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Chen AY, Ku JT, Tsai TP, Hung JJ, Hung BC, Lan EI. Metabolic Engineering Design Strategies for Increasing Carbon Fluxes Relevant for Biosynthesis in Cyanobacteria. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2023; 183:105-144. [PMID: 37093259 DOI: 10.1007/10_2023_218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Cyanobacteria are promising microbial cell factories for the direct production of biochemicals and biofuels from CO2. Through genetic and metabolic engineering, they can be modified to produce a variety of both natural and non-natural compounds. To enhance the yield of these products, various design strategies have been developed. In this chapter, strategies used to enhance metabolic fluxes towards common precursors used in biosynthesis, including pyruvate, acetyl-CoA, malonyl-CoA, TCA cycle intermediates, and aromatics, are discussed. Additionally, strategies related to cofactor availability and mixotrophic conditions for bioproduction are also summarize.
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Affiliation(s)
- Arvin Y Chen
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu City, Taiwan
| | - Jason T Ku
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu City, Taiwan
| | - Teresa P Tsai
- Institute of Biomedical Engineering, National Yang Ming Chiao Tung University, Hsinchu City, Taiwan
| | - Jenny J Hung
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu City, Taiwan
| | - Billy C Hung
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu City, Taiwan
| | - Ethan I Lan
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu City, Taiwan.
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2
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Lai MJ, Tsai JC, Lan EI. CRISPRi-enhanced direct photosynthetic conversion of carbon dioxide to succinic acid by metabolically engineered cyanobacteria. BIORESOURCE TECHNOLOGY 2022; 366:128131. [PMID: 36252759 DOI: 10.1016/j.biortech.2022.128131] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/09/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Engineering photoautotrophic microorganisms to directly convert carbon dioxide into platform chemicals is an attractive approach for chemical sustainability and carbon mitigation. Here, an engineered cyanobacterium Synechococcus elongatus PCC 7942 was developed to produce succinic acid directly from ambient carbon dioxide. Inhibition of succinate dehydrogenase and glycogen synthase by CRIPSR interference increased carbon flux towards succinic acid. Dual inhibition of these two genes led to an 82 % increase in titer. The resulting strain produced 4.8 g/L of succinic acid in a 28-days cultivation. However, cells after the 28-days cultivation became non-viable and cannot continue production. This issue was addressed by re-inoculation with fresh cells into the production medium. This strategy enabled continuous succinic acid accumulation, reaching a final titer of 8.9 g/L. This study provides a sustainable route to succinic acid directly from carbon dioxide and a potential method to overcome the low titer limitation of cyanobacterial-based bioproduction for practical applications.
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Affiliation(s)
- Martin J Lai
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City 300, Taiwan
| | - Jemmy C Tsai
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City 300, Taiwan
| | - Ethan I Lan
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City 300, Taiwan.
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3
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Hao F, Li X, Wang J, Li R, Zou L, Wang K, Chen F, Shi F, Yang H, Wang W, Tian M. Separation of Bioproducts through the Integration of Cyanobacterial Metabolism and Membrane Filtration: Facilitating Cyanobacteria's Industrial Application. MEMBRANES 2022; 12:963. [PMID: 36295722 PMCID: PMC9611232 DOI: 10.3390/membranes12100963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/10/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
In this work, we propose the development of an efficient, economical, automated, and sustainable method for separating bioproducts from culture medium via the integration of a sucrose-secreting cyanobacteria production process and pressure-driven membrane filtration technology. Firstly, we constructed sucrose-secreting cyanobacteria with a sucrose yield of 600-700 mg/L sucrose after 7 days of salt stress, and the produced sucrose could be fully separated from the cyanobacteria cultures through an efficient and automated membrane filtration process. To determine whether this new method is also economical and sustainable, the relationship between membrane species, operating pressure, and the growth status of four cyanobacterial species was systematically investigated. The results revealed that all four cyanobacterial species could continue to grow after UF filtration. The field emission scanning electron microscopy and confocal laser scanning microscopy results indicate that the cyanobacteria did not cause severe destruction to the membrane surface structure. The good cell viability and intact membrane surface observed after filtration indicated that this innovative cyanobacteria-membrane system is economical and sustainable. This work pioneered the use of membrane separation to achieve the in situ separation of cyanobacterial culture and target products, laying the foundation for the industrialization of cyanobacterial bioproducts.
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Affiliation(s)
- Fei Hao
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
- Center of Special Environmental Biomechanics & Biomedical Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Xinyi Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
| | - Jiameng Wang
- School of Astronautics, Northwestern Polytechnical University, Xi’an 710072, China
| | - Ruoyue Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
| | - Liyan Zou
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
| | - Kai Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
| | - Fuqing Chen
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
| | - Feixiong Shi
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
| | - Hui Yang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
- Center of Special Environmental Biomechanics & Biomedical Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Wen Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
| | - Miao Tian
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710072, China
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Velmurugan R, Incharoensakdi A. Metabolic transformation of cyanobacteria for biofuel production. CHEMOSPHERE 2022; 299:134342. [PMID: 35307390 DOI: 10.1016/j.chemosphere.2022.134342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
World-wide, an emerging demand is moving towards the biofuels to replace the fossil fuels. In alternative biofuel production strategies, cyanobacteria have unique characteristic of accumulating glycogen, lipid, and fuel molecules through natural mechanisms. Moreover, the cyanobacteria can be easily engineered to synthesis a plenty of fuel molecules from CO2. To obtain the fuel molecule from cyanobacteria, various techniques were invented in which the metabolic engineering is found to be a prerequisite to develop an economically feasible process. The expression of indigenous or heterologous pathways plays an important role in developing successful production process. In addition, the engineering of photosynthetic apparatus, destruction of competitive pathways and improvement of tolerance were also proven to improve the product specific synthesis. Although various metabolic engineering approaches have been developed, there are certain obstacles when it comes to implementation for the production. In this review, the important biosynthetic pathways for biofuels, alteration of other genes to improve the actual pathway and possibilities of developing cyanobacterial fuel production have been elaborated.
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Affiliation(s)
- Rajendran Velmurugan
- Cyanobacterial Biotechnology Laboratory, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Aran Incharoensakdi
- Cyanobacterial Biotechnology Laboratory, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand; Academy of Science, Royal Society of Thailand, Bangkok, 10300, Thailand.
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Tan X, Nielsen J. The integration of bio-catalysis and electrocatalysis to produce fuels and chemicals from carbon dioxide. Chem Soc Rev 2022; 51:4763-4785. [PMID: 35584360 DOI: 10.1039/d2cs00309k] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dependence on fossil fuels has caused excessive emissions of greenhouse gases (GHGs), leading to climate changes and global warming. Even though the expansion of electricity generation will enable a wider use of electric vehicles, biotechnology represents an attractive route for producing high-density liquid transportation fuels that can reduce GHG emissions from jets, long-haul trucks and ships. Furthermore, to achieve immediate alleviation of the current environmental situation, besides reducing carbon footprint it is urgent to develop technologies that transform atmospheric CO2 into fossil fuel replacements. The integration of bio-catalysis and electrocatalysis (bio-electrocatalysis) provides such a promising avenue to convert CO2 into fuels and chemicals with high-chain lengths. Following an overview of different mechanisms that can be used for CO2 fixation, we will discuss crucial factors for electrocatalysis with a special highlight on the improvement of electron-transfer kinetics, multi-dimensional electrocatalysts and their hybrids, electrolyser configurations, and the integration of electrocatalysis and bio-catalysis. Finally, we prospect key advantages and challenges of bio-electrocatalysis, and end with a discussion of future research directions.
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Affiliation(s)
- Xinyi Tan
- Department of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE41296 Gothenburg, Sweden. .,BioInnovation Institute, Ole Maaløes Vej 3, DK2200 Copenhagen N, Denmark
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6
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Hu L, Guo S, Wang B, Fu R, Fan D, Jiang M, Fei Q, Gonzalez R. Bio-valorization of C1 gaseous substrates into bioalcohols: Potentials and challenges in reducing carbon emissions. Biotechnol Adv 2022; 59:107954. [DOI: 10.1016/j.biotechadv.2022.107954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 03/29/2022] [Accepted: 04/04/2022] [Indexed: 11/02/2022]
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7
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Genetic, Genomics, and Responses to Stresses in Cyanobacteria: Biotechnological Implications. Genes (Basel) 2021; 12:genes12040500. [PMID: 33805386 PMCID: PMC8066212 DOI: 10.3390/genes12040500] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 02/07/2023] Open
Abstract
Cyanobacteria are widely-diverse, environmentally crucial photosynthetic prokaryotes of great interests for basic and applied science. Work to date has focused mostly on the three non-nitrogen fixing unicellular species Synechocystis PCC 6803, Synechococcus PCC 7942, and Synechococcus PCC 7002, which have been selected for their genetic and physiological interests summarized in this review. Extensive "omics" data sets have been generated, and genome-scale models (GSM) have been developed for the rational engineering of these cyanobacteria for biotechnological purposes. We presently discuss what should be done to improve our understanding of the genotype-phenotype relationships of these models and generate robust and predictive models of their metabolism. Furthermore, we also emphasize that because Synechocystis PCC 6803, Synechococcus PCC 7942, and Synechococcus PCC 7002 represent only a limited part of the wide biodiversity of cyanobacteria, other species distantly related to these three models, should be studied. Finally, we highlight the need to strengthen the communication between academic researchers, who know well cyanobacteria and can engineer them for biotechnological purposes, but have a limited access to large photobioreactors, and industrial partners who attempt to use natural or engineered cyanobacteria to produce interesting chemicals at reasonable costs, but may lack knowledge on cyanobacterial physiology and metabolism.
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Stephens S, Mahadevan R, Allen DG. Engineering Photosynthetic Bioprocesses for Sustainable Chemical Production: A Review. Front Bioeng Biotechnol 2021; 8:610723. [PMID: 33490053 PMCID: PMC7820810 DOI: 10.3389/fbioe.2020.610723] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 12/01/2020] [Indexed: 11/13/2022] Open
Abstract
Microbial production of chemicals using renewable feedstocks such as glucose has emerged as a green alternative to conventional chemical production processes that rely primarily on petroleum-based feedstocks. The carbon footprint of such processes can further be reduced by using engineered cells that harness solar energy to consume feedstocks traditionally considered to be wastes as their carbon sources. Photosynthetic bacteria utilize sophisticated photosystems to capture the energy from photons to generate reduction potential with such rapidity and abundance that cells often cannot use it fast enough and much of it is lost as heat and light. Engineering photosynthetic organisms could enable us to take advantage of this energy surplus by redirecting it toward the synthesis of commercially important products such as biofuels, bioplastics, commodity chemicals, and terpenoids. In this work, we review photosynthetic pathways in aerobic and anaerobic bacteria to better understand how these organisms have naturally evolved to harness solar energy. We also discuss more recent attempts at engineering both the photosystems and downstream reactions that transfer reducing power to improve target chemical production. Further, we discuss different methods for the optimization of photosynthetic bioprocess including the immobilization of cells and the optimization of light delivery. We anticipate this review will serve as an important resource for future efforts to engineer and harness photosynthetic bacteria for chemical production.
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Affiliation(s)
- Sheida Stephens
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada.,Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - D Grant Allen
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
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9
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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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10
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Morphological analysis of Spirulina sp. NCIM 5143 and Nostoc ellipsosporum NCIM 2786 and comparative characterization of associated enzymes through in silico approach. Biologia (Bratisl) 2020. [DOI: 10.2478/s11756-020-00526-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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Fan ES, Lu KW, Wen RC, Shen CR. Photosynthetic Reduction of Xylose to Xylitol Using Cyanobacteria. Biotechnol J 2020; 15:e1900354. [PMID: 32388928 DOI: 10.1002/biot.201900354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 04/30/2020] [Indexed: 12/13/2022]
Abstract
Photosynthetic generation of reducing power makes cyanobacteria an attractive host for biochemical reduction compared to cell-free and heterotrophic systems, which require burning of additional resources for the supply of reducing equivalent. Here, using xylitol synthesis as an example, efficient uptake and reduction of xylose photoautotrophically in Synechococcus elongatus PCC7942 are demonstrated upon introduction of an effective xylose transporter from Escherichia coli (Ec-XylE) and the NADPH-dependent xylose reductase from Candida boidinii (Cb-XR). Simultaneous activation of xylose uptake and matching of cofactor specificity enabled an average xylitol yield of 0.9 g g-1 xylose and a maximum productivity of about 0.15 g L-1 day-1 OD-1 with increased level of xylose supply. While long-term cellular maintenance still appears challenging, high-density conversion of xylose to xylitol using concentrated resting cell further pushes the titer of xylitol formation to 33 g L-1 in six days with 85% of maximum theoretical yield. While the results show that the unknown dissipation of xylose can be minimized when coupled to a strong reaction outlet, it remains to be the major hurdle hampering the yield despite the reported inability of cyanobacteria to metabolize xylose.
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Affiliation(s)
- Eric S Fan
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, ROC 30013, Taiwan
| | - Ken W Lu
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, ROC 30013, Taiwan
| | - Rex C Wen
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, ROC 30013, Taiwan
| | - Claire R Shen
- Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, ROC 30013, Taiwan
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12
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100 Years Later, What Is New in Glycerol Bioproduction? Trends Biotechnol 2020; 38:907-916. [PMID: 32584768 DOI: 10.1016/j.tibtech.2020.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 12/23/2022]
Abstract
Industrial production of glycerol by yeast, which began during WWI in the so-called Neuberg fermentation, was the first example of metabolic engineering. However, this process, based on bisulfite addition to fermentation liquid, has many drawbacks and was replaced by other methods of glycerol production. Osmotolerant yeasts and other microorganisms that do not require addition of bisulfite to steer cellular metabolism towards glycerol synthesis have been discovered or engineered. Because the glycerol market is expected to reach 5 billion US$ by 2024, microbial fermentation may again become a promising way to produce glycerol. This review summarizes some problems and perspectives on the production of glycerol by natural or engineered eukaryotic and prokaryotic microorganisms.
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Hirokawa Y, Kubo T, Soma Y, Saruta F, Hanai T. Enhancement of acetyl-CoA flux for photosynthetic chemical production by pyruvate dehydrogenase complex overexpression in Synechococcus elongatus PCC 7942. Metab Eng 2019; 57:23-30. [PMID: 31377410 DOI: 10.1016/j.ymben.2019.07.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 10/26/2022]
Abstract
Genetic manipulation in cyanobacteria enables the direct production of valuable chemicals from carbon dioxide. However, there are still very few reports of the production of highly effective photosynthetic chemicals. Several synthetic metabolic pathways (e.g., isopropanol, acetone, isoprene, and fatty acids) have been constructed by branching from acetyl-CoA and malonyl-CoA, which are key intermediates for photosynthetic chemical production downstream of pyruvate decarboxylation. Recent reports of the absolute determination of cellular metabolites in Synechococcus elongatus PCC 7942 have shown that its acetyl-CoA levels corresponded to about one hundredth of the pyruvate levels. In short, one of the reasons for lower photosynthetic chemical production from acetyl-CoA and malonyl-CoA was the smaller flux to acetyl-CoA. Pyruvate decarboxylation is a primary pathway for acetyl-CoA synthesis from pyruvate and is mainly catalyzed by the pyruvate dehydrogenase complex (PDHc). In this study, we tried to enhance the flux toward acetyl-CoA from pyruvate by overexpressing PDH genes and, thus, catalyzing the conversion of pyruvate to acetyl-CoA via NADH generation. The overexpression of PDH genes cloned from S. elongatus PCC 7942 significantly increased PDHc enzymatic activity and intracellular acetyl-CoA levels in the crude cell extract. Although growth defects were observed in overexpressing strains of PDH genes, the combinational overexpression of PDH genes with the synthetic metabolic pathway for acetate or isopropanol resulted in about 7-fold to 9-fold improvement in its production titer, respectively (9.9 mM, 594.5 mg/L acetate, 4.9 mM, 294.5 mg/L isopropanol). PDH genes overexpression would, therefore, be useful not only for the production of these model chemicals, but also for the production of other chemicals that require acetyl-CoA as a key precursor.
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Affiliation(s)
- Yasutaka Hirokawa
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, W5-729, 744, Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Takeshi Kubo
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, W5-729, 744, Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Yuki Soma
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, W5-729, 744, Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Fumiko Saruta
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, W5-729, 744, Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Taizo Hanai
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, W5-729, 744, Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
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14
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Burkart MD, Hazari N, Tway CL, Zeitler EL. Opportunities and Challenges for Catalysis in Carbon Dioxide Utilization. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02113] [Citation(s) in RCA: 179] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Michael D. Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Nilay Hazari
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
| | - Cathy L. Tway
- Johnson Matthey, 2 Trans Am Plaza Drive, Suite 230, Oakbrook Terrace, Illinois 60181, United States
| | - Elizabeth L. Zeitler
- Board on Energy
and Environmental Systems, National Academies of Sciences, Engineering and Medicine, 500 Fifth Street, NW, Washington, D.C. 20001, United States
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15
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Khan AZ, Bilal M, Mehmood S, Sharma A, Iqbal HMN. State-of-the-Art Genetic Modalities to Engineer Cyanobacteria for Sustainable Biosynthesis of Biofuel and Fine-Chemicals to Meet Bio-Economy Challenges. Life (Basel) 2019; 9:life9030054. [PMID: 31252652 PMCID: PMC6789541 DOI: 10.3390/life9030054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/15/2019] [Accepted: 06/26/2019] [Indexed: 02/07/2023] Open
Abstract
In recent years, metabolic engineering of microorganisms has attained much research interest to produce biofuels and industrially pertinent chemicals. Owing to the relatively fast growth rate, genetic malleability, and carbon neutral production process, cyanobacteria has been recognized as a specialized microorganism with a significant biotechnological perspective. Metabolically engineering cyanobacterial strains have shown great potential for the photosynthetic production of an array of valuable native or non-native chemicals and metabolites with profound agricultural and pharmaceutical significance using CO2 as a building block. In recent years, substantial improvements in developing and introducing novel and efficient genetic tools such as genome-scale modeling, high throughput omics analyses, synthetic/system biology tools, metabolic flux analysis and clustered regularly interspaced short palindromic repeats (CRISPR)-associated nuclease (CRISPR/cas) systems have been made for engineering cyanobacterial strains. Use of these tools and technologies has led to a greater understanding of the host metabolism, as well as endogenous and heterologous carbon regulation mechanisms which consequently results in the expansion of maximum productive ability and biochemical diversity. This review summarizes recent advances in engineering cyanobacteria to produce biofuel and industrially relevant fine chemicals of high interest. Moreover, the development and applications of cutting-edge toolboxes such as the CRISPR-cas9 system, synthetic biology, high-throughput "omics", and metabolic flux analysis to engineer cyanobacteria for large-scale cultivation are also discussed.
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Affiliation(s)
- Aqib Zafar Khan
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Muhammad Bilal
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian 223003, China.
| | - Shahid Mehmood
- Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200030, China
| | - Ashutosh Sharma
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Queretaro, Epigmenio Gonzalez 500, Queretaro CP 76130, Mexico
| | - Hafiz M N Iqbal
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey CP 64849, N.L., Mexico.
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16
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Sawa N, Tatsuke T, Ogawa A, Hirokawa Y, Osanai T, Hanai T. Modification of carbon metabolism in Synechococcus elongatus PCC 7942 by cyanophage-derived sigma factors for bioproduction improvement. J Biosci Bioeng 2019; 127:256-264. [DOI: 10.1016/j.jbiosc.2018.07.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 07/20/2018] [Accepted: 07/23/2018] [Indexed: 12/15/2022]
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17
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Noreña-Caro D, Benton MG. Cyanobacteria as photoautotrophic biofactories of high-value chemicals. J CO2 UTIL 2018. [DOI: 10.1016/j.jcou.2018.10.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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18
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Predicting the metabolic capabilities of Synechococcus elongatus PCC 7942 adapted to different light regimes. Metab Eng 2018; 52:42-56. [PMID: 30439494 DOI: 10.1016/j.ymben.2018.11.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 11/02/2018] [Accepted: 11/06/2018] [Indexed: 12/12/2022]
Abstract
There is great interest in engineering photoautotrophic metabolism to generate bioproducts of societal importance. Despite the success in employing genome-scale modeling coupled with flux balance analysis to engineer heterotrophic metabolism, the lack of proper constraints necessary to generate biologically realistic predictions has hindered broad application of this methodology to phototrophic metabolism. Here we describe a methodology for constraining genome-scale models of photoautotrophy in the cyanobacteria Synechococcus elongatus PCC 7942. Experimental photophysiology parameters coupled to genome-scale flux balance analysis resulted in accurate predictions of growth rates and metabolic reaction fluxes at low and high light conditions. Additionally, by constraining photon uptake fluxes, we characterized the metabolic cost of excess excitation energy. The predicted energy fluxes were consistent with known light-adapted phenotypes in cyanobacteria. Finally, we leveraged the modeling framework to characterize existing photoautotrophic and photomixtotrophic engineering strategies for 2,3-butanediol production in S. elongatus. This methodology, applicable to genome-scale modeling of all phototrophic microorganisms, can facilitate the use of flux balance analysis in the engineering of light-driven metabolism.
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19
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Liu H, Ni J, Xu P, Tao F. Enhancing Light-Driven 1,3-Propanediol Production by Using Natural Compartmentalization of Differentiated Cells. ACS Synth Biol 2018; 7:2436-2446. [PMID: 30234972 DOI: 10.1021/acssynbio.8b00239] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Synthetic biology emerges as a powerful approach for unlocking the potential of cyanobacteria to produce various chemicals. However, the highly oxidative intracellular environment of cyanobacteria is incompatible to numerous introduced enzymes from anaerobes. In this study, we explore a strategy based on natural compartmentalization of cyanobacterial heterocysts to overcome the incompatibility. Hence, the oxygen-sensitive 1,3-propanediol (1,3-PDO) biosynthetic pathway was selected as a model and insulated in heterocysts to evaluate the proposed strategy. Thus, the genes from different sources for 1,3-PDO production were tandemly arrayed with promoter, resulting the assembled 1,3-PDO synthetic cassettes. Then the synthetic cassettes were integrated into the chromosome of Anabaena sp. strain PCC7120 by homologous recombination, respectively. The engineered strain P11 containing the genes from facultative anaerobe Klebsiella pneumoniae (cassette KP) accumulated 46.0 mg L-1 of 1,3-PDO when heterocysts were present, which is approximately 1.7-fold higher than that of no heterocysts. As for the strains (P12, P13, and P14) containing the genes from strictly anaerobic bacterium Clostridium butyricum (cassette CB), the product 1,3-PDO could only be detected when heterocysts were present. These results indicate that insulation of the oxygen-sensitive 1,3-PDO pathway with heterocysts is an effective way to protect these enzymes in cyanobacteria. The strategy may have the potential of serving as a universal strategy to overcome the incompatibility of oxygen-sensitivity in synthetic biology.
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Affiliation(s)
- Hongyu Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Jun Ni
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
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Behler J, Vijay D, Hess WR, Akhtar MK. CRISPR-Based Technologies for Metabolic Engineering in Cyanobacteria. Trends Biotechnol 2018; 36:996-1010. [DOI: 10.1016/j.tibtech.2018.05.011] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/24/2018] [Accepted: 05/29/2018] [Indexed: 12/16/2022]
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Hirokawa Y, Kanesaki Y, Arai S, Saruta F, Hayashihara K, Murakami A, Shimizu K, Honda H, Yoshikawa H, Hanai T. Mutations responsible for alcohol tolerance in the mutant of Synechococcus elongatus PCC 7942 (SY1043) obtained by single-cell screening system. J Biosci Bioeng 2018; 125:572-577. [DOI: 10.1016/j.jbiosc.2017.11.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/10/2017] [Accepted: 11/27/2017] [Indexed: 11/28/2022]
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Ni J, Tao F, Xu P, Yang C. Engineering Cyanobacteria for Photosynthetic Production of C3 Platform Chemicals and Terpenoids from CO 2. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1080:239-259. [PMID: 30091098 DOI: 10.1007/978-981-13-0854-3_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Recent years have witnessed a rising demand for bioproduced chemicals owing to restricted availability of petrochemical resources and increasing environmental concerns. Extensive efforts have been invested in the metabolic engineering of microorganisms for biosynthesis of chemicals and fuels. Among these, direct conversion of CO2 to chemicals by photoautotrophic microorganism cyanobacteria represents a green route with incredibly potent. Cyanobacteria have been engineered for the production of numerous biofuels and chemicals, such as 2,3-butanediol, fatty acids, isobutyraldehyde, and n-butanol. Under the current condition, it might be initially wiser to produce chemicals with higher value or higher yield. Photosynthetic production of C3 platform chemicals could withdraw carbon close to fixation to maximize the pool of available carbon, thus achieving the strong production rates. Photosynthetic production of terpenoids is another good choice due to the higher value of these compounds. Here, we review recent advances in generating C3 chemicals and valuable terpenoids from cyanobacteria.
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Affiliation(s)
- Jun Ni
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Chen Yang
- CAS-Key Laboratory of Synthetic Biology, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
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Hirokawa Y, Matsuo S, Hamada H, Matsuda F, Hanai T. Metabolic engineering of Synechococcus elongatus PCC 7942 for improvement of 1,3-propanediol and glycerol production based on in silico simulation of metabolic flux distribution. Microb Cell Fact 2017; 16:212. [PMID: 29178875 PMCID: PMC5702090 DOI: 10.1186/s12934-017-0824-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 11/13/2017] [Indexed: 12/22/2022] Open
Abstract
Background Production directly from carbon dioxide by engineered cyanobacteria is one of the promising technologies for sustainable future. Previously, we have successfully achieved 1,3-propanediol (1,3-PDO) production using Synechococcus elongatus PCC 7942 with a synthetic metabolic pathway. The strain into which the synthetic metabolic pathway was introduced produced 3.48 mM (0.265 g/L) 1,3-PDO and 14.3 mM (1.32 g/L) glycerol during 20 days of incubation. In this study, the productivities of 1,3-PDO were improved by gene disruption selected by screening with in silico simulation. Methods First, a stoichiometric metabolic model was applied to prediction of cellular metabolic flux distribution in a 1,3-PDO-producing strain of S. elongatus PCC 7942. A genome-scale model of S. elongatus PCC 7942 constructed by Knoop was modified by the addition of a synthetic metabolic pathway for 1,3-PDO production. Next, the metabolic flux distribution predicted by metabolic flux balance analysis (FBA) was used for in silico simulation of gene disruption. As a result of gene disruption simulation, NADPH dehydrogenase 1 (NDH-1) complexes were found by screening to be the most promising candidates for disruption to improve 1,3-PDO production. The effect of disruption of the gene encoding a subunit of the NDH-1 complex was evaluated in the 1,3-PDO-producing strain. Results and Conclusions During 20 days of incubation, the ndhF1-null 1,3-PDO-producing strain showed the highest titers: 4.44 mM (0.338 g/L) 1,3-PDO and 30.3 mM (2.79 g/L) glycerol. In this study, we successfully improved 1,3-PDO productivity on the basis of in silico simulation of gene disruption. Electronic supplementary material The online version of this article (10.1186/s12934-017-0824-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yasutaka Hirokawa
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, 804 Westwing, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Shingo Matsuo
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, 804 Westwing, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Hiroyuki Hamada
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, 804 Westwing, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Fumio Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Taizo Hanai
- Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, 804 Westwing, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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Knoot CJ, Ungerer J, Wangikar PP, Pakrasi HB. Cyanobacteria: Promising biocatalysts for sustainable chemical production. J Biol Chem 2017; 293:5044-5052. [PMID: 28972147 DOI: 10.1074/jbc.r117.815886] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cyanobacteria are photosynthetic prokaryotes showing great promise as biocatalysts for the direct conversion of CO2 into fuels, chemicals, and other value-added products. Introduction of just a few heterologous genes can endow cyanobacteria with the ability to transform specific central metabolites into many end products. Recent engineering efforts have centered around harnessing the potential of these microbial biofactories for sustainable production of chemicals conventionally produced from fossil fuels. Here, we present an overview of the unique chemistry that cyanobacteria have been co-opted to perform. We highlight key lessons learned from these engineering efforts and discuss advantages and disadvantages of various approaches.
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Affiliation(s)
- Cory J Knoot
- From the Department of Biology, Washington University, St. Louis, Missouri 63130 and
| | - Justin Ungerer
- From the Department of Biology, Washington University, St. Louis, Missouri 63130 and
| | - Pramod P Wangikar
- the Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Himadri B Pakrasi
- From the Department of Biology, Washington University, St. Louis, Missouri 63130 and
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Zhang A, Carroll AL, Atsumi S. Carbon recycling by cyanobacteria: improving CO2 fixation through chemical production. FEMS Microbiol Lett 2017; 364:4058408. [DOI: 10.1093/femsle/fnx165] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 07/29/2017] [Indexed: 11/14/2022] Open
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26
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Singh R, Parihar P, Singh M, Bajguz A, Kumar J, Singh S, Singh VP, Prasad SM. Uncovering Potential Applications of Cyanobacteria and Algal Metabolites in Biology, Agriculture and Medicine: Current Status and Future Prospects. Front Microbiol 2017; 8:515. [PMID: 28487674 PMCID: PMC5403934 DOI: 10.3389/fmicb.2017.00515] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 03/13/2017] [Indexed: 12/05/2022] Open
Abstract
Cyanobacteria and algae having complex photosynthetic systems can channelize absorbed solar energy into other forms of energy for production of food and metabolites. In addition, they are promising biocatalysts and can be used in the field of "white biotechnology" for enhancing the sustainable production of food, metabolites, and green energy sources such as biodiesel. In this review, an endeavor has been made to uncover the significance of various metabolites like phenolics, phytoene/terpenoids, phytols, sterols, free fatty acids, photoprotective compounds (MAAs, scytonemin, carotenoids, polysaccharides, halogenated compounds, etc.), phytohormones, cyanotoxins, biocides (algaecides, herbicides, and insecticides) etc. Apart from this, the importance of these metabolites as antibiotics, immunosuppressant, anticancer, antiviral, anti-inflammatory agent has also been discussed. Metabolites obtained from cyanobacteria and algae have several biotechnological, industrial, pharmaceutical, and cosmetic uses which have also been discussed in this review along with the emerging technology of their harvesting for enhancing the production of compounds like bioethanol, biofuel etc. at commercial level. In later sections, we have discussed genetically modified organisms and metabolite production from them. We have also briefly discussed the concept of bioprocessing highlighting the functioning of companies engaged in metabolites production as well as their cost effectiveness and challenges that are being addressed by these companies.
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Affiliation(s)
- Rachana Singh
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Parul Parihar
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Madhulika Singh
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Andrzej Bajguz
- Faculty of Biology and Chemistry, Institute of Biology, University of BialystokBialystok, Poland
| | - Jitendra Kumar
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Samiksha Singh
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Vijay P. Singh
- Department of Botany, Govt. Ramanuj Pratap Singhdev Post-Graduate CollegeBaikunthpur, Koriya, India
| | - Sheo M. Prasad
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
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Xu G, Li C. Identifying the shared metabolic objectives of glycerol bioconversion in Klebsiella pneumoniae under different culture conditions. J Biotechnol 2017; 248:59-68. [DOI: 10.1016/j.jbiotec.2017.03.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 02/24/2017] [Accepted: 03/13/2017] [Indexed: 11/28/2022]
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28
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Cofactor engineering in cyanobacteria to overcome imbalance between NADPH and NADH: A mini review. Front Chem Sci Eng 2017. [DOI: 10.1007/s11705-016-1591-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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29
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Kumar R, Kumar P. Future Microbial Applications for Bioenergy Production: A Perspective. Front Microbiol 2017; 8:450. [PMID: 28377751 PMCID: PMC5359226 DOI: 10.3389/fmicb.2017.00450] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 03/03/2017] [Indexed: 01/19/2023] Open
Affiliation(s)
- Ravinder Kumar
- Department of Biotechnology, ITS Paramedical College Ghaziabad, India
| | - Pradeep Kumar
- Department of Forestry, North Eastern Regional Institute of Science and Technology (Deemed University) Nirjuli, India
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Construction of a novel d-lactate producing pathway from dihydroxyacetone phosphate of the Calvin cycle in cyanobacterium, Synechococcus elongatus PCC 7942. J Biosci Bioeng 2017; 124:54-61. [PMID: 28325659 DOI: 10.1016/j.jbiosc.2017.02.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 02/23/2017] [Accepted: 02/23/2017] [Indexed: 01/10/2023]
Abstract
Using engineered cyanobacteria to produce various chemicals from carbon dioxide is a promising technology for a sustainable future. Lactate is a valuable commodity that can be used for the biodegradable plastic, polylactic acid. Typically, lactate production using engineered cyanobacteria was via the conversion of pyruvate in glycolysis by lactate dehydrogenase. In cyanobacteria, the metabolic flux in the Calvin cycle is higher than that in glycolysis under photoautotrophic conditions. The construction of a novel lactate producing pathway that uses metabolites from the Calvin cycle could potentially increase lactate productivity in cyanobacteria. In order to develop such a novel lactate production pathway, we engineered a cyanobacterium Synechococcus elongatus PCC 7942 strain that produced lactate directly from carbon dioxide using dihydroxyacetone phosphate (DHAP) via methylglyoxal. We confirmed that wild-type strain of S. elongatus PCC 7942 could produce lactate using exogenous methylglyoxal. A methylglyoxal synthase gene, mgsA, from Escherichia coli was introduced into Synechococcus elongates PCC 7942 for conversion of DHAP to methylglyoxal. This engineered strain produced lactate directly from carbon dioxide. Genes encoding intrinsic putative glyoxalase I, II (Synpcc7942_0638, 1403) and the lactate/H+ symporter from E. coli (lldP) were additionally introduced to enhance the production. For higher lactate production, it was important to maintain elevated extracellular pH due to the characteristics of lactate exporting system. In this study, the highest lactate titer of 13.7 mM (1.23 g/l) was achieved during a 24-day incubation with the engineered S. elongatus PCC 7942 strain possessing the novel lactate producing pathway.
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Improvement of 1,3-propanediol production using an engineered cyanobacterium, Synechococcus elongatus by optimization of the gene expression level of a synthetic metabolic pathway and production conditions. Metab Eng 2017; 39:192-199. [DOI: 10.1016/j.ymben.2016.12.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/08/2016] [Accepted: 12/05/2016] [Indexed: 11/17/2022]
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32
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Hirokawa Y, Dempo Y, Fukusaki E, Hanai T. Metabolic engineering for isopropanol production by an engineered cyanobacterium, Synechococcus elongatus PCC 7942, under photosynthetic conditions. J Biosci Bioeng 2017; 123:39-45. [DOI: 10.1016/j.jbiosc.2016.07.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/20/2016] [Accepted: 07/06/2016] [Indexed: 10/21/2022]
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33
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Cyanobacterial metabolic engineering for biofuel and chemical production. Curr Opin Chem Biol 2016; 35:43-50. [DOI: 10.1016/j.cbpa.2016.08.023] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 11/21/2022]
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34
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Metabolic engineering of cyanobacteria for the photosynthetic production of succinate. Metab Eng 2016; 38:483-493. [PMID: 27989804 DOI: 10.1016/j.ymben.2016.10.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 10/07/2016] [Accepted: 10/25/2016] [Indexed: 10/20/2022]
Abstract
Succinate is an important commodity chemical currently used in the food, pharmaceutical, and polymer industries. It can also be chemically converted into other major industrial chemicals such as 1,4-butanediol, butadiene, and tetrahydrofuran. Here we metabolically engineered a model cyanobacterium Synechococcus elongatus PCC 7942 to photosynthetically produce succinate. We expressed the genes encoding for α-ketoglutarate decarboxylase and succinate semialdehyde dehydrogenase in S. elongatus PCC 7942, resulting in a strain capable of producing 120mg/L of succinate. However, this recombinant strain exhibited severe growth retardation upon induction of the genes encoding for the succinate producing pathway, potentially due to the depletion of α-ketoglutarate. To replenish α-ketoglutarate, we expressed the genes encoding for phosphoenolpyruvate carboxylase and citrate synthase from Corynebacterium glutamicum into the succinate producing strain. The resulting strain successfully restored the growth phenotype and produced succinate with a titer of 430mg/L in 8 days. These results demonstrated the possibility of photoautotrophic succinate production.
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Yenkie KM, Wu W, Clark RL, Pfleger BF, Root TW, Maravelias CT. A roadmap for the synthesis of separation networks for the recovery of bio-based chemicals: Matching biological and process feasibility. Biotechnol Adv 2016; 34:1362-1383. [PMID: 27756578 DOI: 10.1016/j.biotechadv.2016.10.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/20/2016] [Accepted: 10/14/2016] [Indexed: 12/20/2022]
Abstract
Microbial conversion of renewable feedstocks to high-value chemicals is an attractive alternative to current petrochemical processes because it offers the potential to reduce net CO2 emissions and integrate with bioremediation objectives. Microbes have been genetically engineered to produce a growing number of high-value chemicals in sufficient titer, rate, and yield from renewable feedstocks. However, high-yield bioconversion is only one aspect of an economically viable process. Separation of biologically synthesized chemicals from process streams is a major challenge that can contribute to >70% of the total production costs. Thus, process feasibility is dependent upon the efficient selection of separation technologies. This selection is dependent on upstream processing or biological parameters, such as microbial species, product titer and yield, and localization. Our goal is to present a roadmap for selection of appropriate technologies and generation of separation schemes for efficient recovery of bio-based chemicals by utilizing information from upstream processing, separation science and commercial requirements. To achieve this, we use a separation system comprising of three stages: (I) cell and product isolation, (II) product concentration, and (III) product purification and refinement. In each stage, we review the technology alternatives available for different tasks in terms of separation principles, important operating conditions, performance parameters, advantages and disadvantages. We generate separation schemes based on product localization and its solubility in water, the two most distinguishing properties. Subsequently, we present ideas for simplification of these schemes based on additional properties, such as physical state, density, volatility, and intended use. This simplification selectively narrows down the technology options and can be used for systematic process synthesis and optimal recovery of bio-based chemicals.
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Affiliation(s)
- Kirti M Yenkie
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - WenZhao Wu
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Ryan L Clark
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Brian F Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Thatcher W Root
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Christos T Maravelias
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States.
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Klassen V, Blifernez-Klassen O, Wobbe L, Schlüter A, Kruse O, Mussgnug JH. Efficiency and biotechnological aspects of biogas production from microalgal substrates. J Biotechnol 2016; 234:7-26. [DOI: 10.1016/j.jbiotec.2016.07.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/13/2016] [Accepted: 07/18/2016] [Indexed: 11/17/2022]
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