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Renganathan P, Puente EOR, Sukhanova NV, Gaysina LA. Hydroponics with Microalgae and Cyanobacteria: Emerging Trends and Opportunities in Modern Agriculture. BIOTECH 2024; 13:27. [PMID: 39051342 PMCID: PMC11270261 DOI: 10.3390/biotech13030027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 07/09/2024] [Accepted: 07/16/2024] [Indexed: 07/27/2024] Open
Abstract
The global population is expected to reach 9.5 billion, which means that crop productivity needs to double to meet the growing population's food demand. Soil degradation and environmental factors, such as climate events, significantly threaten crop production and global food security. Furthermore, rapid urbanization has led to 55% of the world's population migrating to cities, and this proportion is expected to increase to 75% by 2050, which presents significant challenges in producing staple foods through conventional hinterland farming. Numerous studies have proposed various sustainable farming techniques to combat the shortage of farmable land and increase food security in urban areas. Soilless farming techniques such as hydroponics have gained worldwide popularity due to their resource efficiency and production of superior-quality fresh products. However, using chemical nutrients in a conventional hydroponic system can have significant environmental impacts, including eutrophication and resource depletion. Incorporating microalgae into hydroponic systems as biostimulants offers a sustainable and ecofriendly approach toward circular bioeconomy strategies. The present review summarizes the plant growth-promoting activity of microalgae as biostimulants and their mechanisms of action. We discuss their effects on plant growth parameters under different applications, emphasizing the significance of integrating microalgae into a closed-loop circular economy model to sustainably meet global food demands.
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Affiliation(s)
- Prabhaharan Renganathan
- Department of Bioecology and Biological Education, M. Akmullah Bashkir State Pedagogical University, 450000 Ufa, Russia; (P.R.); (N.V.S.)
| | - Edgar Omar Rueda Puente
- Departamento de Agricultura y Ganadería, Universidad de Sonora, Blvd. Luis Encinas y Rosales, Hermosillo 83000, Sonora, Mexico;
| | - Natalia V. Sukhanova
- Department of Bioecology and Biological Education, M. Akmullah Bashkir State Pedagogical University, 450000 Ufa, Russia; (P.R.); (N.V.S.)
| | - Lira A. Gaysina
- Department of Bioecology and Biological Education, M. Akmullah Bashkir State Pedagogical University, 450000 Ufa, Russia; (P.R.); (N.V.S.)
- All-Russian Research Institute of Phytopathology, 143050 Bolshye Vyazemy, Russia
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2
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Rajput BK, Ikram SF, Tripathi BN. Harnessing the potential of microalgae for the production of monoclonal antibodies and other recombinant proteins. PROTOPLASMA 2024:10.1007/s00709-024-01967-6. [PMID: 38970700 DOI: 10.1007/s00709-024-01967-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 06/25/2024] [Indexed: 07/08/2024]
Abstract
Monoclonal antibodies (mAbs) have become indispensable tools in various fields, from research to therapeutics, diagnostics, and industries. However, their production, primarily in mammalian cell culture systems, is cost-intensive and resource-demanding. Microalgae, diverse photosynthetic microorganisms, are gaining attention as a favorable option for manufacturing mAbs and various other recombinant proteins. This review explores the potential of microalgae as a robust expression system for biomanufacturing high-value proteins. It also highlights the diversity of microalgae species suitable for recombinant protein. Nuclear and chloroplast genomes of some microalgae have been engineered to express mAbs and other valuable proteins. Codon optimization, vector construction, and other genetic engineering techniques have significantly improved recombinant protein expression in microalgae. These accomplishments demonstrate the potential of microalgae for biopharmaceutical manufacturing. Microalgal biotechnology holds promise for revolutionizing the production of mAbs and other therapeutic proteins, offering a sustainable and cost-effective solution to address critical healthcare needs.
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Affiliation(s)
- Balwinder Kaur Rajput
- Department of Biotechnology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh, 484887, India
| | - Sana Fatima Ikram
- Department of Biotechnology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh, 484887, India
| | - Bhumi Nath Tripathi
- Department of Biotechnology, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh, 484887, India.
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3
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Zedler JAZ, Schirmacher AM, Russo DA, Hodgson L, Gundersen E, Matthes A, Frank S, Verkade P, Jensen PE. Self-Assembly of Nanofilaments in Cyanobacteria for Protein Co-localization. ACS NANO 2023; 17:25279-25290. [PMID: 38065569 PMCID: PMC10754207 DOI: 10.1021/acsnano.3c08600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 11/12/2023] [Accepted: 11/15/2023] [Indexed: 12/27/2023]
Abstract
Cyanobacteria offer great potential as alternative biotechnological hosts due to their photoautotrophic capacities. However, in comparison to established heterotrophic hosts, several key aspects, such as product titers, are still lagging behind. Nanobiotechnology is an emerging field with great potential to improve existing hosts, but so far, it has barely been explored in microbial photosynthetic systems. Here, we report the establishment of large proteinaceous nanofilaments in the unicellular model cyanobacterium Synechocystis sp. PCC 6803 and the fast-growing cyanobacterial strain Synechococcus elongatus UTEX 2973. Transmission electron microscopy and electron tomography demonstrated that expression of pduA*, encoding a modified bacterial microcompartment shell protein, led to the generation of bundles of longitudinally aligned nanofilaments in S. elongatus UTEX 2973 and shorter filamentous structures in Synechocystis sp. PCC 6803. Comparative proteomics showed that PduA* was at least 50 times more abundant than the second most abundant protein in the cell and that nanofilament assembly had only a minor impact on cellular metabolism. Finally, as a proof-of-concept for co-localization with the filaments, we targeted a fluorescent reporter protein, mCitrine, to PduA* by fusion with an encapsulation peptide that natively interacts with PduA. The establishment of nanofilaments in cyanobacterial cells is an important step toward cellular organization of heterologous pathways and the establishment of cyanobacteria as next-generation hosts.
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Affiliation(s)
- Julie A. Z. Zedler
- Synthetic
Biology of Photosynthetic Organisms, Matthias Schleiden Institute
for Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Alexandra M. Schirmacher
- Synthetic
Biology of Photosynthetic Organisms, Matthias Schleiden Institute
for Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - David A. Russo
- Bioorganic
Analytics, Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Lorna Hodgson
- School
of Biochemistry, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Emil Gundersen
- Department
of Plant and Environmental Sciences, University
of Copenhagen, 1871 Frederiksberg, Denmark
| | - Annemarie Matthes
- Department
of Plant and Environmental Sciences, University
of Copenhagen, 1871 Frederiksberg, Denmark
| | - Stefanie Frank
- Department
of Biochemical Engineering, University College
London, London, WC1E 6BT, United
Kingdom
| | - Paul Verkade
- School
of Biochemistry, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Poul Erik Jensen
- Department
of Food Science, University of Copenhagen, 1958 Frederiksberg, Denmark
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4
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Van de Poel B, de Vries J. Evolution of ethylene as an abiotic stress hormone in streptophytes. ENVIRONMENTAL AND EXPERIMENTAL BOTANY 2023; 214:105456. [PMID: 37780400 PMCID: PMC10518463 DOI: 10.1016/j.envexpbot.2023.105456] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 10/03/2023]
Abstract
All land plants modulate their growth and physiology through intricate signaling cascades. The majority of these are at least modulated-and often triggered-by phytohormones. Over the past decade, it has become apparent that some phytohormones have an evolutionary origin that runs deeper than plant terrestrialization-many emerged in the streptophyte algal progenitors of land plants. Ethylene is such a case. Here we synthesize the current knowledge on the evolution of the phytohormone ethylene and speculate about its deeply conserved role in adjusting stress responses of streptophytes for more than half a billion years of evolution.
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Affiliation(s)
- Bram Van de Poel
- Molecular Plant Hormone Physiology lab, Division of Crop Biotechnics, Department of Biosystems, University of Leuven, Willem de Croylaan 42, 3001 Leuven, Belgium
- KU Leuven Plant Institute (LPI), University of Leuven, Kasteelpark Arenberg 31, 3001 Leuven, Belgium
| | - Jan de Vries
- University of Goettingen, Institute for Microbiology and Genetics, Department of Applied Bioinformatics, Goldschmidtstr. 1, 37077 Goettingen, Germany
- University of Goettingen, Campus Institute Data Science (CIDAS), Goldschmidstr. 1, 37077 Goettingen, Germany
- University of Goettingen, Goettingen Center for Molecular Biosciences (GZMB), Department of Applied Bioinformatics, Goldschmidtstr. 1, 37077 Goettingen, Germany
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5
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Patel VK, Das A, Kumari R, Kajla S. Recent progress and challenges in CRISPR-Cas9 engineered algae and cyanobacteria. ALGAL RES 2023. [DOI: 10.1016/j.algal.2023.103068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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6
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Vamsi Bharadwaj S, Tiwari DS, Ghosh T, Mishra S. Construction of pSM201v: A broad host range replicative vector based on shortening of RSF1010. Heliyon 2023; 9:e14637. [PMID: 37025788 PMCID: PMC10070531 DOI: 10.1016/j.heliyon.2023.e14637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/06/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
Despite possessing attractive features such as autotrophic growth on minimal media, industrial applications of cyanobacteria are hindered by a lack of genetic manipulative tools. There are two important features that are important for an effective manipulation: a vector which can carry the gene, and an induction system activated through external stimuli, giving us control over the expression. In this study, we describe the construction of an improved RSF1010-based vector as well as a temperature-inducible RNA thermometer. RSF1010 is a well-studied incompatibility group Q (IncQ) vector, capable of replication in most Gram negative, and some Gram positive bacteria. Our designed vector, named pSM201v, can be used as an expression vector in some Gram positive and a wide range of Gram negative bacteria including cyanobacteria. An induction system activated via physical external stimuli such as temperature, allows precise control of overexpression. pSM201v addresses several drawbacks of the RSF1010 plasmid; it has a reduced backbone size of 5189 bp compared to 8684 bp of the original plasmid, which provides more space for cloning and transfer of cargo DNA into the host organism. The mobilization function, required for plasmid transfer into several cyanobacterial strains, is reduced to a 99 bp region, as a result that mobilization of this plasmid is no longer linked to the plasmid replication. The RNA thermometer, named DTT1, is based on a RNA hairpin strategy that prevents expression of downstream genes at temperatures below 30 °C. Such RNA elements are expected to find applications in biotechnology to economically control gene expression in a scalable manner.
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7
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Cui Y, Jiang Y, Xiao M, Munir MZ, Riaz S, Rasul F, Daroch M. Discovery of Five New Ethylene-Forming Enzymes for Clean Production of Ethylene in E. coli. Int J Mol Sci 2022; 23:4500. [PMID: 35562889 PMCID: PMC9101411 DOI: 10.3390/ijms23094500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 12/04/2022] Open
Abstract
Ethylene is an essential platform chemical with a conjugated double bond, which can produce many secondary chemical products through copolymerisation. At present, ethylene production is mainly from petroleum fractionation and cracking, which are unsustainable in the long term, and harmful to our environment. Therefore, a hot research field is seeking a cleaner method for ethylene production. Based on the model ethylene-forming enzyme (Efe) AAD16440.1 (6vp4.1.A) from Pseudomonas syringae pv. phaseolicol, we evaluated five putative Efe protein sequences using the data derived from phylogenetic analyses and the conservation of their catalytic structures. Then, pBAD expression frameworks were constructed, and relevant enzymes were expressed in E. coli BL21. Finally, enzymatic activity in vitro and in vivo was detected to demonstrate their catalytic activity. Our results show that the activity in vitro measured by the conversion of α-ketoglutarate was from 0.21-0.72 μmol ethylene/mg/min, which varied across the temperatures. In cells, the activity of the new Efes was 12.28-147.43 μmol/gDCW/h (DCW, dry cellular weight). Both results prove that all the five putative Efes could produce ethylene.
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Affiliation(s)
| | | | | | | | | | | | - Maurycy Daroch
- School of Environment and Energy, Peking University Shenzhen Graduate School, 2199 Lishui Rd., Shenzhen 518055, China; (Y.C.); (Y.J.); (M.X.); (M.Z.M.); (S.R.); (F.R.)
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8
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The Molecular Toolset and Techniques Required to Build Cyanobacterial Cell Factories. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2022. [DOI: 10.1007/10_2022_210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Patyi G, Hódi B, Solymosi D, Vass I, Kós PB. Increased sensitivity of heavy metal bioreporters in transporter deficient Synechocystis PCC6803 mutants. PLoS One 2021; 16:e0261135. [PMID: 34914753 PMCID: PMC8675649 DOI: 10.1371/journal.pone.0261135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/28/2021] [Indexed: 11/30/2022] Open
Abstract
The detection and identification of heavy metal contaminants are becoming increasingly important as environmental pollution causes an ever-increasing health hazard in the last decades. Bacterial heavy metal reporters, which constitute an environmentally friendly and cheap approach, offer great help in this process. Although their application has great potential in the detection of heavy metal contamination, their sensitivity still needs to be improved. In this study, we describe a simple molecular biology approach to improve the sensitivity of bacterial heavy metal biosensors. The constructs are luxAB marker genes regulated by the promoters of heavy metal exporter genes. We constructed a mutant strain lacking the cluster of genes responsible for heavy metal transport and hence achieved increased intracellular heavy metal content of the Synechocystis PCC6803 cyanobacterium. Taking advantage of this increased intracellular heavy metal concentration the Ni2+; Co2+ and Zn2+ detection limits of the constructs were three to tenfold decreased compared to the sensitivity of the same constructs in the wild-type cyanobacterium.
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Affiliation(s)
- Gábor Patyi
- Institute of Plant Biology, Biological Research Centre of the Eötvös Lóránd Research Network, Szeged, Hungary
- Faculty of Science and Informatics, Doctoral School in Biology, University of Szeged, Szeged, Hungary
| | - Barbara Hódi
- Institute of Plant Biology, Biological Research Centre of the Eötvös Lóránd Research Network, Szeged, Hungary
- Faculty of Science and Informatics, Doctoral School in Biology, University of Szeged, Szeged, Hungary
| | - Dániel Solymosi
- Institute of Plant Biology, Biological Research Centre of the Eötvös Lóránd Research Network, Szeged, Hungary
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre of the Eötvös Lóránd Research Network, Szeged, Hungary
| | - Péter B. Kós
- Institute of Plant Biology, Biological Research Centre of the Eötvös Lóránd Research Network, Szeged, Hungary
- Department of Biotechnology, Faculty of Science and Informatics, Szeged University, Szeged, Hungary
- * E-mail:
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10
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Development of a highly sensitive luciferase-based reporter system to study two-step protein secretion in cyanobacteria. J Bacteriol 2021; 204:e0050421. [PMID: 34898262 DOI: 10.1128/jb.00504-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyanobacteria, ubiquitous oxygenic photosynthetic bacteria, interact with the environment and their surrounding microbiome through the secretion of a variety of small molecules and proteins. The release of these compounds is mediated by sophisticated multi-protein complexes, also known as secretion systems. Genomic analyses indicate that protein and metabolite secretion systems are widely found in cyanobacteria; however little is known regarding their function, regulation and secreted effectors. One such system, the type IVa pilus system (T4aPS), is responsible for the assembly of dynamic cell surface appendages, type IVa pili (T4aP), that mediate ecologically relevant processes such as phototactic motility, natural competence and adhesion. Several studies have suggested that the T4aPS can also act as a two-step protein secretion system in cyanobacteria akin to the homologous type II secretion system in heterotrophic bacteria. To determine whether the T4aP are involved in two-step secretion of non-pilin proteins, we developed a NanoLuc-based quantitative secretion reporter for the model cyanobacterium Synechocystis sp. PCC 6803. The NLuc reporter presented a wide dynamic range with at least one order of magnitude more sensitivity than traditional immunoblotting. Application of the reporter to a collection of Synechocystis T4aPS mutants demonstrated that the two-step secretion of NLuc is independent of T4aP. In addition, our data suggest that secretion differences typically observed in T4aPS mutants are likely due to a disruption of cell envelope homeostasis. This study opens the door to explore protein secretion in cyanobacteria further. Importance Protein secretion allows bacteria to interact and communicate with the external environment. Secretion is also biotechnologically relevant, where it is often beneficial to target proteins to the extracellular space. Due to a shortage of quantitative assays, many aspects of protein secretion are not understood. Here we introduce a NanoLuc (NLuc)-based secretion reporter in cyanobacteria. NLuc is highly sensitive and can be assayed rapidly and in small volumes. The NLuc reporter allowed us to clarify the role of type IVa pili in protein secretion and identify mutations that increase secretion yield. This study expands our knowledge on cyanobacterial secretion and offers a valuable tool for future studies of protein secretion systems in cyanobacteria.
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11
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Sawant KR, Savvashe P, Pal D, Sarnaik A, Lali A, Pandit R. Progressive transitional studies of engineered Synechococcus from laboratory to outdoor pilot-scale cultivation for production of ethylene. BIORESOURCE TECHNOLOGY 2021; 341:125852. [PMID: 34479144 DOI: 10.1016/j.biortech.2021.125852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/21/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Cyanobacterial research is impeded by the substantial discrepancies between laboratory studies and outdoor performances, despite successful demonstrations of genetically engineered strains for array of compounds. Therefore, evaluation of adaptive responses is necessary to achieve outdoor scale-up cultivation of cyanobacteria. Under current study, cyanobacterium Synechococcus elongatusPCC7942 engineered for ethylene biosynthesis, was gradually acclimatised, ensuring sustained and progressive transition from laboratory to outdoor conditions. Bubble size of 4.9 ± 0.2 mm and air-flow rate of 0.05 vvm in BG11 supplemented with 5 g/L bicarbonate giving mass transfer coefficient (KLa) of 10.48 h-1 yielded highest specific growth rate (0.24 h-1) with the transformants. At the 100 L photobioreactor scale, ethylene productivity of 1.5 mL.L-1.h-1 was achieved. A comprehensive investigation on photosynthetic responses of the transformants adapted to the outdoor conditions exhibited interesting photosynthetic electron transport regulations, involving antenna density modulation in response to diurnal and dynamic light transitions, indicating successful transition.
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Affiliation(s)
- Kaustubh R Sawant
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, 400019, India
| | - Prashant Savvashe
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, 400019, India; Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai, 400019, India
| | - Divyani Pal
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, 400019, India
| | - Aditya Sarnaik
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, 400019, India; Chemical Engineering Department, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA
| | - Arvind Lali
- Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai, 400019, India
| | - Reena Pandit
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, 400019, India.
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12
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Cross-Activation of Two Nitrogenase Gene Clusters by CnfR1 or CnfR2 in the Cyanobacterium Anabaena variabilis. Microbiol Spectr 2021; 9:e0106021. [PMID: 34612667 PMCID: PMC8510180 DOI: 10.1128/spectrum.01060-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Anabaena variabilis, the nif1 genes, which are activated by CnfR1, produce a Mo-nitrogenase that is expressed only in heterocysts. Similarly, the nif2 genes, which are activated by CnfR2, make a Mo-nitrogenase that is expressed only in anaerobic vegetative cells. However, CnfR1, when it was expressed in anaerobic vegetative cells under the control of the cnfR2 promoter or from the Co2+-inducible coaT promoter, activated the expression of both nifB1 and nifB2. Activation of nifB2, but not nifB1, by CnfR1 required NtcA. Thus, expression of the nif1 system requires no heterocyst-specific factor other than CnfR1. In contrast, CnfR2, when it was expressed in heterocysts under the control of the cnfR1 promoter or from the coaT promoter, did not activate the expression of nifB1 or nifB2. Thus, activation of the nif2 system in anaerobic vegetative cells by CnfR2 requires additional factors absent in heterocysts. CnfR2 made from the coaT promoter activated nifB2 expression in anaerobic vegetative cells grown with fixed nitrogen; however, oxygen inhibited CnfR2 activation of nifB2 expression. In contrast, activation of nifB1 and nifB2 by CnfR1 was unaffected by oxygen. CnfR1, which does not activate the nifB2 promoter in heterocysts, activated the expression of the entire nif2 gene cluster from a nifB2::nifB1::nifB2 hybrid promoter in heterocysts, producing functional Nif2 nitrogenase in heterocysts. However, activity was poor compared to the normal Nif1 nitrogenase. Expression of the nif2 cluster in anaerobic vegetative cells of Nostoc sp. PCC 7120, a strain lacking the nif2 nitrogenase, resulted in expression of the nif2 genes but weak nitrogenase activity. IMPORTANCE Cyanobacterial nitrogen fixation is important in the global nitrogen cycle, in oceanic productivity, and in many plant and fungal symbioses. While the proteins that mediate nitrogen fixation have been well characterized, the regulation of this complex and expensive process is poorly understood in cyanobacteria. Using a genetic approach, we have characterized unique and overlapping functions for two homologous transcriptional activators CnfR1 and CnfR2 that activate two distinct nitrogenases in a single organism. We found that CnfR1 is promiscuous in its ability to activate both nitrogenase systems, whereas CnfR2 depends on additional cellular factors; thus, it activates only one nitrogenase system.
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13
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Kallio P, Kugler A, Pyytövaara S, Stensjö K, Allahverdiyeva Y, Gao X, Lindblad P, Lindberg P. Photoautotrophic production of renewable ethylene by engineered cyanobacteria: Steering the cell metabolism towards biotechnological use. PHYSIOLOGIA PLANTARUM 2021; 173:579-590. [PMID: 33864400 DOI: 10.1111/ppl.13430] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/05/2021] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
Ethylene is a volatile hydrocarbon with a massive global market in the plastic industry. The ethylene now used for commercial applications is produced exclusively from nonrenewable petroleum sources, while competitive biotechnological production systems do not yet exist. This review focuses on the currently developed photoautotrophic bioproduction strategies that enable direct solar-driven conversion of CO2 into ethylene, based on the use of genetically engineered photosynthetic cyanobacteria expressing heterologous ethylene forming enzyme (EFE) from Pseudomonas syringae. The emphasis is on the different engineering strategies to express EFE and to direct the cellular carbon flux towards the primary metabolite 2-oxoglutarate, highlighting associated metabolic constraints, and technical considerations on cultivation strategies and conditional parameters. While the research field has progressed towards more robust strains with better production profiles, and deeper understanding of the associated metabolic limitations, it is clear that there is room for significant improvement to reach industrial relevance. At the same time, existing information and the development of synthetic biology tools for engineering cyanobacteria open new possibilities for improving the prospects for the sustainable production of renewable ethylene.
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Affiliation(s)
- Pauli Kallio
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Amit Kugler
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Uppsala, Sweden
| | - Samuli Pyytövaara
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Karin Stensjö
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Uppsala, Sweden
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Xiang Gao
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Uppsala, Sweden
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, China
| | - Peter Lindblad
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Uppsala, Sweden
| | - Pia Lindberg
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Uppsala, Sweden
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14
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A guanidine-degrading enzyme controls genomic stability of ethylene-producing cyanobacteria. Nat Commun 2021; 12:5150. [PMID: 34446715 PMCID: PMC8390497 DOI: 10.1038/s41467-021-25369-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 08/05/2021] [Indexed: 11/17/2022] Open
Abstract
Recent studies have revealed the prevalence and biological significance of guanidine metabolism in nature. However, the metabolic pathways used by microbes to degrade guanidine or mitigate its toxicity have not been widely studied. Here, via comparative proteomics and subsequent experimental validation, we demonstrate that Sll1077, previously annotated as an agmatinase enzyme in the model cyanobacterium Synechocystis sp. PCC 6803, is more likely a guanidinase as it can break down guanidine rather than agmatine into urea and ammonium. The model cyanobacterium Synechococcus elongatus PCC 7942 strain engineered to express the bacterial ethylene-forming enzyme (EFE) exhibits unstable ethylene production due to toxicity and genomic instability induced by accumulation of the EFE-byproduct guanidine. Co-expression of EFE and Sll1077 significantly enhances genomic stability and enables the resulting strain to achieve sustained high-level ethylene production. These findings expand our knowledge of natural guanidine degradation pathways and demonstrate their biotechnological application to support ethylene bioproduction. The metabolic pathways used by microbes to degrade guanidine or mitigate its toxicity remain unclear. Here, the authors report a guanidine degrading enzyme that controls genomic stability of ethylene producing cyanobacterial strains.
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15
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Nagy C, Thiel K, Mulaku E, Mustila H, Tamagnini P, Aro EM, Pacheco CC, Kallio P. Comparison of alternative integration sites in the chromosome and the native plasmids of the cyanobacterium Synechocystis sp. PCC 6803 in respect to expression efficiency and copy number. Microb Cell Fact 2021; 20:130. [PMID: 34246263 PMCID: PMC8272380 DOI: 10.1186/s12934-021-01622-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/29/2021] [Indexed: 11/10/2022] Open
Abstract
Background Synechocystis sp. PCC 6803 provides a well-established reference point to cyanobacterial metabolic engineering as part of basic photosynthesis research, as well as in the development of next-generation biotechnological production systems. This study focused on expanding the current knowledge on genomic integration of expression constructs in Synechocystis, targeting a range of novel sites in the chromosome and in the native plasmids, together with established loci used in literature. The key objective was to obtain quantitative information on site-specific expression in reference to replicon copy numbers, which has been speculated but never compared side by side in this host. Results An optimized sYFP2 expression cassette was successfully integrated in two novel sites in Synechocystis chromosome (slr0944; sll0058) and in all four endogenous megaplasmids (pSYSM/slr5037-slr5038; pSYSX/slr6037; pSYSA/slr7023; pSYSG/slr8030) that have not been previously evaluated for the purpose. Fluorescent analysis of the segregated strains revealed that the expression levels between the megaplasmids and chromosomal constructs were very similar, and reinforced the view that highest expression in Synechocystis can be obtained using RSF1010-derived replicative vectors or the native small plasmid pCA2.4 evaluated in comparison. Parallel replicon copy number analysis by RT-qPCR showed that the expression from the alternative loci is largely determined by the gene dosage in Synechocystis, thereby confirming the dependence formerly proposed based on literature. Conclusions This study brings together nine different integrative loci in the genome of Synechocystis to demonstrate quantitative differences between target sites in the chromosome, the native plasmids, and a RSF1010-based replicative expression vector. To date, this is the most comprehensive comparison of alternative integrative sites in Synechocystis, and provides the first direct reference between expression efficiency and replicon gene dosage in the context. In the light of existing literature, the findings support the view that the small native plasmids can be notably more difficult to target than the chromosome or the megaplasmids, and that the RSF1010-derived vectors may be surprisingly well maintained under non-selective culture conditions in this cyanobacterial host. Altogether, the work broadens our views on genomic integration and the rational use of different integrative loci versus replicative plasmids, when aiming at expressing heterologous genes in Synechocystis. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01622-2.
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Affiliation(s)
- Csaba Nagy
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Itäinen Pitkäkatu 4 C, 20520, Turku, Finland
| | - Kati Thiel
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Itäinen Pitkäkatu 4 C, 20520, Turku, Finland
| | - Edita Mulaku
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Itäinen Pitkäkatu 4 C, 20520, Turku, Finland
| | - Henna Mustila
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Itäinen Pitkäkatu 4 C, 20520, Turku, Finland
| | - Paula Tamagnini
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.,IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, Edifício FC4, 4169-007, Porto, Portugal
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Itäinen Pitkäkatu 4 C, 20520, Turku, Finland
| | - Catarina C Pacheco
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.,IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal
| | - Pauli Kallio
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Itäinen Pitkäkatu 4 C, 20520, Turku, Finland.
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16
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Genetic, Genomics, and Responses to Stresses in Cyanobacteria: Biotechnological Implications. Genes (Basel) 2021; 12:genes12040500. [PMID: 33805386 PMCID: PMC8066212 DOI: 10.3390/genes12040500] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 02/07/2023] Open
Abstract
Cyanobacteria are widely-diverse, environmentally crucial photosynthetic prokaryotes of great interests for basic and applied science. Work to date has focused mostly on the three non-nitrogen fixing unicellular species Synechocystis PCC 6803, Synechococcus PCC 7942, and Synechococcus PCC 7002, which have been selected for their genetic and physiological interests summarized in this review. Extensive "omics" data sets have been generated, and genome-scale models (GSM) have been developed for the rational engineering of these cyanobacteria for biotechnological purposes. We presently discuss what should be done to improve our understanding of the genotype-phenotype relationships of these models and generate robust and predictive models of their metabolism. Furthermore, we also emphasize that because Synechocystis PCC 6803, Synechococcus PCC 7942, and Synechococcus PCC 7002 represent only a limited part of the wide biodiversity of cyanobacteria, other species distantly related to these three models, should be studied. Finally, we highlight the need to strengthen the communication between academic researchers, who know well cyanobacteria and can engineer them for biotechnological purposes, but have a limited access to large photobioreactors, and industrial partners who attempt to use natural or engineered cyanobacteria to produce interesting chemicals at reasonable costs, but may lack knowledge on cyanobacterial physiology and metabolism.
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17
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Shono C, Ariyanti D, Abe K, Sakai Y, Sakamoto I, Tsukakoshi K, Sode K, Ikebukuro K. A Green Light-Regulated T7 RNA Polymerase Gene Expression System for Cyanobacteria. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2021; 23:31-38. [PMID: 32979137 DOI: 10.1007/s10126-020-09997-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
In this study, we developed a green light-regulated T7 RNA polymerase expression system (T7 RNAP system), to provide a novel and versatile high-expression system for cyanobacteria without using any chemical inducer, realizing high expression levels comparable with previously reported for recombinant gene expression in cyanobacteria. The T7 RNAP system was constructed and introduced into Synechocystis sp. PCC6803. T7 RNAP was inserted downstream of the cpcG2 promoter, which is recognized and activated by the CcaS/CcaR two-component green-light-sensing system, to compose a vector plasmid, pKT-CS01, to achieve the induction of T7 RNAP expression only under green light illumination, with repression under red light illumination. The reporter gene, superfolder green fluorescent protein (sfGFP), was inserted downstream of the T7 promoter. Transcriptional analyses revealed that T7 RNAP was induced under green light but repressed under red light. Expression of the sfGFP protein derived from pKT-CS01 was observed under green light illumination and was approximately 10-fold higher than that in the control transformant, which expressed sfGFP directly under the cpcG2 promoter, which is directly regulated by CcaS/CcaR, under green light illumination. Comparison with the strong promoter expression systems Pcpc560 and PtrcΔlacO revealed that the expression of sfGFP by the T7 RNAP system was comparable with the levels obtained with strong promoters. These results demonstrated that the green light-regulated T7 RNAP gene expression system will be a versatile tool for future technological platform to regulate gene expression in cyanobacterial bioprocesses.
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Affiliation(s)
- Chika Shono
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
| | - Dwi Ariyanti
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
- Faculty of Biotechnology, Sumbawa University of Technology, Olat Maras, Moyo Hulu, Sumbawa, West Nusa Tenggara, 84371, Indonesia
| | - Koichi Abe
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
| | - Yuta Sakai
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
| | - Ippei Sakamoto
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
| | - Kaori Tsukakoshi
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
| | - Koji Sode
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan.
- Joint Department of Biomedical Engineering, The University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, 27599, USA.
| | - Kazunori Ikebukuro
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan.
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18
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Metabolic engineering of Zymomonas moblis for ethylene production from straw hydrolysate. Appl Microbiol Biotechnol 2021; 105:1709-1720. [PMID: 33512573 DOI: 10.1007/s00253-021-11091-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/27/2020] [Accepted: 01/03/2021] [Indexed: 10/22/2022]
Abstract
Biological ethylene production is a promising sustainable alternative approach for fossil-based ethylene production. The high glucose utilization of Z. mobilis makes it as a promising bioethylene producer. In this study, Zymomonas mobilis has been engineered to produce ethylene through the introduction of the synthetic ethylene-forming enzyme (EFE). We also investigated the effect of systematically knocking out the competitive metabolic pathway of pyruvate in an effort to improve the availability of pyruvate for ethylene production in Z. mobilis expressing EFE. Guided by these results, we tested a number of conjectures that could improve the α-ketoglutarate supply. Optimization of these pathways and different substrate supplies resulted in a greater production of ethylene (from 1.36 to 12.83 nmol/OD600/mL), which may guide future engineering work on ethylene production using other organisms. Meanwhile, we achieved an ethylene production of 5.8 nmol/OD600/mL in the ZM532-efe strain using enzymatic straw hydrolysate of corn straw as the sole carbon source. As a preferred host in biorefinery technologies using lignocellulosic biomass as feedstock, heterologous expression of EFE in Z. mobilis converts the non-ethylene producing strain into an ethylene-producing one using a metabolic engineering approach, which is of great significance for the utilization of cellulosic biomass in the future. KEY POINTS: • Heterologous expression of EFE in Z. mobilis successfully converted the non-ethylene producing strain into an ethylene producer (1.36 nmol/OD600/mL). Targeted modifications of the central carbon metabolism can effectively improve ethylene production (peak production: 8.3 nmol/OD600/mL). • The addition of nutrients to the medium can further increase the production of ethylene (peak production: 12.8 nmol/OD600/mL). • The ZM532-efe strain achieved an ethylene production of 5.8 nmol/OD600/mL when enzymatic hydrolysate of corn straw was used as the sole carbon source.
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19
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Muro-Pastor MI, Cutillas-Farray Á, Pérez-Rodríguez L, Pérez-Saavedra J, Vega-de Armas A, Paredes A, Robles-Rengel R, Florencio FJ. CfrA, a Novel Carbon Flow Regulator, Adapts Carbon Metabolism to Nitrogen Deficiency in Cyanobacteria. PLANT PHYSIOLOGY 2020; 184:1792-1810. [PMID: 32900980 PMCID: PMC7723081 DOI: 10.1104/pp.20.00802] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 08/22/2020] [Indexed: 05/03/2023]
Abstract
Cyanobacteria unable to fix atmospheric nitrogen have evolved sophisticated adaptations to survive to long periods of nitrogen starvation. These genetic programs are still largely unknown-as evidenced by the many proteins whose expression is regulated in response to nitrogen availability, but which belong to unknown or hypothetical categories. In Synechocystis sp. PCC 6803, the global nitrogen regulator NtcA activates the expression of the sll0944 gene upon nitrogen deprivation. This gene encodes a protein that is highly conserved in cyanobacteria, but of unknown function. Based on the results described herein, we named the product of sll0944 carbon flow regulator A (CfrA). We analyzed the phenotypes of strains containing different levels of CfrA, including a knock-out strain (ΔcfrA), and two strains overexpressing CfrA from either the constitutive P trc promoter (Ptrc-cfrA) or the arsenite-inducible promoter P arsB (Pars-cfrA). Our results show that the amount of CfrA determines the accumulation of glycogen, and affects the synthesis of protein and photosynthetic pigments as well as amino acid pools. Strains with high levels of CfrA present high levels of glycogen and a decrease in photosynthetic pigments and protein content when nitrogen is available. Possible interactions between CfrA and the pyruvate dehydrogenase complex or PII protein have been revealed. The phenotype associated with CfrA overexpression is also observed in PII-deficient strains; however, it is lethal in this genetic background. Taken together, our results indicate a role for CfrA in the adaptation of carbon flux during acclimation to nitrogen deficiency.
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Affiliation(s)
- M Isabel Muro-Pastor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain
| | - Áureo Cutillas-Farray
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain
| | - Laura Pérez-Rodríguez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain
| | - Julia Pérez-Saavedra
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain
| | - Ana Vega-de Armas
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain
| | - Ana Paredes
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain
| | - Rocío Robles-Rengel
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain
| | - Francisco J Florencio
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain
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20
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Xu W, Wang Y. Post-translational Modifications of Serine/Threonine and Histidine Kinases and Their Roles in Signal Transductions in Synechocystis Sp. PCC 6803. Appl Biochem Biotechnol 2020; 193:687-716. [PMID: 33159456 DOI: 10.1007/s12010-020-03435-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/29/2020] [Indexed: 11/25/2022]
Abstract
Cyanobacterium Synechocystis sp. PCC 6803, a popular model organism for researches in photosynthesis and biofuel production, contains plant-like photosynthetic machineries which significantly contribute to global carbon fixation. There are 12 eukaryotic-type Ser/Thr kinases (SpkA-L) and 49 His kinases (Hik1-49) of two-component systems in the genome of Synechocystis sp. PCC 6803. They are the key regulators in sensing and transmitting stimuli including light- and glucose-mediate signal transduction. Proteomic studies were able to identify all the kinases. The majority of kinases no matter whether they have a predicted transmembrane domain were identified in the membrane fractions. Six Ser/Thr kinases (SpkA-D, F and G) and ten His kinases (Hik4, 12, 14, 21, 26-27, 29, 36, 43, and 46) were identified to have one or more of the three types of post-translational modifications: phosphorylation, acetylation, and thiol oxidation. Interestingly, SpkG has the phosphorylatable threonine residue that was aligned with the phosphorylated threonine residue in the activation loop of human CDK7, demonstrating conserved phosphorylation between cyanobacterial and human kinases. Transcriptomics and proteomics revealed differential expression of the kinases in heterotrophic and photoheterotrophic compared with photoautotrophic conditions, indicating their roles in regulating the growth modes of cyanobacteria. In summary, this review focuses on the discussions on post-transcriptional modifications, transcriptomic, and proteomic studies of Ser/Thr and His kinases. This together with our published review in 2019 present a complete story of an overview of sequences, domain architectures, and biochemical and physiological functions of cyanobacterial kinases with adequate details in the context of high throughput systems. We also emphasize the importance of discovering upstream molecules and substrates to understand the exact functions of the kinases in vivo. As an attempt, a model is proposed in which Hik31, His33, Sll1334, and IcfG are hypothesized to be critical for switching between autotrophic and heterotrophic modes based on the results from the phenotypes of the gene knockout strains combined with their post-translational modifications, and gene expression profiles.
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Affiliation(s)
- Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA.
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd, Beijing, 100101, China.
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21
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Wang F, Gao Y, Yang G. Recent advances in synthetic biology of cyanobacteria for improved chemicals production. Bioengineered 2020; 11:1208-1220. [PMID: 33124500 PMCID: PMC8291842 DOI: 10.1080/21655979.2020.1837458] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cyanobacteria are Gram-negative photoautotrophic prokaryotes and have shown great importance to the Earth’s ecology. Based on their capability in oxygenic photosynthesis and genetic merits, they can be engineered as microbial chassis for direct conversion of carbon dioxide to value-added biofuels and chemicals. In the last decades, attempts have given to the application of synthetic biology tools and approaches in the development of cyanobacterial cell factories. Despite the successful proof-of-principle studies, large-scale application is still a technical challenge due to low yields of bioproducts. Therefore, recent efforts are underway to characterize and develop genetic regulatory parts and strategies for the synthetic biology applications in cyanobacteria. In this review, we present the recent advancements and application in cyanobacterial synthetic biology toolboxes. We also discuss the limitations and future perspectives for using such novel tools in cyanobacterial biotechnology.
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Affiliation(s)
- Fen Wang
- Department of Surgery, College of Medicine, University of Florida , Gainesville, FL, USA
| | - Yuanyuan Gao
- Jining Academy of Agricultural Science , Jining, Shandong, China
| | - Guang Yang
- Department of Aging and Geriatric Research, Institute on Aging, University of Florida , Gainesville, FL, USA
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22
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Behle A, Saake P, Germann AT, Dienst D, Axmann IM. Comparative Dose-Response Analysis of Inducible Promoters in Cyanobacteria. ACS Synth Biol 2020; 9:843-855. [PMID: 32134640 DOI: 10.1021/acssynbio.9b00505] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Design and implementation of synthetic biological circuits highly depends on well-characterized, robust promoters with predictable input-output responses. While great progress has been made with heterotrophic model organisms such as Escherichia coli, the available variety of tunable promoter parts for phototrophic cyanobacteria is still limited. Commonly used synthetic and semisynthetic promoters show weak dynamic ranges or no regulation at all in cyanobacterial models. Well-controlled alternatives such as native metal-responsive promoters, however, pose the problems of inducer toxicity and lacking orthogonality. Here, we present the comparative assessment of dose-response functions of four different inducible promoter systems in the model cyanobacterium Synechocystis sp. PCC 6803. Using the novel bimodular reporter plasmid pSHDY, dose-response dynamics of the re-established vanillate-inducible promoter PvanCC was compared to the previously described rhamnose-inducible Prha, the anhydrotetracycline-inducible PL03, and the Co2+-inducible PcoaT. We estimate individual advantages and disadvantages regarding dynamic range and strength of each promoter, also in comparison with well-established constitutive systems. We observed a delicate balance between transcription factor toxicity and sufficient expression to obtain a dose-dependent response to the inducer. In summary, we expand the current understanding and employability of inducible promoters in cyanobacteria, facilitating the scalability and robustness of synthetic regulatory network designs and of complex metabolic pathway engineering strategies.
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Affiliation(s)
- Anna Behle
- Institute for Synthetic Microbiology, Heinrich Heine University Duesseldorf, 40225 Duesseldorf, Germany
| | - Pia Saake
- Institute for Synthetic Microbiology, Heinrich Heine University Duesseldorf, 40225 Duesseldorf, Germany
| | - Anna T. Germann
- Institute for Synthetic Microbiology, Heinrich Heine University Duesseldorf, 40225 Duesseldorf, Germany
| | - Dennis Dienst
- Department of Chemistry − Ångström, Uppsala University, 75120 Uppsala, Sweden
| | - Ilka M. Axmann
- Institute for Synthetic Microbiology, Heinrich Heine University Duesseldorf, 40225 Duesseldorf, Germany
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23
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Yao L, Shabestary K, Björk SM, Asplund-Samuelsson J, Joensson HN, Jahn M, Hudson EP. Pooled CRISPRi screening of the cyanobacterium Synechocystis sp PCC 6803 for enhanced industrial phenotypes. Nat Commun 2020; 11:1666. [PMID: 32245970 PMCID: PMC7125299 DOI: 10.1038/s41467-020-15491-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/13/2020] [Indexed: 11/09/2022] Open
Abstract
Cyanobacteria are model organisms for photosynthesis and are attractive for biotechnology applications. To aid investigation of genotype-phenotype relationships in cyanobacteria, we develop an inducible CRISPRi gene repression library in Synechocystis sp. PCC 6803, where we aim to target all genes for repression. We track the growth of all library members in multiple conditions and estimate gene fitness. The library reveals several clones with increased growth rates, and these have a common upregulation of genes related to cyclic electron flow. We challenge the library with 0.1 M L-lactate and find that repression of peroxiredoxin bcp2 increases growth rate by 49%. Transforming the library into an L-lactate-secreting Synechocystis strain and sorting top lactate producers enriches clones with sgRNAs targeting nutrient assimilation, central carbon metabolism, and cyclic electron flow. In many examples, productivity can be enhanced by repression of essential genes, which are difficult to access by transposon insertion.
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Affiliation(s)
- Lun Yao
- Science for Life Laboratory, KTH - Royal Institute of Technology, SE-171 21, Stockholm, Sweden.,Department of Protein Science, KTH - Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Kiyan Shabestary
- Science for Life Laboratory, KTH - Royal Institute of Technology, SE-171 21, Stockholm, Sweden.,Department of Protein Science, KTH - Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Sara M Björk
- Science for Life Laboratory, KTH - Royal Institute of Technology, SE-171 21, Stockholm, Sweden.,Department of Protein Science, KTH - Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Johannes Asplund-Samuelsson
- Science for Life Laboratory, KTH - Royal Institute of Technology, SE-171 21, Stockholm, Sweden.,Department of Protein Science, KTH - Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Haakan N Joensson
- Science for Life Laboratory, KTH - Royal Institute of Technology, SE-171 21, Stockholm, Sweden.,Department of Protein Science, KTH - Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Michael Jahn
- Science for Life Laboratory, KTH - Royal Institute of Technology, SE-171 21, Stockholm, Sweden.,Department of Protein Science, KTH - Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Elton P Hudson
- Science for Life Laboratory, KTH - Royal Institute of Technology, SE-171 21, Stockholm, Sweden. .,Department of Protein Science, KTH - Royal Institute of Technology, SE-106 91, Stockholm, Sweden.
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24
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Till P, Toepel J, Bühler B, Mach RL, Mach-Aigner AR. Regulatory systems for gene expression control in cyanobacteria. Appl Microbiol Biotechnol 2020; 104:1977-1991. [PMID: 31965222 PMCID: PMC7007895 DOI: 10.1007/s00253-019-10344-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/21/2019] [Accepted: 12/28/2019] [Indexed: 11/24/2022]
Abstract
As photosynthetic microbes, cyanobacteria are attractive hosts for the production of high-value molecules from CO2 and light. Strategies for genetic engineering and tightly controlled gene expression are essential for the biotechnological application of these organisms. Numerous heterologous or native promoter systems were used for constitutive and inducible expression, yet many of them suffer either from leakiness or from a low expression output. Anyway, in recent years, existing systems have been improved and new promoters have been discovered or engineered for cyanobacteria. Moreover, alternative tools and strategies for expression control such as riboswitches, riboregulators or genetic circuits have been developed. In this mini-review, we provide a broad overview on the different tools and approaches for the regulation of gene expression in cyanobacteria and explain their advantages and disadvantages.
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Affiliation(s)
- Petra Till
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-Active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, A-1060, Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, A-1060, Vienna, Austria
| | - Jörg Toepel
- Department of Solar Materials, Helmholtz-Centre for Environmental Research GmbH-UFZ, Permoserstrasse 15, 04318, Leipzig, Germany
| | - Bruno Bühler
- Department of Solar Materials, Helmholtz-Centre for Environmental Research GmbH-UFZ, Permoserstrasse 15, 04318, Leipzig, Germany
| | - Robert L Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, A-1060, Vienna, Austria
| | - Astrid R Mach-Aigner
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-Active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, A-1060, Vienna, Austria.
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, A-1060, Vienna, Austria.
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25
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D'Agostino PM, Al-Sinawi B, Mazmouz R, Muenchhoff J, Neilan BA, Moffitt MC. Identification of promoter elements in the Dolichospermum circinale AWQC131C saxitoxin gene cluster and the experimental analysis of their use for heterologous expression. BMC Microbiol 2020; 20:35. [PMID: 32070286 PMCID: PMC7027233 DOI: 10.1186/s12866-020-1720-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/03/2020] [Indexed: 01/06/2023] Open
Abstract
Background Dolichospermum circinale is a filamentous bloom-forming cyanobacterium responsible for biosynthesis of the paralytic shellfish toxins (PST), including saxitoxin. PSTs are neurotoxins and in their purified form are important analytical standards for monitoring the quality of water and seafood and biomedical research tools for studying neuronal sodium channels. More recently, PSTs have been recognised for their utility as local anaesthetics. Characterisation of the transcriptional elements within the saxitoxin (sxt) biosynthetic gene cluster (BGC) is a first step towards accessing these molecules for biotechnology. Results In D. circinale AWQC131C the sxt BGC is transcribed from two bidirectional promoter regions encoding five individual promoters. These promoters were identified experimentally using 5′ RACE and their activity assessed via coupling to a lux reporter system in E. coli and Synechocystis sp. PCC 6803. Transcription of the predicted drug/metabolite transporter (DMT) encoded by sxtPER was found to initiate from two promoters, PsxtPER1 and PsxtPER2. In E. coli, strong expression of lux from PsxtP, PsxtD and PsxtPER1 was observed while expression from Porf24 and PsxtPER2 was remarkably weaker. In contrast, heterologous expression in Synechocystis sp. PCC 6803 showed that expression of lux from PsxtP, PsxtPER1, and Porf24 promoters was statistically higher compared to the non-promoter control, while PsxtD showed poor activity under the described conditions. Conclusions Both of the heterologous hosts investigated in this study exhibited high expression levels from three of the five sxt promoters. These results indicate that the majority of the native sxt promoters appear active in different heterologous hosts, simplifying initial cloning efforts. Therefore, heterologous expression of the sxt BGC in either E. coli or Synechocystis could be a viable first option for producing PSTs for industrial or biomedical purposes.
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Affiliation(s)
- Paul M D'Agostino
- School of Science, Western Sydney University, Sydney, NSW, Australia.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.,Biosystems Chemistry, Department of Chemistry, Technische Universität München, Garching, Germany.,Technical Biochemistry, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Bakir Al-Sinawi
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Rabia Mazmouz
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Julia Muenchhoff
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.,Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia. .,School of Environmental and Life Sciences, University of Newcastle, Callaghan, Australia.
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26
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Durall C, Lindberg P, Yu J, Lindblad P. Increased ethylene production by overexpressing phosphoenolpyruvate carboxylase in the cyanobacterium Synechocystis PCC 6803. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:16. [PMID: 32010220 PMCID: PMC6988332 DOI: 10.1186/s13068-020-1653-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/09/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND Cyanobacteria can be metabolically engineered to convert CO2 to fuels and chemicals such as ethylene. A major challenge in such efforts is to optimize carbon fixation and partition towards target molecules. RESULTS The efe gene encoding an ethylene-forming enzyme was introduced into a strain of the cyanobacterium Synechocystis PCC 6803 with increased phosphoenolpyruvate carboxylase (PEPc) levels. The resulting engineered strain (CD-P) showed significantly increased ethylene production (10.5 ± 3.1 µg mL-1 OD-1 day-1) compared to the control strain (6.4 ± 1.4 µg mL-1 OD-1 day-1). Interestingly, extra copies of the native pepc or the heterologous expression of PEPc from the cyanobacterium Synechococcus PCC 7002 (Synechococcus) in the CD-P, increased ethylene production (19.2 ± 1.3 and 18.3 ± 3.3 µg mL-1 OD-1 day-1, respectively) when the cells were treated with the acetyl-CoA carboxylase inhibitor, cycloxydim. A heterologous expression of phosphoenolpyruvate synthase (PPSA) from Synechococcus in the CD-P also increased ethylene production (16.77 ± 4.48 µg mL-1 OD-1 day-1) showing differences in the regulation of the native and the PPSA from Synechococcus in Synechocystis. CONCLUSIONS This work demonstrates that genetic rewiring of cyanobacterial central carbon metabolism can enhance carbon supply to the TCA cycle and thereby further increase ethylene production.
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Affiliation(s)
- Claudia Durall
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20 Uppsala, Sweden
| | - Pia Lindberg
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20 Uppsala, Sweden
| | - Jianping Yu
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Peter Lindblad
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20 Uppsala, Sweden
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27
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Metabolic engineering of Synechocystis sp. PCC 6803 for the production of aromatic amino acids and derived phenylpropanoids. Metab Eng 2020; 57:129-139. [DOI: 10.1016/j.ymben.2019.11.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/14/2019] [Accepted: 11/08/2019] [Indexed: 11/22/2022]
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28
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Kobayashi S, Nakajima M, Asano R, Ferreira EA, Abe K, Tamagnini P, Atsumi S, Sode K. Application of an engineered chromatic acclimation sensor for red-light-regulated gene expression in cyanobacteria. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101691] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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29
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Kirtania P, Hódi B, Mallick I, Vass IZ, Fehér T, Vass I, Kós PB. A single plasmid based CRISPR interference in Synechocystis 6803 - A proof of concept. PLoS One 2019; 14:e0225375. [PMID: 31770415 PMCID: PMC6879144 DOI: 10.1371/journal.pone.0225375] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 11/02/2019] [Indexed: 11/20/2022] Open
Abstract
We developed a simple method to apply CRISPR interference by modifying an existing plasmid pCRISPathBrick containing the native S. pyogenes CRISPR assembly for Synechocystis PCC6803 and named it pCRPB1010. The technique presented here using deadCas9 is easier to implement for gene silencing in Synechocystis PCC6803 than other existing techniques as it circumvents the genome integration and segregation steps thereby significantly shortens the construction of the mutant strains. We executed CRISPR interference against well characterized photosynthetic genes to get a clear phenotype to validate the potential of pCRPB1010 and presented the work as a “proof of concept”. Targeting the non-template strand of psbO gene resulted in decreased amount of PsbO and 50% decrease in oxygen evolution rate. Targeting the template strand of psbA2 and psbA3 genes encoding the D1 subunit of photosystem II (PSII) using a single spacer against the common sequence span of the two genes, resulted in full inhibition of both genes, complete abolition of D1 protein synthesis, complete loss of oxygen evolution as well as photoautotrophic growth arrest. This is the first report of a single plasmid based, completely lesion free and episomal expression and execution of CRISPR interference in Synechocystis PCC6803.
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Affiliation(s)
- Prithwiraj Kirtania
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Barbara Hódi
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Ivy Mallick
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - István Zoltan Vass
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Tamás Fehér
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Peter B Kós
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
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30
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Pauly M, Gawenda N, Wagner C, Fischbach P, Ramírez V, Axmann IM, Voiniciuc C. The Suitability of Orthogonal Hosts to Study Plant Cell Wall Biosynthesis. PLANTS (BASEL, SWITZERLAND) 2019; 8:E516. [PMID: 31744209 PMCID: PMC6918405 DOI: 10.3390/plants8110516] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/08/2019] [Accepted: 11/15/2019] [Indexed: 12/20/2022]
Abstract
Plant cells are surrounded by an extracellular matrix that consists mainly of polysaccharides. Many molecular components involved in plant cell wall polymer synthesis have been identified, but it remains largely unknown how these molecular players function together to define the length and decoration pattern of a polysaccharide. Synthetic biology can be applied to answer questions beyond individual glycosyltransferases by reconstructing entire biosynthetic machineries required to produce a complete wall polysaccharide. Recently, this approach was successful in establishing the production of heteromannan from several plant species in an orthogonal host-a yeast-illuminating the role of an auxiliary protein in the biosynthetic process. In this review we evaluate to what extent a selection of organisms from three kingdoms of life (Bacteria, Fungi and Animalia) might be suitable for the synthesis of plant cell wall polysaccharides. By identifying their key attributes for glycoengineering as well as analyzing the glycosidic linkages of their native polymers, we present a valuable comparison of their key advantages and limitations for the production of different classes of plant polysaccharides.
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Affiliation(s)
- Markus Pauly
- Institute for Plant Cell Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (M.P.); (N.G.); (V.R.)
| | - Niklas Gawenda
- Institute for Plant Cell Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (M.P.); (N.G.); (V.R.)
| | - Christine Wagner
- Independent Junior Research Group–Designer Glycans, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany;
| | - Patrick Fischbach
- Institute of Synthetic Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Vicente Ramírez
- Institute for Plant Cell Biology and Biotechnology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (M.P.); (N.G.); (V.R.)
| | - Ilka M. Axmann
- Institute for Synthetic Microbiology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Cătălin Voiniciuc
- Independent Junior Research Group–Designer Glycans, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany;
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31
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Zhou Y, Sun T, Chen Z, Song X, Chen L, Zhang W. Development of a New Biocontainment Strategy in Model Cyanobacterium Synechococcus Strains. ACS Synth Biol 2019; 8:2576-2584. [PMID: 31577416 DOI: 10.1021/acssynbio.9b00282] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Recent synthetic biology efforts have raised biosafety concerns for possible release of engineered cyanobacteria into natural environments. To address the issues, we developed a controllable metal ion induced biocontainment system for two model cyanobacteria. First, six ion-inducible promoters were respectively evaluated in both Synechococcus elongatus PCC 7942 and the fast-growing cyanobacterium Synechococcus elongatus UTEX 2973, leading to the identification of an iron ion-repressed promoter PisiAB with low leakage and a reduction-fold of 5.4 and 7.9, respectively. Second, holin-endolysin and nuclease NucA systems were introduced, the inhibition rate of which against two Synechococcus strains varied from 61% to 86.4%. Third, two toxin/antitoxin modules were identified capable of inducing programmed suicide in both Synechococcus strains after induction. Furthermore, an escape experiment was conducted and the results showed that the system was able to achieve an escape frequency below the detection limit of 10-9 after 3 days' duration, demonstrating the strategy integrating iron ion-inducible promoter PisiAB and that toxin/antitoxin modules could be a useful tool for cyanobacterium biocontainment.
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Affiliation(s)
- Yuqing Zhou
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
| | | | - Zixi Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
| | | | - Lei Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
| | - Weiwen Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
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32
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Evaluation of New Genetic Toolkits and Their Role for Ethanol Production in Cyanobacteria. ENERGIES 2019. [DOI: 10.3390/en12183515] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Since the public awareness for climate change has risen, increasing scientific effort has been made to find and develop alternative resources and production processes to reduce the dependency on petrol-based fuels and chemicals of our society. Among others, the biotechnological fuel production, as for example fermenting sugar-rich crops to ethanol, is one of the main strategies. For this purpose, various classical production systems like Escherichia coli or Saccharomyces cerevisiae are used and have been optimized via genetic modifications. Despite the progress made, this strategy competes for nutritional resources and agricultural land. To overcome this problem, various attempts were made for direct photosynthetic driven ethanol synthesis with different microalgal species including cyanobacteria. However, compared to existing platforms, the development of cyanobacteria as photoautotrophic cell factories has just started, and accordingly, the ethanol yield of established production systems is still unreached. This is mainly attributed to low ethanol tolerance levels of cyanobacteria and there is still potential for optimizing the cyanobacteria towards alternative gene expression systems. Meanwhile, several improvements were made by establishing new toolboxes for synthetic biology offering new possibilities for advanced genetic modifications of cyanobacteria. Here, current achievements and innovations of those new molecular tools are discussed.
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33
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Vavitsas K, Crozet P, Vinde MH, Davies F, Lemaire SD, Vickers CE. The Synthetic Biology Toolkit for Photosynthetic Microorganisms. PLANT PHYSIOLOGY 2019; 181:14-27. [PMID: 31262955 PMCID: PMC6716251 DOI: 10.1104/pp.19.00345] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/09/2019] [Indexed: 05/10/2023]
Abstract
Photosynthetic microorganisms offer novel characteristics as synthetic biology chassis, and the toolbox of components and techniques for cyanobacteria and algae is rapidly increasing.
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Affiliation(s)
- Konstantinos Vavitsas
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Synthetic Biology Future Science Platform, CSIRO Land & Water, Brisbane, Queensland 4001, Australia
| | - Pierre Crozet
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 8226, Centre National de la Recherche Scientifique, Sorbonne Université, 75005 Paris, France
| | - Marcos Hamborg Vinde
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Synthetic Biology Future Science Platform, CSIRO Land & Water, Brisbane, Queensland 4001, Australia
| | - Fiona Davies
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401
| | - Stéphane D Lemaire
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 8226, Centre National de la Recherche Scientifique, Sorbonne Université, 75005 Paris, France
| | - Claudia E Vickers
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Synthetic Biology Future Science Platform, CSIRO Land & Water, Brisbane, Queensland 4001, Australia
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34
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Bartasun P, Prandi N, Storch M, Aknin Y, Bennett M, Palma A, Baldwin G, Sakuragi Y, Jones PR, Rowland J. The effect of modulating the quantity of enzymes in a model ethanol pathway on metabolic flux in Synechocystis sp. PCC 6803. PeerJ 2019; 7:e7529. [PMID: 31523505 PMCID: PMC6717505 DOI: 10.7717/peerj.7529] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 07/22/2019] [Indexed: 12/17/2022] Open
Abstract
Synthetic metabolism allows new metabolic capabilities to be introduced into strains for biotechnology applications. Such engineered metabolic pathways are unlikely to function optimally as initially designed and native metabolism may not efficiently support the introduced pathway without further intervention. To develop our understanding of optimal metabolic engineering strategies, a two-enzyme ethanol pathway consisting of pyruvate decarboxylase and acetaldehyde reductase was introduced into Synechocystis sp. PCC 6803. We characteriseda new set of ribosome binding site sequences in Synechocystis sp. PCC 6803 providing a range of translation strengths for different genes under test. The effect of ribosome-bindingsite sequence, operon design and modifications to native metabolism on pathway flux was analysed by HPLC. The accumulation of all introduced proteins was also quantified using selected reaction monitoring mass spectrometry. Pathway productivity was more strongly dependent on the accumulation of pyruvate decarboxylase than acetaldehyde reductase. In fact, abolishment of reductase over-expression resulted in the greatest ethanol productivity, most likely because strains harbouringsingle-gene constructs accumulated more pyruvate decarboxylase than strains carrying any of the multi-gene constructs. Overall, several lessons were learned. Firstly, the expression level of the first gene in anyoperon influenced the expression level of subsequent genes, demonstrating that translational coupling can also occur in cyanobacteria. Longer operons resulted in lower protein abundance for proximally-encoded cistrons. And, implementation of metabolic engineering strategies that have previously been shown to enhance the growth or yield of pyruvate dependent products, through co-expression with pyruvate kinase and/or fructose-1,6-bisphosphatase/sedoheptulose-1,7-bisphosphatase, indicated that other factors had greater control over growth and metabolic flux under the tested conditions.
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Affiliation(s)
- Paulina Bartasun
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Nicole Prandi
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Marko Storch
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Imperial College Centre for Synthetic Biology, Imperial College London, London, United Kingdom
| | - Yarin Aknin
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Institute of Plant Sciences and Genetics in Agriculture, Hebrew University of Jerusalem, Rehovot, Israel
| | - Mark Bennett
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Arianna Palma
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Geoff Baldwin
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Imperial College Centre for Synthetic Biology, Imperial College London, London, United Kingdom
| | - Yumiko Sakuragi
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Patrik R Jones
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Imperial College Centre for Synthetic Biology, Imperial College London, London, United Kingdom
| | - John Rowland
- Department of Life Sciences, Imperial College London, London, United Kingdom
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35
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Carbonell V, Vuorio E, Aro EM, Kallio P. Enhanced stable production of ethylene in photosynthetic cyanobacterium Synechococcus elongatus PCC 7942. World J Microbiol Biotechnol 2019; 35:77. [PMID: 31069553 PMCID: PMC6536634 DOI: 10.1007/s11274-019-2652-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 04/26/2019] [Indexed: 11/26/2022]
Abstract
Ethylene is a volatile alkene which is used in large commercial scale as a precursor in plastic industry, and is currently derived from petroleum refinement. As an alternative production strategy, photoautotrophic cyanobacteria Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942 have been previously evaluated as potential biotechnological hosts for producing ethylene directly from CO2, by the over-expression of ethylene forming enzyme (efe) from Pseudomonas syringae. This work addresses various open questions related to the use of Synechococcus as the engineering target, and demonstrates long-term ethylene production at rates reaching 140 µL L−1 h−1 OD750−1 without loss of host vitality or capacity to produce ethylene. The results imply that the genetic instability observed earlier may be associated with the expression strategies, rather than efe over-expression, ethylene toxicity or the depletion of 2-oxoglutarate—derived cellular precursors in Synechococcus. In context with literature, this study underlines the critical differences in expression system design in the alternative hosts, and confirms Synechococcus as a suitable parallel host for further engineering.
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Affiliation(s)
- Veronica Carbonell
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turun yliopisto, Finland
| | - Eerika Vuorio
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turun yliopisto, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turun yliopisto, Finland
| | - Pauli Kallio
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turun yliopisto, Finland.
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36
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Vasudevan R, Gale GAR, Schiavon AA, Puzorjov A, Malin J, Gillespie MD, Vavitsas K, Zulkower V, Wang B, Howe CJ, Lea-Smith DJ, McCormick AJ. CyanoGate: A Modular Cloning Suite for Engineering Cyanobacteria Based on the Plant MoClo Syntax. PLANT PHYSIOLOGY 2019; 180:39-55. [PMID: 30819783 PMCID: PMC6501082 DOI: 10.1104/pp.18.01401] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 02/16/2019] [Indexed: 05/10/2023]
Abstract
Recent advances in synthetic biology research have been underpinned by an exponential increase in available genomic information and a proliferation of advanced DNA assembly tools. The adoption of plasmid vector assembly standards and parts libraries has greatly enhanced the reproducibility of research and the exchange of parts between different labs and biological systems. However, a standardized modular cloning (MoClo) system is not yet available for cyanobacteria, which lag behind other prokaryotes in synthetic biology despite their huge potential regarding biotechnological applications. By building on the assembly library and syntax of the Plant Golden Gate MoClo kit, we have developed a versatile system called CyanoGate that unites cyanobacteria with plant and algal systems. Here, we describe the generation of a suite of parts and acceptor vectors for making (1) marked/unmarked knock-outs or integrations using an integrative acceptor vector, and (2) transient multigene expression and repression systems using known and previously undescribed replicative vectors. We tested and compared the CyanoGate system in the established model cyanobacterium Synechocystis sp. PCC 6803 and the more recently described fast-growing strain Synechococcus elongatus UTEX 2973. The UTEX 2973 fast-growth phenotype was only evident under specific growth conditions; however, UTEX 2973 accumulated high levels of proteins with strong native or synthetic promoters. The system is publicly available and can be readily expanded to accommodate other standardized MoClo parts to accelerate the development of reliable synthetic biology tools for the cyanobacterial community.
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Affiliation(s)
- Ravendran Vasudevan
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Grant A R Gale
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, United Kingdom
| | - Alejandra A Schiavon
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Anton Puzorjov
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - John Malin
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Michael D Gillespie
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Konstantinos Vavitsas
- Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland 4072, Australia
- CSIRO, Synthetic Biology Future Science Platform, Brisbane, Queensland 4001, Australia
| | - Valentin Zulkower
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Baojun Wang
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, United Kingdom
| | - Christopher J Howe
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - David J Lea-Smith
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Alistair J McCormick
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
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37
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Jin H, Lindblad P, Bhaya D. Building an Inducible T7 RNA Polymerase/T7 Promoter Circuit in Synechocystis sp. PCC6803. ACS Synth Biol 2019; 8:655-660. [PMID: 30935196 DOI: 10.1021/acssynbio.8b00515] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To develop tightly regulated orthogonal gene expression circuits in the photoautotrophic cyanobacterium Synechocystis sp. PCC6803 (Syn6803), we designed a circuit in which a native inducible promoter drives the expression of phage T7 RNA polymerase (T7RNAP). T7RNAP, in turn, specifically recognizes the T7 promoter that is designed to drive GFP expression. In Syn6803, this T7RNAP/T7promoter-GFP circuit produces high GFP fluorescence, which was further enhanced by using mutant T7 promoters. We also tested two orthogonal inducible promoters, Trc1O and L03, but these promoters drive T7RNAP to levels that are toxic in E. coli. Introduction of a protein degradation tag alleviated this problem. However, in Syn6803, these circuits did not function successfully. This highlights the underappreciated fact that similar circuits work with varying efficiencies in different chassis organisms. This lays the groundwork for developing new orthogonally controlled phage RNA polymerase-dependent expression systems in Syn6803.
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Affiliation(s)
- Haojie Jin
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, United States
| | - Peter Lindblad
- Microbial Chemistry, Department of Chemistry-Ångström, Uppsala University, Box 523, SE 75120, Uppsala, Sweden
| | - Devaki Bhaya
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, United States
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Russo DA, Zedler JAZ, Wittmann DN, Möllers B, Singh RK, Batth TS, van Oort B, Olsen JV, Bjerrum MJ, Jensen PE. Expression and secretion of a lytic polysaccharide monooxygenase by a fast-growing cyanobacterium. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:74. [PMID: 30976324 PMCID: PMC6442416 DOI: 10.1186/s13068-019-1416-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 03/21/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND Cyanobacteria have the potential to become next-generation cell factories due to their ability to use CO2, light and inorganic nutrients to produce a range of biomolecules of commercial interest. Synechococcus elongatus UTEX 2973, in particular, is a fast-growing, genetically tractable, cyanobacterium that has garnered attention as a potential biotechnological chassis. To establish this unique strain as a host for heterologous protein production, we aimed to demonstrate expression and secretion of the industrially relevant TfAA10A, a lytic polysaccharide monooxygenase from the Gram-positive bacterium Thermobifida fusca. RESULTS Two variations of TfAA10A were successfully expressed in S. elongatus UTEX 2973: One containing the native N-terminal, Sec-targeted, signal peptide and a second with a Tat-targeted signal peptide from the Escherichia coli trimethylamine-N-oxide reductase (TorA). Although the TorA signal peptide correctly targeted the protein to the plasma membrane, the majority of the TorA-TfAA10A was found unprocessed in the plasma membrane with a small fraction of the mature protein ultimately translocated to the periplasm. The native Sec signal peptide allowed for efficient secretion of TfAA10A into the medium with virtually no protein being found in the cytosol, plasma membrane or periplasm. TfAA10A was demonstrated to be correctly cleaved and active on the model substrate phosphoric acid swollen cellulose. Additionally, expression and secretion only had a minor impact on cell growth. The secretion yield was estimated at 779 ± 40 µg L-1 based on densitometric analysis. To our knowledge, this is the highest secretion yield ever registered in cyanobacteria. CONCLUSIONS We have shown for the first time high-titer expression and secretion of an industrially relevant and catalytically active enzyme in S. elongatus UTEX 2973. This proof-of-concept study will be valuable for the development of novel and sustainable applications in the fields of bioremediation and biocatalysis.
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Affiliation(s)
- D. A. Russo
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - J. A. Z. Zedler
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - D. N. Wittmann
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - B. Möllers
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, Denmark
| | - R. K. Singh
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - T. S. Batth
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - B. van Oort
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - J. V. Olsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - M. J. Bjerrum
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - P. E. Jensen
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
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Gordon GC, Pfleger BF. Regulatory Tools for Controlling Gene Expression in Cyanobacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1080:281-315. [PMID: 30091100 PMCID: PMC6662922 DOI: 10.1007/978-981-13-0854-3_12] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cyanobacteria are attractive hosts for converting carbon dioxide and sunlight into desirable chemical products. To engineer these organisms and manipulate their metabolic pathways, the biotechnology community has developed genetic tools to control gene expression. Many native cyanobacterial promoters and related sequence elements have been used to regulate genes of interest, and heterologous tools that use non-native small molecules to induce gene expression have been demonstrated. Overall, IPTG-based induction systems seem to be leaky and initially demonstrate small dynamic ranges in cyanobacteria. Consequently, a variety of other induction systems have been optimized to enable tighter control of gene expression. Tools require significant optimization because they function quite differently in cyanobacteria when compared to analogous use in model heterotrophs. We hypothesize that these differences are due to fundamental differences in physiology between organisms. This review is not intended to summarize all known products made in cyanobacteria nor the performance (titer, rate, yield) of individual strains, but instead will focus on the genetic tools and the inherent aspects of cellular physiology that influence gene expression in cyanobacteria.
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Affiliation(s)
- Gina C Gordon
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Brian F Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA.
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA.
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40
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Yunus IS, Jones PR. Photosynthesis-dependent biosynthesis of medium chain-length fatty acids and alcohols. Metab Eng 2018; 49:59-68. [DOI: 10.1016/j.ymben.2018.07.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/24/2018] [Accepted: 07/24/2018] [Indexed: 12/27/2022]
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Gao SS, Naowarojna N, Cheng R, Liu X, Liu P. Recent examples of α-ketoglutarate-dependent mononuclear non-haem iron enzymes in natural product biosyntheses. Nat Prod Rep 2018; 35:792-837. [PMID: 29932179 PMCID: PMC6093783 DOI: 10.1039/c7np00067g] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Covering: up to 2018 α-Ketoglutarate (αKG, also known as 2-oxoglutarate)-dependent mononuclear non-haem iron (αKG-NHFe) enzymes catalyze a wide range of biochemical reactions, including hydroxylation, ring fragmentation, C-C bond cleavage, epimerization, desaturation, endoperoxidation and heterocycle formation. These enzymes utilize iron(ii) as the metallo-cofactor and αKG as the co-substrate. Herein, we summarize several novel αKG-NHFe enzymes involved in natural product biosyntheses discovered in recent years, including halogenation reactions, amino acid modifications and tailoring reactions in the biosynthesis of terpenes, lipids, fatty acids and phosphonates. We also conducted a survey of the currently available structures of αKG-NHFe enzymes, in which αKG binds to the metallo-centre bidentately through either a proximal- or distal-type binding mode. Future structure-function and structure-reactivity relationship investigations will provide crucial information regarding how activities in this large class of enzymes have been fine-tuned in nature.
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Affiliation(s)
- Shu-Shan Gao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | | | - Ronghai Cheng
- Department of Chemistry, Boston University, Boston, MA 02215, USA.
| | - Xueting Liu
- Department of Chemistry, Boston University, Boston, MA 02215, USA. and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Pinghua Liu
- Department of Chemistry, Boston University, Boston, MA 02215, USA.
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Synthetic Gene Regulation in Cyanobacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1080:317-355. [DOI: 10.1007/978-981-13-0854-3_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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43
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Sun T, Li S, Song X, Diao J, Chen L, Zhang W. Toolboxes for cyanobacteria: Recent advances and future direction. Biotechnol Adv 2018; 36:1293-1307. [DOI: 10.1016/j.biotechadv.2018.04.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/09/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022]
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Li S, Sun T, Xu C, Chen L, Zhang W. Development and optimization of genetic toolboxes for a fast-growing cyanobacterium Synechococcus elongatus UTEX 2973. Metab Eng 2018; 48:163-174. [PMID: 29883802 DOI: 10.1016/j.ymben.2018.06.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/02/2018] [Accepted: 06/04/2018] [Indexed: 10/14/2022]
Abstract
The fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 (hereafter Synechococcus 2973) has been considered a good chassis candidate for "microbial cell factory" as it can perform oxygenic photosynthesis and its doubling time can be as short as 1.9 h. However, the limited genetic tools currently restrict its further research and application efforts using synthetic biology approaches. In this study, a series of genetic tools were systematically developed and optimized for Synechococcus 2973. First, the introduction of Tfp pilus assembly protein encoding gene pilN into Synechococcus 2973 successfully recovered its natural transformability, which greatly simplified the DNA transformation process. Second, a series of promoters with different strengths were evaluated and the super-strong promoters including Pcpc560 from Synechocystis sp. PCC 6803, native PpsbA2 and PpsbA3 of Synechococcus 2973 were found with the highest activity of β-galactosidase among those evaluated by miller values. Some promoters related to photosystems (i.e., PpsbA2, PpsbA3, P6803psbA2 and Pcpc560) were also demonstrated to be induced by high intensity of light. Third, three lactose induction systems were evaluated, among which Plac combined with lacIq showed the best application prospect with great induction capacity, low leakage and middle induced expression. Fourth, the translational on riboswitch theoE* , the transcriptional off riboswitches theo/yitJ and xpt(C74U)/metE and an artificial inducing system combining theoE* with T7 RNA polymerase were successfully developed and characterized in Synechococcus 2973. Finally, by using T7 induction system to control the expression of both small RNA and chaperone Hfq, a small RNA regulatory tool was developed and optimized to be a strictly inducible off system for gene regulation in Synechococcus 2973. The work here presented valuable genetic toolboxes necessary for metabolic engineering and synthetic biology research in Synechococcus 2973, which will facilitate the future application of the fast growing cyanobacterial chassis.
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Affiliation(s)
- Shubin Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Chunxiao Xu
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China.
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China; Center for Biosafety Research and Strategy, Tianjin University, Tianjin, PR China
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45
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Photomixotrophic chemical production in cyanobacteria. Curr Opin Biotechnol 2018; 50:65-71. [DOI: 10.1016/j.copbio.2017.11.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 11/11/2017] [Accepted: 11/13/2017] [Indexed: 11/19/2022]
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46
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De Porcellinis AJ, Nørgaard H, Brey LMF, Erstad SM, Jones PR, Heazlewood JL, Sakuragi Y. Overexpression of bifunctional fructose-1,6-bisphosphatase/sedoheptulose-1,7-bisphosphatase leads to enhanced photosynthesis and global reprogramming of carbon metabolism in Synechococcus sp. PCC 7002. Metab Eng 2018; 47:170-183. [PMID: 29510212 DOI: 10.1016/j.ymben.2018.03.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 02/02/2018] [Accepted: 03/01/2018] [Indexed: 12/25/2022]
Abstract
Cyanobacteria fix atmospheric CO2 to biomass and through metabolic engineering can also act as photosynthetic factories for sustainable productions of fuels and chemicals. The Calvin Benson cycle is the primary pathway for CO2 fixation in cyanobacteria, algae and C3 plants. Previous studies have overexpressed the Calvin Benson cycle enzymes, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and bifunctional sedoheptulose-1,7-bisphosphatase/fructose-1,6-bisphosphatase (hereafter BiBPase), in both plants and algae, although their impacts on cyanobacteria have not yet been rigorously studied. Here, we show that overexpression of BiBPase and RuBisCO have distinct impacts on carbon metabolism in the cyanobacterium Synechococcus sp. PCC 7002 through physiological, biochemical, and proteomic analyses. The former enhanced growth, cell size, and photosynthetic O2 evolution, and coordinately upregulated enzymes in the Calvin Benson cycle including RuBisCO and fructose-1,6-bisphosphate aldolase. At the same time it downregulated enzymes in respiratory carbon metabolism (glycolysis and the oxidative pentose phosphate pathway) including glucose-6-phosphate dehydrogenase (G6PDH). The content of glycogen was also significantly reduced while the soluble carbohydrate content increased. These results indicate that overexpression of BiBPase leads to global reprogramming of carbon metabolism in Synechococcus sp. PCC 7002, promoting photosynthetic carbon fixation and carbon partitioning towards non-storage carbohydrates. In contrast, whilst overexpression of RuBisCO had no measurable impact on growth and photosynthetic O2 evolution, it led to coordinated increase in the abundance of proteins involved in pyruvate metabolism and fatty acid biosynthesis. Our results underpin that singular genetic modifications in the Calvin Benson cycle can have far broader cellular impact than previously expected. These features could be exploited to more efficiently direct carbons towards desired bioproducts.
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Affiliation(s)
- Alice Jara De Porcellinis
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark; Copenhagen Plant Science Center, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark; Carlsberg Research Laboratory, 100 Ny Carlsberg Vej, 1799 Copenhagen V, Denmark
| | - Hanne Nørgaard
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark; Novo Nordisk, Novo Nordisk Park 1, 2760 Måløv, Denmark
| | - Laura Maria Furelos Brey
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark; Copenhagen Plant Science Center, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark
| | - Simon Matthé Erstad
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark; Copenhagen Plant Science Center, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark
| | - Patrik R Jones
- Department Life Sciences, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK
| | - Joshua L Heazlewood
- Joint BioEnergy Institute and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; School of BioSciences, The University of Melbourne, Victoria 3010, Australia
| | - Yumiko Sakuragi
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark; Copenhagen Plant Science Center, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871, Denmark.
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47
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Thiel K, Mulaku E, Dandapani H, Nagy C, Aro EM, Kallio P. Translation efficiency of heterologous proteins is significantly affected by the genetic context of RBS sequences in engineered cyanobacterium Synechocystis sp. PCC 6803. Microb Cell Fact 2018; 17:34. [PMID: 29499707 PMCID: PMC5834881 DOI: 10.1186/s12934-018-0882-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 02/23/2018] [Indexed: 12/26/2022] Open
Abstract
Background Photosynthetic cyanobacteria have been studied as potential host organisms for direct solar-driven production of different carbon-based chemicals from CO2 and water, as part of the development of sustainable future biotechnological applications. The engineering approaches, however, are still limited by the lack of comprehensive information on most optimal expression strategies and validated species-specific genetic elements which are essential for increasing the intricacy, predictability and efficiency of the systems. This study focused on the systematic evaluation of the key translational control elements, ribosome binding sites (RBS), in the cyanobacterial host Synechocystis sp. PCC 6803, with the objective of expanding the palette of tools for more rigorous engineering approaches. Results An expression system was established for the comparison of 13 selected RBS sequences in Synechocystis, using several alternative reporter proteins (sYFP2, codon-optimized GFPmut3 and ethylene forming enzyme) as quantitative indicators of the relative translation efficiencies. The set-up was shown to yield highly reproducible expression patterns in independent analytical series with low variation between biological replicates, thus allowing statistical comparison of the activities of the different RBSs in vivo. While the RBSs covered a relatively broad overall expression level range, the downstream gene sequence was demonstrated in a rigorous manner to have a clear impact on the resulting translational profiles. This was expected to reflect interfering sequence-specific mRNA-level interaction between the RBS and the coding region, yet correlation between potential secondary structure formation and observed translation levels could not be resolved with existing in silico prediction tools. Conclusions The study expands our current understanding on the potential and limitations associated with the regulation of protein expression at translational level in engineered cyanobacteria. The acquired information can be used for selecting appropriate RBSs for optimizing over-expression constructs or multicistronic pathways in Synechocystis, while underlining the complications in predicting the activity due to gene-specific interactions which may reduce the translational efficiency for a given RBS-gene combination. Ultimately, the findings emphasize the need for additional characterized insulator sequence elements to decouple the interaction between the RBS and the coding region for future engineering approaches. Electronic supplementary material The online version of this article (10.1186/s12934-018-0882-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kati Thiel
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Edita Mulaku
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Hariharan Dandapani
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Csaba Nagy
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Pauli Kallio
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turku, Finland.
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48
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Lacey RF, Allen CJ, Bakshi A, Binder BM. Ethylene causes transcriptomic changes in Synechocystis during phototaxis. PLANT DIRECT 2018; 2:e00048. [PMID: 31245714 PMCID: PMC6508509 DOI: 10.1002/pld3.48] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 02/20/2018] [Accepted: 02/22/2018] [Indexed: 05/02/2023]
Abstract
Ethylene is well known as a plant hormone, but its role in bacteria is poorly studied. We recently showed that Synechocystis sp. Strain PCC 6803 has a functional receptor for ethylene, ethylene response 1 (Etr1), that is involved in various processes such as phototaxis in response to directional light and biofilm formation. Here, we use RNA sequencing to examine the changes in gene transcripts caused by ethylene under phototaxis conditions. Over 500 gene transcripts across many functional categories, of approximately 3700 protein-encoding genes, were altered by application of ethylene. In general, ethylene caused both up- and downregulation of genes within a functional category. However, the transcript levels of amino acid metabolism genes were mainly upregulated and cell envelope genes were mostly downregulated by ethylene. The changes in cell envelope genes correlate with our prior observation that ethylene affects cell surface properties to alter cell motility. Ethylene caused a twofold or more change in 62 transcripts with the largest category of upregulated genes annotated as transporters and the largest category of downregulated genes annotated as glycosyltransferases which sometimes are involved in changing the composition of sugars on the cell surface. Consistent with changes in cell envelope, glycosyltransferase, and transporter gene transcripts, application of ethylene altered the levels of specific sugar moieties on the surface of cells. Light signaling from Etr1 involves two proteins (Slr1213 and Slr1214) and a small, noncoding RNA, carbon stress-induced RNA1 (csiR1). Application of ethylene caused a rapid, but transient, decrease in the transcript levels of etr1, slr1213, and slr1214 and a rapid and prolonged decrease in csiR1 transcript. Deletion of Slr1214 caused a large increase in csiR1 transcript levels and ethylene lowered csiR1 transcript. These data combined with prior reports indicate that ethylene functions as a signal to affect a variety of processes altering the physiology of Synechocystis cells.
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Affiliation(s)
- Randy F. Lacey
- Department of Biochemistry & Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTNUSA
| | - Cidney J. Allen
- Department of Biochemistry & Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTNUSA
| | - Arkadipta Bakshi
- Genome Science and Technology ProgramUniversity of TennesseeKnoxvilleTNUSA
- Present address:
Department of BotanyUniversity of WisconsinMadisonWIUSA
| | - Brad M. Binder
- Department of Biochemistry & Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTNUSA
- Genome Science and Technology ProgramUniversity of TennesseeKnoxvilleTNUSA
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Humphreys CM, Minton NP. Advances in metabolic engineering in the microbial production of fuels and chemicals from C1 gas. Curr Opin Biotechnol 2018; 50:174-181. [PMID: 29414057 DOI: 10.1016/j.copbio.2017.12.023] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/21/2017] [Accepted: 12/22/2017] [Indexed: 12/20/2022]
Abstract
The future sustainable production of chemicals and fuels from non-petrochemical sources, while at the same time reducing greenhouse gas (GHG) emissions, represent two of society's greatest challenges. Microbial chassis able to grow on waste carbon monoxide (CO) and carbon dioxide (CO2) can provide solutions to both. Ranging from the anaerobic acetogens, through the aerobic chemoautotrophs to the photoautotrophic cyanobacteria, they are able to convert C1 gases into a range of chemicals and fuels which may be enhanced and extended through appropriate metabolic engineering. The necessary improvements will be facilitated by the increasingly sophisticated gene tools that are beginning to emerge as part of the Synthetic Biology revolution. These tools, in combination with more accurate metabolic and genome scale models, will enable C1 chassis to deliver their full potential.
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Affiliation(s)
- Christopher M Humphreys
- BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK.
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50
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Stensjö K, Vavitsas K, Tyystjärvi T. Harnessing transcription for bioproduction in cyanobacteria. PHYSIOLOGIA PLANTARUM 2018; 162:148-155. [PMID: 28762505 DOI: 10.1111/ppl.12606] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/04/2017] [Accepted: 07/10/2017] [Indexed: 06/07/2023]
Abstract
Sustainable production of biofuels and other valuable compounds is one of our future challenges. One tempting possibility is to use photosynthetic cyanobacteria as production factories. Currently, tools for genetic engineering of cyanobacteria are not good enough to exploit the full potential of cyanobacteria. A wide variety of expression systems will be required to adjust both the expression of heterologous enzyme(s) and metabolic routes to the best possible balance, allowing the optimal production of a particular substance. In bacteria, transcription, especially the initiation of transcription, has a central role in adjusting gene expression and thus also metabolic fluxes of cells according to environmental cues. Here we summarize the recent progress in developing tools for efficient cyanofactories, focusing especially on transcriptional regulation.
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Affiliation(s)
- Karin Stensjö
- Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Konstantinos Vavitsas
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Taina Tyystjärvi
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
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