1
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Allemann MN, Tessman M, Reindel J, Scofield GB, Evans P, Pomeroy RS, Burkart MD, Mayfield SP, Simkovsky R. Rapid biodegradation of microplastics generated from bio-based thermoplastic polyurethane. Sci Rep 2024; 14:6036. [PMID: 38472254 DOI: 10.1038/s41598-024-56492-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/07/2024] [Indexed: 03/14/2024] Open
Abstract
The accumulation of microplastics in various ecosystems has now been well documented and recent evidence suggests detrimental effects on various biological processes due to this pollution. Accumulation of microplastics in the natural environment is ultimately due to the chemical nature of widely used petroleum-based plastic polymers, which typically are inaccessible to biological processing. One way to mitigate this crisis is adoption of plastics that biodegrade if released into natural environments. In this work, we generated microplastic particles from a bio-based, biodegradable thermoplastic polyurethane (TPU-FC1) and demonstrated their rapid biodegradation via direct visualization and respirometry. Furthermore, we isolated multiple bacterial strains capable of using TPU-FC1 as a sole carbon source and characterized their depolymerization products. To visualize biodegradation of TPU materials as real-world products, we generated TPU-coated cotton fabric and an injection molded phone case and documented biodegradation by direct visualization and scanning electron microscopy (SEM), both of which indicated clear structural degradation of these materials and significant biofilm formation.
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Affiliation(s)
- Marco N Allemann
- Algenesis Corporation, 11760 Sorrento Valley Rd. Suite J, San Diego, CA, 92121, USA
| | - Marissa Tessman
- Algenesis Corporation, 11760 Sorrento Valley Rd. Suite J, San Diego, CA, 92121, USA
| | - Jaysen Reindel
- Algenesis Corporation, 11760 Sorrento Valley Rd. Suite J, San Diego, CA, 92121, USA
| | - Gordon B Scofield
- Algenesis Corporation, 11760 Sorrento Valley Rd. Suite J, San Diego, CA, 92121, USA
| | - Payton Evans
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Robert S Pomeroy
- Algenesis Corporation, 11760 Sorrento Valley Rd. Suite J, San Diego, CA, 92121, USA
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Michael D Burkart
- Algenesis Corporation, 11760 Sorrento Valley Rd. Suite J, San Diego, CA, 92121, USA
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Stephen P Mayfield
- Algenesis Corporation, 11760 Sorrento Valley Rd. Suite J, San Diego, CA, 92121, USA
- Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Ryan Simkovsky
- Algenesis Corporation, 11760 Sorrento Valley Rd. Suite J, San Diego, CA, 92121, USA.
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2
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Gupta A, Kang K, Pathania R, Saxton L, Saucedo B, Malik A, Torres-Tiji Y, Diaz CJ, Dutra Molino JV, Mayfield SP. Harnessing genetic engineering to drive economic bioproduct production in algae. Front Bioeng Biotechnol 2024; 12:1350722. [PMID: 38347913 PMCID: PMC10859422 DOI: 10.3389/fbioe.2024.1350722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/16/2024] [Indexed: 02/15/2024] Open
Abstract
Our reliance on agriculture for sustenance, healthcare, and resources has been essential since the dawn of civilization. However, traditional agricultural practices are no longer adequate to meet the demands of a burgeoning population amidst climate-driven agricultural challenges. Microalgae emerge as a beacon of hope, offering a sustainable and renewable source of food, animal feed, and energy. Their rapid growth rates, adaptability to non-arable land and non-potable water, and diverse bioproduct range, encompassing biofuels and nutraceuticals, position them as a cornerstone of future resource management. Furthermore, microalgae's ability to capture carbon aligns with environmental conservation goals. While microalgae offers significant benefits, obstacles in cost-effective biomass production persist, which curtails broader application. This review examines microalgae compared to other host platforms, highlighting current innovative approaches aimed at overcoming existing barriers. These approaches include a range of techniques, from gene editing, synthetic promoters, and mutagenesis to selective breeding and metabolic engineering through transcription factors.
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Affiliation(s)
- Abhishek Gupta
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - Kalisa Kang
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - Ruchi Pathania
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - Lisa Saxton
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - Barbara Saucedo
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - Ashleyn Malik
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - Yasin Torres-Tiji
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - Crisandra J. Diaz
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - João Vitor Dutra Molino
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
| | - Stephen P. Mayfield
- Mayfield Laboratory, Department of Molecular Biology, School of Biological Sciences, University of California San Diego, San Diego, CA, United States
- California Center for Algae Biotechnology, University of California San Diego, San Diego, CA, United States
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3
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Gonzales JN, Treece TR, Mayfield SP, Simkovsky R, Atsumi S. Utilization of lignocellulosic hydrolysates for photomixotrophic chemical production in Synechococcus elongatus PCC 7942. Commun Biol 2023; 6:1022. [PMID: 37813969 PMCID: PMC10562401 DOI: 10.1038/s42003-023-05394-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023] Open
Abstract
To meet the need for environmentally friendly commodity chemicals, feedstocks for biological chemical production must be diversified. Lignocellulosic biomass are an carbon source with the potential for effective use in a large scale and cost-effective production systems. Although the use of lignocellulosic biomass lysates for heterotrophic chemical production has been advancing, there are challenges to overcome. Here we aim to investigate the obligate photoautotroph cyanobacterium Synechococcus elongatus PCC 7942 as a chassis organism for lignocellulosic chemical production. When modified to import monosaccharides, this cyanobacterium is an excellent candidate for lysates-based chemical production as it grows well at high lysate concentrations and can fix CO2 to enhance carbon efficiency. This study is an important step forward in enabling the simultaneous use of two sugars as well as lignocellulosic lysate. Incremental genetic modifications enable catabolism of both sugars concurrently without experiencing carbon catabolite repression. Production of 2,3-butanediol is demonstrated to characterize chemical production from the sugars in lignocellulosic hydrolysates. The engineered strain achieves a titer of 13.5 g L-1 of 2,3-butanediol over 12 days under shake-flask conditions. This study can be used as a foundation for industrial scale production of commodity chemicals from a combination of sunlight, CO2, and lignocellulosic sugars.
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Affiliation(s)
- Jake N Gonzales
- Plant Biology Graduate Group, University of California, Davis, Davis, CA, 95616, USA
| | - Tanner R Treece
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - Stephen P Mayfield
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
- California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ryan Simkovsky
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
- California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Shota Atsumi
- Plant Biology Graduate Group, University of California, Davis, Davis, CA, 95616, USA.
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA.
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4
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Treece TR, Tessman M, Pomeroy RS, Mayfield SP, Simkovsky R, Atsumi S. Fluctuating pH for efficient photomixotrophic succinate production. Metab Eng 2023; 79:118-129. [PMID: 37499856 DOI: 10.1016/j.ymben.2023.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/15/2023] [Accepted: 07/23/2023] [Indexed: 07/29/2023]
Abstract
Cyanobacteria are attracting increasing attention as a photosynthetic chassis organism for diverse biochemical production, however, photoautotrophic production remains inefficient. Photomixotrophy, a method where sugar is used to supplement baseline autotrophic metabolism in photosynthetic hosts, is becoming increasingly popular for enhancing sustainable bioproduction with multiple input energy streams. In this study, the commercially relevant diacid, succinate, was produced photomixotrophically. Succinate is an important industrial chemical that can be used for the production of a wide array of products, from pharmaceuticals to biopolymers. In this system, the substrate, glucose, is transported by a proton symporter and the product, succinate, is hypothesized to be transported by another proton symporter, but in the opposite direction. Thus, low pH is required for the import of glucose and high pH is required for the export of succinate. Succinate production was initiated in a pH 7 medium containing bicarbonate. Glucose was efficiently imported at around neutral pH. Utilization of bicarbonate by CO2 fixation raised the pH of the medium. As succinate, a diacid, was produced, the pH of the medium dropped. By repeating this cycle with additional pH adjustment, those contradictory requirements for transport were overcome. pH affects a variety of biological factors and by cycling from high pH to neutral pH processes such as CO2 fixation rates and CO2 solubility can vary. In this study the engineered strains produced succinate during fluctuating pH conditions, achieving a titer of 5.0 g L-1 after 10 days under shake flask conditions. These results demonstrate the potential for photomixotrophic production as a viable option for the large-scale production of succinate.
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Affiliation(s)
- Tanner R Treece
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | | | - Robert S Pomeroy
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Stephen P Mayfield
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA; California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ryan Simkovsky
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA; California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Shota Atsumi
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA.
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5
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Diaz CJ, Douglas KJ, Kang K, Kolarik AL, Malinovski R, Torres-Tiji Y, Molino JV, Badary A, Mayfield SP. Developing algae as a sustainable food source. Front Nutr 2023; 9:1029841. [PMID: 36742010 PMCID: PMC9892066 DOI: 10.3389/fnut.2022.1029841] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 12/05/2022] [Indexed: 01/20/2023] Open
Abstract
Current agricultural and food production practices are facing extreme stress, posed by climate change and an ever-increasing human population. The pressure to feed nearly 8 billion people while maintaining a minimal impact on the environment has prompted a movement toward new, more sustainable food sources. For thousands of years, both the macro (seaweed and kelp) and micro (unicellular) forms of algae have been cultivated as a food source. Algae have evolved to be highly efficient at resource utilization and have proven to be a viable source of nutritious biomass that could address many of the current food production issues. Particularly for microalgae, studies of their large-scale growth and cultivation come from the biofuel industry; however, this knowledge can be reasonably translated into the production of algae-based food products. The ability of algae to sequester CO2 lends to its sustainability by helping to reduce the carbon footprint of its production. Additionally, algae can be produced on non-arable land using non-potable water (including brackish or seawater), which allows them to complement rather than compete with traditional agriculture. Algae inherently have the desired qualities of a sustainable food source because they produce highly digestible proteins, lipids, and carbohydrates, and are rich in essential fatty acids, vitamins, and minerals. Although algae have yet to be fully domesticated as food sources, a variety of cultivation and breeding tools exist that can be built upon to allow for the increased productivity and enhanced nutritional and organoleptic qualities that will be required to bring algae to mainstream utilization. Here we will focus on microalgae and cyanobacteria to highlight the current advancements that will expand the variety of algae-based nutritional sources, as well as outline various challenges between current biomass production and large-scale economic algae production for the food market.
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Affiliation(s)
- Crisandra J. Diaz
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States
| | - Kai J. Douglas
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States
| | - Kalisa Kang
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States
| | - Ashlynn L. Kolarik
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States
| | - Rodeon Malinovski
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States
| | - Yasin Torres-Tiji
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States
| | - João V. Molino
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States
| | - Amr Badary
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States
| | - Stephen P. Mayfield
- Mayfield Lab, Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, San Diego, CA, United States,California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, United States,*Correspondence: Stephen P. Mayfield,
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6
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Gunawan NR, Tessman M, Zhen D, Johnson L, Evans P, Clements SM, Pomeroy RS, Burkart MD, Simkovsky R, Mayfield SP. Biodegradation of renewable polyurethane foams in marine environments occurs through depolymerization by marine microorganisms. Sci Total Environ 2022; 850:158761. [PMID: 36154974 DOI: 10.1016/j.scitotenv.2022.158761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 08/18/2022] [Accepted: 09/10/2022] [Indexed: 06/16/2023]
Abstract
Accumulation of plastics in the Earth's oceans is causing widespread disruption to marine ecosystems. To help mitigate the environmental burden caused by non-degradable plastics, we have previously developed a commercially relevant polyurethane (PU) foam derived from renewable biological materials that can be depolymerized into its constituent monomers and consumed by microorganisms in soil or compost. Here we demonstrate that these same PU foams can be biodegraded by marine microorganisms in the ocean and by isolated marine microorganisms in an ex situ seawater environment. Using Fourier-transform infrared (FTIR) spectroscopy, we tracked molecular changes imparted by microbial breakdown of the PU polymers; and utilized scanning electron microscopy (SEM) to demonstrate the loss of physical structure associated with colonization of microorganisms on the PU foams. We subsequently enriched, isolated, and identified individual microorganisms, from six marine sites around San Diego, CA, that are capable of depolymerizing, metabolizing, and accumulating biomass using these PU foams as a sole carbon source. Analysis using SEM, FTIR, and gas chromatography-mass spectrometry (GCMS) confirmed that these microorganisms depolymerized the PU into its constitutive diols, diacids, and other PU fragments. SEM and FTIR results from isolated organismal biodegradation experiments exactly matched those from ex situ and ocean biodegradation samples, suggesting that these PU foam would undergo biodegradation in a natural ocean environment by enzymatic depolymerization of the PU foams and eventual uptake of the degradation products into biomass by marine microorganisms, should these foams unintentionally end up in the marine environment, as many plastics do.
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Affiliation(s)
| | | | - Daniel Zhen
- Algenesis Inc., 1238 Sea Village Dr., Cardiff, CA, USA
| | | | - Payton Evans
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Samantha M Clements
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Robert S Pomeroy
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Michael D Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | | | - Stephen P Mayfield
- Department of Molecular Biology, and California Center for Algae Biotechnology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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7
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Torres-Tiji Y, Fields FJ, Yang Y, Heredia V, Horn SJ, Keremane SR, Jin MM, Mayfield SP. Optimized production of a bioactive human recombinant protein from the microalgae Chlamydomonas reinhardtii grown at high density in a fed-batch bioreactor. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Sproles AE, Berndt A, Fields FJ, Mayfield SP. Improved high-throughput screening technique to rapidly isolate Chlamydomonas transformants expressing recombinant proteins. Appl Microbiol Biotechnol 2022; 106:1677-1689. [PMID: 35129657 PMCID: PMC8882119 DOI: 10.1007/s00253-022-11790-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 12/20/2022]
Abstract
Abstract
The single-celled eukaryotic green alga Chlamydomonas reinhardtii has long been a model system for developing genetic tools for algae, and is also considered a potential platform for the production of high-value recombinant proteins. Identifying transformants with high levels of recombinant protein expression has been a challenge in this organism, as random integration of transgenes into the nuclear genome leads to low frequency of cell lines with high gene expression. Here, we describe the design of an optimized vector for the expression of recombinant proteins in Chlamydomonas, that when transformed and screened using a dual antibiotic selection, followed by screening using fluorescence activated cell sorting (FACS), permits rapid identification and isolation of microalgal transformants with high expression of a recombinant protein. This process greatly reduces the time required for the screening process, and can produce large populations of recombinant algae transformants with between 60 and 100% of cells producing the recombinant protein of interest, in as little as 3 weeks, that can then be used for whole population sequencing or individual clone analysis. Utilizing this new vector and high-throughput screening (HTS) process resulted in an order of magnitude improvement over existing methods, which normally produced under 1% of algae transformants expressing the protein of interest. This process can be applied to other algal strains and recombinant proteins to enhance screening efficiency, thereby speeding up the discovery and development of algal-derived recombinant protein products. Key points • A protein expression vector using double-antibiotic resistance genes was designed • Double antibiotic selection causes fewer colonies with more positive for phenotype • Coupling the new vector with FACS improves microalgal screening efficiency > 60% Supplementary Information The online version contains supplementary material available at 10.1007/s00253-022-11790-9.
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Affiliation(s)
- Ashley E Sproles
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Anthony Berndt
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Francis J Fields
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Stephen P Mayfield
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA. .,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
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9
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McQuillan JL, Berndt AJ, Sproles AE, Mayfield SP, Pandhal J. Novel cis-regulatory elements as synthetic promoters to drive recombinant protein expression from the Chlamydomonas reinhardtii nuclear genome. N Biotechnol 2022; 68:9-18. [PMID: 34990855 DOI: 10.1016/j.nbt.2022.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 10/29/2021] [Accepted: 01/01/2022] [Indexed: 12/17/2022]
Abstract
Eukaryotic green microalgae represent a sustainable, photosynthetic biotechnology platform for generating high-value products. The model green alga Chlamydomonas reinhardtii has already been used to generate high value bioproducts such as recombinant proteins and terpenoids. However, low, unstable, and variable nuclear transgene expression has limited the ease and speed of metabolic engineering and recombinant protein expression in this system. Here, novel genetic devices for transgene expression in C. reinhardtii have been developed by identifying cis-regulatory DNA elements capable of driving high transgene expression in C. reinhardtii promoters using de novo motif discovery informatics approaches. Thirteen putative motifs were synthesized as concatemers, linked to a common minimal basal promoter, and assayed for their activity to drive expression of a yellow fluorescent protein reporter gene. Following transformation of the vectors into C. reinhardtii by electroporation, in vivo measurements of yellow fluorescent protein expression by flow cytometry revealed that five of the DNA motifs analyzed displayed significantly higher reporter expression compared to the basal promoter control. Two of the concatemerized motifs, despite being much smaller minimal cis-regulatory elements, drove reporter expression at levels approaching that of the conventionally-used AR1 promoter. This analysis provides insight into C. reinhardtii promoter structure and gene regulation, and provides a new toolbox of cis-regulatory elements that can be used to drive transgene expression at a variety of expression levels.
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Affiliation(s)
- Josie L McQuillan
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - Anthony J Berndt
- California Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, United States
| | - Ashley E Sproles
- California Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, United States
| | - Stephen P Mayfield
- California Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, United States
| | - Jagroop Pandhal
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
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10
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Berndt AJ, Smalley TN, Ren B, Simkovsky R, Badary A, Sproles AE, Fields FJ, Torres-Tiji Y, Heredia V, Mayfield SP. Recombinant production of a functional SARS-CoV-2 spike receptor binding domain in the green algae Chlamydomonas reinhardtii. PLoS One 2021; 16:e0257089. [PMID: 34793485 PMCID: PMC8601568 DOI: 10.1371/journal.pone.0257089] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/25/2021] [Indexed: 01/12/2023] Open
Abstract
Recombinant production of viral proteins can be used to produce vaccine antigens or reagents to identify antibodies in patient serum. Minimally, these proteins must be correctly folded and have appropriate post-translation modifications. Here we report the production of the SARS-CoV-2 spike protein Receptor Binding Domain (RBD) in the green algae Chlamydomonas. RBD fused to a fluorescent reporter protein accumulates as an intact protein when targeted for ER-Golgi retention or secreted from the cell, while a chloroplast localized version is truncated. The ER-retained RBD fusion protein was able to bind the human ACE2 receptor, the host target of SARS-CoV-2, and was specifically out-competed by mammalian cell-produced recombinant RBD, suggesting that the algae produced proteins are sufficiently post-translationally modified to act as authentic SARS-CoV-2 antigens. Because algae can be grown at large scale very inexpensively, this recombinant protein may be a low cost alternative to other expression platforms.
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Affiliation(s)
- Anthony J. Berndt
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Tressa N. Smalley
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Bijie Ren
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Ryan Simkovsky
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Amr Badary
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Ashley E. Sproles
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Francis J. Fields
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Yasin Torres-Tiji
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Vanessa Heredia
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Stephen P. Mayfield
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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11
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Abstract
One of the key challenges that we face in the 21st century is the need to feed an ever-increasing human population with increasingly limited natural resources. Even today it is estimated that roughly 1 out of 9 people in the world are undernourished, of which the most important factor is protein-energy malnutrition. By establishing microalgae as a new food and feed platform, we have the opportunity to increase the supply of these essential products to address global demands in a more efficient and environmentally sustainable way. Many types of algae are nutritionally complete foods, their yields outperform most plant crops, and there is a growing set of tools to develop improved strains of algae. Similar improvements were achieved in traditional crops through thousands of years of breeding and strain selection, whereas with the newest genetic engineering tools and advanced strain selection techniques, similar changes can be implemented in microalgae in just a few years. Here we describe different strategies that could be used to enhance the nutritional content, productivity, and organoleptic traits of algae to help drive development of this new crop. Clearly developing more efficient, sustainable, and nutritious foods and feed would be an enormous benefit for the planet, and algae represents an opportunity to develop a new crop that would complement traditional agriculture, and one that could potential result in a more efficient means to meet the world's food and feed supply.
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Affiliation(s)
- Yasin Torres-Tiji
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA; Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
| | - Francis J Fields
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA; Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Stephen P Mayfield
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA; Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
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12
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Fields FJ, Ostrand JT, Tran M, Mayfield SP. Nuclear genome shuffling significantly increases production of chloroplast-based recombinant protein in Chlamydomonas reinhardtii. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101523] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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13
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14
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Szyjka SJ, Mandal S, Schoepp NG, Tyler BM, Yohn CB, Poon YS, Villareal S, Burkart MD, Shurin JB, Mayfield SP. Evaluation of phenotype stability and ecological risk of a genetically engineered alga in open pond production. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.04.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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15
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Anderson MS, Muff TJ, Georgianna DR, Mayfield SP. Towards a synthetic nuclear transcription system in green algae: Characterization of Chlamydomonas reinhardtii nuclear transcription factors and identification of targeted promoters. ALGAL RES 2017. [DOI: 10.1016/j.algal.2016.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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16
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Affiliation(s)
- Elizabeth A. Specht
- University of California; California Center for Algae Biotechnology; Division of Biological Sciences; 9500 Gilman Drive San Diego, La Jolla CA 92093 USA
| | - Prema S. Karunanithi
- University of California; California Center for Algae Biotechnology; Division of Biological Sciences; 9500 Gilman Drive San Diego, La Jolla CA 92093 USA
| | - Javier A. Gimpel
- Centre for Biotechnology and Bioengineering; Department of Chemical Engineering and Biotechnology, Universidad de Chile; 851 Beaucheff Santiago USA
| | - William S. Ansari
- University of California; California Center for Algae Biotechnology; Division of Biological Sciences; 9500 Gilman Drive San Diego, La Jolla CA 92093 USA
| | - Stephen P. Mayfield
- University of California; California Center for Algae Biotechnology; Division of Biological Sciences; 9500 Gilman Drive San Diego, La Jolla CA 92093 USA
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17
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Abstract
Modern society is fueled by fossil energy produced millions of years ago by photosynthetic organisms. Cultivating contemporary photosynthetic producers to generate energy and capture carbon from the atmosphere is one potential approach to sustaining society without disrupting the climate. Algae, photosynthetic aquatic microorganisms, are the fastest growing primary producers in the world and can therefore produce more energy with less land, water, and nutrients than terrestrial plant crops. We review recent progress and challenges in developing bioenergy technology based on algae. A variety of high-value products in addition to biofuels can be harvested from algal biomass, and these may be key to developing algal biotechnology and realizing the commercial potential of these organisms. Aspects of algal biology that differentiate them from plants demand an integrative approach based on genetics, cell biology, ecology, and evolution. We call for a systems approach to research on algal biotechnology rooted in understanding their biology, from the level of genes to ecosystems, and integrating perspectives from physical, chemical, and social sciences to solve one of the most critical outstanding technological problems.
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Affiliation(s)
- Jonathan B Shurin
- Division of Biological Sciences, University of California, San Diego, California, USA
| | - Michael D Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, California, USA
| | - Stephen P Mayfield
- Division of Biological Sciences, University of California, San Diego, California, USA
| | - Val H Smith
- Department of Ecology and Evolutionary Biology, University of Kansas, Kansas, USA
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18
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Gimpel JA, Nour-Eldin HH, Scranton MA, Li D, Mayfield SP. Refactoring the Six-Gene Photosystem II Core in the Chloroplast of the Green Algae Chlamydomonas reinhardtii. ACS Synth Biol 2016. [PMID: 26214707 DOI: 10.1021/acssynbio.5b00076] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Oxygenic photosynthesis provides the energy to produce all food and most of the fuel on this planet. Photosystem II (PSII) is an essential and rate-limiting component of this process. Understanding and modifying PSII function could provide an opportunity for optimizing photosynthetic biomass production, particularly under specific environmental conditions. PSII is a complex multisubunit enzyme with strong interdependence among its components. In this work, we have deleted the six core genes of PSII in the eukaryotic alga Chlamydomonas reinhardtii and refactored them in a single DNA construct. Complementation of the knockout strain with the core PSII synthetic module from three different green algae resulted in reconstitution of photosynthetic activity to 85, 55, and 53% of that of the wild-type, demonstrating that the PSII core can be exchanged between algae species and retain function. The strains, synthetic cassettes, and refactoring strategy developed for this study demonstrate the potential of synthetic biology approaches for tailoring oxygenic photosynthesis and provide a powerful tool for unraveling PSII structure-function relationships.
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Affiliation(s)
- Javier A. Gimpel
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
| | - Hussam H. Nour-Eldin
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
| | - Melissa A. Scranton
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
| | - Daphne Li
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
| | - Stephen P. Mayfield
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
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19
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Gregory JA, Shepley-McTaggart A, Umpierrez M, Hurlburt BK, Maleki SJ, Sampson HA, Mayfield SP, Berin MC. Immunotherapy using algal-produced Ara h 1 core domain suppresses peanut allergy in mice. Plant Biotechnol J 2016; 14:1541-50. [PMID: 26801740 PMCID: PMC5066676 DOI: 10.1111/pbi.12515] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 05/26/2023]
Abstract
Peanut allergy is an IgE-mediated adverse reaction to a subset of proteins found in peanuts. Immunotherapy aims to desensitize allergic patients through repeated and escalating exposures for several months to years using extracts or flours. The complex mix of proteins and variability between preparations complicates immunotherapy studies. Moreover, peanut immunotherapy is associated with frequent negative side effects and patients are often at risk of allergic reactions once immunotherapy is discontinued. Allergen-specific approaches using recombinant proteins are an attractive alternative because they allow more precise dosing and the opportunity to engineer proteins with improved safety profiles. We tested whether Ara h 1 and Ara h 2, two major peanut allergens, could be produced using chloroplast of the unicellular eukaryotic alga, Chlamydomonas reinhardtii. C. reinhardtii is novel host for producing allergens that is genetically tractable, inexpensive and easy to grow, and is able to produce more complex proteins than bacterial hosts. Compared to the native proteins, algal-produced Ara h 1 core domain and Ara h 2 have a reduced affinity for IgE from peanut-allergic patients. We further found that immunotherapy using algal-produced Ara h 1 core domain confers protection from peanut-induced anaphylaxis in a murine model of peanut allergy.
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Affiliation(s)
- James A Gregory
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ariel Shepley-McTaggart
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Michelle Umpierrez
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Barry K Hurlburt
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA
| | - Soheila J Maleki
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA
| | - Hugh A Sampson
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stephen P Mayfield
- Department of Biology, University of California San Diego, La Jolla, CA, USA
| | - M Cecilia Berin
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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20
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Nour-Eldin HH, Specht EA, Mayfield SP. An improved ARG7-based selection cassette with highly efficient transformation rates and a small size suitable for complex expression constructs. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.03.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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21
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Vinyard DJ, Sun JS, Gimpel J, Ananyev GM, Mayfield SP, Charles Dismukes G. Natural isoforms of the Photosystem II D1 subunit differ in photoassembly efficiency of the water-oxidizing complex. Photosynth Res 2016; 128:141-150. [PMID: 26687161 DOI: 10.1007/s11120-015-0208-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
Oxygenic photosynthesis efficiency at increasing solar flux is limited by light-induced damage (photoinhibition) of Photosystem II (PSII), primarily targeting the D1 reaction center subunit. Some cyanobacteria contain two natural isoforms of D1 that function better under low light (D1:1) or high light (D1:2). Herein, rates and yields of photoassembly of the Mn4CaO5 water-oxidizing complex (WOC) from the free inorganic cofactors (Mn(2+), Ca(2+), water, electron acceptor) and apo-WOC-PSII are shown to differ significantly: D1:1 apo-WOC-PSII exhibits a 2.3-fold faster rate-limiting step of photoassembly and up to seven-fold faster rate to the first light-stable Mn(3+) intermediate, IM1*, but with a much higher rate of photoinhibition than D1:2. Conversely, D1:2 apo-WOC-PSII assembles slower but has up to seven-fold higher yield, achieved by a higher quantum yield of charge separation and slower photoinhibition rate. These results confirm and extend previous observations of the two holoenzymes: D1:2-PSII has a greater quantum yield of primary charge separation, faster [P680 (+) Q A (-) ] charge recombination and less photoinhibition that results in a slower rate and higher yield of photoassembly of its apo-WOC-PSII complex. In contrast, D1:1-PSII has a lower quantum yield of primary charge separation, a slower [P680 (+) Q A (-) ] charge recombination rate, and faster photoinhibition that together result in higher rate but lower yield of photoassembly at higher light intensities. Cyanobacterial PSII reaction centers that contain the high- and low-light D1 isoforms can tailor performance to optimize photosynthesis at varying light conditions, with similar consequences on their photoassembly kinetics and yield. These different efficiencies of photoassembly versus photoinhibition impose differential costs for biosynthesis as a function of light intensity.
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Affiliation(s)
- David J Vinyard
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Rd., Piscataway, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Jennifer S Sun
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Rd., Piscataway, NJ, 08854, USA
- Department of Molecular, Cellular, and Development Biology, Yale University, New Haven, CT, 06520, USA
| | - Javier Gimpel
- San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
- Centre for Biotechnology and Bioengineering, Universidad de Chile, Santiago, Chile
| | - Gennady M Ananyev
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Rd., Piscataway, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Stephen P Mayfield
- San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - G Charles Dismukes
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Rd., Piscataway, NJ, 08854, USA.
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA.
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22
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Scranton MA, Ostrand JT, Georgianna DR, Lofgren SM, Li D, Ellis RC, Carruthers DN, Dräger A, Masica DL, Mayfield SP. Synthetic promoters capable of driving robust nuclear gene expression in the green alga Chlamydomonas reinhardtii. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.02.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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23
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Gimpel JA, Henríquez V, Mayfield SP. In Metabolic Engineering of Eukaryotic Microalgae: Potential and Challenges Come with Great Diversity. Front Microbiol 2015; 6:1376. [PMID: 26696985 PMCID: PMC4678203 DOI: 10.3389/fmicb.2015.01376] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 11/20/2015] [Indexed: 12/03/2022] Open
Abstract
The great phylogenetic diversity of microalgae is corresponded by a wide arrange of interesting and useful metabolites. Nonetheless metabolic engineering in microalgae has been limited, since specific transformation tools must be developed for each species for either the nuclear or chloroplast genomes. Microalgae as production platforms for metabolites offer several advantages over plants and other microorganisms, like the ability of GMO containment and reduced costs in culture media, respectively. Currently, microalgae have proved particularly well suited for the commercial production of omega-3 fatty acids and carotenoids. Therefore most metabolic engineering strategies have been developed for these metabolites. Microalgal biofuels have also drawn great attention recently, resulting in efforts for improving the production of hydrogen and photosynthates, particularly triacylglycerides. Metabolic pathways of microalgae have also been manipulated in order to improve photosynthetic growth under specific conditions and for achieving trophic conversion. Although these pathways are not strictly related to secondary metabolites, the synthetic biology approaches could potentially be translated to this field and will also be discussed.
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Affiliation(s)
- Javier A Gimpel
- Chemical and Biotechnology Engineering Department, Centre for Biotechnology and Bioengineering, Universidad de Chile Santiago, Chile
| | - Vitalia Henríquez
- Instituto de Biología, Pontificia Universidad Católica de Valparaíso Valparaiso, Chile
| | - Stephen P Mayfield
- Division of Biological Sciences, California Center for Algae Biotechnology, University of California, San Diego La Jolla, CA, USA
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24
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Ferreira-Camargo LS, Tran M, Beld J, Burkart MD, Mayfield SP. Selenocystamine improves protein accumulation in chloroplasts of eukaryotic green algae. AMB Express 2015; 5:126. [PMID: 26137911 PMCID: PMC4489976 DOI: 10.1186/s13568-015-0126-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 06/22/2015] [Indexed: 12/30/2022] Open
Abstract
Eukaryotic green algae have become an increasingly popular platform for recombinant proteins production. In particular, Chlamydomonas reinhardtii, has garnered increased attention for having the necessary biochemical machinery to produce vaccines, human antibodies and next generation cancer targeting immunotoxins. While it has been shown that chloroplasts contain chaperones, peptidyl prolylisomerases and protein disulfide isomerases that facilitate these complex proteins folding and assembly, little has been done to determine which processes serve as rate-limiting steps for protein accumulation. In other expression systems, as Escherichia coli, Chinese hamster ovary cells, and insect cells, recombinant protein accumulation can be hampered by cell's inability to fold the target polypeptide into the native state, resulting in aggregation and degradation. To determine if chloroplasts' ability to oxidize proteins that require disulfide bonds into a stable conformation is a rate-limiting step of protein accumulation, three recombinant strains, each expressing a different recombinant protein, were analyzed. These recombinant proteins included fluorescent GFP, a reporter containing no disulfide bonds; Gaussia princeps luciferase, a luminescent reporter containing disulfide bonds; and an immunotoxin, an antibody-fusion protein containing disulfide bonds. Each strain was analyzed for its ability to accumulate proteins when supplemented with selenocystamine, a small molecule capable of catalyzing the formation of disulfide bonds. Selenocystamine supplementation led to an increase in luciferase and immunotoxin but not GFP accumulation. These results demonstrated that selenocystamine can increase the accumulation of proteins containing disulfide bonds and suggests that a rate-limiting step in chloroplast protein accumulation is the disulfide bonds formation in recombinant proteins native structure.
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25
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Patra KP, Li F, Carter D, Gregory JA, Baga S, Reed SG, Mayfield SP, Vinetz JM. Alga-produced malaria transmission-blocking vaccine candidate Pfs25 formulated with a human use-compatible potent adjuvant induces high-affinity antibodies that block Plasmodium falciparum infection of mosquitoes. Infect Immun 2015; 83:1799-808. [PMID: 25690099 PMCID: PMC4399074 DOI: 10.1128/iai.02980-14] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 02/08/2015] [Indexed: 01/21/2023] Open
Abstract
A vaccine to prevent the transmission of malaria parasites from infected humans to mosquitoes is an important component for the elimination of malaria in the 21st century, yet it remains neglected as a priority of malaria vaccine development. The lead candidate for Plasmodium falciparum transmission-blocking vaccine development, Pfs25, is a sexual stage surface protein that has been produced for vaccine testing in a variety of heterologous expression systems. Any realistic malaria vaccine will need to optimize proper folding balanced against cost of production, yield, and potentially reactogenic contaminants. Here Chlamydomonas reinhardtii microalga-produced recombinant Pfs25 protein was formulated with four different human-compatible adjuvants (alum, Toll-like receptor 4 [TLR-4] agonist glucopyranosal lipid A [GLA] plus alum, squalene-oil-in-water emulsion, and GLA plus squalene-oil-in-water emulsion) and compared for their ability to induce malaria transmission-blocking antibodies. Alga-produced recombinant Pfs25 plus GLA plus squalene-oil-in-water adjuvant induced the highest titer and avidity in IgG antibodies, measured using alga-produced recombinant Pfs25 as the enzyme-linked immunosorbent assay (ELISA) antigen. These antibodies specifically reacted with the surface of P. falciparum macrogametes and zygotes and effectively prevented parasites from developing within the mosquito vector in standard membrane feeding assays. Alga-produced Pfs25 in combination with a human-compatible adjuvant composed of a TLR-4 agonist in a squalene-oil-in-water emulsion is an attractive new vaccine candidate that merits head-to-head comparison with other modalities of vaccine production and administration.
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MESH Headings
- Adjuvants, Immunologic/administration & dosage
- Animals
- Antibodies, Protozoan/blood
- Antibody Affinity
- Chlamydomonas reinhardtii/genetics
- Chlamydomonas reinhardtii/metabolism
- Culicidae/parasitology
- Enzyme-Linked Immunosorbent Assay
- Female
- Humans
- Immunoglobulin G/blood
- Malaria Vaccines/administration & dosage
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Malaria Vaccines/isolation & purification
- Mice, Inbred BALB C
- Plasmodium falciparum/immunology
- Plasmodium falciparum/isolation & purification
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/isolation & purification
- Treatment Outcome
- Vaccines, Subunit/administration & dosage
- Vaccines, Subunit/genetics
- Vaccines, Subunit/immunology
- Vaccines, Subunit/isolation & purification
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Vaccines, Synthetic/isolation & purification
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Affiliation(s)
- Kailash P Patra
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Fengwu Li
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Darrick Carter
- Infectious Disease Research Institute, Seattle, Washington, USA
| | - James A Gregory
- Infectious Disease Research Institute, Seattle, Washington, USA
| | - Sheyenne Baga
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Steven G Reed
- Infectious Disease Research Institute, Seattle, Washington, USA
| | - Stephen P Mayfield
- Division of Biological Science and the San Diego Center for Algae Biotechnology, University of California San Diego, La Jolla, California, USA
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California, USA
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26
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Scranton MA, Ostrand JT, Fields FJ, Mayfield SP. Chlamydomonas as a model for biofuels and bio-products production. Plant J 2015; 82:523-531. [PMID: 25641390 PMCID: PMC5531182 DOI: 10.1111/tpj.12780] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/08/2015] [Accepted: 01/12/2015] [Indexed: 05/18/2023]
Abstract
Developing renewable energy sources is critical to maintaining the economic growth of the planet while protecting the environment. First generation biofuels focused on food crops like corn and sugarcane for ethanol production, and soybean and palm for biodiesel production. Second generation biofuels based on cellulosic ethanol produced from terrestrial plants, has received extensive funding and recently pilot facilities have been commissioned, but to date output of fuels from these sources has fallen well short of what is needed. Recent research and pilot demonstrations have highlighted the potential of algae as one of the most promising sources of sustainable liquid transportation fuels. Algae have also been established as unique biofactories for industrial, therapeutic, and nutraceutical co-products. Chlamydomonas reinhardtii's long established role in the field of basic research in green algae has paved the way for understanding algal metabolism and developing genetic engineering protocols. These tools are now being utilized in C. reinhardtii and in other algal species for the development of strains to maximize biofuels and bio-products yields from the lab to the field.
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27
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Rasala BA, Mayfield SP. Photosynthetic biomanufacturing in green algae; production of recombinant proteins for industrial, nutritional, and medical uses. Photosynth Res 2015; 123:227-39. [PMID: 24659086 DOI: 10.1007/s11120-014-9994-7] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 03/03/2014] [Indexed: 05/18/2023]
Abstract
Recombinant proteins are widely used for industrial, nutritional, and medical applications. Green microalgae have attracted considerable attention recently as a biomanufacturing platform for the production of recombinant proteins for a number of reasons. These photosynthetic eukaryotic microorganisms are safe, scalable, easy to genetically modify through transformation, mutagenesis, or breeding, and inexpensive to grow. Many microalgae species are genetically transformable, but the green alga Chlamydomonas reinhardtii is the most widely used host for recombinant protein expression. An extensive suite of molecular genetic tools has been developed for C. reinhardtii over the last 25 years, including a fully sequenced genome, well-established methods for transformation, mutagenesis and breeding, and transformation vectors for high levels of recombinant protein accumulation and secretion. Here, we review recent successes in the development of C. reinhardtii as a biomanufacturing host for recombinant proteins, including antibodies and immunotoxins, hormones, industrial enzymes, an orally-active colostral protein for gastrointestinal health, and subunit vaccines. In addition, we review the biomanufacturing potential of other green algae from the genera Dunaliella and Chlorella.
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Affiliation(s)
- Beth A Rasala
- California Center for Algae Biotechnology and Division of Biological Sciences, University of California, 9500 Gilman Dr, La Jolla, San Diego, CA, 92093-0368, USA
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28
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Abstract
Simple and rapid extraction of lipids and hydrophobic metabolites from unmodified microbial and plant aqueous slurries was accomplished at a scale larger than ever previously reported.
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Affiliation(s)
- Nathan G. Schoepp
- Department of Chemistry & Biochemistry
- University of California San Diego
- La Jolla
- USA
- The California Center for Algae Biotechnology
| | - Wilson Wong
- Department of Chemistry & Biochemistry
- University of California San Diego
- La Jolla
- USA
| | - Stephen P. Mayfield
- The California Center for Algae Biotechnology
- University of California San Diego
- La Jolla
- USA
- Division of Biological Sciences
| | - Michael D. Burkart
- Department of Chemistry & Biochemistry
- University of California San Diego
- La Jolla
- USA
- The California Center for Algae Biotechnology
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29
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Barrera DJ, Rosenberg JN, Chiu JG, Chang YN, Debatis M, Ngoi SM, Chang JT, Shoemaker CB, Oyler GA, Mayfield SP. Algal chloroplast produced camelid VH H antitoxins are capable of neutralizing botulinum neurotoxin. Plant Biotechnol J 2015; 13:117-24. [PMID: 25229405 PMCID: PMC4620920 DOI: 10.1111/pbi.12244] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 06/11/2014] [Accepted: 07/16/2014] [Indexed: 05/18/2023]
Abstract
We have produced three antitoxins consisting of the variable domains of camelid heavy chain-only antibodies (VH H) by expressing the genes in the chloroplast of green algae. These antitoxins accumulate as soluble proteins capable of binding and neutralizing botulinum neurotoxin. Furthermore, they accumulate at up to 5% total soluble protein, sufficient expression to easily produce these antitoxins at scale from algae. The genes for the three different antitoxins were transformed into Chlamydomonas reinhardtii chloroplasts and their products purified from algae lysates and assayed for in vitro biological activity using toxin protection assays. The produced antibody domains bind to botulinum neurotoxin serotype A (BoNT/A) with similar affinities as camelid antibodies produced in Escherichia coli, and they are similarly able to protect primary rat neurons from intoxication by BoNT/A. Furthermore, the camelid antibodies were produced in algae without the use of solubilization tags commonly employed in E. coli. These camelid antibody domains are potent antigen-binding proteins and the heterodimer fusion protein containing two VH H domains was capable of neutralizing BoNT/A at near equimolar concentrations with the toxin. Intact antibody domains were detected in the gastrointestinal (GI) tract of mice treated orally with antitoxin-producing microalgae. These findings support the use of orally delivered antitoxins produced in green algae as a novel treatment for botulism.
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Affiliation(s)
- Daniel J Barrera
- Division of Biological Sciences, The California Center for Algae Biotechnology, UC-San Diego, La Jolla, CA, USA
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Specht EA, Nour-Eldin HH, Hoang KTD, Mayfield SP. An improved ARS2-derived nuclear reporter enhances the efficiency and ease of genetic engineering inChlamydomonas. Biotechnol J 2014; 10:473-9. [DOI: 10.1002/biot.201400172] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 08/11/2014] [Accepted: 09/15/2014] [Indexed: 01/11/2023]
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Gimpel JA, Hyun JS, Schoepp NG, Mayfield SP. Production of recombinant proteins in microalgae at pilot greenhouse scale. Biotechnol Bioeng 2014; 112:339-45. [DOI: 10.1002/bit.25357] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/19/2014] [Accepted: 07/22/2014] [Indexed: 12/22/2022]
Affiliation(s)
- Javier A. Gimpel
- California Center for Algae Biotechnology, Division of Biological Sciences; University of California; San Diego, 9500 Gilman Dr. La Jolla CA 92093-0368 California
| | - James S. Hyun
- California Center for Algae Biotechnology, Division of Biological Sciences; University of California; San Diego, 9500 Gilman Dr. La Jolla CA 92093-0368 California
| | - Nathan G. Schoepp
- California Center for Algae Biotechnology, Division of Biological Sciences; University of California; San Diego, 9500 Gilman Dr. La Jolla CA 92093-0368 California
| | - Stephen P. Mayfield
- California Center for Algae Biotechnology, Division of Biological Sciences; University of California; San Diego, 9500 Gilman Dr. La Jolla CA 92093-0368 California
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Schoepp NG, Stewart RL, Sun V, Quigley AJ, Mendola D, Mayfield SP, Burkart MD. System and method for research-scale outdoor production of microalgae and cyanobacteria. Bioresour Technol 2014; 166:273-281. [PMID: 24926599 DOI: 10.1016/j.biortech.2014.05.046] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/05/2014] [Accepted: 05/07/2014] [Indexed: 06/03/2023]
Abstract
Eukaryotic microalgae and cyanobacteria have recently reemerged as promising organisms in the effort to develop sustainable options for production of food and fuel. However, substantial discrepancies consistently arise between laboratory and outdoor cultivation, and gains demonstrated using laboratory technologies have not paralleled gains observed in field demonstrations. For these reasons, a low-maintenance system and process for research-scale outdoor cultivation of a variety of both freshwater and marine microalgae and cyanobacteria was developed. Nine genera were evaluated in the system, demonstrating cultivation of both laboratory model and commercial-production organisms. Hundreds to thousands of grams of dry biomass could be produced in a single growth cycle, suitable for a variety of uses including inoculum generation, protein production, and biofuel applications. Following testing in outdoor stock-ponds, Scenedesmus and Nannochloropsis were grown semi-continuously in an 8000 L airlift-driven raceway, yielding in total over 8 kg of dry biomass for each strain.
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Affiliation(s)
- Nathan G Schoepp
- Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States; The California Center for Algae Biotechnology, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States
| | - Ryan L Stewart
- The California Center for Algae Biotechnology, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States; Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States
| | - Vincent Sun
- The California Center for Algae Biotechnology, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States; Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States
| | - Alexandra J Quigley
- Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States; The California Center for Algae Biotechnology, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States
| | - Dominick Mendola
- The California Center for Algae Biotechnology, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States; Scripps Institute of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States
| | - Stephen P Mayfield
- The California Center for Algae Biotechnology, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States; Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States
| | - Michael D Burkart
- Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States; The California Center for Algae Biotechnology, University of California San Diego, 9500 Gilman Drive MC0368, La Jolla, CA 92093, United States.
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O'Sullivan T, Saddawi-Konefka R, Gross E, Tran M, Mayfield SP, Ikeda H, Bui JD. Interleukin-17D mediates tumor rejection through recruitment of natural killer cells. Cell Rep 2014; 7:989-98. [PMID: 24794441 DOI: 10.1016/j.celrep.2014.03.073] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 01/08/2014] [Accepted: 03/31/2014] [Indexed: 01/02/2023] Open
Abstract
The process of cancer immunoediting generates a repertoire of cancer cells that can persist in immune-competent hosts. In its most complex form, this process begins with the elimination of highly immunogenic unedited tumor cells followed by the escape of less immunogenic edited cells. Although edited tumors can release immunosuppressive factors, it is unknown whether unedited tumors produce cytokines that enhance antitumor function. Utilizing gene microarray analysis, we found the cytokine interleukin 17D (IL-17D) was highly expressed in certain unedited tumors but not in edited mouse tumor cell lines. Moreover, forced expression of IL-17D in edited tumor cells induced rejection by stimulating MCP-1 production from tumor endothelial cells, leading to the recruitment of natural killer (NK) cells. NK cells promoted M1 macrophage development and adaptive immune responses. IL-17D expression was also decreased in certain high-grade and metastatic human tumors, suggesting that it can be targeted for tumor immune therapy.
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Affiliation(s)
- Timothy O'Sullivan
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive MC 0612, La Jolla, CA 92093, USA
| | - Robert Saddawi-Konefka
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive MC 0612, La Jolla, CA 92093, USA
| | - Emilie Gross
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive MC 0612, La Jolla, CA 92093, USA
| | - Miller Tran
- Department of Biology, University of California, San Diego, 9500 Gilman Drive MC 0612, La Jolla, CA 92093, USA
| | - Stephen P Mayfield
- Department of Biology, University of California, San Diego, 9500 Gilman Drive MC 0612, La Jolla, CA 92093, USA
| | - Hiroaki Ikeda
- Department of Immuno-Gene Therapy, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
| | - Jack D Bui
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive MC 0612, La Jolla, CA 92093, USA.
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Rasala BA, Chao SS, Pier M, Barrera DJ, Mayfield SP. Enhanced genetic tools for engineering multigene traits into green algae. PLoS One 2014; 9:e94028. [PMID: 24710110 PMCID: PMC3978050 DOI: 10.1371/journal.pone.0094028] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 03/12/2014] [Indexed: 01/04/2023] Open
Abstract
Transgenic microalgae have the potential to impact many diverse biotechnological industries including energy, human and animal nutrition, pharmaceuticals, health and beauty, and specialty chemicals. However, major obstacles to sophisticated genetic and metabolic engineering in algae have been the lack of well-characterized transformation vectors to direct engineered gene products to specific subcellular locations, and the inability to robustly express multiple nuclear-encoded transgenes within a single cell. Here we validate a set of genetic tools that enable protein targeting to distinct subcellular locations, and present two complementary methods for multigene engineering in the eukaryotic green microalga Chlamydomonas reinhardtii. The tools described here will enable advanced metabolic and genetic engineering to promote microalgae biotechnology and product commercialization.
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Affiliation(s)
- Beth A. Rasala
- California Center for Algae Biotechnology and Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Syh-Shiuan Chao
- California Center for Algae Biotechnology and Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Matthew Pier
- California Center for Algae Biotechnology and Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Daniel J. Barrera
- California Center for Algae Biotechnology and Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Stephen P. Mayfield
- California Center for Algae Biotechnology and Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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Vinyard DJ, Gimpel J, Ananyev GM, Mayfield SP, Dismukes GC. Engineered Photosystem II reaction centers optimize photochemistry versus photoprotection at different solar intensities. J Am Chem Soc 2014; 136:4048-55. [PMID: 24548276 DOI: 10.1021/ja5002967] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The D1 protein of Photosystem II (PSII) provides most of the ligating amino acid residues for the Mn4CaO5 water-oxidizing complex (WOC) and half of the reaction center cofactors, and it is present as two isoforms in the cyanobacterium Synechococcus elongatus PCC 7942. These isoforms, D1:1 and D1:2, confer functional advantages for photosynthetic growth at low and high light intensities, respectively. D1:1, D1:2, and seven point mutations in the D1:2 background that are native to D1:1 were expressed in the green alga Chlamydomonas reinhardtii. We used these nine strains to show that those strains that confer a higher yield of PSII charge separation under light-limiting conditions (where charge recombination is significant) have less efficient photochemical turnover, measured in terms of both a lower WOC turnover probability and a longer WOC cycle period. Conversely, these same strains under light saturation (where charge recombination does not compete) confer a correspondingly faster O2 evolution rate and greater protection against photoinhibition. Taken together, the data clearly establish that PSII primary charge separation is a trade-off between photochemical productivity (water oxidation and plastoquinone reduction) and charge recombination (photoprotection). These trade-offs add up to a significant growth advantage for the two natural isoforms. These insights provide fundamental design principles for engineering of PSII reaction centers with optimal photochemical efficiencies for growth at low versus high light intensities.
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Affiliation(s)
- David J Vinyard
- Department of Chemistry and Chemical Biology and ‡Waksman Institute of Microbiology, Rutgers, The State University of New Jersey , Piscataway, New Jersey 08854, United States
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Abstract
Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for “molecular pharming” in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae could be poised to become the next candidate in recombinant subunit vaccine production, as they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and systemic immune reactivity.
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Affiliation(s)
- Elizabeth A Specht
- California Center for Algae Biotechnology, University of California at San Diego La Jolla, CA, USA
| | - Stephen P Mayfield
- California Center for Algae Biotechnology, University of California at San Diego La Jolla, CA, USA
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Gimpel JA, Specht EA, Georgianna DR, Mayfield SP. Advances in microalgae engineering and synthetic biology applications for biofuel production. Curr Opin Chem Biol 2013; 17:489-95. [DOI: 10.1016/j.cbpa.2013.03.038] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/18/2013] [Accepted: 03/28/2013] [Indexed: 01/17/2023]
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Gimpel JA, Specht EA, Georgianna DR, Mayfield SP. Advances in microalgae engineering and synthetic biology applications for biofuel production. Curr Opin Chem Biol 2013. [PMID: 23684717 DOI: 10.1016/j.cbpa.2013.03.0.38] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Among the technologies being examined to produce renewable fuels, microalgae are viewed by many in the scientific community as having the greatest potential to become economically viable. Algae are capable of producing greater than 50,000 kg/acre/year of biomass [1]. Additionally, most algae naturally accumulate energy-dense oils that can easily be converted into transportation fuels. To reach economic parity with fossil fuels there are still several challenges. These include identifying crop protection strategies, improving harvesting and oil extraction processes, and increasing biomass productivity and oil content. All of these challenges can be impacted by genetic, molecular, and ultimately synthetic biology techniques, and all of these technologies are being deployed to enable algal biofuels to become economically competitive with fossil fuels.
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Affiliation(s)
- Javier A Gimpel
- The San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
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40
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Rasala BA, Barrera DJ, Ng J, Plucinak TM, Rosenberg JN, Weeks DP, Oyler GA, Peterson TC, Haerizadeh F, Mayfield SP. Expanding the spectral palette of fluorescent proteins for the green microalga Chlamydomonas reinhardtii. Plant J 2013; 74:545-56. [PMID: 23521393 DOI: 10.1111/tpj.12165] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/14/2013] [Accepted: 02/19/2013] [Indexed: 05/21/2023]
Abstract
Fluorescent proteins (FPs) have become essential tools for a growing number of fields in biology. However, such tools have not been widely adopted for use in microalgal research. The aim of this study was to express and compare six FPs (blue mTagBFP, cyan mCerulean, green CrGFP, yellow Venus, orange tdTomato and red mCherry) in the popular model microalga Chlamydomonas reinhardtii. To circumvent the transgene silencing that often occurs in C. reinhardtii, the FPs were expressed from the nuclear genome as transcriptional fusions with the sh-ble antibiotic resistance gene, with the foot and mouth disease virus 2A self-cleaving sequence placed between the coding sequences. All ble-2A-FPs tested are well-expressed and efficiently processed to yield mature, unfused FPs that localize throughout the cytoplasm. The fluorescence signals of each FP were detectable in whole cells by fluorescence microplate reader analysis, live-cell fluorescence microscopy, and flow cytometry. Furthermore, we report a comparative analysis of fluorescence levels relative to auto-fluorescence for the chosen FPs. Finally, we demonstrate that the ble-2A expression vector may be used to fluorescently label an endogenous protein (α-tubulin). We show that the mCerulean-α-tubulin fusion protein localizes to the cytoskeleton and flagella, as expected, and that cells containing this fusion protein had normal cellular function. Overall, our results indicate that, by use of the ble-2A nuclear expression construct, a wide array of FP tools and technologies may be applied to microalgal research, opening up many possibilities for microalgal biology and biotechnology.
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Affiliation(s)
- Beth A Rasala
- The San Diego Center for Algae Biotechnology and Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0368, USA
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Abstract
Gene expression in chloroplasts is highly regulated during translation by sequence and secondary-structure elements in the 5' untranslated region (UTR) of mRNAs. These chloroplast mRNA 5' UTRs interact with nuclear-encoded factors to regulate mRNA processing, stability, and translation initiation. Although several UTR elements in chloroplast mRNAs have been identified by site-directed mutagenesis, the complete set of elements required for expression of plastid mRNAs remains undefined. Here we present a synthetic biology approach using an arrayed oligonucleotide library to examine in vivo hundreds of designed variants of endogenous UTRs from Chlamydomonas reinhardtii and quantitatively identify essential regions through next-generation sequencing of thousands of mutants. We validate this strategy by characterizing the relatively well-studied 5' UTR of the psbD mRNA encoding the D2 protein in photosystem II and find that our analysis generally agrees with previous work identifying regions of importance but significantly expands and clarifies the boundaries of these regulatory regions. We then use this strategy to characterize the previously unstudied psaA 5' UTR and obtain a detailed map of regions essential for both positive and negative regulation. This analysis can be performed in a high-throughput manner relative to previous site-directed mutagenesis methods, enabling compilation of a large unbiased data set of regulatory elements of chloroplast gene expression. Finally, we create a novel synthetic UTR based on aggregate sequence analysis from the libraries and demonstrate that it significantly increases accumulation of an exogenous protein, attesting to the utility of this strategy for enhancing protein production in algal chloroplasts.
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Affiliation(s)
- Elizabeth A. Specht
- The San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California San Diego, La Jolla, California 92093, United States
| | - Stephen P. Mayfield
- The San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California San Diego, La Jolla, California 92093, United States
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Georgianna DR, Hannon MJ, Marcuschi M, Wu S, Botsch K, Lewis AJ, Hyun J, Mendez M, Mayfield SP. Production of recombinant enzymes in the marine alga Dunaliella tertiolecta. ALGAL RES 2013. [DOI: 10.1016/j.algal.2012.10.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Vinyard DJ, Gimpel J, Ananyev GM, Cornejo MA, Golden SS, Mayfield SP, Dismukes GC. Natural variants of photosystem II subunit D1 tune photochemical fitness to solar intensity. J Biol Chem 2012; 288:5451-62. [PMID: 23271739 DOI: 10.1074/jbc.m112.394668] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photosystem II (PSII) is composed of six core polypeptides that make up the minimal unit capable of performing the primary photochemistry of light-driven charge separation and water oxidation in all oxygenic phototrophs. The D1 subunit of this complex contains most of the ligating amino acid residues for the Mn(4)CaO(5) core of the water-oxidizing complex (WOC). Most cyanobacteria have 3-5 copies of the psbA gene coding for at least two isoforms of D1, whereas algae and plants have only one isoform. Synechococcus elongatus PCC 7942 contains two D1 isoforms; D1:1 is expressed under low light conditions, and D1:2 is up-regulated in high light or stress conditions. Using a heterologous psbA expression system in the green alga Chlamydomonas reinhardtii, we have measured growth rate, WOC cycle efficiency, and O(2) yield as a function of D1:1, D1:2, or the native algal D1 isoform. D1:1-PSII cells outcompete D1:2-PSII cells and accumulate more biomass in light-limiting conditions. However, D1:2-PSII cells easily outcompete D1:1-PSII cells at high light intensities. The native C. reinhardtii-PSII WOC cycles less efficiently at all light intensities and produces less O(2) than either cyanobacterial D1 isoform. D1:2-PSII makes more O(2) per saturating flash than D1:1-PSII, but it exhibits lower WOC cycling efficiency at low light intensities due to a 40% faster charge recombination rate in the S(3) state. These functional advantages of D1:1-PSII and D1:2-PSII at low and high light regimes, respectively, can be explained by differences in predicted redox potentials of PSII electron acceptors that control kinetic performance.
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Affiliation(s)
- David J Vinyard
- Department of Chemistry and Chemical Biology, State University of New Jersey, Piscataway, New Jersey 08854, USA
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Abstract
The basic photosynthetic apparatus is highly conserved across all photosynthetic organisms, and this conservation can be seen in both protein composition and amino acid sequence. Conservation of regulatory elements also seems possible in chloroplast genes, as many mRNA untranslated regions (UTRs) appear to have similar structural elements. The D1 protein of Photosystem II (psbA gene) is a highly conserved core reaction center protein that shows very similar regulation from cyanobacteria through higher plants. We engineered full and partial psbA genes from a diverse set of photosynthetic organisms into a psbA deficient strain of Chlamydomonas reinhardtii. Analysis of D1 protein accumulation and photosynthetic growth revealed that coding sequences and promoters are interchangeable even between anciently diverged species. On the other hand functional recognition of 5' UTRs is limited to closely related organisms. Furthermore transformation of heterologous promoters and 5' UTRs from the atpA, tufA and psbD genes conferred psbA mRNA accumulation but not translation. Overall, our results show that heterologous D1 proteins can be expressed and complement Photosystem II function in green algae, while RNA regulatory elements appear to be very specific and function only from closely related species. Nonetheless, there is great potential for the expression of heterologous photosynthetic coding sequences for studying and modifying photosynthesis in C. reinhardtii chloroplasts.
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Affiliation(s)
- Javier A Gimpel
- San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0368, USA
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Blatti JL, Beld J, Behnke CA, Mendez M, Mayfield SP, Burkart MD. Manipulating fatty acid biosynthesis in microalgae for biofuel through protein-protein interactions. PLoS One 2012; 7:e42949. [PMID: 23028438 PMCID: PMC3441505 DOI: 10.1371/journal.pone.0042949] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 07/16/2012] [Indexed: 02/04/2023] Open
Abstract
Microalgae are a promising feedstock for renewable fuels, and algal metabolic engineering can lead to crop improvement, thus accelerating the development of commercially viable biodiesel production from algae biomass. We demonstrate that protein-protein interactions between the fatty acid acyl carrier protein (ACP) and thioesterase (TE) govern fatty acid hydrolysis within the algal chloroplast. Using green microalga Chlamydomonas reinhardtii (Cr) as a model, a structural simulation of docking CrACP to CrTE identifies a protein-protein recognition surface between the two domains. A virtual screen reveals plant TEs with similar in silico binding to CrACP. Employing an activity-based crosslinking probe designed to selectively trap transient protein-protein interactions between the TE and ACP, we demonstrate in vitro that CrTE must functionally interact with CrACP to release fatty acids, while TEs of vascular plants show no mechanistic crosslinking to CrACP. This is recapitulated in vivo, where overproduction of the endogenous CrTE increased levels of short-chain fatty acids and engineering plant TEs into the C. reinhardtii chloroplast did not alter the fatty acid profile. These findings highlight the critical role of protein-protein interactions in manipulating fatty acid biosynthesis for algae biofuel engineering as illuminated by activity-based probes.
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Affiliation(s)
- Jillian L. Blatti
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America
| | - Joris Beld
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America
| | - Craig A. Behnke
- Sapphire Energy Inc., San Diego, California, United States of America
| | - Michael Mendez
- Sapphire Energy Inc., San Diego, California, United States of America
| | - Stephen P. Mayfield
- Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Michael D. Burkart
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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Abstract
Modern life is intimately linked to the availability of fossil fuels, which continue to meet the world's growing energy needs even though their use drives climate change, exhausts finite reserves and contributes to global political strife. Biofuels made from renewable resources could be a more sustainable alternative, particularly if sourced from organisms, such as algae, that can be farmed without using valuable arable land. Strain development and process engineering are needed to make algal biofuels practical and economically viable.
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Affiliation(s)
- D Ryan Georgianna
- San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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Jones CS, Mayfield SP. Algae biofuels: versatility for the future of bioenergy. Curr Opin Biotechnol 2012; 23:346-51. [DOI: 10.1016/j.copbio.2011.10.013] [Citation(s) in RCA: 299] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 10/17/2011] [Accepted: 10/28/2011] [Indexed: 11/24/2022]
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Jones CS, Luong T, Hannon M, Tran M, Gregory JA, Shen Z, Briggs SP, Mayfield SP. Heterologous expression of the C-terminal antigenic domain of the malaria vaccine candidate Pfs48/45 in the green algae Chlamydomonas reinhardtii. Appl Microbiol Biotechnol 2012; 97:1987-95. [DOI: 10.1007/s00253-012-4071-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 03/28/2012] [Accepted: 03/29/2012] [Indexed: 12/18/2022]
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Jones CS, Mayfield SP. Steps toward a globally available malaria vaccine: harnessing the potential of algae for future low cost vaccines. Bioengineered 2012; 4:164-7. [PMID: 23090388 DOI: 10.4161/bioe.22577] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Malaria is an infectious disease that threatens half of the world's population. This debilitating disease is caused by infection from parasites of the genus Plasmodium. Insecticides, bed nets and drug therapies have lowered the prevalence and death rate associated with malaria but this disease continues to plague many populations around the world. In recent years, many organizations have suggested developing methods for a complete eradication of malaria. The most straightforward and effective method for this potential eradication will be through the development of a low-cost vaccine. To achieve eradication, it will be necessary to develop new vaccine candidates and novel systems for both the production and delivery of these vaccines. Recently, the green algae Chlamydomonas reinhardtii has been used for the recombinant expression of malaria vaccine candidates including the transmission blocking vaccine candidate Pfs48/45. Here, we discuss the potential of this research on the future development of a low-cost malaria vaccine candidate.
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Affiliation(s)
- Carla S Jones
- The San Diego Center for Algae Biotechnology and the Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
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Yu WL, Ansari W, Schoepp NG, Hannon MJ, Mayfield SP, Burkart MD. Modifications of the metabolic pathways of lipid and triacylglycerol production in microalgae. Microb Cell Fact 2011; 10:91. [PMID: 22047615 PMCID: PMC3234195 DOI: 10.1186/1475-2859-10-91] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 11/02/2011] [Indexed: 01/03/2023] Open
Abstract
Microalgae have presented themselves as a strong candidate to replace diminishing oil reserves as a source of lipids for biofuels. Here we describe successful modifications of terrestrial plant lipid content which increase overall lipid production or shift the balance of lipid production towards lipid varieties more useful for biofuel production. Our discussion ranges from the biosynthetic pathways and rate limiting steps of triacylglycerol formation to enzymes required for the formation of triacylglycerol containing exotic lipids. Secondarily, we discuss techniques for genetic engineering and modification of various microalgae which can be combined with insights gained from research in higher plants to aid in the creation of production strains of microalgae.
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Affiliation(s)
- Wei-Luen Yu
- Department of Chemistry & Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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