1
|
Cheah LC, Liu L, Stark T, Plan MR, Peng B, Lu Z, Schenk G, Sainsbury F, Vickers CE. Metabolic flux enhancement from the translational fusion of terpene synthases is linked to terpene synthase accumulation. Metab Eng 2023; 77:143-151. [PMID: 36990382 DOI: 10.1016/j.ymben.2023.03.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/13/2023] [Accepted: 03/26/2023] [Indexed: 03/30/2023]
Abstract
The end-to-end fusion of enzymes that catalyse successive steps in a reaction pathway is a metabolic engineering strategy that has been successfully applied in a variety of pathways and is particularly common in terpene bioproduction. Despite its popularity, limited work has been done to interrogate the mechanism of metabolic enhancement from enzyme fusion. We observed a remarkable >110-fold improvement in nerolidol production upon translational fusion of nerolidol synthase (a sesquiterpene synthase) to farnesyl diphosphate synthase. This delivered a titre increase from 29.6 mg/L up to 4.2 g/L nerolidol in a single engineering step. Whole-cell proteomic analysis revealed that nerolidol synthase levels in the fusion strains were greatly elevated compared to the non-fusion control. Similarly, the fusion of nerolidol synthase to non-catalytic domains also produced comparable increases in titre, which coincided with improved enzyme expression. When farnesyl diphosphate synthase was fused to other terpene synthases, we observed more modest improvements in terpene titre (1.9- and 3.8-fold), corresponding with increases of a similar magnitude in terpene synthase levels. Our data demonstrate that increased in vivo enzyme levels - resulting from improved expression and/or improved protein stability - is a major driver of catalytic enhancement from enzyme fusion.
Collapse
Affiliation(s)
- Li Chen Cheah
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia; CSIRO Future Science Platform in Synthetic Biology, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Dutton Park, QLD, 4102, Australia
| | - Lian Liu
- Metabolomics Australia (Queensland Node), The University of Queensland, QLD, 4072, Australia
| | - Terra Stark
- Metabolomics Australia (Queensland Node), The University of Queensland, QLD, 4072, Australia
| | - Manuel R Plan
- Metabolomics Australia (Queensland Node), The University of Queensland, QLD, 4072, Australia
| | - Bingyin Peng
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia; CSIRO Future Science Platform in Synthetic Biology, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Dutton Park, QLD, 4102, Australia; ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - Zeyu Lu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia; ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - Gerhard Schenk
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia; School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Frank Sainsbury
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia; CSIRO Future Science Platform in Synthetic Biology, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Dutton Park, QLD, 4102, Australia; Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, 4111, Australia.
| | - Claudia E Vickers
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia; CSIRO Future Science Platform in Synthetic Biology, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Dutton Park, QLD, 4102, Australia; ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, QLD, 4000, Australia; School of Biological and Environmental Science, Queensland University of Technology, Brisbane, QLD, 4000, Australia; Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, 4111, Australia.
| |
Collapse
|
2
|
Wichmann J, Eggert A, Elbourne LDH, Paulsen IT, Lauersen KJ, Kruse O. Farnesyl pyrophosphate compartmentalization in the green microalga Chlamydomonas reinhardtii during heterologous (E)-α-bisabolene production. Microb Cell Fact 2022; 21:190. [PMID: 36104783 PMCID: PMC9472337 DOI: 10.1186/s12934-022-01910-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/26/2022] [Indexed: 11/10/2022] Open
Abstract
Background Eukaryotic algae have recently emerged as hosts for metabolic engineering efforts to generate heterologous isoprenoids. Isoprenoid metabolic architectures, flux, subcellular localization, and transport dynamics have not yet been fully elucidated in algal hosts. Results In this study, we investigated the accessibility of different isoprenoid precursor pools for C15 sesquiterpenoid generation in the cytoplasm and chloroplast of Chlamydomonas reinhardtii using the Abies grandis bisabolene synthase (AgBS) as a reporter. The abundance of the C15 sesquiterpene precursor farnesyl pyrophosphate (FPP) was not increased in the cytosol by co-expression and fusion of AgBS with different FPP synthases (FPPSs), indicating limited C5 precursor availability in the cytoplasm. However, FPP was shown to be available in the plastid stroma, where bisabolene titers could be improved several-fold by FPPSs. Sesquiterpene production was greatest when AgBS-FPPS fusions were directed to the plastid and could further be improved by increasing the gene dosage. During scale-up cultivation with different carbon sources and light regimes, specific sesquiterpene productivities from the plastid were highest with CO2 as the only carbon source and light:dark illumination cycles. Potential prenyl unit transporters are proposed based on bioinformatic analyses, which may be in part responsible for our observations. Conclusions Our findings indicate that the algal chloroplast can be harnessed in addition to the cytosol to exploit the full potential of algae as green cell factories for non-native sesquiterpenoid generation. Identification of a prenyl transporter may be leveraged for further extending this capacity. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01910-5.
Collapse
|
3
|
Ma K, Deng L, Wu H, Fan J. Towards green biomanufacturing of high-value recombinant proteins using promising cell factory: Chlamydomonas reinhardtii chloroplast. BIORESOUR BIOPROCESS 2022; 9:83. [PMID: 38647750 PMCID: PMC10992328 DOI: 10.1186/s40643-022-00568-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/29/2022] [Indexed: 11/10/2022] Open
Abstract
Microalgae are cosmopolitan organisms in nature with short life cycles, playing a tremendous role in reducing the pressure of industrial carbon emissions. Besides, microalgae have the unique advantages of being photoautotrophic and harboring both prokaryotic and eukaryotic expression systems, becoming a popular host for recombinant proteins. Currently, numerous advanced molecular tools related to microalgal transgenesis have been explored and established, especially for the model species Chlamydomonas reinhardtii (C. reinhardtii hereafter). The development of genetic tools and the emergence of new strategies further increase the feasibility of developing C. reinhardtii chloroplasts as green factories, and the strong genetic operability of C. reinhardtii endows it with enormous potential as a synthetic biology platform. At present, C. reinhardtii chloroplasts could successfully produce plenty of recombinant proteins, including antigens, antibodies, antimicrobial peptides, protein hormones and enzymes. However, additional techniques and toolkits for chloroplasts need to be developed to achieve efficient and markerless editing of plastid genomes. Mining novel genetic elements and selectable markers will be more intensively studied in the future, and more factors affecting protein expression are urged to be explored. This review focuses on the latest technological progress of selectable markers for Chlamydomonas chloroplast genetic engineering and the factors that affect the efficiency of chloroplast protein expression. Furthermore, urgent challenges and prospects for future development are pointed out.
Collapse
Affiliation(s)
- Ke Ma
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Lei Deng
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Haizhen Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
- Department of Applied Biology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
| | - Jianhua Fan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
- Department of Applied Biology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
- School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, People's Republic of China.
| |
Collapse
|
4
|
Jackson HO, Taunt HN, Mordaka PM, Smith AG, Purton S. The Algal Chloroplast as a Testbed for Synthetic Biology Designs Aimed at Radically Rewiring Plant Metabolism. FRONTIERS IN PLANT SCIENCE 2021; 12:708370. [PMID: 34630459 PMCID: PMC8497815 DOI: 10.3389/fpls.2021.708370] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/10/2021] [Indexed: 05/04/2023]
Abstract
Sustainable and economically viable support for an ever-increasing global population requires a paradigm shift in agricultural productivity, including the application of biotechnology to generate future crop plants. Current genetic engineering approaches aimed at enhancing the photosynthetic efficiency or composition of the harvested tissues involve relatively simple manipulations of endogenous metabolism. However, radical rewiring of central metabolism using new-to-nature pathways, so-called "synthetic metabolism", may be needed to really bring about significant step changes. In many cases, this will require re-programming the metabolism of the chloroplast, or other plastids in non-green tissues, through a combination of chloroplast and nuclear engineering. However, current technologies for sophisticated chloroplast engineering ("transplastomics") of plants are limited to just a handful of species. Moreover, the testing of metabolic rewiring in the chloroplast of plant models is often impractical given their obligate phototrophy, the extended time needed to create stable non-chimeric transplastomic lines, and the technical challenges associated with regeneration of whole plants. In contrast, the unicellular green alga, Chlamydomonas reinhardtii is a facultative heterotroph that allows for extensive modification of chloroplast function, including non-photosynthetic designs. Moreover, chloroplast engineering in C. reinhardtii is facile, with the ability to generate novel lines in a matter of weeks, and a well-defined molecular toolbox allows for rapid iterations of the "Design-Build-Test-Learn" (DBTL) cycle of modern synthetic biology approaches. The recent development of combinatorial DNA assembly pipelines for designing and building transgene clusters, simple methods for marker-free delivery of these clusters into the chloroplast genome, and the pre-existing wealth of knowledge regarding chloroplast gene expression and regulation in C. reinhardtii further adds to the versatility of transplastomics using this organism. Herein, we review the inherent advantages of the algal chloroplast as a simple and tractable testbed for metabolic engineering designs, which could then be implemented in higher plants.
Collapse
Affiliation(s)
- Harry O. Jackson
- Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Henry N. Taunt
- Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Pawel M. Mordaka
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Alison G. Smith
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Saul Purton
- Department of Structural and Molecular Biology, University College London, London, United Kingdom
- *Correspondence: Saul Purton
| |
Collapse
|