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Rajput BK, Ikram SF, Tripathi BN. Harnessing the potential of microalgae for the production of monoclonal antibodies and other recombinant proteins. PROTOPLASMA 2024:10.1007/s00709-024-01967-6. [PMID: 38970700 DOI: 10.1007/s00709-024-01967-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 06/25/2024] [Indexed: 07/08/2024]
Abstract
Monoclonal antibodies (mAbs) have become indispensable tools in various fields, from research to therapeutics, diagnostics, and industries. However, their production, primarily in mammalian cell culture systems, is cost-intensive and resource-demanding. Microalgae, diverse photosynthetic microorganisms, are gaining attention as a favorable option for manufacturing mAbs and various other recombinant proteins. This review explores the potential of microalgae as a robust expression system for biomanufacturing high-value proteins. It also highlights the diversity of microalgae species suitable for recombinant protein. Nuclear and chloroplast genomes of some microalgae have been engineered to express mAbs and other valuable proteins. Codon optimization, vector construction, and other genetic engineering techniques have significantly improved recombinant protein expression in microalgae. These accomplishments demonstrate the potential of microalgae for biopharmaceutical manufacturing. Microalgal biotechnology holds promise for revolutionizing the production of mAbs and other therapeutic proteins, offering a sustainable and cost-effective solution to address critical healthcare needs.
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Affiliation(s)
- Balwinder Kaur Rajput
- Department of Biotechnology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh, 484887, India
| | - Sana Fatima Ikram
- Department of Biotechnology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh, 484887, India
| | - Bhumi Nath Tripathi
- Department of Biotechnology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh, 484887, India.
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2
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Walker EJL, Pampuch M, Chang N, Cochrane RR, Karas BJ. Design and assembly of the 117-kb Phaeodactylum tricornutum chloroplast genome. PLANT PHYSIOLOGY 2024; 194:2217-2228. [PMID: 38114089 PMCID: PMC10980414 DOI: 10.1093/plphys/kiad670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 11/02/2023] [Accepted: 11/27/2023] [Indexed: 12/21/2023]
Abstract
There is growing impetus to expand the repertoire of chassis available to synthetic biologists. Chloroplast genomes present an interesting alternative for engineering photosynthetic eukaryotes; however, development of the chloroplast as a synthetic biology chassis has been limited by a lack of efficient techniques for whole-genome cloning and engineering. Here, we demonstrate two approaches for cloning the 117-kb Phaeodactylum tricornutum chloroplast genome that have 90% to 100% efficiency when screening as few as 10 yeast (Saccharomyces cerevisiae) colonies following yeast assembly. The first method reconstitutes the genome from PCR-amplified fragments, whereas the second method involves precloning these fragments into individual plasmids from which they can later be released. In both cases, overlapping fragments of the chloroplast genome and a cloning vector are homologously recombined into a singular contig through yeast assembly. The cloned chloroplast genome can be stably maintained and propagated within Escherichia coli, which provides an exciting opportunity for engineering a delivery mechanism for bringing DNA directly to the algal chloroplast. Also, one of the cloned genomes was designed to contain a single SapI site within the yeast URA3 (coding for orotidine-5'-phosphate decarboxylase) open-reading frame, which can be used to linearize the genome and integrate designer cassettes via golden-gate cloning or further iterations of yeast assembly. The methods presented here could be extrapolated to other species-particularly those with a similar chloroplast genome size and architecture (e.g. Thalassiosira pseudonana).
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Affiliation(s)
- Emma J L Walker
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Mark Pampuch
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Nelson Chang
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Ryan R Cochrane
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
| | - Bogumil J Karas
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5C1, Canada
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3
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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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Sheludko YV, Gerasymenko IM, Herrmann FJ, Warzecha H. Evaluation of biotransformation capacity of transplastomic plants and hairy roots of Nicotiana tabacum expressing human cytochrome P450 2D6. Transgenic Res 2022; 31:351-368. [PMID: 35416604 PMCID: PMC9135824 DOI: 10.1007/s11248-022-00305-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 03/19/2022] [Indexed: 11/24/2022]
Abstract
Cytochrome P450 monooxygenases (CYPs) are important tools for regio- and stereoselective oxidation of target molecules or engineering of metabolic pathways. Functional heterologous expression of eukaryotic CYPs is often problematic due to their dependency on the specific redox partner and the necessity of correct association with the membranes for displaying enzymatic activity. Plant hosts offer advantages of accessibility of reducing partners and a choice of membranes to insert heterologous CYPs. For the evaluation of plant systems for efficient CYP expression, we established transplastomic plants and hairy root cultures of Nicotiana tabacum carrying the gene encoding human CYP2D6 with broad substrate specificity. The levels of CYP2D6 transcript accumulation and enzymatic activity were estimated and compared with the data of CYP2D6 transient expression in N. benthamiana. The relative level of CYP2D6 transcripts in transplastomic plants was 2-3 orders of magnitude higher of that observed after constitutive or transient expression from the nucleus. CYP2D6 expressed in chloroplasts converted exogenous synthetic substrate loratadine without the need for co-expression of the cognate CYP reductase. The loratadine conversion rate in transplastomic plants was comparable to that in N. benthamiana plants transiently expressing a chloroplast targeted CYP2D6 from the nucleus, but was lower than the value reported for transiently expressed CYP2D6 with the native endoplasmic reticulum signal-anchor sequence. Hairy roots showed the lowest substrate conversion rate, but demonstrated the ability to release the product into the culture medium. The obtained results illustrate the potential of plant-based expression systems for exploiting the enzymatic activities of eukaryotic CYPs with broad substrate specificities.
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Affiliation(s)
- Y V Sheludko
- Plant Biotechnology and Metabolic Engineering, Technical University of Darmstadt, 64287, Darmstadt, Germany.
- Centre for Synthetic Biology, Technical University of Darmstadt, 64287, Darmstadt, Germany.
- Department of Organic Chemistry and Biochemistry, Technical University of Darmstadt, 64287, Darmstadt, Germany.
| | - I M Gerasymenko
- Plant Biotechnology and Metabolic Engineering, Technical University of Darmstadt, 64287, Darmstadt, Germany
- Centre for Synthetic Biology, Technical University of Darmstadt, 64287, Darmstadt, Germany
| | - F J Herrmann
- Plant Biotechnology and Metabolic Engineering, Technical University of Darmstadt, 64287, Darmstadt, Germany
- Centre for Synthetic Biology, Technical University of Darmstadt, 64287, Darmstadt, Germany
| | - H Warzecha
- Plant Biotechnology and Metabolic Engineering, Technical University of Darmstadt, 64287, Darmstadt, Germany
- Centre for Synthetic Biology, Technical University of Darmstadt, 64287, Darmstadt, Germany
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Overcoming Poor Transgene Expression in the Wild-Type Chlamydomonas Chloroplast: Creation of Highly Mosquitocidal Strains of Chlamydomonas reinhardtii. Microorganisms 2022; 10:microorganisms10061087. [PMID: 35744605 PMCID: PMC9229432 DOI: 10.3390/microorganisms10061087] [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: 04/26/2022] [Revised: 05/19/2022] [Accepted: 05/21/2022] [Indexed: 12/10/2022] Open
Abstract
High-level expression of transgenes in the chloroplast of wild-type Chlamydomonas reinhardtii (C. reinhardtii) remains challenging for many genes (e.g., the cry toxin genes from Bacillus thuringiensis israelensis). The bottleneck is presumed to be post-transcriptional and mediated by the 5′ element and the coding region. Using 5′ elements from highly expressed photosynthesis genes such as atpA did not improve the outcome with cry11A regardless of the promoter. However, when we employed the 5′ UTR from mature rps4 mRNA with clean fusions to promoters, production of the rCry11A protein became largely promoter-dependent. The best results were obtained with the native 16S rrn promoter (−91 to −1). When it was fused to the mature 5′ rps4 UTR, rCry11A protein levels were ~50% higher than was obtained with the inducible system, or ~0.6% of total protein. This level was sufficient to visualize the 73-kDa rCry11A protein on Coomassie-stained gels of total algal protein. In addition, analysis of the expression of these transgenes by RT-PCR indicated that RNA levels roughly correlated with protein production. Live cell bioassays using the best strains as food for 3rd instar Aedes aegypti larvae showed that most larvae were killed even when the cell concentration was as low as 2 × 104 cells/mL. Finally, the results indicate that these highly toxic strains are also quite stable, and thus represent a key milestone in using C. reinhardtii for mosquito control.
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Harnessing the Algal Chloroplast for Heterologous Protein Production. Microorganisms 2022; 10:microorganisms10040743. [PMID: 35456794 PMCID: PMC9025058 DOI: 10.3390/microorganisms10040743] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 02/04/2023] Open
Abstract
Photosynthetic microbes are gaining increasing attention as heterologous hosts for the light-driven, low-cost production of high-value recombinant proteins. Recent advances in the manipulation of unicellular algal genomes offer the opportunity to establish engineered strains as safe and viable alternatives to conventional heterotrophic expression systems, including for their use in the feed, food, and biopharmaceutical industries. Due to the relatively small size of their genomes, algal chloroplasts are excellent targets for synthetic biology approaches, and are convenient subcellular sites for the compartmentalized accumulation and storage of products. Different classes of recombinant proteins, including enzymes and peptides with therapeutical applications, have been successfully expressed in the plastid of the model organism Chlamydomonas reinhardtii, and of a few other species, highlighting the emerging potential of transplastomic algal biotechnology. In this review, we provide a unified view on the state-of-the-art tools that are available to introduce protein-encoding transgenes in microalgal plastids, and discuss the main (bio)technological bottlenecks that still need to be addressed to develop robust and sustainable green cell biofactories.
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7
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Yazdani M, Croen MG, Fish TL, Thannhauser TW, Ahner BA. Overexpression of native ORANGE (OR) and OR mutant protein in Chlamydomonas reinhardtii enhances carotenoid and ABA accumulation and increases resistance to abiotic stress. Metab Eng 2021; 68:94-105. [PMID: 34571147 DOI: 10.1016/j.ymben.2021.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 09/01/2021] [Accepted: 09/18/2021] [Indexed: 01/13/2023]
Abstract
The carotenoid content of plants can be increased by overexpression of the regulatory protein ORANGE (OR) or a mutant variant known as the 'golden SNP'. In the present study, a strong light-inducible promoter was used to overexpress either wild type CrOR (CrORWT) or a mutated CrOR (CrORHis) containing a single histidine substitution for a conserved arginine in the microalgae Chlamydomonas reinhardtii. Overexpression of CrORWT and CrORHis roughly doubled and tripled, respectively, the accumulation of several different carotenoids, including β-carotene, α-carotene, lutein and violaxanthin in C. reinhardtii and upregulated the transcript abundance of nearly all relevant carotenoid biosynthetic genes. In addition, microscopic analysis revealed that the OR transgenic cells were larger than control cells and exhibited larger chloroplasts with a disrupted morphology. Moreover, both CrORWT and CrORHis cell lines showed increased tolerance to salt and paraquat stress. The levels of endogenous phytohormone abscisic acid (ABA) were also increased in CrORWT and CrORHis lines, not only in normal growth conditions but also in growth medium supplemented with salt and paraquat. Together these results offer new insights regarding the role of the native OR protein in regulating carotenoid biosynthesis and the accumulation of several carotenoids in microalgae, and establish a new functional role for OR to modulate oxidative stress tolerance potentially mediated by ABA.
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Affiliation(s)
- Mohammad Yazdani
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Michelle G Croen
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Tara L Fish
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, USA
| | - Theodore W Thannhauser
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY, USA
| | - Beth A Ahner
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
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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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Benedetti M, Barera S, Longoni P, Guardini Z, Herrero Garcia N, Bolzonella D, Lopez‐Arredondo D, Herrera‐Estrella L, Goldschmidt‐Clermont M, Bassi R, Dall’Osto L. A microalgal-based preparation with synergistic cellulolytic and detoxifying action towards chemical-treated lignocellulose. PLANT BIOTECHNOLOGY JOURNAL 2021; 19:124-137. [PMID: 32649019 PMCID: PMC7769238 DOI: 10.1111/pbi.13447] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/19/2020] [Accepted: 06/28/2020] [Indexed: 05/28/2023]
Abstract
High-temperature bioconversion of lignocellulose into fermentable sugars has drawn attention for efficient production of renewable chemicals and biofuels, because competing microbial activities are inhibited at elevated temperatures and thermostable cell wall degrading enzymes are superior to mesophilic enzymes. Here, we report on the development of a platform to produce four different thermostable cell wall degrading enzymes in the chloroplast of Chlamydomonas reinhardtii. The enzyme blend was composed of the cellobiohydrolase CBM3GH5 from C. saccharolyticus, the β-glucosidase celB from P. furiosus, the endoglucanase B and the endoxylanase XynA from T. neapolitana. In addition, transplastomic microalgae were engineered for the expression of phosphite dehydrogenase D from Pseudomonas stutzeri, allowing for growth in non-axenic media by selective phosphite nutrition. The cellulolytic blend composed of the glycoside hydrolase (GH) domain GH12/GH5/GH1 allowed the conversion of alkaline-treated lignocellulose into glucose with efficiencies ranging from 14% to 17% upon 48h of reaction and an enzyme loading of 0.05% (w/w). Hydrolysates from treated cellulosic materials with extracts of transgenic microalgae boosted both the biogas production by methanogenic bacteria and the mixotrophic growth of the oleaginous microalga Chlorella vulgaris. Notably, microalgal treatment suppressed the detrimental effect of inhibitory by-products released from the alkaline treatment of biomass, thus allowing for efficient assimilation of lignocellulose-derived sugars by C. vulgaris under mixotrophic growth.
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Affiliation(s)
- Manuel Benedetti
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
- Present address:
Dipartimento MESVAUniversità dell'AquilaCoppitoAQItaly
| | - Simone Barera
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | - Paolo Longoni
- Faculty of ScienceInstitute of BiologyUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Zeno Guardini
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | | | | | - Damar Lopez‐Arredondo
- StelaGenomics MexicoS de RL de CVIrapuato, GuanajuatoMexico
- Institute of Genomics for Crop Abiotic Stress ToleranceTexas Tech UniversityLubbockTXUSA
| | - Luis Herrera‐Estrella
- Laboratorio Nacional de Genómica para la BiodiversidadCentro de Investigación y de Estudios Avanzados del Instituto Politécnico NacionalIrapuato, GuanajuatoMexico
- Institute of Genomics for Crop Abiotic Stress ToleranceTexas Tech UniversityLubbockTXUSA
| | | | - Roberto Bassi
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | - Luca Dall’Osto
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
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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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Ho SH, Zhang C, Tao F, Zhang C, Chen WH. Microalgal Torrefaction for Solid Biofuel Production. Trends Biotechnol 2020; 38:1023-1033. [DOI: 10.1016/j.tibtech.2020.02.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 12/19/2022]
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12
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Larrea-Alvarez M, Purton S. Multigenic engineering of the chloroplast genome in the green alga Chlamydomonas reinhardtii. MICROBIOLOGY (READING, ENGLAND) 2020; 166:510-515. [PMID: 32250732 PMCID: PMC7376270 DOI: 10.1099/mic.0.000910] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/11/2020] [Indexed: 12/25/2022]
Abstract
The chloroplast of microalgae such as Chlamydomonas reinhardtii represents an attractive chassis for light-driven production of novel recombinant proteins and metabolites. Methods for the introduction and expression of transgenes in the chloroplast genome (=plastome) of C. reinhardtii are well-established and over 100 different proteins have been successfully produced. However, in almost all reported cases the complexity of the genetic engineering is low, and typically involves introduction into the plastome of just a single transgene together with a selectable marker. In order to exploit fully the potential of the algal chassis it is necessary to establish methods for multigenic engineering in which many transgenes can be stably incorporated into the plastome. This would allow the synthesis of multi-subunit proteins and the introduction into the chloroplast of whole new metabolic pathways. In this short communication we report a proof-of-concept study involving both a combinatorial and serial approach, with the goal of synthesizing five different test proteins in the C. reinhardtii chloroplast. Analysis of the various transgenic lines confirmed the successful integration of the transgenes and accumulation of the gene products. However, the work also highlights an issue of genetic instability when using the same untranslated region for each of the transgenes. Our findings therefore help to define appropriate strategies for robust multigenic engineering of the algal chloroplast.
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Affiliation(s)
- Marco Larrea-Alvarez
- Algal Research Group, Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK
- Present address: School of Biological Sciences and Engineering. Yachay-Tech University Hacienda San José, Urcuquí-Imbabura, Ecuador
| | - Saul Purton
- Algal Research Group, Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK
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Giovannoni M, Gramegna G, Benedetti M, Mattei B. Industrial Use of Cell Wall Degrading Enzymes: The Fine Line Between Production Strategy and Economic Feasibility. Front Bioeng Biotechnol 2020; 8:356. [PMID: 32411686 PMCID: PMC7200985 DOI: 10.3389/fbioe.2020.00356] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 03/31/2020] [Indexed: 12/14/2022] Open
Abstract
Cell Wall Degrading Enzymes (CWDEs) are a heterogeneous group of enzymes including glycosyl-hydrolases, oxidoreductases, lyases, and esterases. Microbes with degrading activities toward plant cell wall polysaccharides are the most relevant source of CWDEs for industrial applications. These organisms secrete a wide array of CWDEs in amounts strictly necessary for their own sustenance, nonetheless the production of CWDEs from wild type microbes can be increased at large-scale by using optimized fermentation strategies. In the last decades, advances in genetic engineering allowed the expression of recombinant CWDEs also in lab-domesticated organisms such as E. coli, yeasts and plants, dramatically increasing the available options for the large-scale production of CWDEs. The optimization of a CWDE-producing biofactory is a hard challenge that biotechnologists tackle by testing different expression strategies and expression-hosts. Although both the yield and production costs are critical factors to produce biomolecules at industrial scale, these parameters are often disregarded in basic research. This review presents the main characteristics and industrial applications of CWDEs directed toward the cell wall of plants, bacteria, fungi and microalgae. Different biofactories for CWDE expression are compared in order to highlight strengths and weaknesses of each production system and how these aspects impact the final enzyme cost and, consequently, the economic feasibility of using CWDEs for industrial applications.
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Affiliation(s)
- Moira Giovannoni
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Giovanna Gramegna
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Manuel Benedetti
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Benedetta Mattei
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
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Siddiqui A, Wei Z, Boehm M, Ahmad N. Engineering microalgae through chloroplast transformation to produce high‐value industrial products. Biotechnol Appl Biochem 2020; 67:30-40. [DOI: 10.1002/bab.1823] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/16/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Ayesha Siddiqui
- Agricultural Biotechnology DivisionNational Institute for Biotechnology & Genetic Engineering (NIBGE) Faisalabad Pakistan
| | - Zhengyi Wei
- Institute of Agricultural BiotechnologyJilin Academy of Agricultural Sciences Changchun Jilin Province People's Republic of China
| | - Marko Boehm
- Botanical InstituteChristian‐Albrechts‐University Kiel Germany
| | - Niaz Ahmad
- Agricultural Biotechnology DivisionNational Institute for Biotechnology & Genetic Engineering (NIBGE) Faisalabad Pakistan
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15
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Richter LV, Yang H, Yazdani M, Hanson MR, Ahner BA. Correction to: A downstream box fusion allows stable accumulation of a bacterial cellulase in Chlamydomonas reinhardtii chloroplasts. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:284. [PMID: 31827612 PMCID: PMC6902506 DOI: 10.1186/s13068-019-1622-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 04/23/2018] [Indexed: 06/10/2023]
Abstract
[This corrects the article DOI: 10.1186/s13068-018-1127-7.].
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Affiliation(s)
- Lubna V. Richter
- Department of Biological and Environmental Engineering, Cornell University, 111 Wing Drive, Ithaca, NY USA
| | - Huijun Yang
- Department of Biological and Environmental Engineering, Cornell University, 111 Wing Drive, Ithaca, NY USA
- Department of Molecular Biology and Genetics, Cornell University, Biotechnology Building, Ithaca, NY USA
| | - Mohammad Yazdani
- Department of Biological and Environmental Engineering, Cornell University, 111 Wing Drive, Ithaca, NY USA
| | - Maureen R. Hanson
- Department of Molecular Biology and Genetics, Cornell University, Biotechnology Building, Ithaca, NY USA
| | - Beth A. Ahner
- Department of Biological and Environmental Engineering, Cornell University, 111 Wing Drive, Ithaca, NY USA
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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.
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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
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Young R, Purton S. CITRIC: cold-inducible translational readthrough in the chloroplast of Chlamydomonas reinhardtii using a novel temperature-sensitive transfer RNA. Microb Cell Fact 2018; 17:186. [PMID: 30474564 PMCID: PMC6260665 DOI: 10.1186/s12934-018-1033-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 11/16/2018] [Indexed: 01/17/2023] Open
Abstract
Background The chloroplast of eukaryotic microalgae such as Chlamydomonas reinhardtii is a potential platform for metabolic engineering and the production of recombinant proteins. In industrial biotechnology, inducible expression is often used so that the translation or function of the heterologous protein does not interfere with biomass accumulation during the growth stage. However, the existing systems used in bacterial or fungal platforms do not transfer well to the microalgal chloroplast. We sought to develop a simple inducible expression system for the microalgal chloroplast, exploiting an unused stop codon (TGA) in the plastid genome. We have previously shown that this codon can be translated as tryptophan when we introduce into the chloroplast genome a trnWUCA gene encoding a plastidial transfer RNA with a modified anticodon sequence, UCA. Results A mutated version of our trnWUCA gene was developed that encodes a temperature-sensitive variant of the tRNA. This allows transgenes that have been modified to contain one or more internal TGA codons to be translated differentially according to the culture temperature, with a gradient of recombinant protein accumulation from 35 °C (low/off) to 15 °C (high). We have named this the CITRIC system, an acronym for cold-inducible translational readthrough in chloroplasts. The exact induction behaviour can be tailored by altering the number of TGA codons within the transgene. Conclusions CITRIC adds to the suite of genetic engineering tools available for the microalgal chloroplast, allowing a greater degree of control over the timing of heterologous protein expression. It could also be used as a heat-repressible system for studying the function of essential native genes in the chloroplast. The genetic components of CITRIC are entirely plastid-based, so no engineering of the nuclear genome is required. Electronic supplementary material The online version of this article (10.1186/s12934-018-1033-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rosanna Young
- Algal Research Group, Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK.,Department of Medicine, Sir Alexander Fleming Building, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Saul Purton
- Algal Research Group, Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK.
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