1
|
Mazzoli R, Pescarolo S, Gilli G, Gilardi G, Valetti F. Hydrogen production pathways in Clostridia and their improvement by metabolic engineering. Biotechnol Adv 2024; 73:108379. [PMID: 38754796 DOI: 10.1016/j.biotechadv.2024.108379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 05/13/2024] [Accepted: 05/13/2024] [Indexed: 05/18/2024]
Abstract
Biological production of hydrogen has a tremendous potential as an environmentally sustainable technology to generate a clean fuel. Among the different available methods to produce biohydrogen, dark fermentation features the highest productivity and can be used as a means to dispose of organic waste biomass. Within this approach, Clostridia have the highest theoretical H2 production yield. Nonetheless, most strains show actual yields far lower than the theoretical maximum: improving their efficiency becomes necessary for achieving cost-effective fermentation processes. This review aims at providing a survey of the metabolic network involved in H2 generation in Clostridia and strategies used to improve it through metabolic engineering. Together with current achievements, a number of future perspectives to implement these results will be illustrated.
Collapse
Affiliation(s)
- Roberto Mazzoli
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy.
| | - Simone Pescarolo
- Biology applied to the environment, Laboratories of microbiology and ecotoxicology, Ecobioqual, Environment Park. Via Livorno 60, 10144 Torino, Italy
| | - Giorgio Gilli
- Department of Sciences of Public Health and Pediatrics, School of Medicine, University of Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Gianfranco Gilardi
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy
| | - Francesca Valetti
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Torino, Italy.
| |
Collapse
|
2
|
Wada K, Uebayashi K, Toya Y, Putri SP, Matsuda F, Fukusaki E, C Liao J, Shimizu H. Effects of n-butanol production on metabolism and the photosystem in Synecococcus elongatus PCC 7942 based on metabolic flux and target proteome analyses. J GEN APPL MICROBIOL 2024; 69:185-195. [PMID: 36935115 DOI: 10.2323/jgam.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Although n-butanol (BuOH) is an ideal fuel because of its superior physical properties, it has toxicity to microbes. Previously, a Synechococcus elongatus PCC 7942 derivative strain that produces BuOH from CO2 was developed by introducing six heterologous genes (BUOH-SE strain). To identify the bottleneck in BuOH production, the effects of BuOH production and its toxicity on central metabolism and the photosystem were investigated. Parental (WT) and BUOH-SE strains were cultured under autotrophic conditions. Consistent with the results of a previous study, BuOH production was observed only in the BUOH-SE strain. Isotopically non-stationary 13C-metabolic flux analysis revealed that the CO2 fixation rate was much larger than the BuOH production rate in the BUOH-SE strain (1.70 vs 0.03 mmol gDCW-1 h-1), implying that the carbon flow for BuOH biosynthesis was less affected by the entire flux distribution. No large difference was observed in the flux of metabolism between the WT and BUOH-SE strains. Contrastingly, in the photosystem, the chlorophyll content and maximum O2 evolution rate per dry cell weight of the BUOH-SE strain were decreased to 81% and 43% of the WT strain, respectively. Target proteome analysis revealed that the amounts of some proteins related to antennae (ApcA, ApcD, ApcE, and CpcC), photosystem II (PsbB, PsbU, and Psb28-2), and cytochrome b6f complex (PetB and PetC) in photosystems decreased in the BUOH-SE strain. The activation of photosynthesis would be a novel approach for further enhancing BuOH production in S. elongatus PCC 7942.
Collapse
Affiliation(s)
- Keisuke Wada
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University
| | - Kiyoka Uebayashi
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University
| | - Yoshihiro Toya
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University
| | - Sastia Prama Putri
- Department of Biotechnology, Graduate School of Engineering, Osaka University
| | - Fumio Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University
| | - James C Liao
- Department of Chemical and Biomolocular Engineering, University of California
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University
| |
Collapse
|
3
|
Nie M, Wang J, Zhang K. Engineering a Novel Acetyl-CoA Pathway for Efficient Biosynthesis of Acetyl-CoA-Derived Compounds. ACS Synth Biol 2024; 13:358-369. [PMID: 38151239 DOI: 10.1021/acssynbio.3c00613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Acetyl-CoA is an essential central metabolite in living organisms and a key precursor for various value-added products as well. However, the intracellular availability of acetyl-CoA limits the efficient production of these target products due to complex and strict regulation. Here, we proposed a new acetyl-CoA pathway, relying on two enzymes, threonine aldolase and acetaldehyde dehydrogenase (acetylating), which can convert one l-threonine into one acetyl-CoA, one glycine, and generate one NADH, without carbon loss. Introducing the acetyl-CoA pathway could increase the intracellular concentration of acetyl-CoA by 8.6-fold compared with the wild-type strain. To develop a cost-competitive and genetically stable acetyl-CoA platform strain, the new acetyl-CoA pathway, driven by the constitutive strong promoter, was integrated into the chromosome of Escherichia coli. We demonstrated the practical application of this new acetyl-CoA pathway by high titer production of β-alanine, mevalonate, and N-acetylglucosamine. At the same time, this pathway achieved a high-yield production of glycine, a value-added commodity chemical for the synthesis of glyphosate and thiamphenicol. This work shows the potential of this new acetyl-CoA pathway for the industrial production of acetyl-CoA-derived compounds.
Collapse
Affiliation(s)
- Mengzhen Nie
- Zhejiang University, Hangzhou, Zhejiang 310027, China
- Center of Synthetic Biology and Integrated Bioengineering, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China
| | - Jingyu Wang
- Center of Synthetic Biology and Integrated Bioengineering, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China
| | - Kechun Zhang
- Center of Synthetic Biology and Integrated Bioengineering, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China
| |
Collapse
|
4
|
Wu J, Huang H, Wang L, Gao M, Meng S, Zou S, Feng Y, Feng Z, Zhu Z, Cao X, Li B, Kang G. A tailored series of engineered yeasts for the cell-dependent treatment of inflammatory bowel disease by rational butyrate supplementation. Gut Microbes 2024; 16:2316575. [PMID: 38381494 PMCID: PMC10883098 DOI: 10.1080/19490976.2024.2316575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/06/2024] [Indexed: 02/22/2024] Open
Abstract
Intestinal microbiota dysbiosis and metabolic disruption are considered essential characteristics in inflammatory bowel disorders (IBD). Reasonable butyrate supplementation can help patients regulate intestinal flora structure and promote mucosal repair. Here, to restore microbiota homeostasis and butyrate levels in the patient's intestines, we modified the genome of Saccharomyces cerevisiae to produce butyrate. We precisely regulated the relevant metabolic pathways to enable the yeast to produce sufficient butyrate in the intestine with uneven oxygen distribution. A series of engineered strains with different butyrate synthesis abilities was constructed to meet the needs of different patients, and the strongest can reach 1.8 g/L title of butyrate. Next, this series of strains was used to co-cultivate with gut microbiota collected from patients with mild-to-moderate ulcerative colitis. After receiving treatment with engineered strains, the gut microbiota and the butyrate content have been regulated to varying degrees depending on the synthetic ability of the strain. The abundance of probiotics such as Bifidobacterium and Lactobacillus increased, while the abundance of harmful bacteria like Candidatus Bacilloplasma decreased. Meanwhile, the series of butyrate-producing yeast significantly improved trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice by restoring butyrate content. Among the series of engineered yeasts, the strain with the second-highest butyrate synthesis ability showed the most significant regulatory and the best therapeutic effect on the gut microbiota from IBD patients and the colitis mouse model. This study confirmed the existence of a therapeutic window for IBD treatment by supplementing butyrate, and it is necessary to restore butyrate levels according to the actual situation of patients to restore intestinal flora.
Collapse
Affiliation(s)
- Jiahao Wu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - He Huang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Lina Wang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Mengxue Gao
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Shuxian Meng
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Shaolan Zou
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Yuanhang Feng
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Zeling Feng
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin, China
| | - Zhixin Zhu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Xiaocang Cao
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, Tianjin, China
| | - Bingzhi Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontiers Research Institute for Synthetic Biology, Tianjin University, Tianjin, China
| | - Guangbo Kang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontiers Research Institute for Synthetic Biology, Tianjin University, Tianjin, China
| |
Collapse
|
5
|
Olavarria K, Becker MV, Sousa DZ, van Loosdrecht MC, Wahl SA. Design and thermodynamic analysis of a pathway enabling anaerobic production of poly-3-hydroxybutyrate in Escherichia coli. Synth Syst Biotechnol 2023; 8:629-639. [PMID: 37823039 PMCID: PMC10562921 DOI: 10.1016/j.synbio.2023.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 09/14/2023] [Accepted: 09/19/2023] [Indexed: 10/13/2023] Open
Abstract
Utilizing anaerobic metabolisms for the production of biotechnologically relevant products presents potential advantages, such as increased yields and reduced energy dissipation. However, lower energy dissipation may indicate that certain reactions are operating closer to their thermodynamic equilibrium. While stoichiometric analyses and genetic modifications are frequently employed in metabolic engineering, the use of thermodynamic tools to evaluate the feasibility of planned interventions is less documented. In this study, we propose a novel metabolic engineering strategy to achieve an efficient anaerobic production of poly-(R)-3-hydroxybutyrate (PHB) in the model organism Escherichia coli. Our approach involves re-routing of two-thirds of the glycolytic flux through non-oxidative glycolysis and coupling PHB synthesis with NADH re-oxidation. We complemented our stoichiometric analysis with various thermodynamic approaches to assess the feasibility and the bottlenecks in the proposed engineered pathway. According to our calculations, the main thermodynamic bottleneck are the reactions catalyzed by the acetoacetyl-CoA β-ketothiolase (EC 2.3.1.9) and the acetoacetyl-CoA reductase (EC 1.1.1.36). Furthermore, we calculated thermodynamically consistent sets of kinetic parameters to determine the enzyme amounts required for sustaining the conversion fluxes. In the case of the engineered conversion route, the protein pool necessary to sustain the desired fluxes could account for 20% of the whole cell dry weight.
Collapse
Affiliation(s)
- Karel Olavarria
- Laboratory of Microbiology, Wageningen University and Research, Stippenenweg 4, 6708 WE, Wageningen, The Netherlands
- Centre for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - Marco V. Becker
- Department of Biotechnology, Applied Sciences Faculty, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Diana Z. Sousa
- Laboratory of Microbiology, Wageningen University and Research, Stippenenweg 4, 6708 WE, Wageningen, The Netherlands
- Centre for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - Mark C.M. van Loosdrecht
- Department of Biotechnology, Applied Sciences Faculty, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - S. Aljoscha Wahl
- Lehrstuhl für Bioverfahrenstechnik, Friedrich-Alexander-Universität, Paul-Gordan-Strasse 3, 91052, Erlangen, Germany
| |
Collapse
|
6
|
Treece TR, Pattanayak S, Matson MM, Cepeda MM, Berben LA, Atsumi S. Electrical-biological hybrid system for carbon efficient isobutanol production. Metab Eng 2023; 80:142-150. [PMID: 37739158 DOI: 10.1016/j.ymben.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/04/2023] [Accepted: 09/14/2023] [Indexed: 09/24/2023]
Abstract
We have developed an electrical-biological hybrid system wherein an engineered microorganism consumes electrocatalytically produced formate from CO2 to supplement the bioproduction of isobutanol, a valuable fuel chemical. Biological CO2 sequestration is notoriously slow compared to electrochemical CO2 reduction, while electrochemical methods struggle to generate carbon-carbon bonds which readily form in biological systems. A hybrid system provides a promising method for combining the benefits of both biology and electrochemistry. Previously, Escherichia coli was engineered to assimilate formate and CO2 in central metabolism using the reductive glycine pathway. In this work, we have shown that chemical production in E. coli can benefit from single carbon substrates when equipped with the RGP. By installing the RGP and the isobutanol biosynthetic pathway into E. coli and by further genetic modifications, we have generated a strain of E. coli that can consume formate and produce isobutanol at a yield of >100% of theoretical maximum from glucose. Our results demonstrate that carbon produced from electrocatalytically reduced CO2 can bolster chemical production in E. coli. This study shows that E. coli can be engineered towards carbon efficient methods of chemical production.
Collapse
Affiliation(s)
- Tanner R Treece
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - Santanu Pattanayak
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - Morgan M Matson
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - Mateo M Cepeda
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA
| | - Louise A Berben
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA.
| | - Shota Atsumi
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA.
| |
Collapse
|
7
|
Sen O, Hinks J, Lin Q, Lin Q, Kjelleberg S, Rice SA, Seviour T. Escherichia coli displays a conserved membrane proteomic response to a range of alcohols. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:147. [PMID: 37789404 PMCID: PMC10546733 DOI: 10.1186/s13068-023-02401-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 09/18/2023] [Indexed: 10/05/2023]
Abstract
BACKGROUND Alcohol is a good and environment-friendly fuel that can be microbially produced, capable of eliminating many of the limitations of the present-day fossil fuels. However, the inherent toxic nature of alcohols to the microbial cells leads to end-product inhibition that limits large-scale alcohol production by fermentation. Fundamental knowledge about the stress responses of microorganisms to alcohols would greatly facilitate to improve the microbial alcohol tolerance. The current study elucidates and compares the changes in the membrane proteome of Escherichia coli in response to a range of alcohols. RESULTS Although alcohol toxicity increased exponentially with alcohol chain length (2-6 carbon), similar stress responses were observed in the inner and outer membrane proteome of E. coli in the presence of 2-, 4- and 6-carbon alcohols at the MIC50. This pertains to: (1) increased levels of inner membrane transporters for uptake of energy-producing metabolites, (2) reduced levels of non-essential proteins, associated with anaerobic, carbon starvation and osmotic stress, for energy conservation, (3) increased levels of murein degrading enzymes (MltA, EmtA, MliC and DigH) promoting cell elongation and 4) reduced levels of most outer membrane β-barrel proteins (LptD, FadL, LamB, TolC and BamA). Major outer membrane β-barrel protein OmpC, which is known to contribute to ethanol tolerance and membrane integrity, was notably reduced by alcohol stress. While LPS is important for OmpC trimerisation, LPS release by EDTA did not lower OmpC levels. This suggests that LPS release, which is reported under alcohol stress, does not contribute to the reduced levels of OmpC in the presence of alcohol. CONCLUSIONS Since alcohol primarily targets the integrity of the membrane, maintenance of outer membrane OmpC levels in the presence of alcohol might help in the survival of E. coli to higher alcohol concentrations. The study provides important information about the membrane protein responses of E. coli to a range of alcohols, which can be used to develop targeted strategies for increased microbial alcohol tolerance and hence bioalcohol production.
Collapse
Affiliation(s)
- Oishi Sen
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Jamie Hinks
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Qifeng Lin
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Qingsong Lin
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Staffan Kjelleberg
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, 2052, Australia
| | - Scott A Rice
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- The Australian Institute for Microbiology and Immunology, University of Technology Sydney, Sydney, 2007, Australia
- CSIRO, Agriculture and Food, Westmead and Microbiomes for One Systems Health, Sydney, Australia
| | - Thomas Seviour
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
- WATEC Aarhus University Centre for Water Technology, Universitetsbyen 36, Bldg 1783, 8000, Aarhus, Denmark.
| |
Collapse
|
8
|
Wang CH, Hou J, Deng HK, Wang LJ. Microbial Production of Mevalonate. J Biotechnol 2023; 370:1-11. [PMID: 37209831 DOI: 10.1016/j.jbiotec.2023.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/20/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023]
Abstract
Mevalonate, an important intermediate product of the mevalonate pathway, has a broad spectrum of applications. With the rapid growth of metabolic engineering and synthetic biology, mevalonate biosynthesis by microorganisms is feasible and holds great promise in the future. In this review, we summarize the applications of mevalonate and its derivatives and describe the biosynthesis pathways of mevalonate. The current status of mevalonate biosynthesis is also detailed with an emphasis on metabolic engineering strategies to enhance mevalonate production in typical industrial organisms, including Escherichia coli, Saccharomyces cerevisiae, and Pseudomonas putida, suggesting new insights for the efficient production of biosynthesized mevalonate.
Collapse
Affiliation(s)
- Cong-Han Wang
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Jie Hou
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Hong-Kuan Deng
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China.
| | - Li-Juan Wang
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China.
| |
Collapse
|
9
|
Courtney DK, Su Y, Jacobson T, Khana D, Ailiani A, Amador-Noguez D, Pfleger BF. Relative Activities of the β-ketoacyl-CoA and Acyl-CoA Reductases Influence Product Profile and Flux in a Reversed β-Oxidation Pathway. ACS Catal 2023; 13:5914-5925. [PMID: 38094510 PMCID: PMC10718561 DOI: 10.1021/acscatal.3c00379] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
The β-Oxidation pathway, normally involved in the catabolism of fatty acids, can be functionally made to act as a fermentative, iterative, elongation pathway when driven by the activity of a trans-enoyl-CoA reductase. The terminal acyl-CoA reduction to alcohol can occur on substrates with varied chain lengths, leading to a broad distribution of fermentation products in vivo. Tight control of the average chain length and product profile is desirable as chain length greatly influences molecular properties and commercial value. Lacking a termination enzyme with a narrow chain length preference, we sought alternative factors that could influence the product profile and pathway flux in the iterative pathway. In this study, we reconstituted the reversed β-oxidation (R-βox) pathway in vitro with a purified tri-functional complex (FadBA) responsible for the thiolase, enoyl-CoA hydratase and hydroxyacyl-CoA dehydrogenase activities, a trans-enoyl-CoA reductase (TER), and an acyl-CoA reductase (ACR). Using this system, we determined the rate limiting step of the elongation cycle and demonstrated that by controlling the ratio of these three enzymes and the ratio of NADH and NADPH, we can influence the average chain length of the alcohol product profile.
Collapse
Affiliation(s)
- Dylan K. Courtney
- Department of Chemical and Biological Engineering, University of Wisconsin – Madison, Madison, WI, USA
| | - Yun Su
- Department of Chemical and Biological Engineering, University of Wisconsin – Madison, Madison, WI, USA
| | - Tyler Jacobson
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI, USA
| | - Daven Khana
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI, USA
| | - Aditya Ailiani
- Department of Biomedical Engineering, University of Wisconsin – Madison, Madison, WI, USA
| | | | - Brian F. Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin – Madison, Madison, WI, USA
| |
Collapse
|
10
|
Garces Daza F, Haitz F, Born A, Boles E. An optimized reverse β-oxidation pathway to produce selected medium-chain fatty acids in Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:71. [PMID: 37101299 PMCID: PMC10134560 DOI: 10.1186/s13068-023-02317-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/06/2023] [Indexed: 04/28/2023]
Abstract
BACKGROUND Medium-chain fatty acids are molecules with applications in different industries and with growing demand. However, the current methods for their extraction are not environmentally sustainable. The reverse β-oxidation pathway is an energy-efficient pathway that produces medium-chain fatty acids in microorganisms, and its use in Saccharomyces cerevisiae, a broadly used industrial microorganism, is desired. However, the application of this pathway in this organism has so far either led to low titers or to the predominant production of short-chain fatty acids. RESULTS We genetically engineered Saccharomyces cerevisiae to produce the medium-chain fatty acids hexanoic and octanoic acid using novel variants of the reverse β-oxidation pathway. We first knocked out glycerolphosphate dehydrogenase GPD2 in an alcohol dehydrogenases knock-out strain (△adh1-5) to increase the NADH availability for the pathway, which significantly increased the production of butyric acid (78 mg/L) and hexanoic acid (2 mg/L) when the pathway was expressed from a plasmid with BktB as thiolase. Then, we tested different enzymes for the subsequent pathway reactions: the 3-hydroxyacyl-CoA dehydrogenase PaaH1 increased hexanoic acid production to 33 mg/L, and the expression of enoyl-CoA hydratases Crt2 or Ech was critical to producing octanoic acid, reaching titers of 40 mg/L in both cases. In all cases, Ter from Treponema denticola was the preferred trans-enoyl-CoA reductase. The titers of hexanoic acid and octanoic acid were further increased to almost 75 mg/L and 60 mg/L, respectively, when the pathway expression cassette was integrated into the genome and the fermentation was performed in a highly buffered YPD medium. We also co-expressed a butyryl-CoA pathway variant to increase the butyryl-CoA pool and support the chain extension. However, this mainly increased the titers of butyric acid and only slightly increased that of hexanoic acid. Finally, we also tested the deletion of two potential medium-chain acyl-CoA depleting reactions catalyzed by the thioesterase Tes1 and the medium-chain fatty acyl CoA synthase Faa2. However, their deletion did not affect the production titers. CONCLUSIONS By engineering the NADH metabolism and testing different reverse β-oxidation pathway variants, we extended the product spectrum and obtained the highest titers of octanoic acid and hexanoic acid reported in S. cerevisiae. Product toxicity and enzyme specificity must be addressed for the industrial application of the pathway in this organism.
Collapse
Affiliation(s)
- Fernando Garces Daza
- Faculty of Biological Sciences, Institute of Molecular Bioscience, Goethe-Universität Frankfurt Am Main, Max-von-Laue-Str.9, 60438, Frankfurt am Main, Germany
| | - Fabian Haitz
- Faculty of Biological Sciences, Institute of Molecular Bioscience, Goethe-Universität Frankfurt Am Main, Max-von-Laue-Str.9, 60438, Frankfurt am Main, Germany
| | - Alice Born
- Faculty of Biological Sciences, Institute of Molecular Bioscience, Goethe-Universität Frankfurt Am Main, Max-von-Laue-Str.9, 60438, Frankfurt am Main, Germany
| | - Eckhard Boles
- Faculty of Biological Sciences, Institute of Molecular Bioscience, Goethe-Universität Frankfurt Am Main, Max-von-Laue-Str.9, 60438, Frankfurt am Main, Germany.
| |
Collapse
|
11
|
Huang T, Ma Y. Advances in biosynthesis of higher alcohols in Escherichia coli. World J Microbiol Biotechnol 2023; 39:125. [PMID: 36941474 DOI: 10.1007/s11274-023-03580-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/13/2023] [Indexed: 03/23/2023]
Abstract
In recent years, the development of green energy to replace fossil fuels has been the focus of research. Higher alcohols are important biofuels and chemicals. The production of higher alcohols in microbes has gained attention due to its environmentally friendly character. Higher alcohols have been synthesized in model microorganism Escherichia coli, and the production has reached the gram level through enhancement of metabolic flow, the balance of reducing power and the optimization of fermentation processes. Sustainable bio-higher alcohols production is expected to replace fossil fuels as a green and renewable energy source. Therefore, this review summarizes the latest developments in producing higher alcohols (C3-C6) by E. coli, elucidate the main bottlenecks limiting the biosynthesis of higher alcohols, and proposes potential engineering strategies of improving the production of biological higher alcohols. This review would provide a theoretical basis for further research on higher alcohols production by E. coli.
Collapse
Affiliation(s)
- Tong Huang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China
| | - Yuanyuan Ma
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
- School of Marin Science and Technology, Tianjin University, Tianjin, 300072, China.
- R&D Center for Petrochemical Technology, Tianjin University, Tianjin, 300072, China.
| |
Collapse
|
12
|
Nielsen JR, Weusthuis RA, Huang WE. Growth-coupled enzyme engineering through manipulation of redox cofactor regeneration. Biotechnol Adv 2023; 63:108102. [PMID: 36681133 DOI: 10.1016/j.biotechadv.2023.108102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 01/11/2023] [Accepted: 01/15/2023] [Indexed: 01/20/2023]
Abstract
Enzymes need to be efficient, robust, and highly specific for their effective use in commercial bioproduction. These properties can be introduced using various enzyme engineering techniques, with random mutagenesis and directed evolution (DE) often being chosen when there is a lack of structural information -or mechanistic understanding- of the enzyme. The screening or selection step of DE is the limiting part of this process, since it must ideally be (ultra)-high throughput, specifically target the catalytic activity of the enzyme and have an accurately quantifiable metric for said activity. Growth-coupling selection strategies involve coupling a desired enzyme activity to cellular metabolism and therefore growth, where growth (rate) becomes the output metric. Redox cofactors (NAD+/NADH and NADP+/NADPH) have recently been identified as promising target molecules for growth coupling, owing to their essentiality for cellular metabolism and ubiquitous nature. Redox cofactor oxidation or reduction can be disrupted through metabolic engineering and the use of specific culturing conditions, rendering the cell inviable unless a 'rescue' reaction complements the imposed metabolic deficiency. Using this principle, enzyme variants displaying improved cofactor oxidation or reduction rates can be selected for through an increased growth rate of the cell. In recent years, several E. coli strains have been developed that are deficient in the oxidation or reduction of NAD+/NADH and NADP+/NADPH pairs, and of non-canonical redox cofactor pairs NMN+/NMNH and NCD+/NCDH, which provides researchers with a versatile toolbox of enzyme engineering platforms. A range of redox cofactor dependent enzymes have since been engineered using a variety of these strains, demonstrating the power of using this growth-coupling technique for enzyme engineering. This review aims to summarize the metabolic engineering involved in creating strains auxotrophic for the reduced or oxidized state of redox cofactors, and the resulting successes in using them for enzyme engineering. Perspectives on the unique features and potential future applications of this technique are also presented.
Collapse
Affiliation(s)
- Jochem R Nielsen
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom.
| | - Ruud A Weusthuis
- Department of Bioprocess Engineering, Wageningen University & Research, Wageningen 6700AA, the Netherlands.
| | - Wei E Huang
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom.
| |
Collapse
|
13
|
Madhavan A, Arun KB, Sindhu R, Nair BG, Pandey A, Awasthi MK, Szakacs G, Binod P. Design and genome engineering of microbial cell factories for efficient conversion of lignocellulose to fuel. BIORESOURCE TECHNOLOGY 2023; 370:128555. [PMID: 36586428 DOI: 10.1016/j.biortech.2022.128555] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/26/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
The gradually increasing need for fossil fuels demands renewable biofuel substitutes. This has fascinated an increasing investigation to design innovative energy fuels that have comparable Physico-chemical and combustion characteristics with fossil-derived fuels. The efficient microbes for bioenergy synthesis desire the proficiency to consume a large quantity of carbon substrate, transfer various carbohydrates through efficient metabolic pathways, capability to withstand inhibitory components and other degradation compounds, and improve metabolic fluxes to synthesize target compounds. Metabolically engineered microbes could be an efficient methodology for synthesizing biofuel from cellulosic biomass by cautiously manipulating enzymes and metabolic pathways. This review offers a comprehensive perspective on the trends and advances in metabolic and genetic engineering technologies for advanced biofuel synthesis by applying various heterologous hosts. Probable technologies include enzyme engineering, heterologous expression of multiple genes, CRISPR-Cas technologies for genome editing, and cell surface display.
Collapse
Affiliation(s)
- Aravind Madhavan
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kollam 690525 Kerala, India.
| | - K B Arun
- Department of Life Sciences, CHRIST (Deemed to be University), Bengaluru 560029, Karnataka, India
| | - Raveendran Sindhu
- Department of Food Technology, TKM Institute of Technology, Kollam 689 122, India
| | - Bipin G Nair
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kollam 690525 Kerala, India
| | - Ashok Pandey
- Center for Innovation and Translational Research, CSIR-Indian Institute of Toxicology Research, Lucknow 226 001, India; Sustainability Cluster, School of Engineering, University of Petroleum and Energy Studies, Dehradun 248007, Uttarkhand, India; Centre for Energy and Environmental Sustainability, Lucknow 226 029, Uttar Pradesh, India
| | - Mukesh Kumar Awasthi
- College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712 100, China
| | - George Szakacs
- Budapest University of Technology and Economics, Department of Applied Biotechnology and Food Science, 1111 Budapest, Szent Gellert ter 4, Hungary
| | - Parameswaran Binod
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695 019, India
| |
Collapse
|
14
|
Hoang Trung Chau T, Duc Nguyen A, Lee EY. Engineering type I methanotrophic bacteria as novel platform for sustainable production of 3-hydroxybutyrate and biodegradable polyhydroxybutyrate from methane and xylose. BIORESOURCE TECHNOLOGY 2022; 363:127898. [PMID: 36108944 DOI: 10.1016/j.biortech.2022.127898] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/27/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
Methylotuvimicrobium alcaliphilum20Z recombinant strain co-utilizing methane and xylose from anthropogenic activities and lignocellulose biomassis a promising cell factory platform. In this study, the production of (R)-3-hydroxybutyrate and poly (3-hydroxybutyrate) inM. alcaliphilum20Z was demonstrated. The production of (R)-3-hydroxybutyrate was optimized by introducing additional thioesterase, and a tunable genetic module. The final recombinant strain produced the highest titer of 334.52 ± 2 mg/L (R)-3-hydroxybutyrate (yield of 1,853 ± 429 mg/g dry cell weight). The poly (3-hydroxybutyrate) yielded 1.29 ± 0.08% (w/w) from methane and xylose in one-stage cultivation. Moreover, the study demonstrated the importance of pathway reversibility as an effective design strategy for balancing the driving force and intermediate accumulation. This is the first demonstration of the production ofbiodegradablepoly (3-hydroxybutyrate) from methane in type I methanotrophs, which is a key step toward sustainable biomanufacturing and carbon-neutral society.
Collapse
Affiliation(s)
- Tin Hoang Trung Chau
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, South Korea
| | - Anh Duc Nguyen
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, South Korea
| | - Eun Yeol Lee
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, South Korea.
| |
Collapse
|
15
|
Re A, Mazzoli R. Current progress on engineering microbial strains and consortia for production of cellulosic butanol through consolidated bioprocessing. Microb Biotechnol 2022; 16:238-261. [PMID: 36168663 PMCID: PMC9871528 DOI: 10.1111/1751-7915.14148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/01/2022] [Accepted: 09/07/2022] [Indexed: 01/27/2023] Open
Abstract
In the last decades, fermentative production of n-butanol has regained substantial interest mainly owing to its use as drop-in-fuel. The use of lignocellulose as an alternative to traditional acetone-butanol-ethanol fermentation feedstocks (starchy biomass and molasses) can significantly increase the economic competitiveness of biobutanol over production from non-renewable sources (petroleum). However, the low cost of lignocellulose is offset by its high recalcitrance to biodegradation which generally requires chemical-physical pre-treatment and multiple bioreactor-based processes. The development of consolidated processing (i.e., single-pot fermentation) can dramatically reduce lignocellulose fermentation costs and promote its industrial application. Here, strategies for developing microbial strains and consortia that feature both efficient (hemi)cellulose depolymerization and butanol production will be depicted, that is, rational metabolic engineering of native (hemi)cellulolytic or native butanol-producing or other suitable microorganisms; protoplast fusion of (hemi)cellulolytic and butanol-producing strains; and co-culture of (hemi)cellulolytic and butanol-producing microbes. Irrespective of the fermentation feedstock, biobutanol production is inherently limited by the severe toxicity of this solvent that challenges process economic viability. Hence, an overview of strategies for developing butanol hypertolerant strains will be provided.
Collapse
Affiliation(s)
- Angela Re
- Centre for Sustainable Future TechnologiesFondazione Istituto Italiano di TecnologiaTorinoItaly,Department of Applied Science and TechnologyPolitecnico di TorinoTurinItaly
| | - Roberto Mazzoli
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems BiologyUniversity of TorinoTorinoItaly
| |
Collapse
|
16
|
An Alternative Approach to Improve the Butanol Production Efficiency from Sweet Sorghum Stem Juice Using Immobilized Cells Combined with an In Situ Gas Stripping System. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8090464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effects of the nitrogen source and buffers used in butanol production with Clostridium beijerinckii TISTR 1461 from sweet sorghum stem juice (SSJ) containing 60 g/L of total sugar were first studied in this paper. Among the various nitrogen sources (dried spent yeast, urea, ammonium acetate, ammonium sulfate), urea was found to be the most suitable for butanol production. SSJ supplemented with urea (0.64 g/L) and cocktail buffers (KH2PO4, 0.5 g/L; K2HPO4, 0.5 g/L; ammonium acetate, 2.2 g/L) gave the highest butanol concentration (PB, 10.13 g/L). Then, the capability of immobilized C. beijerinckii TISTR 1461 cells for butanol fermentation was investigated. Two residual waste materials were examined as immobilized cell carriers. Bamboo chopstick pieces were more appropriate as carriers for cell immobilization than cigarette filter tips. The PB value of the immobilized cells on the bamboo chopstick pieces was ~13% higher than that on the cigarette filter tips. Using the response surface methodology (RSM), 1.9 cm bamboo chopstick pieces with a carrier loading of 1:32 (w/v) were the optimum conditions for cell immobilization for butanol production. Under these conditions, the PB value was 11.62 g/L. To improve the butanol production efficiency, a gas stripping system (GS) was connected to the fermenter. It was found that the PB (14.02 g/L) and butanol productivity (QB, 0.29 g/L·h) values improved by ~21% compared to butanol fermentation using no gas stripping.
Collapse
|
17
|
Agarwal P, Soni R, Kaur P, Madan A, Mishra R, Pandey J, Singh S, Singh G. Cyanobacteria as a Promising Alternative for Sustainable Environment: Synthesis of Biofuel and Biodegradable Plastics. Front Microbiol 2022; 13:939347. [PMID: 35903468 PMCID: PMC9325326 DOI: 10.3389/fmicb.2022.939347] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/09/2022] [Indexed: 11/13/2022] Open
Abstract
With the aim to alleviate the increasing plastic burden and carbon footprint on Earth, the role of certain microbes that are capable of capturing and sequestering excess carbon dioxide (CO2) generated by various anthropogenic means was studied. Cyanobacteria, which are photosynthetic prokaryotes, are promising alternative for carbon sequestration as well as biofuel and bioplastic production because of their minimal growth requirements, higher efficiency of photosynthesis and growth rates, presence of considerable amounts of lipids in thylakoid membranes, and cosmopolitan nature. These microbes could prove beneficial to future generations in achieving sustainable environmental goals. Their role in the production of polyhydroxyalkanoates (PHAs) as a source of intracellular energy and carbon sink is being utilized for bioplastic production. PHAs have emerged as well-suited alternatives for conventional plastics and are a parallel competitor to petrochemical-based plastics. Although a lot of studies have been conducted where plants and crops are used as sources of energy and bioplastics, cyanobacteria have been reported to have a more efficient photosynthetic process strongly responsible for increased production with limited land input along with an acceptable cost. The biodiesel production from cyanobacteria is an unconventional choice for a sustainable future as it curtails toxic sulfur release and checks the addition of aromatic hydrocarbons having efficient oxygen content, with promising combustion potential, thus making them a better choice. Here, we aim at reporting the application of cyanobacteria for biofuel production and their competent biotechnological potential, along with achievements and constraints in its pathway toward commercial benefits. This review article also highlights the role of various cyanobacterial species that are a source of green and clean energy along with their high potential in the production of biodegradable plastics.
Collapse
|
18
|
Vamsi Krishna K, Bharathi N, George Shiju S, Alagesan Paari K, Malaviya A. An updated review on advancement in fermentative production strategies for biobutanol using Clostridium spp. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:47988-48019. [PMID: 35562606 DOI: 10.1007/s11356-022-20637-9] [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: 12/12/2021] [Accepted: 04/30/2022] [Indexed: 06/15/2023]
Abstract
A significant concern of our fuel-dependent era is the unceasing exhaustion of petroleum fuel supplies. In parallel to this, environmental issues such as the greenhouse effect, change in global climate, and increasing global temperature must be addressed on a priority basis. Biobutanol, which has fuel characteristics comparable to gasoline, has attracted global attention as a viable green fuel alternative among the many biofuel alternatives. Renewable biomass could be used for the sustainable production of biobutanol by the acetone-butanol-ethanol (ABE) pathway. Non-extinguishable resources, such as algal and lignocellulosic biomass, and starch are some of the most commonly used feedstock for fermentative production of biobutanol, and each has its particular set of advantages. Clostridium, a gram-positive endospore-forming bacterium that can produce a range of compounds, along with n-butanol is traditionally known for its biobutanol production capabilities. Clostridium fermentation produces biobased n-butanol through ABE fermentation. However, low butanol titer, a lack of suitable feedstock, and product inhibition are the primary difficulties in biobutanol synthesis. Critical issues that are essential for sustainable production of biobutanol include (i) developing high butanol titer producing strains utilizing genetic and metabolic engineering approaches, (ii) renewable biomass that could be used for biobutanol production at a larger scale, and (iii) addressing the limits of traditional batch fermentation by integrated bioprocessing technologies with effective product recovery procedures that have increased the efficiency of biobutanol synthesis. Our paper reviews the current progress in all three aspects of butanol production and presents recent data on current practices in fermentative biobutanol production technology.
Collapse
Affiliation(s)
- Kondapalli Vamsi Krishna
- Applied and Industrial Biotechnology Laboratory, CHRIST (Deemed-to-Be University), Hosur road, Bangalore, Karnataka, India
| | - Natarajan Bharathi
- Department of Life Sciences, CHRIST (Deemed to Be University), Bengaluru, India
| | - Shon George Shiju
- Applied and Industrial Biotechnology Laboratory, CHRIST (Deemed-to-Be University), Hosur road, Bangalore, Karnataka, India
| | | | - Alok Malaviya
- Applied and Industrial Biotechnology Laboratory, CHRIST (Deemed-to-Be University), Hosur road, Bangalore, Karnataka, India.
- Department of Life Sciences, CHRIST (Deemed to Be University), Bengaluru, India.
| |
Collapse
|
19
|
Xia M, Wang D, Xia Y, Shi H, Tian Z, Zheng Y, Wang M. Oxidoreduction potential controlling for increasing the fermentability of enzymatically hydrolyzed steam-exploded corn stover for butanol production. Microb Cell Fact 2022; 21:130. [PMID: 35761287 PMCID: PMC9238237 DOI: 10.1186/s12934-022-01824-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/12/2022] [Indexed: 11/10/2022] Open
Abstract
Background Lignocellulosic biomass is recognized as an effective potential substrate for biobutanol production. Though many pretreatment and detoxification methods have been set up, the fermentability of detoxicated lignocellulosic substrate is still far lower than that of starchy feedstocks. On the other hand, the number of recent efforts on rational metabolic engineering approaches to increase butanol production in Clostridium strains is also quite limited, demonstrating the physiological complexity of solventogenic clostridia. In fact, the strain performance is greatly impacted by process control. developing efficient process control strategies could be a feasible solution to this problem. Results In this study, oxidoreduction potential (ORP) controlling was applied to increase the fermentability of enzymatically hydrolyzed steam-exploded corn stover (SECS) for butanol production. When ORP of detoxicated SECS was controlled at − 350 mV, the period of fermentation was shortened by 6 h with an increase of 27.5% in the total solvent (to 18.1 g/L) and 34.2% in butanol (to 10.2 g/L) respectively. Silico modeling revealed that the fluxes of NADPH, NADH and ATP strongly differed between the different scenarios. Quantitative analysis showed that intracellular concentrations of ATP, NADPH/NADP+, and NADH/NAD+ were increased by 25.1%, 81.8%, and 62.5%. ORP controlling also resulted in a 2.1-fold increase in butyraldehyde dehydrogenase, a 1.2-fold increase in butanol dehydrogenase and 29% increase in the cell integrity. Conclusion ORP control strategy effectively changed the intracellular metabolic spectrum and significantly improved Clostridium cell growth and butanol production. The working mechanism can be summarized into three aspects: First, Glycolysis and TCA circulation pathways were strengthened through key nodes such as pyruvate carboxylase [EC: 6.4.1.1], which provided sufficient NADH and NADPH for the cell. Second, sufficient ATP was provided to avoid “acid crash”. Third, the key enzymes activities regulating butanol biosynthesis and cell membrane integrity were improved. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01824-2.
Collapse
Affiliation(s)
- Menglei Xia
- State Key Laboratory of Food Nutrition and Safety. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education. College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China
| | - Di Wang
- State Key Laboratory of Food Nutrition and Safety. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education. College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China
| | - Yiming Xia
- State Key Laboratory of Food Nutrition and Safety. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education. College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China
| | - Haijiao Shi
- State Key Laboratory of Food Nutrition and Safety. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education. College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China
| | - Zhongyu Tian
- State Key Laboratory of Food Nutrition and Safety. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education. College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China
| | - Yu Zheng
- State Key Laboratory of Food Nutrition and Safety. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education. College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China
| | - Min Wang
- State Key Laboratory of Food Nutrition and Safety. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education. College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, People's Republic of China.
| |
Collapse
|
20
|
Lauer I, Philipps G, Jennewein S. Metabolic engineering of Clostridium ljungdahlii for the production of hexanol and butanol from CO 2 and H 2. Microb Cell Fact 2022; 21:85. [PMID: 35568911 PMCID: PMC9107641 DOI: 10.1186/s12934-022-01802-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The replacement of fossil fuels and petrochemicals with sustainable alternatives is necessary to mitigate the effects of climate change and also to counteract diminishing fossil resources. Acetogenic microorganisms such as Clostridium spp. are promising sources of fuels and basic chemical precursors because they efficiently utilize CO and CO2 as carbon source. However the conversion into high titers of butanol and hexanol is challenging. RESULTS Using a metabolic engineering approach we transferred a 17.9-kb gene cluster via conjugation, containing 13 genes from C. kluyveri and C. acetobutylicum for butanol and hexanol biosynthesis, into C. ljungdahlii. Plasmid-based expression resulted in 1075 mg L-1 butanol and 133 mg L-1 hexanol from fructose in complex medium, and 174 mg L-1 butanol and 15 mg L-1 hexanol from gaseous substrate (20% CO2 and 80% H2) in minimal medium. Product formation was increased by the genomic integration of the heterologous gene cluster. We confirmed the expression of all 13 enzymes by targeted proteomics and identified potential rate-limiting steps. Then, we removed the first-round selection marker using CRISPR/Cas9 and integrated an additional 7.8 kb gene cluster comprising 6 genes from C. carboxidivorans. This led to a significant increase in the hexanol titer (251 mg L-1) at the expense of butanol (158 mg L-1), when grown on CO2 and H2 in serum bottles. Fermentation of this strain at 2-L scale produced 109 mg L-1 butanol and 393 mg L-1 hexanol. CONCLUSIONS We thus confirmed the function of the butanol/hexanol biosynthesis genes and achieved hexanol biosynthesis in the syngas-fermenting species C. ljungdahlii for the first time, reaching the levels produced naturally by C. carboxidivorans. The genomic integration strain produced hexanol without selection and is therefore suitable for continuous fermentation processes.
Collapse
Affiliation(s)
- Ira Lauer
- Department for Industrial Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstr. 6, 52074, Aachen, Germany
| | - Gabriele Philipps
- Department for Industrial Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstr. 6, 52074, Aachen, Germany
| | - Stefan Jennewein
- Department for Industrial Biotechnology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstr. 6, 52074, Aachen, Germany.
| |
Collapse
|
21
|
Joshi S, Mishra S. Recent advances in biofuel production through metabolic engineering. BIORESOURCE TECHNOLOGY 2022; 352:127037. [PMID: 35318143 DOI: 10.1016/j.biortech.2022.127037] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Rising global energy demands and climate crisis has created an unprecedented need for the bio-based circular economy to ensure sustainable development with the minimized carbon footprint. Along with conventional biofuels such as ethanol, microbes can be used to produce advanced biofuels which are equivalent to traditional fuels in their energy efficiencies and are compatible with already established infrastructure and hence can be directly blended in higher proportions without overhauling of the pre-existing setup. Metabolic engineering is at the frontiers to develop microbial chassis for biofuel bio-foundries to meet the industrial needs for clean energy. This review does a thorough inquiry of recent developments in metabolic engineering for increasing titers, rates, and yields (TRY) of biofuel production by engineered microorganisms.
Collapse
Affiliation(s)
- Swati Joshi
- ICMR-National Institute of Occupational Health (NIOH), Ahmedabad, Gujarat, India; Central University of Gujarat, Gandhinagar, Gujarat, India.
| | - SukhDev Mishra
- ICMR-National Institute of Occupational Health (NIOH), Ahmedabad, Gujarat, India
| |
Collapse
|
22
|
Engineering E. coli to synthesize butanol. Biochem Soc Trans 2022; 50:867-876. [PMID: 35356968 DOI: 10.1042/bst20211009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 02/22/2022] [Accepted: 03/15/2022] [Indexed: 11/17/2022]
Abstract
Biobutanol is gaining much attention as a potential biofuel due to its superior properties over ethanol. Butanol has been naturally produced via acetone-butanol-ethanol (ABE) fermentation by many Clostridium species, which are not very user-friendly bacteria. Therefore, to improve butanol titers and yield, various butanol synthesis pathways have been engineered in Escherichia coli, a much more robust and convenient host than Clostridium species. This review mainly focuses on the biosynthesis of n-butanol in engineered E. coli with an emphasis on efficient enzymes for butanol production in E. coli, butanol competing pathways, and genome engineering of E. coli for butanol production. In addition, the use of alternate strategies for butanol biosynthesis/enhancement, alternate substrates for the low cost of butanol production, and genetic improvement for butanol tolerance in E. coli have also been discussed.
Collapse
|
23
|
Igbokwe VC, Ezugworie FN, Onwosi CO, Aliyu GO, Obi CJ. Biochemical biorefinery: A low-cost and non-waste concept for promoting sustainable circular bioeconomy. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 305:114333. [PMID: 34952394 DOI: 10.1016/j.jenvman.2021.114333] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 12/11/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
The transition from a fossil-based linear economy to a circular bioeconomy is no longer an option but rather imperative, given worldwide concerns about the depletion of fossil resources and the demand for innovative products that are ecocompatible. As a critical component of sustainable development, this discourse has attracted wide attention at the regional and international levels. Biorefinery is an indispensable technology to implement the blueprint of the circular bioeconomy. As a low-cost, non-waste innovative concept, the biorefinery concept will spur a myriad of new economic opportunities across a wide range of sectors. Consequently, scaling up biorefinery processes is of the essence. Despite several decades of research and development channeled into upscaling biorefinery processes, the commercialization of biorefinery technology appears unrealizable. In this review, challenges limiting the commercialization of biorefinery technologies are discussed, with a particular focus on biofuels, biochemicals, and biomaterials. To counteract these challenges, various process intensification strategies such as consolidated bioprocessing, integrated biorefinery configurations, the use of highly efficient bioreactors, simultaneous saccharification and fermentation, have been explored. This study also includes an overview of biomass pretreatment-generated inhibitory compounds as platform chemicals to produce other essential biocommodities. There is a detailed examination of the technological, economic, and environmental considerations of a sustainable biorefinery. Finally, the prospects for establishing a viable circular bioeconomy in Nigeria are briefly discussed.
Collapse
Affiliation(s)
- Victor C Igbokwe
- Bioconversion and Renewable Energy Research Unit, University of Nigeria, Nsukka, Enugu State, Nigeria; Department of Materials Science and Engineering, Université de Pau et des Pays de l'Adour, 64012, Pau Cedex, France
| | - Flora N Ezugworie
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria; Bioconversion and Renewable Energy Research Unit, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Chukwudi O Onwosi
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria; Bioconversion and Renewable Energy Research Unit, University of Nigeria, Nsukka, Enugu State, Nigeria.
| | - Godwin O Aliyu
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria; Bioconversion and Renewable Energy Research Unit, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Chinonye J Obi
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
| |
Collapse
|
24
|
Luo S, Lin PP, Nieh LY, Liao GB, Tang PW, Chen C, Liao JC. A cell-free self-replenishing CO2-fixing system. Nat Catal 2022. [DOI: 10.1038/s41929-022-00746-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
AbstractBiological CO2 fixation is so far the most effective means for CO2 reduction at scale and accounts for most of the CO2 fixed on Earth. Through this process, carbon is fixed in cellular components and biomass during organismal growth. To uncouple CO2 fixation from growth and cellular regulation, cell-free CO2 fixation systems represent an alternative approach since the rate can be independently manipulated. Here we designed an oxygen-insensitive, self-replenishing CO2 fixation system with opto-sensing. The system comprises a synthetic reductive glyoxylate and pyruvate synthesis (rGPS) cycle and the malyl-CoA-glycerate (MCG) pathway to produce acetyl-coenzyme A (CoA), pyruvate and malate from CO2, which are also intermediates in the cycle. We solved various problems associated with the in vitro system, and implemented opto-sensing modules to control the regeneration of cofactors. We accomplished sustained operation for 6 hours with a CO2-fixing rate comparable to or greater than typical CO2 fixation rates of photosynthetic or lithoautotrophic organisms.
Collapse
|
25
|
Ku JT, Chen AY, Lan EI. Metabolic engineering of Escherichia coli for efficient biosynthesis of butyl acetate. Microb Cell Fact 2022; 21:28. [PMID: 35193559 PMCID: PMC8864926 DOI: 10.1186/s12934-022-01755-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 02/07/2022] [Indexed: 11/30/2022] Open
Abstract
Background Butyl acetate is a versatile compound that is widely used in the chemical and food industry. The conventional butyl acetate synthesis via Fischer esterification of butanol and acetic acid using catalytic strong acids under high temperature is not environmentally benign. Alternative lipase-catalyzed ester formation requires a significant amount of organic solvent which also presents another environmental challenge. Therefore, a microbial cell factory capable of producing butyl acetate through fermentation of renewable resources would provide a greener approach to butyl acetate production. Result Here, we developed a metabolically engineered strain of Escherichia coli that efficiently converts glucose to butyl acetate. A modified Clostridium CoA-dependent butanol production pathway was used to synthesize butanol which was then condensed with acetyl-CoA through an alcohol acetyltransferase. Optimization of alcohol acetyltransferase expression and redox balance with auto-inducible fermentative controlled gene expression led to an effective titer of 22.8 ± 1.8 g/L butyl acetate produced in a bench-top bioreactor. Conclusion Building on the well-developed Clostridium CoA-dependent butanol biosynthetic pathway, expression of an alcohol acetyltransferase converts the butanol produced into butyl acetate. The results from this study provided a strain of E. coli capable of directly producing butyl acetate from renewable resources at ambient conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01755-y.
Collapse
Affiliation(s)
- Jason T Ku
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.,Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan
| | - Arvin Y Chen
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.,Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan
| | - Ethan I Lan
- Department of Biological Science and Technology, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan. .,Department of Biological Science and Technology, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.
| |
Collapse
|
26
|
Finkelstein J, Swartz J, Koffas M. Bioelectrosynthesis systems. Curr Opin Biotechnol 2021; 74:211-219. [PMID: 34979469 DOI: 10.1016/j.copbio.2021.11.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/19/2021] [Accepted: 11/25/2021] [Indexed: 11/16/2022]
Abstract
Bioelectrosynthesis (BES) systems exploit extracellular electron transport pathways to augment cellular metabolism. This strategy can be used to improve the economic viability of bio-based syntheses versus conventional methods, most notably petrochemical-based syntheses. It also has the potential to reduce the carbon footprint of biomanufacturing processes. Efficient channeling of cathode-derived electrons towards biosynthesis requires a better understanding of the biological mechanisms of electron transport as well as detailed evaluation of all aspects of process performance. More advanced solutions may deploy cell free systems that use ex situ generated reducing equivalents to improve economic performance.
Collapse
Affiliation(s)
- Joshua Finkelstein
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - James Swartz
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
| | - Mattheos Koffas
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| |
Collapse
|
27
|
Controlling selectivity of modular microbial biosynthesis of butyryl-CoA-derived designer esters. Metab Eng 2021; 69:262-274. [PMID: 34883244 DOI: 10.1016/j.ymben.2021.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/21/2021] [Accepted: 12/01/2021] [Indexed: 02/02/2023]
Abstract
Short-chain esters have broad utility as flavors, fragrances, solvents, and biofuels. Controlling selectivity of ester microbial biosynthesis has been an outstanding metabolic engineering problem. In this study, we enabled the de novo fermentative microbial biosynthesis of butyryl-CoA-derived designer esters (e.g., butyl acetate, ethyl butyrate, butyl butyrate) in Escherichia coli with controllable selectivity. Using the modular design principles, we generated the butyryl-CoA-derived ester pathways as exchangeable production modules compatible with an engineered chassis cell for anaerobic production of designer esters. We designed these modules derived from an acyl-CoA submodule (e.g., acetyl-CoA, butyryl-CoA), an alcohol submodule (e.g., ethanol, butanol), a cofactor regeneration submodule (e.g., NADH), and an alcohol acetyltransferase (AAT) submodule (e.g., ATF1, SAAT) for rapid module construction and optimization by manipulating replication (e.g., plasmid copy number), transcription (e.g., promoters), translation (e.g., codon optimization), pathway enzymes, and pathway induction conditions. To further enhance production of designer esters with high selectivity, we systematically screened various strategies of protein solubilization using protein fusion tags and chaperones to improve the soluble expression of multiple pathway enzymes. Finally, our engineered ester-producing strains could achieve 19-fold increase in butyl acetate production (0.64 g/L, 96% selectivity), 6-fold increase in ethyl butyrate production (0.41 g/L, 86% selectivity), and 13-fold increase in butyl butyrate production (0.45 g/L, 54% selectivity) as compared to the initial strains. Overall, this study presented a generalizable framework to engineer modular microbial platforms for anaerobic production of butyryl-CoA-derived designer esters from renewable feedstocks.
Collapse
|
28
|
Wang ZQ, Song H, Koleski EJ, Hara N, Park DS, Kumar G, Min Y, Dauenhauer PJ, Chang MCY. A dual cellular-heterogeneous catalyst strategy for the production of olefins from glucose. Nat Chem 2021; 13:1178-1185. [PMID: 34811478 DOI: 10.1038/s41557-021-00820-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 09/23/2021] [Indexed: 11/09/2022]
Abstract
Living systems provide a promising approach to chemical synthesis, having been optimized by evolution to convert renewable carbon sources, such as glucose, into an enormous range of small molecules. However, a large number of synthetic structures can still be difficult to obtain solely from cells, such as unsubstituted hydrocarbons. In this work, we demonstrate the use of a dual cellular-heterogeneous catalytic strategy to produce olefins from glucose using a selective hydrolase to generate an activated intermediate that is readily deoxygenated. Using a new family of iterative thiolase enzymes, we genetically engineered a microbial strain that produces 4.3 ± 0.4 g l-1 of fatty acid from glucose with 86% captured as 3-hydroxyoctanoic and 3-hydroxydecanoic acids. This 3-hydroxy substituent serves as a leaving group that enables heterogeneous tandem decarboxylation-dehydration routes to olefinic products on Lewis acidic catalysts without the additional redox input required for enzymatic or chemical deoxygenation of simple fatty acids.
Collapse
Affiliation(s)
- Zhen Q Wang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA. .,Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA.
| | - Heng Song
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.,College of Chemistry & Molecular Science, Wuhan University, Wuhan, P. R. China
| | - Edward J Koleski
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Noritaka Hara
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Dae Sung Park
- Department of Chemical Engineering & Materials Science, University of Minnesota, Minneapolis, MN, USA.,Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Gaurav Kumar
- Department of Chemical Engineering & Materials Science, University of Minnesota, Minneapolis, MN, USA
| | - Yejin Min
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Paul J Dauenhauer
- Department of Chemical Engineering & Materials Science, University of Minnesota, Minneapolis, MN, USA
| | - Michelle C Y Chang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA. .,Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA, USA. .,Department of Chemical & Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, USA.
| |
Collapse
|
29
|
Sellés Vidal L, Murray JW, Heap JT. Versatile selective evolutionary pressure using synthetic defect in universal metabolism. Nat Commun 2021; 12:6859. [PMID: 34824282 PMCID: PMC8616928 DOI: 10.1038/s41467-021-27266-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
The non-natural needs of industrial applications often require new or improved enzymes. The structures and properties of enzymes are difficult to predict or design de novo. Instead, semi-rational approaches mimicking evolution entail diversification of parent enzymes followed by evaluation of isolated variants. Artificial selection pressures coupling desired enzyme properties to cell growth could overcome this key bottleneck, but are usually narrow in scope. Here we show diverse enzymes using the ubiquitous cofactors nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP) can substitute for defective NAD regeneration, representing a very broadly-applicable artificial selection. Inactivation of Escherichia coli genes required for anaerobic NAD regeneration causes a conditional growth defect. Cells are rescued by foreign enzymes connected to the metabolic network only via NAD or NADP, but only when their substrates are supplied. Using this principle, alcohol dehydrogenase, imine reductase and nitroreductase variants with desired selectivity modifications, and a high-performing isopropanol metabolic pathway, are isolated from libraries of millions of variants in single-round experiments with typical limited information to guide design.
Collapse
Affiliation(s)
- Lara Sellés Vidal
- grid.7445.20000 0001 2113 8111Imperial College Centre for Synthetic Biology, Imperial College London, London, SW7 2AZ UK ,grid.7445.20000 0001 2113 8111Department of Life Sciences, Imperial College London, London, SW7 2AZ UK
| | - James W. Murray
- grid.7445.20000 0001 2113 8111Department of Life Sciences, Imperial College London, London, SW7 2AZ UK
| | - John T. Heap
- grid.7445.20000 0001 2113 8111Imperial College Centre for Synthetic Biology, Imperial College London, London, SW7 2AZ UK ,grid.7445.20000 0001 2113 8111Department of Life Sciences, Imperial College London, London, SW7 2AZ UK ,grid.4563.40000 0004 1936 8868School of Life Sciences, The University of Nottingham, Biodiscovery Institute, University Park, Nottingham, NG7 2RD UK
| |
Collapse
|
30
|
Bai W, Ranaivoarisoa TO, Singh R, Rengasamy K, Bose A. n-Butanol production by Rhodopseudomonas palustris TIE-1. Commun Biol 2021; 4:1257. [PMID: 34732832 PMCID: PMC8566592 DOI: 10.1038/s42003-021-02781-z] [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: 12/10/2020] [Accepted: 10/06/2021] [Indexed: 11/09/2022] Open
Abstract
Anthropogenic carbon dioxide (CO2) release in the atmosphere from fossil fuel combustion has inspired scientists to study CO2 to biofuel conversion. Oxygenic phototrophs such as cyanobacteria have been used to produce biofuels using CO2. However, oxygen generation during oxygenic photosynthesis adversely affects biofuel production efficiency. To produce n-butanol (biofuel) from CO2, here we introduce an n-butanol biosynthesis pathway into an anoxygenic (non-oxygen evolving) photoautotroph, Rhodopseudomonas palustris TIE-1 (TIE-1). Using different carbon, nitrogen, and electron sources, we achieve n-butanol production in wild-type TIE-1 and mutants lacking electron-consuming (nitrogen-fixing) or acetyl-CoA-consuming (polyhydroxybutyrate and glycogen synthesis) pathways. The mutant lacking the nitrogen-fixing pathway produce the highest n-butanol. Coupled with novel hybrid bioelectrochemical platforms, this mutant produces n-butanol using CO2, solar panel-generated electricity, and light with high electrical energy conversion efficiency. Overall, this approach showcases TIE-1 as an attractive microbial chassis for carbon-neutral n-butanol bioproduction using sustainable, renewable, and abundant resources.
Collapse
Affiliation(s)
- Wei Bai
- grid.4367.60000 0001 2355 7002Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO USA
| | - Tahina Onina Ranaivoarisoa
- grid.4367.60000 0001 2355 7002Department of Biology, Washington University in St. Louis, St. Louis, MO USA
| | - Rajesh Singh
- grid.4367.60000 0001 2355 7002Department of Biology, Washington University in St. Louis, St. Louis, MO USA
| | - Karthikeyan Rengasamy
- grid.4367.60000 0001 2355 7002Department of Biology, Washington University in St. Louis, St. Louis, MO USA
| | - Arpita Bose
- grid.4367.60000 0001 2355 7002Department of Biology, Washington University in St. Louis, St. Louis, MO USA
| |
Collapse
|
31
|
Keasling J, Garcia Martin H, Lee TS, Mukhopadhyay A, Singer SW, Sundstrom E. Microbial production of advanced biofuels. Nat Rev Microbiol 2021; 19:701-715. [PMID: 34172951 DOI: 10.1038/s41579-021-00577-w] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2021] [Indexed: 02/06/2023]
Abstract
Concerns over climate change have necessitated a rethinking of our transportation infrastructure. One possible alternative to carbon-polluting fossil fuels is biofuels produced by engineered microorganisms that use a renewable carbon source. Two biofuels, ethanol and biodiesel, have made inroads in displacing petroleum-based fuels, but their uptake has been limited by the amounts that can be used in conventional engines and by their cost. Advanced biofuels that mimic petroleum-based fuels are not limited by the amounts that can be used in existing transportation infrastructure but have had limited uptake due to costs. In this Review, we discuss engineering metabolic pathways to produce advanced biofuels, challenges with substrate and product toxicity with regard to host microorganisms and methods to engineer tolerance, and the use of functional genomics and machine learning approaches to produce advanced biofuels and prospects for reducing their costs.
Collapse
Affiliation(s)
- Jay Keasling
- Joint BioEnergy Institute, Emeryville, CA, USA. .,Department of Chemical & Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, USA. .,Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA. .,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. .,Center for Biosustainability, Danish Technical University, Lyngby, Denmark. .,Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, China.
| | - Hector Garcia Martin
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,DOE Agile BioFoundry, Emeryville, CA, USA.,BCAM,Basque Center for Applied Mathematics, Bilbao, Spain.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Taek Soon Lee
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Aindrila Mukhopadhyay
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Steven W Singer
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Eric Sundstrom
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Advanced Biofuels and Bioproducts Process Development Unit, Emeryville, CA, USA
| |
Collapse
|
32
|
Li Q, Zhang J, Yang J, Jiang Y, Yang S. Recent progress on n-butanol production by lactic acid bacteria. World J Microbiol Biotechnol 2021; 37:205. [PMID: 34698975 DOI: 10.1007/s11274-021-03173-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 10/13/2021] [Indexed: 11/26/2022]
Abstract
n-Butanol is an essential chemical intermediate produced through microbial fermentation. However, its toxicity to microbial cells has limited its production to a great extent. The anaerobe lactic acid bacteria (LAB) are the most resistant to n-butanol, so it should be the first choice for improving n-butanol production. The present article aims to review the following aspects of n-butanol production by LAB: (1) the tolerance of LAB to n-butanol, including its tolerance level and potential tolerance mechanisms; (2) genome editing tools in the n-butanol-resistant LAB; (3) methods of LAB modification for n-butanol production and the production levels after modification. This review will provide a theoretical basis for further research on n-butanol production by LAB.
Collapse
Affiliation(s)
- Qi Li
- College of Life Sciences, Sichuan Normal University, Chengdu, 610101, China
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Jieze Zhang
- Department of Chemistry, University of Southern California, Los Angeles, CA, 90089, USA
| | - Junjie Yang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
| | - Yu Jiang
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Huzhou, 313000, China
- Shanghai Taoyusheng Biotechnology Company Ltd, Shanghai, 200032, China
| | - Sheng Yang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China.
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Huzhou, 313000, China.
| |
Collapse
|
33
|
Recent Progress and Trends in the Development of Microbial Biofuels from Solid Waste—A Review. ENERGIES 2021. [DOI: 10.3390/en14196011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review covers the recent progress in the design and application of microbial biofuels, assessing the advancement of genetic engineering undertakings and their marketability, and lignocellulosic biomass pretreatment issues. Municipal solid waste (MSW) is a promising sustainable biofuel feedstock due to its high content of lignocellulosic fiber. In this review, we compared the production of fatty alcohols, alkanes, and n-butanol from residual biogenic waste and the environmental/economic parameters to that of conventional biofuels. New synthetic biology tools can be used to engineer fermentation pathways within micro-organisms to produce long-chain alcohols, isoprenoids, long-chain fatty acids, and esters, along with alkanes, as substitutes to petroleum-derived fuels. Biotechnological advances have struggled to address problems with bioethanol, such as lower energy density compared to gasoline and high corrosive and hygroscopic qualities that restrict its application in present infrastructure. Biofuels derived from the organic fraction of municipal solid waste (OFMSW) may have less environmental impacts compared to traditional fuel production, with the added benefit of lower production costs. Unfortunately, current advanced biofuel production suffers low production rates, which hinders commercial scaling-up efforts. Microbial-produced biofuels can address low productivity while increasing the spectrum of produced bioenergy molecules.
Collapse
|
34
|
Maxel S, Saleh S, King E, Aspacio D, Zhang L, Luo R, Li H. Growth-Based, High-Throughput Selection for NADH Preference in an Oxygen-Dependent Biocatalyst. ACS Synth Biol 2021; 10:2359-2370. [PMID: 34469126 PMCID: PMC10362907 DOI: 10.1021/acssynbio.1c00258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclohexanone monooxygenases (CHMO) consume molecular oxygen and NADPH to catalyze the valuable oxidation of cyclic ketones. However, CHMO usage is restricted by poor stability and stringent specificity for NADPH. Efforts to engineer CHMO have been limited by the sensitivity of the enzyme to perturbations in conformational dynamics and long-range interactions that cannot be predicted. We demonstrate an aerobic, high-throughput growth selection platform in Escherichia coli for oxygenase evolution based on NADH redox balance. We applied this NADH-dependent selection to alter the cofactor specificity of CHMO to accept NADH, a less expensive cofactor than NADPH. We first identified the variant CHMO DTNP (S208D-K326T-K349N-L143P) with a ∼1200-fold relative cofactor specificity switch from NADPH to NADH compared to the wild type through semirational design. Molecular modeling suggests CHMO DTNP activity is driven by cooperative fine-tuning of cofactor contacts. Additional evolution of CHMO DTNP through random mutagenesis yielded the variant CHMO DTNPY with a ∼2900-fold relative specificity switch compared to the wild type afforded by an additional distal mutation, H163Y. These results highlight the difficulty in engineering functionally innovative variants from static models and rational designs, and the need for high throughput selection methods. Our introduced tools for oxygenase engineering accelerate the advancements of characteristics essential for industrial feasibility.
Collapse
Affiliation(s)
- Sarah Maxel
- Departments of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697, United States
| | - Samer Saleh
- Departments of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697, United States
| | - Edward King
- Molecular Biology and Biochemistry, University of California, Irvine, California 92697, United States
| | - Derek Aspacio
- Departments of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697, United States
| | - Linyue Zhang
- Departments of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697, United States
| | - Ray Luo
- Departments of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697, United States
- Molecular Biology and Biochemistry, University of California, Irvine, California 92697, United States
- Biomedical Engineering, University of California, Irvine, California 92697, United States
| | - Han Li
- Departments of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697, United States
- Biomedical Engineering, University of California, Irvine, California 92697, United States
| |
Collapse
|
35
|
Liu X, Xie H, Roussou S, Lindblad P. Current advances in engineering cyanobacteria and their applications for photosynthetic butanol production. Curr Opin Biotechnol 2021; 73:143-150. [PMID: 34411807 DOI: 10.1016/j.copbio.2021.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/06/2021] [Accepted: 07/10/2021] [Indexed: 11/03/2022]
Abstract
Cyanobacteria are natural photosynthetic microbes which can be engineered for sustainable conversion of solar energy and carbon dioxide into chemical products. Attempts to improve target production often require an improved understanding of the native cyanobacterial host system. Valuable insights into cyanobacterial metabolism, biochemistry and physiology have been steadily increasing in recent years, stimulating key advancements of cyanobacteria as cell factories for biochemical, including biofuel, production. In the present review, we summarize the current progress in engineering cyanobacteria and discuss the achieved and potential utilization of these advances in cyanobacteria for the production of the bulk chemical butanol, specifically isobutanol and 1-butanol.
Collapse
Affiliation(s)
- Xufeng Liu
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Hao Xie
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Stamatina Roussou
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Peter Lindblad
- Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden.
| |
Collapse
|
36
|
Metabolic engineering for the production of butanol, a potential advanced biofuel, from renewable resources. Biochem Soc Trans 2021; 48:2283-2293. [PMID: 32897293 DOI: 10.1042/bst20200603] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/14/2020] [Accepted: 08/17/2020] [Indexed: 12/20/2022]
Abstract
Butanol is an important chemical and potential fuel. For more than 100 years, acetone-butanol-ethanol (ABE) fermentation of Clostridium strains has been the most successful process for biological butanol production. In recent years, other microbes have been engineered to produce butanol as well, among which Escherichia coli was the best one. Considering the crude oil price fluctuation, minimizing the cost of butanol production is of highest priority for its industrial application. Therefore, using cheaper feedstocks instead of pure sugars is an important project. In this review, we summarized butanol production from different renewable resources, such as industrial and food waste, lignocellulosic biomass, syngas and other renewable resources. This review will present the current progress in this field and provide insights for further engineering efforts on renewable butanol production.
Collapse
|
37
|
Flores AD, Holland SC, Mhatre A, Sarnaik AP, Godar A, Onyeabor M, Varman AM, Wang X, Nielsen DR. A coculture-coproduction system designed for enhanced carbon conservation through inter-strain CO 2 recycling. Metab Eng 2021; 67:387-395. [PMID: 34365009 DOI: 10.1016/j.ymben.2021.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/08/2021] [Accepted: 08/04/2021] [Indexed: 11/30/2022]
Abstract
Carbon loss in the form of CO2 is an intrinsic and persistent challenge faced during conventional and advanced biofuel production from biomass feedstocks. Current mechanisms for increasing carbon conservation typically require the provision of reduced co-substrates as additional reducing equivalents. This need can be circumvented, however, by exploiting the natural heterogeneity of lignocellulosic sugars mixtures and strategically using specific fractions to drive complementary CO2 emitting vs. CO2 fixing pathways. As a demonstration of concept, a coculture-coproduction system was developed by pairing two catabolically orthogonal Escherichia coli strains; one converting glucose to ethanol (G2E) and the other xylose to succinate (X2S). 13C-labeling studies reveled that G2E + X2S cocultures were capable of recycling 24% of all evolved CO2 and achieved a carbon conservation efficiency of 77%; significantly higher than the 64% achieved when all sugars are instead converted to just ethanol. In addition to CO2 exchange, the latent exchange of pyruvate between strains was discovered, along with significant carbon rearrangement within X2S.
Collapse
Affiliation(s)
- Andrew D Flores
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, AZ 85287, ECG 301, 501 E. Tyler Mall, Arizona, 85287, United States
| | - Steven C Holland
- School of Life Sciences, Arizona State University, 427 E. Tyler Mall, Tempe, AZ, 85287, United States
| | - Apurv Mhatre
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, AZ 85287, ECG 301, 501 E. Tyler Mall, Arizona, 85287, United States
| | - Aditya P Sarnaik
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, AZ 85287, ECG 301, 501 E. Tyler Mall, Arizona, 85287, United States
| | - Amanda Godar
- School of Life Sciences, Arizona State University, 427 E. Tyler Mall, Tempe, AZ, 85287, United States
| | - Moses Onyeabor
- School of Life Sciences, Arizona State University, 427 E. Tyler Mall, Tempe, AZ, 85287, United States
| | - Arul M Varman
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, AZ 85287, ECG 301, 501 E. Tyler Mall, Arizona, 85287, United States
| | - Xuan Wang
- School of Life Sciences, Arizona State University, 427 E. Tyler Mall, Tempe, AZ, 85287, United States.
| | - David R Nielsen
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, AZ 85287, ECG 301, 501 E. Tyler Mall, Arizona, 85287, United States.
| |
Collapse
|
38
|
Garcia S, Trinh CT. Computational design and analysis of modular cells for large libraries of exchangeable product synthesis modules. Metab Eng 2021; 67:453-463. [PMID: 34339856 DOI: 10.1016/j.ymben.2021.07.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/15/2021] [Accepted: 07/21/2021] [Indexed: 11/19/2022]
Abstract
Microbial metabolism can be harnessed to produce a large library of useful chemicals from renewable resources such as plant biomass. However, it is laborious and expensive to create microbial biocatalysts to produce each new product. To tackle this challenge, we have recently developed modular cell (ModCell) design principles that enable rapid generation of production strains by assembling a modular (chassis) cell with exchangeable production modules to achieve overproduction of target molecules. Previous computational ModCell design methods are limited to analyze small libraries of around 20 products. In this study, we developed a new computational method, named ModCell-HPC, that can design modular cells for large libraries with hundreds of products with a highly-parallel and multi-objective evolutionary algorithm and enable us to elucidate modular design properties. We demonstrated ModCell-HPC to design Escherichia coli modular cells towards a library of 161 endogenous production modules. From these simulations, we identified E. coli modular cells with few genetic manipulations that can produce dozens of molecules in a growth-coupled manner with different types of fermentable sugars. These designs revealed key genetic manipulations at the chassis and module levels to accomplish versatile modular cells, involving not only in the removal of major by-products but also modification of branch points in the central metabolism. We further found that the effect of various sugar degradation on redox metabolism results in lower compatibility between a modular cell and production modules for growth on pentoses than hexoses. To better characterize the degree of compatibility, we developed a method to calculate the minimal set cover, identifying that only three modular cells are all needed to couple with all of 161 production modules. By determining the unknown compatibility contribution metric, we further elucidated the design features that allow an existing modular cell to be re-purposed towards production of new molecules. Overall, ModCell-HPC is a useful tool for understanding modularity of biological systems and guiding more efficient and generalizable design of modular cells that help reduce research and development cost in biocatalysis.
Collapse
Affiliation(s)
- Sergio Garcia
- Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, TN, United States; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Cong T Trinh
- Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, TN, United States; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States.
| |
Collapse
|
39
|
Joseph RC, Kelley SQ, Kim NM, Sandoval NR. Metabolic Engineering and the Synthetic Biology Toolbox for
Clostridium. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
40
|
Luo ZW, Ahn JH, Chae TU, Choi SY, Park SY, Choi Y, Kim J, Prabowo CPS, Lee JA, Yang D, Han T, Xu H, Lee SY. Metabolic Engineering of
Escherichia
coli. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
41
|
Noda S, Mori Y, Fujiwara R, Shirai T, Tanaka T, Kondo A. Reprogramming Escherichia coli pyruvate-forming reaction towards chorismate derivatives production. Metab Eng 2021; 67:1-10. [PMID: 34044138 DOI: 10.1016/j.ymben.2021.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/30/2021] [Accepted: 05/13/2021] [Indexed: 11/18/2022]
Abstract
Microbial metabolic pathway engineering is a potent strategy used worldwide to produce aromatic compounds. We drastically rewired the primary metabolic pathway of Escherichia coli to produce aromatics and their derivatives. The metabolic pathway of E. coli was compartmentalized into the production and energy modules. We focused on the pyruvate-forming reaction in the biosynthesis pathway of some compounds as the reaction connecting those modules. E. coli strains were engineered to show no growth unless pyruvate was synthesized along with the compounds of interest production. Production of salicylate and maleate was demonstrated to confirm our strategy's versatility. In maleate production, the production, yield against the theoretical yield, and production rate reached 12.0 g L-1, 67%, and up to fourfold compared to that in previous reports, respectively; these are the highest values of maleate production in microbes to our knowledge. The results reveal that our strategy strongly promotes the production of aromatics and their derivatives.
Collapse
Affiliation(s)
- Shuhei Noda
- Center for Sustainable Resource Science, RIKEN, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
| | - Yutaro Mori
- Center for Sustainable Resource Science, RIKEN, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Ryosuke Fujiwara
- Center for Sustainable Resource Science, RIKEN, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Tomokazu Shirai
- Center for Sustainable Resource Science, RIKEN, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Tsutomu Tanaka
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Akihiko Kondo
- Center for Sustainable Resource Science, RIKEN, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan; Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| |
Collapse
|
42
|
Escherichia coli as a platform microbial host for systems metabolic engineering. Essays Biochem 2021; 65:225-246. [PMID: 33956149 DOI: 10.1042/ebc20200172] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022]
Abstract
Bio-based production of industrially important chemicals and materials from non-edible and renewable biomass has become increasingly important to resolve the urgent worldwide issues including climate change. Also, bio-based production, instead of chemical synthesis, of food ingredients and natural products has gained ever increasing interest for health benefits. Systems metabolic engineering allows more efficient development of microbial cell factories capable of sustainable, green, and human-friendly production of diverse chemicals and materials. Escherichia coli is unarguably the most widely employed host strain for the bio-based production of chemicals and materials. In the present paper, we review the tools and strategies employed for systems metabolic engineering of E. coli. Next, representative examples and strategies for the production of chemicals including biofuels, bulk and specialty chemicals, and natural products are discussed, followed by discussion on materials including polyhydroxyalkanoates (PHAs), proteins, and nanomaterials. Lastly, future perspectives and challenges remaining for systems metabolic engineering of E. coli are discussed.
Collapse
|
43
|
Zhu L, Zhang J, Yang J, Jiang Y, Yang S. Strategies for optimizing acetyl-CoA formation from glucose in bacteria. Trends Biotechnol 2021; 40:149-165. [PMID: 33965247 DOI: 10.1016/j.tibtech.2021.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/02/2021] [Accepted: 04/02/2021] [Indexed: 12/17/2022]
Abstract
Acetyl CoA is an important precursor for various chemicals. We provide a metabolic engineering guideline for the production of acetyl-CoA and other end products from a bacterial chassis. Among 13 pathways that produce acetyl-CoA from glucose, 11 lose carbon in the process, and two do not. The first 11 use the Embden-Meyerhof-Parnas (EMP) pathway to produce redox cofactors and gain or lose ATP. The other two pathways function via phosphoketolase with net consumption of ATP, so they must therefore be combined with one of the 11 glycolytic pathways or auxiliary pathways. Optimization of these pathways can maximize the theoretical acetyl-CoA yield, thereby minimizing the overall cost of subsequent acetyl-CoA-derived molecules. Other strategies for generating hyper-producer strains are also addressed.
Collapse
Affiliation(s)
- Li Zhu
- Shanghai Laiyi Center for Biopharmaceutical R&D, Shanghai 200240, China
| | - Jieze Zhang
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Jiawei Yang
- College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yu Jiang
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Huzhou 313000, China; Shanghai Taoyusheng Biotechnology Company Ltd, Shanghai 200032, China
| | - Sheng Yang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Huzhou Center of Industrial Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Huzhou 313000, China.
| |
Collapse
|
44
|
Wirth S, Dürre P. Investigation of putative genes for the production of medium-chained acids and alcohols in autotrophic acetogenic bacteria. Metab Eng 2021; 66:296-307. [PMID: 33894339 DOI: 10.1016/j.ymben.2021.04.010] [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] [Received: 12/23/2020] [Revised: 04/06/2021] [Accepted: 04/16/2021] [Indexed: 10/21/2022]
Abstract
Gas fermentation is a technology for producing platform chemicals as well as fuels and one of the most promising alternatives to petrochemicals. Medium-chained acids and alcohols such as hexanoate and hexanol are particularly interesting due to their versatile application. This study elucidated the pathway of chain elongation in native C6 compound-producing acetogens. Essential genes of Clostridium carboxidivorans for synthesis of medium-chained acids and alcohols were identified in order to demonstrate their catalytic activity in the acetogenic model organism Acetobacterium woodii. Two such gene clusters were identified, which are responsible for conversion of acetyl-CoA to butyryl-CoA by reverse β-oxidation. Using RT-PCR it could be demonstrated that only genes of cluster 1 are expressed constitutively with simultaneous formation of C6 compounds. Based on genes from C. carboxidivorans, a modular hexanoyl-CoA synthesis (hcs) plasmid system was constructed and transferred into A. woodii. With the recombinant A. woodii strains AWO [pPta_hcs1], AWO [pPta_hcs2], AWO [pTet_hcs1], and AWO [pTet_hcs2] butyrate and hexanoate production under heterotrophic (1.22-4.15 mM hexanoate) and autotrophic conditions (0.48-1.56 mM hexanoate) with both hcs clusters could be detected. hcs Cluster 1 from C. carboxidivorans was transferred into the ABE-fermenting strain Clostridium saccharoperbutylacetonicum as well. For further analysis, genes were also cloned into the hcs plasmid system individually. The resulting recombinant C. saccharoperbutylacetonicum strains with just individual genes neither produced hexanoate nor hexanol, but the strains containing the entire gene cluster were capable of chain elongation. A production of 0.8 mM hexanoate and 5.2 mM hexanol in the fermentation with glucose could be observed.
Collapse
Affiliation(s)
- Steffen Wirth
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, D-89081, Ulm, Germany.
| | - Peter Dürre
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, D-89081, Ulm, Germany
| |
Collapse
|
45
|
Shanmugam KT, Ingram LO. Principles and practice of designing microbial biocatalysts for fuel and chemical production. J Ind Microbiol Biotechnol 2021; 49:6158391. [PMID: 33686428 PMCID: PMC9118985 DOI: 10.1093/jimb/kuab016] [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: 11/20/2020] [Accepted: 03/03/2021] [Indexed: 11/14/2022]
Abstract
The finite nature of fossil fuels and the environmental impact of its use have raised interest in alternate renewable energy sources. Specifically, non-food carbohydrates, such as lignocellulosic biomass, can be used to produce next generation biofuels, including cellulosic ethanol and other non-ethanol fuels like butanol. However, currently there is no native microorganism that can ferment all lignocellulosic sugars to fuel molecules. Thus, research is focused on engineering improved microbial biocatalysts for production of liquid fuels at high productivity, titer and yield. A clear understanding and application of the basic principles of microbial physiology and biochemistry are crucial to achieve this goal. In this review, we present and discuss the construction of microbial biocatalysts that integrate these principles with ethanol-producing Escherichia coli as an example of metabolic engineering. These principles also apply to fermentation of lignocellulosic sugars to other chemicals that are currently produced from petroleum.
Collapse
Affiliation(s)
- K T Shanmugam
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Lonnie O Ingram
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| |
Collapse
|
46
|
Blatt-Janmaat K, Qu Y. The Biochemistry of Phytocannabinoids and Metabolic Engineering of Their Production in Heterologous Systems. Int J Mol Sci 2021; 22:ijms22052454. [PMID: 33671077 PMCID: PMC7957758 DOI: 10.3390/ijms22052454] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 12/12/2022] Open
Abstract
The medicinal properties of cannabis and the its legal status in several countries and jurisdictions has spurred the massive growth of the cannabis economy around the globe. The value of cannabis stems from its euphoric activity offered by the unique phytocannabinoid tetrahydrocannabinol (THC). However, this is rapidly expanding beyond THC owing to other non-psychoactive phytocannabinoids with new bioactivities that will contribute to their development into clinically useful drugs. The discovery of the biosynthesis of major phytocannabinoids has allowed the exploration of their heterologous production by synthetic biology, which may lead to the industrial production of rare phytocannabinoids or novel synthetic cannabinoid pharmaceuticals that are not easily offered by cannabis plants. This review summarizes the biosynthesis of major phytocannabinoids in detail, the most recent development of their metabolic engineering in various systems, and the engineering approaches and strategies used to increase the yield.
Collapse
Affiliation(s)
- Kaitlyn Blatt-Janmaat
- Department of Chemistry, University of New Brunswick, Fredericton, NB E3B 5A3, Canada;
| | - Yang Qu
- Department of Chemistry, University of New Brunswick, Fredericton, NB E3B 5A3, Canada;
- Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
- Correspondence:
| |
Collapse
|
47
|
Zhang M, Zhang H, Li Q, Gao Y, Guo L, He L, Zang S, Guo X, Huang J, Li L. Structural Insights into the Trans-Acting Enoyl Reductase in the Biosynthesis of Long-Chain Polyunsaturated Fatty Acids in Shewanella piezotolerans. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:2316-2324. [PMID: 33587627 DOI: 10.1021/acs.jafc.0c07386] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Two long-chain polyunsaturated fatty acids (LC-PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), play vital roles in human health. Similarly, two biosynthetic pathways, based on desaturase/elongase and polyketide synthase, have been implicated in the synthesis of microbial LC-PUFA. Up to now, only several microalgae, no bacteria, have been used in the commercial production of oils rich in DHA and/or EPA. Fully understanding the enzymatic mechanism in the biosynthesis of LC-PUFA would contribute significantly to produce EPA and/or DHA by the bacteria. In this study, we report a 1.998 Å-resolution crystal structure of trans-acting enoyl reductase (ER), SpPfaD, from Shewanella piezotolerans. The SpPfaD model consists of one homodimer in the asymmetric unit, and each subunit contains three domains. These include an N-terminal, a central domain forming a classic TIM barrel with a single FMN cofactor molecule bound atop the barrel, and a C-terminal domain with a lid above the TIM barrel. Furthermore, we docked oxidized nicotinamide adenine dinucleotide phosphate (NADP) and an inhibitor 2-(4-(2-((3-(5-(pyridin-2-ylthio)thiazol-2-yl)ureido)methyl)-1H-imidazole-4-yl)phenoxy)acetic acid (TUI) molecule into the active site and analyzed the inhibition and catalytic mechanisms of the enoyl reductase SpPfaD. To the best of our knowledge, this is the first crystal structure of trans-ER in the biosynthesis of bacterial polyketides.
Collapse
Affiliation(s)
- Mingliang Zhang
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
| | - Huaidong Zhang
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Wuhan 430071, P. R. China
| | - Qin Li
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
- The State Key Laboratory of Virology, Wuhan 430071, P. R. China
| | - Yangle Gao
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
| | - Lijun Guo
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
| | - Liu He
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
| | - Shanshan Zang
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
| | - Xing Guo
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
| | - Jianzhong Huang
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
| | - Li Li
- Engineering Research Center of Industrial Microbiology, Ministry of Education; Collaborative Innovation Center of Haixi Green Bio-Manufacturing Technology, Ministry of Education; National & Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, National Development and Reform Commission; College of Life Sciences, Fujian Normal University, Fuzhou, 350117, P. R. China
| |
Collapse
|
48
|
Adaptive laboratory evolution of the fast-growing cyanobacterium Synechococcus elongatus PCC 11801 for improved solvent tolerance. J Biosci Bioeng 2021; 131:491-500. [PMID: 33610455 DOI: 10.1016/j.jbiosc.2020.11.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 01/09/2023]
Abstract
Cyanobacteria hold promise as cell factories for the photoautotrophic conversion of carbon dioxide to useful chemicals. For the eventual commercial viability of such processes, cyanobacteria need to be engineered for (i) efficient channeling of carbon flux toward the product of interest and (ii) improved product tolerance, the latter being the focus of this study. We chose the recently reported, fast-growing, high light and CO2 tolerant cyanobacterium Synechococcus elongatus PCC 11801 for adaptive laboratory evolution. In two parallel experiments that lasted over 8400 h of culturing and 100 serial passages, S. elongatus PCC 11801 was evolved to tolerate 5 g/L n-butanol or 30 g/L 2,3-butanediol representing a 100% improvement in concentrations tolerated. The evolved strains retained alcohol tolerance even after being passaged several times without the alcohol stress suggesting that the changes were permanent. Whole genome sequencing of the n-butanol evolved strains revealed mutations in a number of stress responsive genes encoding translation initiation factors, RpoB and an ABC transporter. In 2,3-butanediol evolved strains, genes for ClpC, a different ABC transporter, glyceraldehyde-3-phosphate dehydrogenase and phosphoribulokinase were found to be mutated. Furthermore, the evolved strains showed significant improvement in tolerance toward several other alcohols. Notably, the n-butanol evolved strain could tolerate up to 32 g/L ethanol, thereby making it a promising host for photosynthetic production of biofuels via metabolic engineering.
Collapse
|
49
|
Bañares AB, Nisola GM, Valdehuesa KNG, Lee WK, Chung WJ. Engineering of xylose metabolism in Escherichia coli for the production of valuable compounds. Crit Rev Biotechnol 2021; 41:649-668. [PMID: 33563072 DOI: 10.1080/07388551.2021.1873243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The lignocellulosic sugar d-xylose has recently gained prominence as an inexpensive alternative substrate for the production of value-added compounds using genetically modified organisms. Among the prokaryotes, Escherichia coli has become the de facto host for the development of engineered microbial cell factories. The favored status of E. coli resulted from a century of scientific explorations leading to a deep understanding of its systems. However, there are limited literature reviews that discuss engineered E. coli as a platform for the conversion of d-xylose to any target compounds. Additionally, available critical review articles tend to focus on products rather than the host itself. This review aims to provide relevant and current information about significant advances in the metabolic engineering of d-xylose metabolism in E. coli. This focusses on unconventional and synthetic d-xylose metabolic pathways as several review articles have already discussed the engineering of native d-xylose metabolism. This paper, in particular, is essential to those who are working on engineering of d-xylose metabolism using E. coli as the host.
Collapse
Affiliation(s)
- Angelo B Bañares
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Grace M Nisola
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Kris N G Valdehuesa
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| | - Won-Keun Lee
- Division of Bioscience and Bioinformatics, Myongji University, Yongin, Gyeonggi, South Korea
| | - Wook-Jin Chung
- Environmental Waste Recycle Institute (EWRI), Department of Energy Science and Technology (DEST), Myongji University, Yongin, Gyeonggi, South Korea
| |
Collapse
|
50
|
Metabolic engineering of E. coli for pyocyanin production. Metab Eng 2021; 64:15-25. [PMID: 33454430 DOI: 10.1016/j.ymben.2021.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 11/17/2020] [Accepted: 01/10/2021] [Indexed: 01/07/2023]
Abstract
Pyocyanin is a secondary metabolite from Pseudomonas aeruginosa that belongs to the class of phenazines, which are aromatic nitrogenous compounds with numerous biological functions. Besides its antifungal and antimicrobial activities, pyocyanin is a remarkable redox-active molecule with potential applications ranging from the pharma industry to the development of microbial fuel cells. Nevertheless, pyocyanin production has been restricted to P. aeruginosa strains, limiting its practical applicability. In this study, the pyocyanin biosynthetic pathway was engineered for the first time for high level production of this compound in a heterologous host. Escherichia coli cells harboring the nine-gene pathway divided into two plasmids were able to produce and secrete pyocyanin at higher levels than some Pseudomonas aeruginosa strains. The influence of culture and induction parameters were evaluated, and the optimized conditions led to an increase of 3.5-fold on pyocyanin accumulation. Pathway balancing was achieved by testing a set of plasmids with different copy numbers to optimize the expression levels of pyocyanin biosynthetic genes, resulting in a fourfold difference in product titer among the engineered strains. Further improvements were achieved by co-expression of Vitreoscilla hemoglobin Vhb, which relieved oxygen limitations and led to a final titer of 18.8 mg/L pyocyanin. These results show promise to use E. coli for phenazines production, and the engineered strain developed here has the potential to be used in electro-fermentation systems where pyocyanin plays a role as electron-shuttle.
Collapse
|