1
|
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]
|
2
|
Minagawa J, Dann M. Extracellular CahB1 from Sodalinema gerasimenkoae IPPAS B-353 Acts as a Functional Carboxysomal β-Carbonic Anhydrase in Synechocystis sp. PCC6803. PLANTS (BASEL, SWITZERLAND) 2023; 12:265. [PMID: 36678979 PMCID: PMC9865033 DOI: 10.3390/plants12020265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 12/27/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Cyanobacteria mostly rely on the active uptake of hydrated CO2 (i.e., bicarbonate ions) from the surrounding media to fuel their inorganic carbon assimilation. The dehydration of bicarbonate in close vicinity of RuBisCO is achieved through the activity of carboxysomal carbonic anhydrase (CA) enzymes. Simultaneously, many cyanobacterial genomes encode extracellular α- and β-class CAs (EcaA, EcaB) whose exact physiological role remains largely unknown. To date, the CahB1 enzyme of Sodalinema gerasimenkoae (formerly Microcoleus/Coleofasciculus chthonoplastes) remains the sole described active extracellular β-CA in cyanobacteria, but its molecular features strongly suggest it to be a carboxysomal rather than a secreted protein. Upon expression of CahB1 in Synechocystis sp. PCC6803, we found that its expression complemented the loss of endogenous CcaA. Moreover, CahB1 was found to localize to a carboxysome-harboring and CA-active cell fraction. Our data suggest that CahB1 retains all crucial properties of a cellular carboxysomal CA and that the secretion mechanism and/or the machinations of the Sodalinema gerasimenkoae carboxysome are different from those of Synechocystis.
Collapse
Affiliation(s)
- Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology (NIBB), Aichi, Okazaki 444-8585, Japan
| | - Marcel Dann
- Division of Environmental Photobiology, National Institute for Basic Biology (NIBB), Aichi, Okazaki 444-8585, Japan
- Plant Molecular Biology, Ludwig-Maximilian University (LMU) Munich, 82152 Planegg, Germany
| |
Collapse
|
3
|
Rew L, Harris MD, Goldie J. The ketogenic diet: its impact on human gut microbiota and potential consequent health outcomes: a systematic literature review. GASTROENTEROLOGY AND HEPATOLOGY FROM BED TO BENCH 2022; 15:326-342. [PMID: 36762214 PMCID: PMC9876773 DOI: 10.22037/ghfbb.v15i4.2600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 09/21/2022] [Indexed: 02/11/2023]
Abstract
Aim This systematic review examined the diet's impact on the human gut microbiota to identify potential consequent health outcomes. Background The extreme macronutrient profile of the ketogenic diet (KD) instigates compositional shifts in the gut's microbial community. Methods In this systematic literature review, an evidence-based and methodical approach was undertaken, which involved systematic searches of the Medical Literature Analysis and Retrieval System Online (MEDLINE), PubMed and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, generating a total of 263 relevant research papers. Following the application of inclusion and exclusion criteria, eight papers were deemed suitable for inclusion. These papers were critically appraised using a checklist tool adapted from the National Institute of Care and Excellence (NICE). The findings were analysed using a simplified thematic analysis. Results The results provide strong evidence for a persistent reduction in Bifidobacterium abundance following KD adherence. A reduced abundance of key Firmicutes butyrate-producing bacteria was found to be a likely impact, although two studies with extended intervention periods indicate this may be time-limited. Studies investigating short-chain fatty acids (SCFA's) indicate KD reduces total faecal SCFA's, acetate, and butyrate. Conclusion Changes to microbial communities resulting from KD adherence are potentially detrimental to colonic health. The persistent reduction in Bifidobacterium abundance was concerning, with obesity, type-2 diabetes, and depression highlighted as potential consequent risks. For nutrition and healthcare professionals, the findings emphasize the importance of considering KDs microbial effects and resulting health implications at an individual level.
Collapse
Affiliation(s)
- Leslyn Rew
- The School of Allied Health and Community, University of Worcester, Henwick Grove, WR2 6AJ, United Kingdom
| | - Miranda D Harris
- The School of Allied Health and Community, University of Worcester, Henwick Grove, WR2 6AJ, United Kingdom
| | - Joanna Goldie
- The School of Allied Health and Community, University of Worcester, Henwick Grove, WR2 6AJ, United Kingdom
| |
Collapse
|
4
|
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]
|
5
|
Dietsch M, Behle A, Westhoff P, Axmann IM. Metabolic engineering of Synechocystis sp. PCC 6803 for the photoproduction of the sesquiterpene valencene. Metab Eng Commun 2021; 13:e00178. [PMID: 34466381 PMCID: PMC8382996 DOI: 10.1016/j.mec.2021.e00178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 07/05/2021] [Accepted: 07/22/2021] [Indexed: 11/05/2022] Open
Abstract
Cyanobacteria are extremely adaptable, fast-growing, solar-powered cell factories that, like plants, are able to convert carbon dioxide into sugar and oxygen and thereby produce a large number of important compounds. Due to their unique phototrophy-associated physiological properties, i.e. naturally occurring isoprenoid metabolic pathway, they represent a highly promising platform for terpenoid biosynthesis. Here, we implemented a carefully devised engineering strategy to boost the biosynthesis of commercially attractive plant sequiterpenes, in particular valencene. Sesquiterpenes are a diverse group of bioactive metabolites, mainly produced in higher plants, but with often low concentrations and expensive downstream extraction. In this work we successfully demonstrate a multi-component engineering approach towards the photosynthetic production of valencene in the cyanobacterium Synechocystis sp. PCC 6803. First, we improved the flux towards valencene by markerless genomic deletions of shc and sqs. Secondly, we downregulated the formation of carotenoids, which are essential for viability of the cell, using CRISPRi on crtE. Finally, we intended to increase the spatial proximity of the two enzymes, ispA and CnVS, involved in valencene formation by creating an operon construct, as well as a fusion protein. Combining the most successful strategies resulted in a valencene production of 19 mg/g DCW in Synechocystis. In this work, we have devised a useful platform for future engineering steps.
Collapse
Affiliation(s)
- Maximilian Dietsch
- Institute for Synthetic Microbiology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Anna Behle
- Institute for Synthetic Microbiology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Philipp Westhoff
- Plant Metabolism and Metabolomics Laboratory, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University Düsseldorf, D-40001, Düsseldorf, Germany
| | - Ilka M. Axmann
- Institute for Synthetic Microbiology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| |
Collapse
|
6
|
Racharaks R, Arnold W, Peccia J. Development of CRISPR-Cas9 knock-in tools for free fatty acid production using the fast-growing cyanobacterial strain Synechococcus elongatus UTEX 2973. J Microbiol Methods 2021; 189:106315. [PMID: 34454980 DOI: 10.1016/j.mimet.2021.106315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/23/2021] [Accepted: 08/23/2021] [Indexed: 12/26/2022]
Abstract
Synechococcus elongatus UTEX 2973 has one of the fastest measured doubling time of cyanobacteria making it an important candidate for metabolic engineering. Traditional genetic engineering methods, which rely on homologous recombination, however, are inefficient, labor-intensive, and time-consuming due to the oligoploidy or polyploidy nature of cyanobacteria and the reliance on unique antibiotic resistance markers. CRISPR-Cas9 has emerged as an effective and versatile editing platform in a wide variety of organisms, but its application for cyanobacterial engineering is limited by the inherent toxicity of Cas9 resulting in poor transformation efficiencies. Here, we demonstrated that a single-plasmid CRISPR-Cas9 system, pCRISPOmyces-2, can effectively knock-in a truncated thioesterase gene from Escherichia coli to generate free fatty acid (FFA) producing mutants of Syn2973. To do so, three parameters were evaluated on the effect of generating recipient colonies after conjugation with pCRISPOmyces-2-based plasmids: 1) a modified conjugation protocol termed streaked conjugation, 2) the deletion of the gene encoding RecJ exonuclease, and 3) single guide RNA (sgRNA) sequence. With the use of the streaked conjugation protocol and a ΔrecJ mutant strain of Syn2973, the conjugation efficiency for the pCRISPomyces-2 plasmid could be improved by 750-fold over the wildtype (WT) for a conjugation efficiency of 2.0 × 10-6 transconjugants/recipient cell. While deletion of the RecJ exonuclease alone increased the conjugation efficiency by 150-fold over the WT, FFA generation was impaired in FFA-producing mutants with the ΔrecJ background, and the large number of poor FFA-producing isolates indicated the potential increase in spontaneous mutation rates. The sgRNA sequence was found to be critical in achieving the desired CRISPR-Cas9-mediated knock-in mutation as the sgRNA impacts conjugation efficiency, likelihood of homogenous recombinants, and free fatty acid production in engineered strains.
Collapse
Affiliation(s)
- Ratanachat Racharaks
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA
| | - Wyatt Arnold
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA
| | - Jordan Peccia
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA.
| |
Collapse
|
7
|
Chen L, Liu H, Wang L, Tan X, Yang S. Synthetic counter-selection markers and their application in genetic modification of Synechococcus elongatus UTEX2973. Appl Microbiol Biotechnol 2021; 105:5077-5086. [PMID: 34106311 DOI: 10.1007/s00253-021-11391-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/26/2021] [Accepted: 06/02/2021] [Indexed: 10/21/2022]
Abstract
Due to its robustness to environmental stresses and fast growth, Synechococcus elongatus UTEX2973 is developed as a new model for researches on cyanobacterial molecular biology and biotechnology. However, systematic genetic modifications of S. elongatus UTEX2973 were hindered by the lack of effective genetic manipulation tools, especially available counter-selection markers. Here, six synthetic counter-selection markers (SCOMs) were assembled by fusing six toxin genes from either Escherichia coli or cyanobacteria with a theophylline-inducible promoter. The SCOMs containing SYNPCC7002_G0085 from Synechococcus sp. PCC7002 or mazF from E. coli were proved to be inducible by theophylline in S. elongatus UTEX2973. By using the mazF-based SCOM, the neutral locus 1 and 23 small regulatory RNAs were completely deleted from the genome of S. elongatus UTEX2973 after one round of selection with both kanamycin and theophylline. The genetic tools developed in this work will facilitate future researches on molecular genetics and synthetic biology in S. elongatus UTEX2973. KEY POINTS: • Two inducible counter-selection markers are lethal to S. elongatus UTEX2973. • The counter-selection marker benefits the gene targeting in S. elongatus UTEX2973. • Twentry-three small regulatory RNAs were fully deleted via the novel gene targeting method.
Collapse
Affiliation(s)
- Liyuan Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Hai Liu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Li Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Xiaoming Tan
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, 430062, China.
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, and School of Life Sciences, Hubei University, Wuhan, 430062, China
| |
Collapse
|
8
|
Dann M, Ortiz EM, Thomas M, Guljamow A, Lehmann M, Schaefer H, Leister D. Enhancing photosynthesis at high light levels by adaptive laboratory evolution. NATURE PLANTS 2021; 7:681-695. [PMID: 33941908 PMCID: PMC7612648 DOI: 10.1038/s41477-021-00904-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 03/23/2021] [Indexed: 05/19/2023]
Abstract
Photosynthesis is readily impaired by high light (HL) levels. Photosynthetic organisms have therefore evolved various mechanisms to cope with the problem. Here, we have dramatically enhanced the light tolerance of the cyanobacterium Synechocystis by adaptive laboratory evolution (ALE). By combining repeated mutagenesis and exposure to increasing light intensities, we generated strains that grow under extremely HL intensities. HL tolerance was associated with more than 100 mutations in proteins involved in various cellular functions, including gene expression, photosynthesis and metabolism. Co-evolved mutations were grouped into five haplotypes, and putative epistatic interactions were identified. Two representative mutations, introduced into non-adapted cells, each confer enhanced HL tolerance, but they affect photosynthesis and respiration in different ways. Mutations identified by ALE that allow photosynthetic microorganisms to cope with altered light conditions could be employed in assisted evolution approaches and could strengthen the robustness of photosynthesis in crop plants.
Collapse
Affiliation(s)
- Marcel Dann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Edgardo M Ortiz
- Plant Biodiversity Research, Technical University of Munich, Freising, Germany
| | - Moritz Thomas
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Institute of Computational Biology, Helmholtz Zentrum München-German Research Center for Environmental Health, Oberschleißheim-Neuherberg, Germany
| | - Arthur Guljamow
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Department of Microbiology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam-Golm, Germany
| | - Martin Lehmann
- Mass Spectrometry of Biomolecules (MSBioLMU), Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Hanno Schaefer
- Plant Biodiversity Research, Technical University of Munich, Freising, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.
| |
Collapse
|
9
|
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.
Collapse
|
10
|
Synthetic Biology Approaches To Enhance Microalgal Productivity. Trends Biotechnol 2021; 39:1019-1036. [PMID: 33541719 DOI: 10.1016/j.tibtech.2020.12.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022]
Abstract
The major bottleneck in commercializing biofuels and other commodities produced by microalgae is the high cost associated with phototrophic cultivation. Improving microalgal productivities could be a solution to this problem. Synthetic biology methods have recently been used to engineer the downstream production pathways in several microalgal strains. However, engineering upstream photosynthetic and carbon fixation metabolism to enhance growth, productivity, and yield has barely been explored in microalgae. We describe strategies to improve the generation of reducing power from light, as well as to improve the assimilation of CO2 by either the native Calvin cycle or synthetic alternatives. Overall, we are optimistic that recent technological advances will prompt long-awaited breakthroughs in microalgal research.
Collapse
|
11
|
Batista-Silva W, da Fonseca-Pereira P, Martins AO, Zsögön A, Nunes-Nesi A, Araújo WL. Engineering Improved Photosynthesis in the Era of Synthetic Biology. PLANT COMMUNICATIONS 2020; 1:100032. [PMID: 33367233 PMCID: PMC7747996 DOI: 10.1016/j.xplc.2020.100032] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/20/2020] [Accepted: 02/08/2020] [Indexed: 05/08/2023]
Abstract
Much attention has been given to the enhancement of photosynthesis as a strategy for the optimization of crop productivity. As traditional plant breeding is most likely reaching a plateau, there is a timely need to accelerate improvements in photosynthetic efficiency by means of novel tools and biotechnological solutions. The emerging field of synthetic biology offers the potential for building completely novel pathways in predictable directions and, thus, addresses the global requirements for higher yields expected to occur in the 21st century. Here, we discuss recent advances and current challenges of engineering improved photosynthesis in the era of synthetic biology toward optimized utilization of solar energy and carbon sources to optimize the production of food, fiber, and fuel.
Collapse
Affiliation(s)
- Willian Batista-Silva
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Paula da Fonseca-Pereira
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | | | - Agustín Zsögön
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Wagner L. Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| |
Collapse
|
12
|
Dann M, Leister D. Evidence that cyanobacterial Sll1217 functions analogously to PGRL1 in enhancing PGR5-dependent cyclic electron flow. Nat Commun 2019; 10:5299. [PMID: 31757966 PMCID: PMC6876563 DOI: 10.1038/s41467-019-13223-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/29/2019] [Indexed: 11/19/2022] Open
Abstract
In plants and cyanobacteria, the PGR5 protein contributes to cyclic electron flow around photosystem I. In plants, PGR5 interacts with PGRL1 during cyclic electron flow, but cyanobacteria appear to lack PGRL1 proteins. We have heterologously expressed the PGR5 and PGRL1 proteins from the plant Arabidopsis in various genetic backgrounds in the cyanobacterium Synechocystis. Our results show that plant PGR5 suffices to re-establish cyanobacterial cyclic electron flow (CEF), albeit less efficiently than the cyanobacterial PGR5 or the plant PGR5 and PGRL1 proteins together. A mutation that inactivates Arabidopsis PGR5 destabilises the protein in Synechocystis. Furthermore, the Synechocystis protein Sll1217, which exhibits weak sequence similarity with PGRL1, physically interacts with both plant and cyanobacterial PGR5 proteins, and stimulates CEF in Synechocystis. Therefore, Sll1217 partially acts as a PGRL1 analogue, the mode of action of PGR5 and PGRL1/Sll1217 proteins is similar in cyanobacteria and plants, and PGRL1 could have evolved from a cyanobacterial ancestor.
Collapse
Affiliation(s)
- Marcel Dann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University Munich, Großhaderner Str. 2, D-82152, Planegg-Martinsried, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University Munich, Großhaderner Str. 2, D-82152, Planegg-Martinsried, Germany.
| |
Collapse
|
13
|
Mock M, Schmid A, Bühler K. Photoautotrophic production of succinate via the oxidative branch of the tricarboxylic acid cycle influences glycogen accumulation in Synechocystis sp. PCC 6803. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
14
|
Leister D. Genetic Engineering, Synthetic Biology and the Light Reactions of Photosynthesis. PLANT PHYSIOLOGY 2019; 179:778-793. [PMID: 29991483 PMCID: PMC6393809 DOI: 10.1104/pp.18.00360] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/14/2018] [Indexed: 05/21/2023]
Abstract
Applications of synthetic biology to photosynthesis currently range from exchanging photosynthetic proteins to the utilization of photosynthesis as a source of electrons for entirely unrelated reactions.
Collapse
Affiliation(s)
- Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-University Munich, D-82152 Planegg-Martinsried, Germany
| |
Collapse
|
15
|
Santos-Merino M, Singh AK, Ducat DC. New Applications of Synthetic Biology Tools for Cyanobacterial Metabolic Engineering. Front Bioeng Biotechnol 2019; 7:33. [PMID: 30873404 PMCID: PMC6400836 DOI: 10.3389/fbioe.2019.00033] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/05/2019] [Indexed: 01/25/2023] Open
Abstract
Cyanobacteria are promising microorganisms for sustainable biotechnologies, yet unlocking their potential requires radical re-engineering and application of cutting-edge synthetic biology techniques. In recent years, the available devices and strategies for modifying cyanobacteria have been increasing, including advances in the design of genetic promoters, ribosome binding sites, riboswitches, reporter proteins, modular vector systems, and markerless selection systems. Because of these new toolkits, cyanobacteria have been successfully engineered to express heterologous pathways for the production of a wide variety of valuable compounds. Cyanobacterial strains with the potential to be used in real-world applications will require the refinement of genetic circuits used to express the heterologous pathways and development of accurate models that predict how these pathways can be best integrated into the larger cellular metabolic network. Herein, we review advances that have been made to translate synthetic biology tools into cyanobacterial model organisms and summarize experimental and in silico strategies that have been employed to increase their bioproduction potential. Despite the advances in synthetic biology and metabolic engineering during the last years, it is clear that still further improvements are required if cyanobacteria are to be competitive with heterotrophic microorganisms for the bioproduction of added-value compounds.
Collapse
Affiliation(s)
- María Santos-Merino
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - Amit K. Singh
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - Daniel C. Ducat
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
| |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
Xue Y, He Q. Synthetic Biology Approaches to the Sustainable Production of p-Coumaric Acid and Its Derivatives in Cyanobacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1080:261-277. [PMID: 30091099 DOI: 10.1007/978-981-13-0854-3_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photosynthetic cyanobacteria are promising candidates for the sustainable production of a plethora of plant secondary metabolites, which are beneficial to human health but are difficult to produce and purify in other systems. This chapter focuses on genetic engineering of Synechocystis PCC 6803 for production of p-coumaric acid and its derivatives. Cyanobacterial engineering approaches are briefly reviewed. Strategies to increase production yield are discussed, including codon optimization of genes expressing enzymatic proteins and a laccase-coding gene knockout from Synechocystis genome which degrades polyphenols.
Collapse
Affiliation(s)
- Yong Xue
- Division of Microbiology, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, USA
| | - Qingfang He
- Department of Biology, University of Arkansas at Little Rock, Little Rock, AR, USA.
| |
Collapse
|
18
|
Dann M, Leister D. Enhancing (crop) plant photosynthesis by introducing novel genetic diversity. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0380. [PMID: 28808099 DOI: 10.1098/rstb.2016.0380] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2017] [Indexed: 12/22/2022] Open
Abstract
Although some elements of the photosynthetic light reactions might appear to be ideal, the overall efficiency of light conversion to biomass has not been optimized during evolution. Because crop plants are depleted of genetic diversity for photosynthesis, efforts to enhance its efficiency with respect to light conversion to yield must generate new variation. In principle, three sources of natural variation are available: (i) rare diversity within extant higher plant species, (ii) photosynthetic variants from algae, and (iii) reconstruction of no longer extant types of plant photosynthesis. Here, we argue for a novel approach that outsources crop photosynthesis to a cyanobacterium that is amenable to adaptive evolution. This system offers numerous advantages, including a short generation time, virtually unlimited population sizes and high mutation rates, together with a versatile toolbox for genetic manipulation. On such a synthetic bacterial platform, 10 000 years of (crop) plant evolution can be recapitulated within weeks. Limitations of this system arise from its unicellular nature, which cannot reproduce all aspects of crop photosynthesis. But successful establishment of such a bacterial host for crop photosynthesis promises not only to enhance the performance of eukaryotic photosynthesis but will also reveal novel facets of the molecular basis of photosynthetic flexibility.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
Collapse
Affiliation(s)
- Marcel Dann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University of Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| |
Collapse
|
19
|
Liu D, Pakrasi HB. Exploring native genetic elements as plug-in tools for synthetic biology in the cyanobacterium Synechocystis sp. PCC 6803. Microb Cell Fact 2018; 17:48. [PMID: 29580240 PMCID: PMC5868059 DOI: 10.1186/s12934-018-0897-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 03/21/2018] [Indexed: 11/24/2022] Open
Abstract
Background The unicellular cyanobacterium Synechocystis sp. PCC 6803 has been widely used as a photoautotrophic host for synthetic biology studies. However, as a green chassis to capture CO2 for biotechnological applications, the genetic toolbox for Synechocystis 6803 is still a limited factor. Results We systematically characterized endogenous genetic elements of Synechocystis 6803, including promoters, ribosome binding sites, transcription terminators, and plasmids. Expression from twelve native promoters was compared by measuring fluorescence from the reporter protein EYFP in an identical setup, exhibiting an 8000-fold range of promoter activities. Moreover, we measured the strength of twenty native ribosome binding sites and eight native terminators, indicating their influence on the expression of the reporter genes. In addition, two shuttle vectors, pCA-UC118 and pCB-SC101, capable of replication in both Synechocystis 6803 and E. coli were constructed. Expression of reporter proteins were significantly enhanced in cells containing these new plasmids, thus providing superior gene expression platforms in this cyanobacterium. Conclusions The results of this study provide useful and well characterized native tools for bioengineering work in the model cyanobacterium Synechocystis 6803. Electronic supplementary material The online version of this article (10.1186/s12934-018-0897-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Deng Liu
- Department of Biology, Washington University, Campus Box 1137, One Brookings Drive, St. Louis, MO, 63130, USA
| | - Himadri B Pakrasi
- Department of Biology, Washington University, Campus Box 1137, One Brookings Drive, St. Louis, MO, 63130, USA.
| |
Collapse
|
20
|
Ueno K, Sakai Y, Shono C, Sakamoto I, Tsukakoshi K, Hihara Y, Sode K, Ikebukuro K. Applying a riboregulator as a new chromosomal gene regulation tool for higher glycogen production in Synechocystis sp. PCC 6803. Appl Microbiol Biotechnol 2017; 101:8465-8474. [PMID: 29038975 DOI: 10.1007/s00253-017-8570-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 09/18/2017] [Accepted: 09/26/2017] [Indexed: 11/29/2022]
Abstract
Cyanobacteria are one of the most attractive hosts for biofuel production; however, genetic approaches to regulate specific chromosomal genes in cyanobacteria remain limited. With the aim of developing a novel method to regulate chromosomal gene expression in cyanobacteria, we focused on riboregulatory technology. Riboregulators are composed of two RNA fragments whose interaction leads to target gene regulation with high specificity. In this study, we inserted a riboregulator sequence upstream of the chromosomal gene encoding AbrB-like transcriptional regulator, cyAbrB2, to investigate the utility of this tool. The inserted riboregulator was able to regulate cyabrB2 gene expression, with a high ON-OFF ratio up to approximately 50-fold. The transcription levels of several genes for which cyAbrB2 acts as a transcriptional upregulator were also decreased. Further, the cyAbrB2 expression-repressed mutant showed high glycogen accumulation, equivalent to that in the cyabrB2 deletion mutant (ΔcyabrB2). Phenotypic similarities between the cyabrB2 expression-repressed mutant and the ΔcyabrB2 mutant suggest that the riboregulator can potentially be used as a new chromosomal gene regulation tool in cyanobacteria.
Collapse
Affiliation(s)
- Kinuko Ueno
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Yuta Sakai
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Chika Shono
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Ippei Sakamoto
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Kaori Tsukakoshi
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Yukako Hihara
- Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan
| | - Koji Sode
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Kazunori Ikebukuro
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
| |
Collapse
|
21
|
Gandini C, Schmidt SB, Husted S, Schneider A, Leister D. The transporter SynPAM71 is located in the plasma membrane and thylakoids, and mediates manganese tolerance in Synechocystis PCC6803. THE NEW PHYTOLOGIST 2017; 215:256-268. [PMID: 28318016 DOI: 10.1111/nph.14526] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/19/2017] [Indexed: 05/24/2023]
Abstract
Manganese (Mn) is an essential constituent of photosystem II (PSII) and therefore indispensable for oxygenic photosynthesis. Very little is known about how Mn is transported, delivered and retained in photosynthetic cells. Recently, the thylakoid-localized transporter PAM71 has been linked to chloroplast Mn homeostasis in Arabidopsis thaliana. Here, we characterize the function of its homolog in Synechocystis (SynPAM71). We used a loss-of-function line (ΔSynPAM71), wild-type (WT) cells exposed to Mn stress and strains expressing a tagged variant of SynPAM71 to characterize the role of SynPAM71 in cyanobacterial Mn homeostasis. The ΔSynPAM71 strain displays an Mn-sensitive phenotype with reduced levels of chlorophyll and PSI accumulation, defects in PSII photochemistry and intracellular Mn enrichment, particularly in the thylakoid membranes. These effects are attributable to Mn toxicity, as very similar symptoms were observed in WT cells exposed to excess Mn. Moreover, CyanoP, which is involved in the early steps of PSII assembly, is massively upregulated in ΔSynPAM71. SynPAM71 was detected in both the plasma membrane and, to a lesser extent, the thylakoid membranes. Our results suggest that SynPAM71 is involved in the maintenance of Mn homeostasis through the export of Mn from the cytoplasm into the periplasmic and luminal compartments, where it can be stored without interfering with cytoplasmic metabolic processes.
Collapse
Affiliation(s)
- Chiara Gandini
- Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität München, Martinsried, 82152, Germany
| | - Sidsel Birkelund Schmidt
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre (CPSC), Faculty of Science, University of Copenhagen, Frederiksberg C, 1871, Denmark
| | - Søren Husted
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Centre (CPSC), Faculty of Science, University of Copenhagen, Frederiksberg C, 1871, Denmark
| | - Anja Schneider
- Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität München, Martinsried, 82152, Germany
| | - Dario Leister
- Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig-Maximilians-Universität München, Martinsried, 82152, Germany
| |
Collapse
|
22
|
Shabestary K, Hudson EP. Computational metabolic engineering strategies for growth-coupled biofuel production by Synechocystis. Metab Eng Commun 2016; 3:216-226. [PMID: 29468126 PMCID: PMC5779732 DOI: 10.1016/j.meteno.2016.07.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/31/2016] [Accepted: 07/19/2016] [Indexed: 11/28/2022] Open
Abstract
Chemical and fuel production by photosynthetic cyanobacteria is a promising technology but to date has not reached competitive rates and titers. Genome-scale metabolic modeling can reveal limitations in cyanobacteria metabolism and guide genetic engineering strategies to increase chemical production. Here, we used constraint-based modeling and optimization algorithms on a genome-scale model of Synechocystis PCC6803 to find ways to improve productivity of fermentative, fatty-acid, and terpene-derived fuels. OptGene and MOMA were used to find heuristics for knockout strategies that could increase biofuel productivity. OptKnock was used to find a set of knockouts that led to coupling between biofuel and growth. Our results show that high productivity of fermentation or reversed beta-oxidation derived alcohols such as 1-butanol requires elimination of NADH sinks, while terpenes and fatty-acid based fuels require creating imbalances in intracellular ATP and NADPH production and consumption. The FBA-predicted productivities of these fuels are at least 10-fold higher than those reported so far in the literature. We also discuss the physiological and practical feasibility of implementing these knockouts. This work gives insight into how cyanobacteria could be engineered to reach competitive biofuel productivities.
Collapse
Affiliation(s)
| | - Elton P. Hudson
- School of Biotechnology, KTH - Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| |
Collapse
|
23
|
Al-Haj L, Lui YT, Abed RMM, Gomaa MA, Purton S. Cyanobacteria as Chassis for Industrial Biotechnology: Progress and Prospects. Life (Basel) 2016; 6:life6040042. [PMID: 27916886 PMCID: PMC5198077 DOI: 10.3390/life6040042] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/13/2016] [Accepted: 11/25/2016] [Indexed: 12/24/2022] Open
Abstract
Cyanobacteria hold significant potential as industrial biotechnology (IB) platforms for the production of a wide variety of bio-products ranging from biofuels such as hydrogen, alcohols and isoprenoids, to high-value bioactive and recombinant proteins. Underpinning this technology, are the recent advances in cyanobacterial “omics” research, the development of improved genetic engineering tools for key species, and the emerging field of cyanobacterial synthetic biology. These approaches enabled the development of elaborate metabolic engineering programs aimed at creating designer strains tailored for different IB applications. In this review, we provide an overview of the current status of the fields of cyanobacterial omics and genetic engineering with specific focus on the current molecular tools and technologies that have been developed in the past five years. The paper concludes by giving insights on future commercial applications of cyanobacteria and highlights the challenges that need to be addressed in order to make cyanobacterial industrial biotechnology more feasible in the near future.
Collapse
Affiliation(s)
- Lamya Al-Haj
- Biology Department, College of Science, Sultan Qaboos University, Al-Khoud, P.O. Box 36, Muscat 123, Oman.
| | - Yuen Tin Lui
- Institute of Structural & Molecular Biology, University College London, London WC1E 6BT, UK.
| | - Raeid M M Abed
- Biology Department, College of Science, Sultan Qaboos University, Al-Khoud, P.O. Box 36, Muscat 123, Oman.
| | - Mohamed A Gomaa
- Biology Department, College of Science, Sultan Qaboos University, Al-Khoud, P.O. Box 36, Muscat 123, Oman.
| | - Saul Purton
- Institute of Structural & Molecular Biology, University College London, London WC1E 6BT, UK.
| |
Collapse
|
24
|
Ramey CJ, Barón-Sola Á, Aucoin HR, Boyle NR. Genome Engineering in Cyanobacteria: Where We Are and Where We Need To Go. ACS Synth Biol 2015; 4:1186-96. [PMID: 25985322 DOI: 10.1021/acssynbio.5b00043] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Genome engineering of cyanobacteria is a promising area of development in order to produce fuels, feedstocks, and value-added chemicals in a sustainable way. Unfortunately, the current state of genome engineering tools for cyanobacteria lags far behind those of model organisms such as Escherichia coli and Saccharomyces cerevisiae. In this review, we present the current state of synthetic biology tools for genome engineering efforts in the most widely used cyanobacteria strains and areas that need concerted research efforts to improve tool development. Cyanobacteria pose unique challenges to genome engineering efforts because their cellular biology differs significantly from other eubacteria; therefore, tools developed for other genera are not directly transferrable. Standardized parts, such as promoters and ribosome binding sites, which control gene expression, require characterization in cyanobacteria in order to have fully predictable results. The application of these tools to genome engineering efforts is also discussed; the ability to do genome-wide searching and to introduce multiple mutations simultaneously is an area that needs additional research in order to enable fast and efficient strain engineering.
Collapse
Affiliation(s)
- C. Josh Ramey
- Chemical and Biological Engineering
Department, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Ángel Barón-Sola
- Chemical and Biological Engineering
Department, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Hanna R. Aucoin
- Chemical and Biological Engineering
Department, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Nanette R. Boyle
- Chemical and Biological Engineering
Department, Colorado School of Mines, Golden, Colorado 80401, United States
| |
Collapse
|
25
|
Immethun CM, Ng KM, DeLorenzo DM, Waldron-Feinstein B, Lee YC, Moon TS. Oxygen-responsive genetic circuits constructed in Synechocystis sp. PCC 6803. Biotechnol Bioeng 2015; 113:433-42. [PMID: 26264210 DOI: 10.1002/bit.25722] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/18/2015] [Accepted: 08/04/2015] [Indexed: 02/03/2023]
Abstract
As photoautotrophic prokaryotes, cyanobacteria are promising platforms for producing value-added bioproducts. However, few regulatory genetic parts and devices (e.g., inducible promoters and regulatory circuits) have been developed for these potential hosts. Furthermore, the devices that have been created respond only to a single input. To address these issues, we developed an inducible genetic circuit that generates heterologous proteins in response to oxygen, an environmental signal. To test its performance and utility in Synechocystis sp. PCC 6803, a model cyanobacterial strain, we connected this circuit to either heterologous nifHDK genes, which encode oxygen-sensitive nitrogenase's structural proteins, or a fluorescent protein gene. The circuit was transcriptionally activated to generate nifHDK transcripts or fluorescent output only in low oxygen conditions. We expanded the oxygen-responsive circuit into a more complex circuit by building a two-input AND gate, which allows Synechocystis to specifically control expression of the fluorescent reporter in response to two signals, low oxygen and high anhydrotetracycline. To our knowledge, the AND gate is the first complex logic circuit built in a cyanobacterial strain. This work expands the synthetic biology tools available for complex gene expression in cyanobacteria, increasing their potential as biotechnology platforms.
Collapse
Affiliation(s)
- Cheryl M Immethun
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Kenneth M Ng
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Drew M DeLorenzo
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Ben Waldron-Feinstein
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Ying-Chiang Lee
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri.
| |
Collapse
|
26
|
Savakis P, Hellingwerf KJ. Engineering cyanobacteria for direct biofuel production from CO2. Curr Opin Biotechnol 2015; 33:8-14. [DOI: 10.1016/j.copbio.2014.09.007] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 09/22/2014] [Accepted: 09/24/2014] [Indexed: 02/02/2023]
|
27
|
Angermayr SA, Gorchs Rovira A, Hellingwerf KJ. Metabolic engineering of cyanobacteria for the synthesis of commodity products. Trends Biotechnol 2015; 33:352-61. [DOI: 10.1016/j.tibtech.2015.03.009] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 11/24/2022]
|
28
|
Xue Y, He Q. Cyanobacteria as cell factories to produce plant secondary metabolites. Front Bioeng Biotechnol 2015; 3:57. [PMID: 25973419 PMCID: PMC4412135 DOI: 10.3389/fbioe.2015.00057] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 04/14/2015] [Indexed: 01/23/2023] Open
Abstract
Cyanobacteria represent a promising platform for the production of plant secondary metabolites. Their capacity to express plant P450 proteins, which have essential functions in the biosynthesis of many plant secondary metabolites, makes cyanobacteria ideal for this purpose, and their photosynthetic capability allows cyanobacteria to grow with simple nutrient inputs. This review summarizes the advantages of using cyanobacteria to transgenically produce plant secondary metabolites. Some techniques to improve heterologous gene expression in cyanobacteria are discussed.
Collapse
Affiliation(s)
- Yong Xue
- Department of Applied Science, University of Arkansas at Little Rock , Little Rock, AR , USA
| | - Qingfang He
- Department of Applied Science, University of Arkansas at Little Rock , Little Rock, AR , USA
| |
Collapse
|
29
|
Rühle T, Leister D. Photosystem II Assembly from Scratch. FRONTIERS IN PLANT SCIENCE 2015; 6:1234. [PMID: 26793213 PMCID: PMC4709462 DOI: 10.3389/fpls.2015.01234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 12/19/2015] [Indexed: 05/06/2023]
Affiliation(s)
- Thilo Rühle
- Plant Molecular Biology, Department of Biology, Ludwig-Maximilians-University MunichMunich, Germany
| | - Dario Leister
- Plant Molecular Biology, Department of Biology, Ludwig-Maximilians-University MunichMunich, Germany
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of CopenhagenCopenhagen, Denmark
- *Correspondence: Dario Leister
| |
Collapse
|
30
|
Branco dos Santos F, Du W, Hellingwerf KJ. Synechocystis: Not Just a Plug-Bug for CO2, but a Green E. coli. Front Bioeng Biotechnol 2014; 2:36. [PMID: 25279375 PMCID: PMC4166995 DOI: 10.3389/fbioe.2014.00036] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 09/03/2014] [Indexed: 01/23/2023] Open
Abstract
Following multiple reports warning for threats posed by raising levels of atmospheric CO2, it is of paramount importance that human society rapidly evolves to be sustainable. Processes relying on photosynthetic microorganisms, converting CO2 and water into compounds of interest, fueled by light, are very pertinent, particularly if not directly competing for arable land. Here, we identify specific research questions that remain to be targeted to exploit the full potential of cyanobacterial cell factories. We argue that this approach will be more likely to be successful if organisms such as Synechocystis are not perceived as mere chassis for CO2 fixation, but rather considered as the "green" E. coli.
Collapse
Affiliation(s)
- Filipe Branco dos Santos
- Molecular Microbial Physiology Group, Faculty of Life Sciences, Swammerdam Institute of Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Wei Du
- Molecular Microbial Physiology Group, Faculty of Life Sciences, Swammerdam Institute of Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Klaas J. Hellingwerf
- Molecular Microbial Physiology Group, Faculty of Life Sciences, Swammerdam Institute of Life Sciences, University of Amsterdam, Amsterdam, Netherlands
- Photanol B.V., Amsterdam, Netherlands
| |
Collapse
|
31
|
Jensen PE, Leister D. Cyanobacteria as an Experimental Platform for Modifying Bacterial and Plant Photosynthesis. Front Bioeng Biotechnol 2014; 2:7. [PMID: 25024050 PMCID: PMC4090889 DOI: 10.3389/fbioe.2014.00007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 04/03/2014] [Indexed: 11/28/2022] Open
Affiliation(s)
- Poul Erik Jensen
- Copenhagen Plant Science Center (CPSC), Department of Plant and Environmental Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Dario Leister
- Copenhagen Plant Science Center (CPSC), Department of Plant and Environmental Sciences, University of Copenhagen , Copenhagen , Denmark ; Plant Molecular Biology (Botany), Department of Biology I, Ludwig-Maximilians-University Munich , Munich , Germany
| |
Collapse
|