevated. Our findings indicate that in addition to mechanisms involving MET1, transgene expression is regulated by a DNA methylation-independent transgene silencing system in Chlamydomonas. This is in agreement with the fact that DNA methylation occurs rarely in this organism. The generated mutants may be useful for the low-cost production of therapeutic proteins and eukaryotic enzymes based on their rapid growth in simple salt-based media.
Collapse
Affiliation(s)
- Sari Dewi Kurniasih
- School of Environmental Science and Engineering, Kochi University of Technology, Tosayamada, Kochi, 782-8502, Japan
| | - Tomohito Yamasaki
- School of Environmental Science and Engineering, Kochi University of Technology, Tosayamada, Kochi, 782-8502, Japan
| | - Fantao Kong
- School of Environmental Science and Engineering, Kochi University of Technology, Tosayamada, Kochi, 782-8502, Japan
| | - Sigeru Okada
- Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural & Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Dwiyantari Widyaningrum
- School of Environmental Science and Engineering, Kochi University of Technology, Tosayamada, Kochi, 782-8502, Japan
| | - Takeshi Ohama
- School of Environmental Science and Engineering, Kochi University of Technology, Tosayamada, Kochi, 782-8502, Japan.
| |
Collapse
|
26
|
Current advances in molecular, biochemical, and computational modeling analysis of microalgal triacylglycerol biosynthesis. Biotechnol Adv 2016; 34:1046-1063. [DOI: 10.1016/j.biotechadv.2016.06.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/08/2016] [Accepted: 06/12/2016] [Indexed: 12/12/2022]
|