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Li Z, Li S, Chen L, Sun T, Zhang W. Fast-growing cyanobacterial chassis for synthetic biology application. Crit Rev Biotechnol 2024; 44:414-428. [PMID: 36842999 DOI: 10.1080/07388551.2023.2166455] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/19/2022] [Accepted: 12/28/2022] [Indexed: 02/28/2023]
Abstract
Carbon neutrality by 2050 has become one of the most urgent challenges the world faces today. To address the issue, it is necessary to develop and promote new technologies related with CO2 recycling. Cyanobacteria are the only prokaryotes performing oxygenic photosynthesis, capable of fixing CO2 into biomass under sunlight and serving as one of the most important primary producers on earth. Notably, recent progress on synthetic biology has led to utilizing model cyanobacteria such as Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942 as chassis for "light-driven autotrophic cell factories" to produce several dozens of biofuels and various fine chemicals directly from CO2. However, due to the slow growth rate and low biomass accumulation in the current chassis, the productivity for most products is still lower than the threshold necessary for large-scale commercial application, raising the importance of developing high-efficiency cyanobacterial chassis with fast growth and/or higher biomass accumulation capabilities. In this article, we critically reviewed recent progresses on identification, systems biology analysis, and engineering of fast-growing cyanobacterial chassis. Specifically, fast-growing cyanobacteria identified in recent years, such as S. elongatus UTEX 2973, S. elongatus PCC 11801, S. elongatus PCC 11802 and Synechococcus sp. PCC 11901 was comparatively analyzed. In addition, the progresses on their recent application in converting CO2 into chemicals, and genetic toolboxes developed for these new cyanobacterial chassis were discussed. Finally, the article provides insights into future challenges and perspectives on the synthetic biology application of cyanobacterial chassis.
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Affiliation(s)
- Zhixiang Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
| | - Shubin Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, P.R. China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, P.R. China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, P.R. China
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2
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Mudtham NA, Promariya A, Duangsri C, Maneeruttanarungroj C, Ngamkala S, Akrimajirachoote N, Powtongsook S, Salminen TA, Raksajit W. Exogenous Trehalose Improves Growth, Glycogen and Poly-3-Hydroxybutyrate (PHB) Contents in Photoautotrophically Grown Arthrospira platensis under Nitrogen Deprivation. BIOLOGY 2024; 13:127. [PMID: 38392345 PMCID: PMC10886759 DOI: 10.3390/biology13020127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/09/2024] [Accepted: 02/16/2024] [Indexed: 02/24/2024]
Abstract
Glycogen and poly-3-hydroxybutyrate (PHB) are excellent biopolymer products from cyanobacteria. In this study, we demonstrate that nitrogen metabolism is positively influenced by the exogenous application of trehalose (Tre) in Arthrospira platensis under nitrogen-deprived (-N) conditions. Cells were cultivated photoautotrophically for 5 days under -N conditions, with or without the addition of exogenous Tre. The results revealed that biomass and chlorophyll-a content of A. platensis experienced enhancement with the addition of 0.003 M and 0.03 M Tre in the -N medium after one day, indicating relief from growth inhibition caused by nitrogen deprivation. The highest glycogen content (54.09 ± 1.6% (w/w) DW) was observed in cells grown for 2 days under the -N + 0.003 M Tre condition (p < 0.05), while the highest PHB content (15.2 ± 0.2% (w/w) DW) was observed in cells grown for 3 days under the -N + 0.03 M Tre condition (p < 0.05). The RT-PCR analysis showed a significant increase in glgA and phaC transcript levels, representing approximately 1.2- and 1.3-fold increases, respectively, in A. platensis grown under -N + 0.003 M Tre and -N + 0.03 M Tre conditions. This was accompanied by the induction of enzyme activities, including glycogen synthase and PHA synthase with maximal values of 89.15 and 0.68 µmol min-1 mg-1 protein, respectively. The chemical structure identification of glycogen and PHB from A. platensis was confirmed by FTIR and NMR analysis. This research represents the first study examining the performance of trehalose in promoting glycogen and PHB production in cyanobacteria under nitrogen-deprived conditions.
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Affiliation(s)
- Nat-Anong Mudtham
- Program of Animal Health Technology, Department of Veterinary Nursing, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
| | - Authen Promariya
- Program of Animal Health Technology, Department of Veterinary Nursing, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
| | - Chanchanok Duangsri
- Department of Animal Science, Faculty of Agricultural Technology and Agro-Industry, Rajamangala University of Technology Suvarnabhumi, Phranakhon Si Ayutthaya 13000, Thailand
| | - Cherdsak Maneeruttanarungroj
- Department of Biology, School of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand
| | - Suchanit Ngamkala
- Program of Animal Health Technology, Department of Veterinary Nursing, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
| | | | - Sorawit Powtongsook
- Center of Excellence for Marine Biotechnology, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathum Thani 12120, Thailand
| | - Tiina A Salminen
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6 A, FI-20520 Turku, Finland
| | - Wuttinun Raksajit
- Program of Animal Health Technology, Department of Veterinary Nursing, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
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3
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Simple transformation of the filamentous thermophilic cyanobacterium Leptolyngbya sp. KC45. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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4
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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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5
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Dhakal D, Chen M, Luesch H, Ding Y. Heterologous production of cyanobacterial compounds. J Ind Microbiol Biotechnol 2021; 48:6119914. [PMID: 33928376 PMCID: PMC8210676 DOI: 10.1093/jimb/kuab003] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/17/2020] [Indexed: 12/29/2022]
Abstract
Cyanobacteria produce a plethora of compounds with unique chemical structures and diverse biological activities. Importantly, the increasing availability of cyanobacterial genome sequences and the rapid development of bioinformatics tools have unraveled the tremendous potential of cyanobacteria in producing new natural products. However, the discovery of these compounds based on cyanobacterial genomes has progressed slowly as the majority of their corresponding biosynthetic gene clusters (BGCs) are silent. In addition, cyanobacterial strains are often slow-growing, difficult for genetic engineering, or cannot be cultivated yet, limiting the use of host genetic engineering approaches for discovery. On the other hand, genetically tractable hosts such as Escherichia coli, Actinobacteria, and yeast have been developed for the heterologous expression of cyanobacterial BGCs. More recently, there have been increased interests in developing model cyanobacterial strains as heterologous production platforms. Herein, we present recent advances in the heterologous production of cyanobacterial compounds in both cyanobacterial and noncyanobacterial hosts. Emerging strategies for BGC assembly, host engineering, and optimization of BGC expression are included for fostering the broader applications of synthetic biology tools in the discovery of new cyanobacterial natural products.
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Affiliation(s)
- Dipesh Dhakal
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL 31610, USA
| | - Manyun Chen
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL 31610, USA
| | - Hendrik Luesch
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL 31610, USA
| | - Yousong Ding
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL 31610, USA
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6
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Choi YN, Shin YR, Park JM, Lee JW. Cell-Free Transcription-Coupled CRISPR/Cas12a Assay for Prototyping Cyanobacterial Promoters. ACS Synth Biol 2021; 10:1300-1307. [PMID: 34015913 DOI: 10.1021/acssynbio.1c00148] [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] [Indexed: 12/27/2022]
Abstract
Cyanobacteria are promising microbial hosts for the production of diverse biofuels and biochemicals. However, compared to other model microbial hosts such as Escherichia coli and yeast, it takes a long time to genetically modify cyanobacteria. One way to efficiently engineer cyanobacteria while minimizing genetic engineering would be to develop a fast, high-throughput prototyping tool for cyanobacteria. In this study, we developed a CRISPR/Cas12a-based assay coupled with cyanobacteria cell-free systems to rapidly prototype promoter characteristics. Using this newly developed assay, we demonstrated cyanobacteria cell-free transcription for the first time and confirmed a positive correlation between the in vitro and in vivo transcription performance. Furthermore, we generated a synthetic promoter library and evaluated the characteristics of promoter subregions by using the assay. Varied promoter strength derived from random mutations were rapidly and effectively measured in a high-throughput way. We believe that this study offers an easily applicable and rapid prototyping platform to characterize promoters for cyanobacterial engineering.
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Affiliation(s)
- Yun-Nam Choi
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
| | - Ye Rim Shin
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
| | - Jong Moon Park
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Integrated Technology, Yonsei University (POSTECH-Yonsei Open Campus), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk, 37673, Korea
| | - Jeong Wook Lee
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Integrated Technology, Yonsei University (POSTECH-Yonsei Open Campus), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk, 37673, Korea
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7
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Zhang X, Betterle N, Hidalgo Martinez D, Melis A. Recombinant Protein Stability in Cyanobacteria. ACS Synth Biol 2021; 10:810-825. [PMID: 33684287 DOI: 10.1021/acssynbio.0c00610] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The living cell possesses extraordinary molecular and biochemical mechanisms by which to recognize and efficiently remove foreign, damaged, or denatured proteins. This essential function has been a barrier to the overexpression of recombinant proteins in most expression systems. A notable exception is the overexpression in E. coli of recombinant proteins, most of which, however, end-up as "inclusion bodies", i.e., cytoplasmic aggregates of proteins that are inaccessible to the cell's proteasome. "Fusion constructs as protein overexpression vectors" proved to be unparalleled in their ability to cause substantial accumulation of recombinant proteins from plants, animals, and bacteria, as soluble proteins in unicellular cyanobacteria. Recombinant protein levels in the range of 10-20% of the total cellular protein can be achieved. The present work investigated this unique property in the context of recombinant protein stability in Synechocystis sp. PCC 6803 by developing and applying an in vivo cellular tobacco etch virus cleavage system with the objective of separating the target heterologous proteins from their fusion leader sequences. The work provides new insights about the overexpression, cellular stability, and exploitation of transgenes with commercial interest, highly expressed in a cyanobacterial biofactory. The results support the notion that eukaryotic plant- and animal-origin recombinant proteins are unstable, when free in the cyanobacterial cytosol but stable when in a fusion configuration with a highly expressed cyanobacterial native or heterologous protein. Included in this analysis are recombinant proteins of the plant isoprenoid biosynthetic pathway (isoprene synthase, β-phellandrene synthase, geranyl diphosphate synthase), the human interferon protein, as well as prokaryotic proteins (tetanus toxin fragment C and the antibiotic resistance genes kanamycin and chloramphenicol). The future success of synthetic biology approaches with cyanobacteria and other systems would require overexpression of pathway enzymes to attain product volume, and the work reported in this paper sets the foundation for such recombinant pathway enzyme overexpression.
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Affiliation(s)
- Xianan Zhang
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720-3102, United States
| | - Nico Betterle
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720-3102, United States
| | - Diego Hidalgo Martinez
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720-3102, United States
| | - Anastasios Melis
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720-3102, United States
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8
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Gupta JK, Srivastava S. The Effect of Promoter and RBS Combination on the Growth and Glycogen Productivity of Sodium-Dependent Bicarbonate Transporter (SbtA) Overexpressing Synechococcus sp. PCC 7002 Cells. Front Microbiol 2021; 12:607411. [PMID: 33927699 PMCID: PMC8076525 DOI: 10.3389/fmicb.2021.607411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 03/22/2021] [Indexed: 12/20/2022] Open
Abstract
Sodium dependent bicarbonate transporter, SbtA is a high-affinity, inducible bicarbonate transporter in cyanobacterial cells. Our previous work has shown that overexpression of this transporter can significantly increase growth and glycogen accumulation in Synechococcus sp. PCC 7002 cells. In this work, we have tested the effect of two different RBS sequences (RBS1: GGAGGA and RBS2: AGGAGA) and three different promoters (PcpcB, PcpcB560, and PrbcL2) on the growth and glycogen production in SbtA-overexpressing Synechococcus sp. PCC 7002 cells. Our results show that PcpcB or PcpcB560 were more effective than PrbcL2 in increasing the growth and glycogen content. The choice of RBS sequence had relatively minor effect, though RBS2 was more effective than RBS1. The transformant E, with PcpcB560 and RBS2, showed the highest growth. The biomass after 5 days of growth on air or 1% CO2 was increased by about 90% in the strain E compared to PCC 7002 cells. All transformants overexpressing SbtA had higher glycogen content. However, growing the cells with bubbling of 1% CO2 did not increase cellular glycogen content any further. The strain E had about 80% higher glycogen content compared to WT PCC 7002 cells. Therefore, the glycogen productivity of the strain E grown with air-bubbling was about 2.5-fold that of the WT PCC 7002 cells grown similarly. Additionally, some of the transformants had higher chlorophyll content while all the transformants had higher carotenoid content compared to the PCC 7002 cells, suggesting interaction between carbon transport and pigment levels. Thus, this work shows that the choice of photosynthetic promoters and RBSs sequences can impact growth and glycogen accumulation in SbtA-overexpressing cells.
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Affiliation(s)
- Jai Kumar Gupta
- Systems Biology for Biofuels Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Shireesh Srivastava
- Systems Biology for Biofuels Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India.,Department of Biotechnology-International Centre for Genetic Engineering and Biotechnology (DBT-ICGEB), Centre for Advanced Bioenergy Research, New Delhi, India
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9
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McNulty MJ, Xiong YM, Yates K, Karuppanan K, Hilzinger JM, Berliner AJ, Delzio J, Arkin AP, Lane NE, Nandi S, McDonald KA. Molecular pharming to support human life on the moon, mars, and beyond. Crit Rev Biotechnol 2021; 41:849-864. [PMID: 33715563 DOI: 10.1080/07388551.2021.1888070] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Space missions have always assumed that the risk of spacecraft malfunction far outweighs the risk of human system failure. This assumption breaks down for longer duration exploration missions and exposes vulnerabilities in space medical systems. Space agencies can no longer reduce the majority of the human health and performance risks through crew members selection process and emergency re-supply or evacuation. No mature medical solutions exist to address this risk. With recent advances in biotechnology, there is promise for lessening this risk by augmenting a space pharmacy with a biologically-based space foundry for the on-demand manufacturing of high-value medical products. Here we review the challenges and opportunities of molecular pharming, the production of pharmaceuticals in plants, as the basis of a space medical foundry to close the risk gap in current space medical systems. Plants have long been considered to be an important life support object in space and can now also be viewed as programmable factories in space. Advances in molecular pharming-based space foundries will have widespread applications in promoting simple and accessible pharmaceutical manufacturing on Earth.
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Affiliation(s)
- Matthew J McNulty
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Chemical Engineering, University of California, Davis, CA, USA
| | - Yongao Mary Xiong
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Chemical Engineering, University of California, Davis, CA, USA
| | - Kevin Yates
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Chemical Engineering, University of California, Davis, CA, USA
| | - Kalimuthu Karuppanan
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Radcliffe Department of Medicine, Oxford University, Oxford, UK
| | - Jacob M Hilzinger
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Aaron J Berliner
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Jesse Delzio
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Chemical Engineering, University of California, Davis, CA, USA
| | - Adam P Arkin
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Nancy E Lane
- Center for Musculoskeletal Health, School of Medicine, University of California, Davis, CA, USA
| | - Somen Nandi
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Chemical Engineering, University of California, Davis, CA, USA.,Global HealthShare® Initiative, University of California, Davis, CA, USA
| | - Karen A McDonald
- Center for the Utilization of Biological Engineering in Space (CUBES), Berkeley, CA, USA.,Department of Chemical Engineering, University of California, Davis, CA, USA.,Global HealthShare® Initiative, University of California, Davis, CA, USA
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10
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Madsen MA, Hamilton G, Herzyk P, Amtmann A. Environmental Regulation of PndbA600, an Auto-Inducible Promoter for Two-Stage Industrial Biotechnology in Cyanobacteria. Front Bioeng Biotechnol 2021; 8:619055. [PMID: 33542914 PMCID: PMC7853294 DOI: 10.3389/fbioe.2020.619055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/09/2020] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria are photosynthetic prokaryotes being developed as sustainable platforms that use renewable resources (light, water, and air) for diverse applications in energy, food, environment, and medicine. Despite the attractive promise that cyanobacteria offer to industrial biotechnology, slow growth rates pose a major challenge in processes which typically require large amounts of biomass and are often toxic to the cells. Two-stage cultivation strategies are an attractive solution to prevent any undesired growth inhibition by de-coupling biomass accumulation (stage I) and the industrial process (stage II). In cyanobacteria, two-stage strategies involve costly transfer methods between stages I and II, and little work has been focussed on using the distinct growth and stationary phases of batch cultures to autoregulate stage transition. In the present study, we identified and characterised a growth phase-specific promoter, which can serve as an auto-inducible switch to regulate two-stage bioprocesses in cyanobacteria. First, growth phase-specific genes were identified from a new RNAseq dataset comparing two growth phases and six nutrient conditions in Synechocystis sp. PCC 6803, including two new transcriptomes for low Mg and low K. A type II NADH dehydrogenase (ndbA) showed robust induction when the cultures transitioned from exponential to stationary phase growth. Behaviour of a 600-bp promoter sequence (PndbA600) was then characterised in detail following the expression of PndbA600:GFP in Synechococcus sp. PCC 7002. Culture density and growth media analyses showed that PndbA600 activation was not dependent on increases in culture density per se but on N availability and on another activating factor present in the spent media of stationary phase cultures (Factor X). PndbA600 deactivation was dependent on the changes in culture density and in either N availability or Factor X. Electron transport inhibition studies revealed a photosynthesis-specific enhancement of active PndbA600 levels. Our findings are summarised in a model describing the environmental regulation of PndbA600, which can now inform the rational design of two-stage industrial processes in cyanobacteria.
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Affiliation(s)
- Mary Ann Madsen
- College of Medical, Veterinary and Life Sciences, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Graham Hamilton
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Pawel Herzyk
- College of Medical, Veterinary and Life Sciences, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom.,Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Anna Amtmann
- College of Medical, Veterinary and Life Sciences, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
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11
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Jodlbauer J, Rohr T, Spadiut O, Mihovilovic MD, Rudroff F. Biocatalysis in Green and Blue: Cyanobacteria. Trends Biotechnol 2021; 39:875-889. [PMID: 33468423 DOI: 10.1016/j.tibtech.2020.12.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/17/2022]
Abstract
Recently, several studies have proven the potential of cyanobacteria as whole-cell biocatalysts for biotransformation. Compared to heterotrophic hosts, cyanobacteria show unique advantages thanks to their photoautotrophic metabolism. Their ability to use light as energy and CO2 as carbon source promises a truly sustainable production platform. Their photoautotrophic metabolism offers an encouraging source of reducing power, which makes them attractive for redox-based biotechnological purposes. To exploit the full potential of these whole-cell biocatalysts, cyanobacterial cells must be considered in their entirety. With this emphasis, this review summarizes the latest developments in cyanobacteria research with a strong focus on the benefits associated with their unique metabolism. Remaining bottlenecks and recent strategies to overcome them are evaluated for their potential in future applications.
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Affiliation(s)
- Julia Jodlbauer
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/OC-163, 1060 Vienna, Austria
| | - Thomas Rohr
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/OC-163, 1060 Vienna, Austria
| | - Oliver Spadiut
- Institute of Chemical Engineering, research area Biochemical Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
| | - Marko D Mihovilovic
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/OC-163, 1060 Vienna, Austria
| | - Florian Rudroff
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/OC-163, 1060 Vienna, Austria.
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12
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Metabolic Engineering and Synthetic Biology of Cyanobacteria for Carbon Capture and Utilization. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-019-0447-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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13
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Wang W, Sheng Y. Gene expression concerning fatty acid and amino acid metabolism in Chlorella vulgaris cultured with antibiotics. Appl Microbiol Biotechnol 2020; 104:8025-8036. [PMID: 32794019 DOI: 10.1007/s00253-020-10822-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 07/16/2020] [Accepted: 08/06/2020] [Indexed: 12/17/2022]
Abstract
The green alga Chlorella vulgaris has potential as a source of clean bioenergy with abundant metabolites and a high oil content, and antibiotics are often applied to remove bacteria from culture to obtain axenic algal strains. In this work, ceftazidime and gentamicin sulphate (GS) were added separately and in combination in the aseptic processing of C. vulgaris, and gene expression and metabolites were evaluated. The results showed that ceftazidime and GS effectively inhibited the proliferation of Cyanobacteria and Bacteroidetes, respectively. Overall, the effects of antibiotics on C. vulgaris differed: GS increased the algal concentration, whereas ceftazidime alone and in combination with GS treatment decreased the specific algal growth rate. Based on comparative transcription analysis, 5917 and 5899 differentially expressed genes (DEGs) were respectively upregulated and downregulated by ceftazidime, 963 and 3921 DEGs by GS, and 4532 and 1675 DEGs by the ceftazidime and GS combination. Pathway enrichment analysis showed that the downregulated DEGs in the ceftazidime groups were enriched in the fatty acid biosynthesis pathway but that the upregulated DEGs in the GS group were enriched in the fatty acid degradation pathway. Some pathways related to amino acid metabolism were markably influenced by antibiotic treatment. The results further indicated that antibiotics affected the intracellular concentration of fatty acids and amino acids in C. vulgaris. This study provides a new viewpoint regarding the response of C. vulgaris to antibiotics in the process of obtaining axenic algal strains. KEY POINTS: • Ceftazidime and gentamicin sulphate influenced bacterial proliferation. • Downregulated differentially expressed genes mapped to the fatty acid biosynthesis pathway. • Antibiotics affected intracellular concentrations of fatty acids and amino acids.
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Affiliation(s)
- Wenjing Wang
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 7 Chunhui Road, Yantai, 264003, Shandong, China
| | - Yanqing Sheng
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 7 Chunhui Road, Yantai, 264003, Shandong, China.
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Sengupta A, Madhu S, Wangikar PP. A Library of Tunable, Portable, and Inducer-Free Promoters Derived from Cyanobacteria. ACS Synth Biol 2020; 9:1790-1801. [PMID: 32551554 DOI: 10.1021/acssynbio.0c00152] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cyanobacteria are emerging as hosts for various biotechnological applications. The ability to engineer these photosynthetic prokaryotes greatly depends on the availability of well-characterized promoters. Inducer-free promoters of a range of activities may be desirable for the eventual large-scale, outdoor cultivations. Further, several native promoters of cyanobacteria are repressed by high carbon dioxide or light, and it would be of interest to alter this property. We started with PrbcL and PcpcB, the well-characterized native promoters of the model cyanobacterium Synechococcus elongatus PCC 7942, found upstream of the two abundantly expressed genes, Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase, and phycocyanin β-1 subunit, respectively. The library of 48 promoters created via error-prone PCR of these 300-bp-long native promoters showed 2 orders of magnitude dynamic range with activities that were both lower and higher than those of the wild-type promoters. A few mutants of the PrbcL showed greater strength than PcpcB, which is widely considered a superstrong promoter. A number of mutant promoters did not show repression by high CO2 or light, typically found for PrbcL and PcpcB, respectively. Further, the wild-type and mutant promoters showed comparable activities in the fast-growing and stress-tolerant strains S. elongatus PCC 11801 and PCC 11802, suggesting that the library can be used in different cyanobacteria. Interestingly, the majority of the promoters showed strong expression in E. coli, thus adding to the repertoire of inducer-free promoters for this heterotrophic workhorse. Our results have implications in the metabolic engineering of cyanobacteria and E. coli.
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Liu D, Johnson VM, Pakrasi HB. A Reversibly Induced CRISPRi System Targeting Photosystem II in the Cyanobacterium Synechocystis sp. PCC 6803. ACS Synth Biol 2020; 9:1441-1449. [PMID: 32379958 DOI: 10.1021/acssynbio.0c00106] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The cyanobacterium Synechocystis sp. PCC 6803 is used as a model organism to study photosynthesis, as it can utilize glucose as the sole carbon source to support its growth under heterotrophic conditions. CRISPR interference (CRISPRi) has been widely applied to repress the transcription of genes in a targeted manner in cyanobacteria. However, a robust and reversible induced CRISPRi system has not been explored in Synechocystis 6803 to knock down and recover the expression of a targeted gene. In this study, we built a tightly controlled chimeric promoter, P rhaBAD-RSW, in which a theophylline responsive riboswitch was integrated into a rhamnose-inducible promoter system. We applied this promoter to drive the expression of ddCpf1 (DNase-dead Cpf1 nuclease) in a CRISPRi system and chose the PSII reaction center gene psbD (D2 protein) to target for repression. psbD was specifically knocked down by over 95% of its native expression, leading to severely inhibited photosystem II activity and growth of Synechocystis 6803 under photoautotrophic conditions. Significantly, removal of the inducers rhamnose and theophylline reversed repression by CRISPRi. Expression of PsbD recovered following release of repression, coupled with increased photosystem II content and activity. This reversibly induced CRISPRi system in Synechocystis 6803 represents a new strategy for study of the biogenesis of photosynthetic complexes in cyanobacteria.
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Affiliation(s)
- Deng Liu
- Department of Biology, Washington University, St. Louis, Missouri 63130, United States
| | - Virginia M Johnson
- Department of Biology, Washington University, St. Louis, Missouri 63130, United States
| | - Himadri B Pakrasi
- Department of Biology, Washington University, St. Louis, Missouri 63130, United States
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Sengupta S, Jaiswal D, Sengupta A, Shah S, Gadagkar S, Wangikar PP. Metabolic engineering of a fast-growing cyanobacterium Synechococcus elongatus PCC 11801 for photoautotrophic production of succinic acid. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:89. [PMID: 32467730 PMCID: PMC7236211 DOI: 10.1186/s13068-020-01727-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/09/2020] [Indexed: 05/11/2023]
Abstract
BACKGROUND Cyanobacteria, a group of photosynthetic prokaryotes, are being increasingly explored for direct conversion of carbon dioxide to useful chemicals. However, efforts to engineer these photoautotrophs have resulted in low product titers. This may be ascribed to the bottlenecks in metabolic pathways, which need to be identified for rational engineering. We engineered the recently reported, fast-growing and robust cyanobacterium, Synechococcus elongatus PCC 11801 to produce succinate, an important platform chemical. Previously, engineering of the model cyanobacterium S. elongatus PCC 7942 has resulted in succinate titer of 0.43 g l-1 in 8 days. RESULTS Building on the previous report, expression of α-ketoglutarate decarboxylase, succinate semialdehyde dehydrogenase and phosphoenolpyruvate carboxylase yielded a succinate titer of 0.6 g l-1 in 5 days suggesting that PCC 11801 is better suited as host for production. Profiling of the engineered strains for 57 intermediate metabolites, a number of enzymes and qualitative analysis of key transcripts revealed potential flux control points. Based on this, we evaluated the effects of overexpression of sedoheptulose-1,7-bisphosphatase, citrate synthase and succinate transporters and knockout of succinate dehydrogenase and glycogen synthase A. The final construct with seven genes overexpressed and two genes knocked out resulted in photoautotrophic production of 0.93 g l-1 succinate in 5 days. CONCLUSION While the fast-growing strain PCC 11801 yielded a much higher titer than the model strain, the efficient photoautotrophy of this novel isolate needs to be harnessed further for the production of desired chemicals. Engineered strains of S. elongatus PCC 11801 showed dramatic alterations in the levels of several metabolites suggesting far reaching effects of pathway engineering. Attempts to overexpress enzymes deemed to be flux controlling led to the emergence of other potential rate-limiting steps. Thus, this process of debottlenecking of the pathway needs to be repeated several times to obtain a significantly superior succinate titer.
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Affiliation(s)
- Shinjinee Sengupta
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
- DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Damini Jaiswal
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Annesha Sengupta
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Shikha Shah
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
- DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Shruti Gadagkar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Pramod P. Wangikar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
- DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
- Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
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