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Consolidated Bioprocessing: Synthetic Biology Routes to Fuels and Fine Chemicals. Microorganisms 2021; 9:microorganisms9051079. [PMID: 34069865 PMCID: PMC8157379 DOI: 10.3390/microorganisms9051079] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/27/2021] [Accepted: 05/14/2021] [Indexed: 11/17/2022] Open
Abstract
The long road from emerging biotechnologies to commercial “green” biosynthetic routes for chemical production relies in part on efficient microbial use of sustainable and renewable waste biomass feedstocks. One solution is to apply the consolidated bioprocessing approach, whereby microorganisms convert lignocellulose waste into advanced fuels and other chemicals. As lignocellulose is a highly complex network of polymers, enzymatic degradation or “saccharification” requires a range of cellulolytic enzymes acting synergistically to release the abundant sugars contained within. Complications arise from the need for extracellular localisation of cellulolytic enzymes, whether they be free or cell-associated. This review highlights the current progress in the consolidated bioprocessing approach, whereby microbial chassis are engineered to grow on lignocellulose as sole carbon sources whilst generating commercially useful chemicals. Future perspectives in the emerging biofoundry approach with bacterial hosts are discussed, where solutions to existing bottlenecks could potentially be overcome though the application of high throughput and iterative Design-Build-Test-Learn methodologies. These rapid automated pathway building infrastructures could be adapted for addressing the challenges of increasing cellulolytic capabilities of microorganisms to commercially viable levels.
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152
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Yoo JI, Sohn YJ, Son J, Jo SY, Pyo J, Park SK, Choi JI, Joo JC, Kim HT, Park SJ. Recent advances in the microbial production of C4 alcohols by metabolically engineered microorganisms. Biotechnol J 2021; 17:e2000451. [PMID: 33984183 DOI: 10.1002/biot.202000451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND The heavy global dependence on petroleum-based industries has led to serious environmental problems, including climate change and global warming. As a result, there have been calls for a paradigm shift towards the use of biorefineries, which employ natural and engineered microorganisms that can utilize various carbon sources from renewable resources as host strains for the carbon-neutral production of target products. PURPOSE AND SCOPE C4 alcohols are versatile chemicals that can be used directly as biofuels and bulk chemicals and in the production of value-added materials such as plastics, cosmetics, and pharmaceuticals. C4 alcohols can be effectively produced by microorganisms using DCEO biotechnology (tools to design, construct, evaluate, and optimize) and metabolic engineering strategies. SUMMARY OF NEW SYNTHESIS AND CONCLUSIONS In this review, we summarize the production strategies and various synthetic tools available for the production of C4 alcohols and discuss the potential development of microbial cell factories, including the optimization of fermentation processes, that offer cost competitiveness and potential industrial commercialization.
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Affiliation(s)
- Jee In Yoo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Yu Jung Sohn
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Jina Son
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Seo Young Jo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Jiwon Pyo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Su Kyeong Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
| | - Jong-Il Choi
- Department of Biotechnology and Engineering, Interdisciplinary Program of Bioenergy and Biomaterials, Chonnam National University, Gwangju, Republic of Korea
| | - Jeong Chan Joo
- Department of Biotechnology, The Catholic University of Korea, Bucheon, Gyenggi-do, Republic of Korea
| | - Hee Taek Kim
- Department of Food Science and Technology, College of Agriculture and Life Sciences, Chungnam National University, Daejeon, Republic of Korea
| | - Si Jae Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul, Republic of Korea
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153
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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.
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154
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155
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Li J, Zhao H, Zheng L, An W. Advances in Synthetic Biology and Biosafety Governance. Front Bioeng Biotechnol 2021; 9:598087. [PMID: 33996776 PMCID: PMC8120004 DOI: 10.3389/fbioe.2021.598087] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 02/17/2021] [Indexed: 11/22/2022] Open
Abstract
Tremendous advances in the field of synthetic biology have been witnessed in multiple areas including life sciences, industrial development, and environmental bio-remediation. However, due to the limitations of human understanding in the code of life, any possible intended or unintended uses of synthetic biology, and other unknown reasons, the development and application of this technology has raised concerns over biosafety, biosecurity, and even cyberbiosecurity that they may expose public health and the environment to unknown hazards. Over the past decades, some countries in Europe, America, and Asia have enacted laws and regulations to control the application of synthetic biology techniques in basic and applied research and this has resulted in some benefits. The outbreak of the COVID-19 caused by novel coronavirus SARS-CoV-2 and various speculations about the origin of this virus have attracted more attention on bio-risk concerns of synthetic biology because of its potential power and uncertainty in the synthesis and engineering of living organisms. Therefore, it is crucial to scrutinize the control measures put in place to ensure appropriate use, promote the development of synthetic biology, and strengthen the governance of pathogen-related research, although the true origin of coronavirus remains hotly debated and unresolved. This article reviews the recent progress made in the field of synthetic biology and combs laws and regulations in governing bio-risk issues. We emphasize the urgent need for legislative and regulatory constraints and oversight to address the biological risks of synthetic biology.
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Affiliation(s)
- Jing Li
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Huimiao Zhao
- College of Humanities and Law, Beijing University of Chemical Technology, Beijing, China
| | - Lanxin Zheng
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Wenlin An
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
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156
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Weitz S, Hermann M, Linder S, Bengelsdorf FR, Takors R, Dürre P. Isobutanol Production by Autotrophic Acetogenic Bacteria. Front Bioeng Biotechnol 2021; 9:657253. [PMID: 33912549 PMCID: PMC8072342 DOI: 10.3389/fbioe.2021.657253] [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: 01/22/2021] [Accepted: 03/22/2021] [Indexed: 02/04/2023] Open
Abstract
Two different isobutanol synthesis pathways were cloned into and expressed in the two model acetogenic bacteria Acetobacterium woodii and Clostridium ljungdahlii. A. woodii is specialized on using CO2 + H2 gas mixtures for growth and depends on sodium ions for ATP generation by a respective ATPase and Rnf system. On the other hand, C. ljungdahlii grows well on syngas (CO + H2 + CO2 mixture) and depends on protons for energy conservation. The first pathway consisted of ketoisovalerate ferredoxin oxidoreductase (Kor) from Clostridium thermocellum and bifunctional aldehyde/alcohol dehydrogenase (AdhE2) from C. acetobutylicum. Three different kor gene clusters are annotated in C. thermocellum and were all tested. Only in recombinant A. woodii strains, traces of isobutanol could be detected. Additional feeding of ketoisovalerate increased isobutanol production to 2.9 mM under heterotrophic conditions using kor3 and to 1.8 mM under autotrophic conditions using kor2. In C. ljungdahlii, isobutanol could only be detected upon additional ketoisovalerate feeding under autotrophic conditions. kor3 proved to be the best suited gene cluster. The second pathway consisted of ketoisovalerate decarboxylase from Lactococcus lactis and alcohol dehydrogenase from Corynebacterium glutamicum. For increasing the carbon flux to ketoisovalerate, genes encoding ketol-acid reductoisomerase, dihydroxy-acid dehydratase, and acetolactate synthase from C. ljungdahlii were subcloned downstream of adhA. Under heterotrophic conditions, A. woodii produced 0.2 mM isobutanol and 0.4 mM upon additional ketoisovalerate feeding. Under autotrophic conditions, no isobutanol formation could be detected. Only upon additional ketoisovalerate feeding, recombinant A. woodii produced 1.5 mM isobutanol. With C. ljungdahlii, no isobutanol was formed under heterotrophic conditions and only 0.1 mM under autotrophic conditions. Additional feeding of ketoisovalerate increased these values to 1.5 mM and 0.6 mM, respectively. A further increase to 2.4 mM and 1 mM, respectively, could be achieved upon inactivation of the ilvE gene in the recombinant C. ljungdahlii strain. Engineering the coenzyme specificity of IlvC of C. ljungdahlii from NADPH to NADH did not result in improved isobutanol production.
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Affiliation(s)
- Sandra Weitz
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Ulm, Germany
| | - Maria Hermann
- Institut für Bioverfahrenstechnik, Universität Stuttgart, Stuttgart, Germany
| | - Sonja Linder
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Ulm, Germany
| | - Frank R Bengelsdorf
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Ulm, Germany
| | - Ralf Takors
- Institut für Bioverfahrenstechnik, Universität Stuttgart, Stuttgart, Germany
| | - Peter Dürre
- Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Ulm, Germany
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157
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Monedeiro F, Railean-Plugaru V, Monedeiro-Milanowski M, Pomastowski P, Buszewski B. Metabolic Profiling of VOCs Emitted by Bacteria Isolated from Pressure Ulcers and Treated with Different Concentrations of Bio-AgNPs. Int J Mol Sci 2021; 22:4696. [PMID: 33946710 PMCID: PMC8124631 DOI: 10.3390/ijms22094696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/22/2021] [Accepted: 04/27/2021] [Indexed: 12/30/2022] Open
Abstract
Considering the advent of antibiotic resistance, the study of bacterial metabolic behavior stimulated by novel antimicrobial agents becomes a relevant tool to elucidate involved adaptive pathways. Profiling of volatile metabolites was performed to monitor alterations of bacterial metabolism induced by biosynthesized silver nanoparticles (bio-AgNPs). Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae and Proteus mirabilis were isolated from pressure ulcers, and their cultures were prepared in the presence/absence of bio-AgNPs at 12.5, 25 and 50 µg mL-1. Headspace solid phase microextraction associated to gas chromatography-mass spectrometry was the employed analytical platform. At the lower concentration level, the agent promoted positive modulation of products of fermentation routes and bioactive volatiles, indicating an attempt of bacteria to adapt to an ongoing suppression of cellular respiration. Augmented response of aldehydes and other possible products of lipid oxidative cleavage was noticed for increasing levels of bio-AgNPs. The greatest concentration of agent caused a reduction of 44 to 80% in the variety of compounds found in the control samples. Pathway analysis indicated overall inhibition of amino acids and fatty acids routes. The present assessment may provide a deeper understanding of molecular mechanisms of bio-AgNPs and how the metabolic response of bacteria is untangled.
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Affiliation(s)
- Fernanda Monedeiro
- Interdisciplinary Centre of Modern Technologies, Nicolaus Copernicus University in Toruń, 4 Wileńska St., 87-100 Toruń, Poland; (F.M.); (V.R.-P.); (M.M.-M.); (P.P.)
| | - Viorica Railean-Plugaru
- Interdisciplinary Centre of Modern Technologies, Nicolaus Copernicus University in Toruń, 4 Wileńska St., 87-100 Toruń, Poland; (F.M.); (V.R.-P.); (M.M.-M.); (P.P.)
| | - Maciej Monedeiro-Milanowski
- Interdisciplinary Centre of Modern Technologies, Nicolaus Copernicus University in Toruń, 4 Wileńska St., 87-100 Toruń, Poland; (F.M.); (V.R.-P.); (M.M.-M.); (P.P.)
| | - Paweł Pomastowski
- Interdisciplinary Centre of Modern Technologies, Nicolaus Copernicus University in Toruń, 4 Wileńska St., 87-100 Toruń, Poland; (F.M.); (V.R.-P.); (M.M.-M.); (P.P.)
| | - Bogusław Buszewski
- Interdisciplinary Centre of Modern Technologies, Nicolaus Copernicus University in Toruń, 4 Wileńska St., 87-100 Toruń, Poland; (F.M.); (V.R.-P.); (M.M.-M.); (P.P.)
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University in Toruń, 7 Gagarina St., 87-100 Toruń, Poland
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158
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Constraint-based metabolic control analysis for rational strain engineering. Metab Eng 2021; 66:191-203. [PMID: 33895366 DOI: 10.1016/j.ymben.2021.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/10/2021] [Accepted: 03/02/2021] [Indexed: 11/20/2022]
Abstract
The advancements in genome editing techniques over the past years have rekindled interest in rational metabolic engineering strategies. While Metabolic Control Analysis (MCA) is a well-established method for quantifying the effects of metabolic engineering interventions on flows in metabolic networks and metabolite concentrations, it does not consider the physiological limitations of the cellular environment and metabolic engineering design constraints. We report here a constraint-based framework, Network Response Analysis (NRA), for rational genetic strain design. NRA is cast as a Mixed-Integer Linear Programming problem that integrates MCA, Thermodynamically-based Flux Analysis (TFA), biologically relevant constraints, as well as genome editing restrictions into a comprehensive platform for identifying metabolic engineering targets. We show that the NRA formulation and its core constraints are equivalent to the ones of Flux Balance Analysis (FBA) and TFA, which allows it to be used for a wide range of optimization criteria and with various physiological constraints. We also show how the parametrization and introduction of biological constraints enhance the NRA formulation compared to the classical MCA approach, and we demonstrate its features and its ability to generate multiple alternative optimal strategies given several user-defined boundaries and objectives. In summary, NRA is a sophisticated alternative to classical MCA for rational metabolic engineering that accommodates the incorporation of physiological data at metabolic flux, metabolite concentration, and enzyme expression levels.
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159
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Seo H, Lee JW, Giannone RJ, Dunlap NJ, Trinh CT. Engineering promiscuity of chloramphenicol acetyltransferase for microbial designer ester biosynthesis. Metab Eng 2021; 66:179-190. [PMID: 33872779 DOI: 10.1016/j.ymben.2021.04.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/06/2021] [Accepted: 04/11/2021] [Indexed: 02/07/2023]
Abstract
Robust and efficient enzymes are essential modules for metabolic engineering and synthetic biology strategies across biological systems to engineer whole-cell biocatalysts. By condensing an acyl-CoA and an alcohol, alcohol acyltransferases (AATs) can serve as interchangeable metabolic modules for microbial biosynthesis of a diverse class of ester molecules with broad applications as flavors, fragrances, solvents, and drop-in biofuels. However, the current lack of robust and efficient AATs significantly limits their compatibility with heterologous precursor pathways and microbial hosts. Through bioprospecting and rational protein engineering, we identified and engineered promiscuity of chloramphenicol acetyltransferases (CATs) from mesophilic prokaryotes to function as robust and efficient AATs compatible with at least 21 alcohol and 8 acyl-CoA substrates for microbial biosynthesis of linear, branched, saturated, unsaturated and/or aromatic esters. By plugging the best engineered CAT (CATec3 Y20F) into the gram-negative mesophilic bacterium Escherichia coli, we demonstrated that the recombinant strain could effectively convert various alcohols into desirable esters, for instance, achieving a titer of 13.9 g/L isoamyl acetate with 95% conversion by fed-batch fermentation. The recombinant E. coli was also capable of simulating the ester profile of roses with high conversion (>97%) and titer (>1 g/L) from fermentable sugars at 37 °C. Likewise, a recombinant gram-positive, cellulolytic, thermophilic bacterium Clostridium thermocellum harboring CATec3 Y20F could produce many of these esters from recalcitrant cellulosic biomass at elevated temperatures (>50 °C) due to the engineered enzyme's remarkable thermostability. Overall, the engineered CATs can serve as a robust and efficient platform for designer ester biosynthesis from renewable and sustainable feedstocks.
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Affiliation(s)
- Hyeongmin Seo
- Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, TN, USA; Center of Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Jong-Won Lee
- Bredesen Center for Interdisciplinary Research and Graduate Education, The University of Tennessee, Knoxville, TN, USA; Center of Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Richard J Giannone
- Center of Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Noah J Dunlap
- Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, TN, USA
| | - Cong T Trinh
- Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, TN, USA; Bredesen Center for Interdisciplinary Research and Graduate Education, The University of Tennessee, Knoxville, TN, USA; Center of Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
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160
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Guo S, Asset T, Atanassov P. Catalytic Hybrid Electrocatalytic/Biocatalytic Cascades for Carbon Dioxide Reduction and Valorization. ACS Catal 2021. [DOI: 10.1021/acscatal.0c04862] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Shengyuan Guo
- Department of Chemical and Biomolecular Engineering, National Fuel Cell Research Center, University of California Irvine, Irvine, California 92697, United States
| | - Tristan Asset
- Department of Chemical and Biomolecular Engineering, National Fuel Cell Research Center, University of California Irvine, Irvine, California 92697, United States
| | - Plamen Atanassov
- Department of Chemical and Biomolecular Engineering, National Fuel Cell Research Center, University of California Irvine, Irvine, California 92697, United States
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161
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Choi K. Nitrogen‐Neutral Amino Acids Refinery: Deamination of Amino Acids for Bio‐Alcohol and Ammonia Production. CHEMBIOENG REVIEWS 2021. [DOI: 10.1002/cben.202000031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Kwon‐Young Choi
- Ajou University Department of Environmental and Safety Engineering College of Engineering Suwon, Gyeonggi-do South Korea
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162
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Ma ZX, Zhang M, Zhang CT, Zhang H, Mo XH, Xing XH, Yang S. Metabolomic analysis improves bioconversion of methanol to isobutanol in Methylorubrum extorquens AM1. Biotechnol J 2021; 16:e2000413. [PMID: 33595188 DOI: 10.1002/biot.202000413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/09/2021] [Accepted: 02/15/2021] [Indexed: 11/12/2022]
Abstract
BACKGROUND Methylorubrum extorquens AM1 can be engineered to convert methanol to value-added chemicals. Most of these chemicals derive from acetyl-CoA involved in the serine cycle. However, recent studies on methylotrophic metabolism have suggested that C3 pyruvate is a good potential precursor for broadening the types of synthesized products. METHODS AND RESULTS In the present study, we found that isobutanol was a model chemical that could be generated from pyruvate through a 2-keto acid pathway. Initially, the engineered M. extorquens AM1 could only produce a trace amount of isobutanol at 0.62 mgL-1 after introducing the heterologous 2-ketoisovalerate decarboxylase and alcohol dehydrogenase. Furthermore, the metabolomic analysis revealed that insufficient carbon fluxes through 2-ketoisovalerate and pyruvate were the key limitation steps for efficient biosynthesis of isobutanol. Based on this analysis, the titer of isobutanol was improved by over 20-fold after overexpressing alsS gene encoding acetolactate synthase and deleting ldhA gene for lactate dehydrogenase. Moreover, substituting the cell chassis with the isobutanol-tolerant strain isolated from adaptive evolution of M. extorquens AM1 further increased the production of isobutanol by 1.7-fold, resulting in the final titer of 19 mgL-1 in flask cultivation. CONCLUSION Our current findings provided promising insights into engineering methylotrophic cell factories capable of converting methanol to isobutanol or value-added chemicals using pyruvate as the precursor.
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Affiliation(s)
- Zeng-Xin Ma
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao, Shandong Province, People's Republic of China
| | - Min Zhang
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao, Shandong Province, People's Republic of China.,Shandong Longkete Enzyme Co., Ltd., Linyi, Shandong, People's Republic of China
| | - Chang-Tai Zhang
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao, Shandong Province, People's Republic of China
| | - Hui Zhang
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao, Shandong Province, People's Republic of China
| | - Xu-Hua Mo
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao, Shandong Province, People's Republic of China
| | - Xin-Hui Xing
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, People's Republic of China.,Center for Synthetic and Systems Biology, Tsinghua University, Beijing, People's Republic of China.,Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, and Institute of Biomedical Health Technology and Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
| | - Song Yang
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao, Shandong Province, People's Republic of China.,Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin, People's Republic of China
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163
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Porokhin V, Amin SA, Nicks TB, Gopinarayanan VE, Nair NU, Hassoun S. Analysis of metabolic network disruption in engineered microbial hosts due to enzyme promiscuity. Metab Eng Commun 2021; 12:e00170. [PMID: 33850714 PMCID: PMC8039717 DOI: 10.1016/j.mec.2021.e00170] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/22/2021] [Accepted: 03/01/2021] [Indexed: 11/30/2022] Open
Abstract
Increasing understanding of metabolic and regulatory networks underlying microbial physiology has enabled creation of progressively more complex synthetic biological systems for biochemical, biomedical, agricultural, and environmental applications. However, despite best efforts, confounding phenotypes still emerge from unforeseen interplay between biological parts, and the design of robust and modular biological systems remains elusive. Such interactions are difficult to predict when designing synthetic systems and may manifest during experimental testing as inefficiencies that need to be overcome. Transforming organisms such as Escherichia coli into microbial factories is achieved via several engineering strategies, used individually or in combination, with the goal of maximizing the production of chosen target compounds. One technique relies on suppressing or overexpressing selected genes; another involves introducing heterologous enzymes into a microbial host. These modifications steer mass flux towards the set of desired metabolites but may create unexpected interactions. In this work, we develop a computational method, termed Metabolic Disruption Workflow (MDFlow), for discovering interactions and network disruptions arising from enzyme promiscuity – the ability of enzymes to act on a wide range of molecules that are structurally similar to their native substrates. We apply MDFlow to two experimentally verified cases where strains with essential genes knocked out are rescued by interactions resulting from overexpression of one or more other genes. We demonstrate how enzyme promiscuity may aid cells in adapting to disruptions of essential metabolic functions. We then apply MDFlow to predict and evaluate a number of putative promiscuous reactions that can interfere with two heterologous pathways designed for 3-hydroxypropionic acid (3-HP) production. Using MDFlow, we can identify putative enzyme promiscuity and the subsequent formation of unintended and undesirable byproducts that are not only disruptive to the host metabolism but also to the intended end-objective of high biosynthetic productivity and yield. As we demonstrate, MDFlow provides an innovative workflow to systematically identify incompatibilities between the native metabolism of the host and its engineered modifications due to enzyme promiscuity. Engineering modifications to cellular hosts result in undesirable byproducts. Metabolic Disruption: changes in engineered host due to enzyme promiscuity. Metabolic Disruption Workflow (MDFlow) uncovers metabolic disruption. MDFlow corroborates previously experimentally verified promiscuous interactions. MDFlow compares disruption due to heterologous pathways targeting 3-HP production.
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Affiliation(s)
| | - Sara A Amin
- Department of Computer Science, Tufts University, Medford, MA, USA
| | - Trevor B Nicks
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, USA
| | | | - Nikhil U Nair
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, USA
| | - Soha Hassoun
- Department of Computer Science, Tufts University, Medford, MA, USA.,Department of Chemical and Biological Engineering, Tufts University, Medford, MA, USA
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164
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Liu Y, Cruz-Morales P, Zargar A, Belcher MS, Pang B, Englund E, Dan Q, Yin K, Keasling JD. Biofuels for a sustainable future. Cell 2021; 184:1636-1647. [PMID: 33639085 DOI: 10.1016/j.cell.2021.01.052] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/16/2021] [Accepted: 01/27/2021] [Indexed: 12/26/2022]
Abstract
Rapid increases of energy consumption and human dependency on fossil fuels have led to the accumulation of greenhouse gases and consequently, climate change. As such, major efforts have been taken to develop, test, and adopt clean renewable fuel alternatives. Production of bioethanol and biodiesel from crops is well developed, while other feedstock resources and processes have also shown high potential to provide efficient and cost-effective alternatives, such as landfill and plastic waste conversion, algal photosynthesis, as well as electrochemical carbon fixation. In addition, the downstream microbial fermentation can be further engineered to not only increase the product yield but also expand the chemical space of biofuels through the rational design and fine-tuning of biosynthetic pathways toward the realization of "designer fuels" and diverse future applications.
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Affiliation(s)
- Yuzhong Liu
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA
| | - Pablo Cruz-Morales
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA
| | - Amin Zargar
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA
| | - Michael S Belcher
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Bo Pang
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA
| | - Elias Englund
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA
| | - Qingyun Dan
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA
| | - Kevin Yin
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Jay D Keasling
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, USA; Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA; Departments of Chemical and Biomolecular Engineering and of Bioengineering, University of California, Berkeley, Berkeley, CA, USA; Novo Nordisk Foundation Center for Biosustainability, Technical University Denmark, Horsholm, Denmark; Center for Synthetic Biochemistry, Shenzhen Institutes for Advanced Technologies, Shenzhen, China.
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165
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Su Y, Shao W, Zhang A, Zhang W. Improving isobutanol tolerance and titers through EMS mutagenesis in Saccharomyces cerevisiae. FEMS Yeast Res 2021; 21:6147039. [PMID: 33620449 DOI: 10.1093/femsyr/foab012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 02/20/2021] [Indexed: 11/14/2022] Open
Abstract
Improving yeast tolerance toward isobutanol is a critical issue enabling high-titer industrial production. Here, we used EMS mutagenesis to screen Saccharomyces cerevisiae with greater tolerance toward isobutanol. By this method, we obtained EMS39 with high-viability in medium containing 16 g/L isobutanol. Then, we metabolically engineered isobutanol synthesis in EMS39. About 2μ plasmids carrying PGK1p-ILV2, PGK1p-ILV3 and TDH3p-cox4-ARO10 were used to over-express ILV2, ILV3 and ARO10 genes, respectively, in EMS39 and wild type W303-1A. And the resulting strains were designated as EMS39-20 and W303-1A-20. Our results showed that EMS39-20 increased isobutanol titers by 49.9% compared to W303-1A-20. Whole genome resequencing analysis of EMS39 showed that more than 59 genes had mutations in their open reading frames or regulatory regions. These 59 genes are enriched mainly into cell growth, basal transcription factors, cell integrity signaling, translation initiation and elongation, ribosome assembly and function, oxidative stress response, etc. Additionally, transcriptomic analysis of EMS39-20 was carried out. Finally, reverse engineering tests showed that overexpression of CWP2 and SRP4039 could improve tolerance of S.cerevisiae toward isobutanol. In conclusion, EMS mutagenesis could be used to increase yeast tolerance toward isobutanol. Our study supplied new insights into mechanisms of tolerance toward isobutanol and enhancing isobutanol production in S. cerevisiae.
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Affiliation(s)
- Yide Su
- School of Chemical Engineering and Technology, Hebei University of Technology, No. 8 Guangrong Road, Hongqiao District, Tianjin 300130, PR China
| | - Wenju Shao
- School of Chemical Engineering and Technology, Hebei University of Technology, No. 8 Guangrong Road, Hongqiao District, Tianjin 300130, PR China
| | - Aili Zhang
- School of Chemical Engineering and Technology, Hebei University of Technology, No. 8 Guangrong Road, Hongqiao District, Tianjin 300130, PR China
| | - Weiwei Zhang
- School of Chemical Engineering and Technology, Hebei University of Technology, No. 8 Guangrong Road, Hongqiao District, Tianjin 300130, PR China
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166
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Liang YF, Long ZX, Zhang YJ, Luo CY, Yan LT, Gao WY, Li H. The chemical mechanisms of the enzymes in the branched-chain amino acids biosynthetic pathway and their applications. Biochimie 2021; 184:72-87. [PMID: 33607240 DOI: 10.1016/j.biochi.2021.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/04/2021] [Accepted: 02/10/2021] [Indexed: 12/27/2022]
Abstract
l-Valine, l-isoleucine, and l-leucine are three key proteinogenic amino acids, and they are also the essential amino acids required for mammalian growth, possessing important and to some extent, special physiological and biological functions. Because of the branched structures in their carbon chains, they are also named as branched-chain amino acids (BCAAs). This review will highlight the advance in studies of the enzymes involved in the biosynthetic pathway of BCAAs, concentrating on their chemical mechanisms and applications in screening herbicides and antibacterial agents. The uses of some of these enzymes in lab scale organic synthesis are also discussed.
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Affiliation(s)
- Yan-Fei Liang
- College of Life Sciences, National Engineering Research Center for Miniaturized Detection Systems, Northwest University, Xi'an, 710069, China
| | - Zi-Xian Long
- College of Life Sciences, National Engineering Research Center for Miniaturized Detection Systems, Northwest University, Xi'an, 710069, China
| | - Ya-Jian Zhang
- College of Life Sciences, National Engineering Research Center for Miniaturized Detection Systems, Northwest University, Xi'an, 710069, China
| | - Cai-Yun Luo
- College of Life Sciences, National Engineering Research Center for Miniaturized Detection Systems, Northwest University, Xi'an, 710069, China
| | - Le-Tian Yan
- College of Life Sciences, National Engineering Research Center for Miniaturized Detection Systems, Northwest University, Xi'an, 710069, China
| | - Wen-Yun Gao
- College of Life Sciences, National Engineering Research Center for Miniaturized Detection Systems, Northwest University, Xi'an, 710069, China.
| | - Heng Li
- College of Life Sciences, National Engineering Research Center for Miniaturized Detection Systems, Northwest University, Xi'an, 710069, China.
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167
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Wang YP, Sun ZG, Wei XQ, Guo XW, Xiao DG. Identification of Core Regulatory Genes and Metabolic Pathways for the n-Propanol Synthesis in Saccharomyces cerevisiae. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:1637-1646. [PMID: 33502852 DOI: 10.1021/acs.jafc.0c06810] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The n-propanol produced by Saccharomyces cerevisiae has a remarkable effect on the taste and flavor of Chinese Baijiu. The n-propanol metabolism-related genes were deleted to evaluate the role in the synthesis of n-propanol to ascertain the key genes and pathways for the production of n-propanol by S. cerevisiae. The results showed that CYS3, GLY1, ALD6, PDC1, ADH5, and YML082W were the key genes affecting the n-propanol metabolism in yeast. The n-propanol concentrations of α5ΔGLY1, α5ΔCYS3, and α5ΔALD6 increased by 121.75, 22.75, and 17.78%, respectively, compared with α5. The n-propanol content of α5ΔPDC1, α5ΔADH5, and α5ΔYML082W decreased by 24.98, 8.35, and 8.44%, respectively, compared with α5. The contents of intermediate metabolites were measured, and results showed that the mutual transformation of glycine and threonine in the threonine pathway and the formation of propanal from 2-ketobutyrate were the core pathways for the formation of n-propanol. Additionally, YML082W played important role in the synthesis of n-propanol by directly producing 2-ketobutyric acid through l-homoserine. This study provided valuable insights into the n-propanol synthesis in S. cerevisiae and the theoretical basis for future optimization of yeast strains in Baijiu making.
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Affiliation(s)
- Ya-Ping Wang
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, P. R. China
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | | | - Xiao-Qing Wei
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, P. R. China
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Xue-Wu Guo
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, P. R. China
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Dong-Guang Xiao
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science and Technology, Ministry of Education, Tianjin 300457, P. R. China
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
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168
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Research progress and the biotechnological applications of multienzyme complex. Appl Microbiol Biotechnol 2021; 105:1759-1777. [PMID: 33564922 DOI: 10.1007/s00253-021-11121-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 01/07/2021] [Accepted: 01/16/2021] [Indexed: 11/26/2022]
Abstract
The multienzyme complex system has become a research focus in synthetic biology due to its highly efficient overall catalytic ability and has been applied to various fields. Multienzyme complexes are formed by cascading complexes, which are multiple functionally related enzymes that continuously and efficiently catalyze the production of substrates. Compared with current mainstream microbial cell catalytic systems, in vitro multienzyme molecular machines have many advantages, such as fewer side reactions, a high product yield, a fast reaction speed, easy product separation, a tolerable toxic environment, and robust system operability, showing increasing competitiveness in the field of biomanufacturing. In this review, the research progress of multienzyme complexes in nature and multienzyme cascades in vivo or in vitro will be introduced, and the discovered enzyme cascades concerning scaffolding proteins will also be discussed. This review is expected to provide a more theoretical basis for the modification of multienzyme complexes and broaden their application in the field of synthetic biology. KEY POINTS: • The cascade reactions of some natural multienzyme complexes are reviewed. • The main approaches of constructing artificial multienzyme complexes are summarized. • The structure and application of cellulosomes are discussed and prospected.
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169
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Cheng J, Tu W, Luo Z, Gou X, Li Q, Wang D, Zhou J. A High-Efficiency Artificial Synthetic Pathway for 5-Aminovalerate Production From Biobased L-Lysine in Escherichia coli. Front Bioeng Biotechnol 2021; 9:633028. [PMID: 33634090 PMCID: PMC7900509 DOI: 10.3389/fbioe.2021.633028] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/20/2021] [Indexed: 12/11/2022] Open
Abstract
Bioproduction of 5-aminovalerate (5AVA) from renewable feedstock can support a sustainable biorefinery process to produce bioplastics, such as nylon 5 and nylon 56. In order to achieve the biobased production of 5AVA, a 2-keto-6-aminocaproate-mediated synthetic pathway was established. Combination of L-Lysine α-oxidase from Scomber japonicus, α-ketoacid decarboxylase from Lactococcus lactis and aldehyde dehydrogenase from Escherichia coli could achieve the biosynthesis of 5AVA from biobased L-Lysine in E. coli. The H2O2 produced by L-Lysine α-oxidase was decomposed by the expression of catalase KatE. Finally, 52.24 g/L of 5AVA were obtained through fed-batch biotransformation. Moreover, homology modeling, molecular docking and molecular dynamic simulation analyses were used to identify mutation sites and propose a possible trait-improvement strategy: the expanded catalytic channel of mutant and more hydrogen bonds formed might be beneficial for the substrates stretch. In summary, we have developed a promising artificial pathway for efficient 5AVA synthesis.
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Affiliation(s)
- Jie Cheng
- Key Laboratory of Meat Processing of Sichuan Province, Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, College of Food and Biological Engineering, Chengdu University, Chengdu, China
| | - Wenying Tu
- Key Laboratory of Meat Processing of Sichuan Province, Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, College of Food and Biological Engineering, Chengdu University, Chengdu, China
| | - Zhou Luo
- Key Laboratory of Meat Processing of Sichuan Province, Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, College of Food and Biological Engineering, Chengdu University, Chengdu, China
| | - Xinghua Gou
- Key Laboratory of Meat Processing of Sichuan Province, Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, College of Food and Biological Engineering, Chengdu University, Chengdu, China
| | - Qiang Li
- Key Laboratory of Meat Processing of Sichuan Province, Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, College of Food and Biological Engineering, Chengdu University, Chengdu, China
| | - Dan Wang
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China
| | - Jingwen Zhou
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
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170
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Luo Z, Yu S, Zeng W, Zhou J. Comparative analysis of the chemical and biochemical synthesis of keto acids. Biotechnol Adv 2021; 47:107706. [PMID: 33548455 DOI: 10.1016/j.biotechadv.2021.107706] [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: 09/10/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/28/2022]
Abstract
Keto acids are essential organic acids that are widely applied in pharmaceuticals, cosmetics, food, beverages, and feed additives as well as chemical synthesis. Currently, most keto acids on the market are prepared via chemical synthesis. The biochemical synthesis of keto acids has been discovered with the development of metabolic engineering and applied toward the production of specific keto acids from renewable carbohydrates using different metabolic engineering strategies in microbes. In this review, we provide a systematic summary of the types and applications of keto acids, and then summarize and compare the chemical and biochemical synthesis routes used for the production of typical keto acids, including pyruvic acid, oxaloacetic acid, α-oxobutanoic acid, acetoacetic acid, ketoglutaric acid, levulinic acid, 5-aminolevulinic acid, α-ketoisovaleric acid, α-keto-γ-methylthiobutyric acid, α-ketoisocaproic acid, 2-keto-L-gulonic acid, 2-keto-D-gluconic acid, 5-keto-D-gluconic acid, and phenylpyruvic acid. We also describe the current challenges for the industrial-scale production of keto acids and further strategies used to accelerate the green production of keto acids via biochemical routes.
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Affiliation(s)
- Zhengshan Luo
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Shiqin Yu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Weizhu Zeng
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
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171
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Abstract
Biofuels are receiving increased scientific attention, and recently different biofuels have been proposed for spark ignition engines. This paper presents the state of art of using biofuels in spark ignition engines (SIE). Different biofuels, mainly ethanol, methanol, i-butanol-n-butanol, and acetone, are blended together in single dual issues and evaluated as renewables for SIE. The biofuels were compared with each other as well as with the fossil fuel in SIE. Future biofuels for SIE are highlighted. A proposed method to reduce automobile emissions and reformulate the emissions into new fuels is presented and discussed. The benefits and weaknesses of using biofuels in SIE are summarized. The study established that ethanol has several benefits as a biofuel for SIE; it enhanced engine performance and decreased pollutant emissions significantly; however, ethanol showed some drawbacks, which cause problems in cold starting conditions and, additionally, the engine may suffer from a vapor lock situation. Methanol also showed improvements in engine emissions/performance similarly to ethanol, but it is poisonous biofuel and it has some sort of incompatibility with engine materials/systems; its being miscible with water is another disadvantage. The lowest engine performance was displayed by n-butanol and i-butanol biofuels, and they also showed the greatest amount of unburned hydrocarbons (UHC) and CO emissions, but the lowest greenhouse effect. Ethanol and methanol introduced the highest engine performance, but they also showed the greatest CO2 emissions. Acetone introduced a moderate engine performance and the best/lowest CO and UHC emissions. Single biofuel blends are also compared with dual ones, and the results showed the benefits of the dual ones. The study concluded that the next generation of biofuels is expected to be dual blended biofuels. Different dual biofuel blends are also compared with each other, and the results showed that the ethanol–methanol (EM) biofuel is superior in comparison with n-butanol–i-butanol (niB) and i-butanol–ethanol (iBE).
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172
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Saleski TE, Chung MT, Carruthers DN, Khasbaatar A, Kurabayashi K, Lin XN. Optimized gene expression from bacterial chromosome by high-throughput integration and screening. SCIENCE ADVANCES 2021; 7:7/7/eabe1767. [PMID: 33579713 PMCID: PMC7880599 DOI: 10.1126/sciadv.abe1767] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/30/2020] [Indexed: 06/01/2023]
Abstract
Chromosomal integration of recombinant genes is desirable compared with expression from plasmids due to increased stability, reduced cell-to-cell variability, and elimination of the need for antibiotics for plasmid maintenance. Here, we present a new approach for tuning pathway gene expression levels via random integration and high-throughput screening. We demonstrate multiplexed gene integration and expression-level optimization for isobutanol production in Escherichia coli The integrated strains could, with far lower expression levels than plasmid-based expression, produce high titers (10.0 ± 0.9 g/liter isobutanol in 48 hours) and yields (69% of the theoretical maximum). Close examination of pathway expression in the top-performing, as well as other isolates, reveals the complexity of cellular metabolism and regulation, underscoring the need for precise optimization while integrating pathway genes into the chromosome. We expect this method for pathway integration and optimization can be readily extended to a wide range of pathways and chassis to create robust and efficient production strains.
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Affiliation(s)
- Tatyana E Saleski
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Meng Ting Chung
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - David N Carruthers
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Azzaya Khasbaatar
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Katsuo Kurabayashi
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA
| | - Xiaoxia Nina Lin
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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173
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Schalck T, den Bergh BV, Michiels J. Increasing Solvent Tolerance to Improve Microbial Production of Alcohols, Terpenoids and Aromatics. Microorganisms 2021; 9:249. [PMID: 33530454 PMCID: PMC7912173 DOI: 10.3390/microorganisms9020249] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 12/16/2022] Open
Abstract
Fuels and polymer precursors are widely used in daily life and in many industrial processes. Although these compounds are mainly derived from petrol, bacteria and yeast can produce them in an environment-friendly way. However, these molecules exhibit toxic solvent properties and reduce cell viability of the microbial producer which inevitably impedes high product titers. Hence, studying how product accumulation affects microbes and understanding how microbial adaptive responses counteract these harmful defects helps to maximize yields. Here, we specifically focus on the mode of toxicity of industry-relevant alcohols, terpenoids and aromatics and the associated stress-response mechanisms, encountered in several relevant bacterial and yeast producers. In practice, integrating heterologous defense mechanisms, overexpressing native stress responses or triggering multiple protection pathways by modifying the transcription machinery or small RNAs (sRNAs) are suitable strategies to improve solvent tolerance. Therefore, tolerance engineering, in combination with metabolic pathway optimization, shows high potential in developing superior microbial producers.
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Affiliation(s)
- Thomas Schalck
- VIB Center for Microbiology, Flanders Institute for Biotechnology, B-3001 Leuven, Belgium; (T.S.); (B.V.d.B.)
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
| | - Bram Van den Bergh
- VIB Center for Microbiology, Flanders Institute for Biotechnology, B-3001 Leuven, Belgium; (T.S.); (B.V.d.B.)
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
| | - Jan Michiels
- VIB Center for Microbiology, Flanders Institute for Biotechnology, B-3001 Leuven, Belgium; (T.S.); (B.V.d.B.)
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
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174
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Fouilloux H, Thomas CM. Production and Polymerization of Biobased Acrylates and Analogs. Macromol Rapid Commun 2021; 42:e2000530. [DOI: 10.1002/marc.202000530] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/23/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Hugo Fouilloux
- PSL University Chimie ParisTech CNRS Institut de Recherche de Chimie Paris Paris 75005 France
| | - Christophe M. Thomas
- PSL University Chimie ParisTech CNRS Institut de Recherche de Chimie Paris Paris 75005 France
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175
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Kim DI, Chae TU, Kim HU, Jang WD, Lee SY. Microbial production of multiple short-chain primary amines via retrobiosynthesis. Nat Commun 2021; 12:173. [PMID: 33420084 PMCID: PMC7794544 DOI: 10.1038/s41467-020-20423-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/27/2020] [Indexed: 01/11/2023] Open
Abstract
Bio-based production of many chemicals is not yet possible due to the unknown biosynthetic pathways. Here, we report a strategy combining retrobiosynthesis and precursor selection step to design biosynthetic pathways for multiple short-chain primary amines (SCPAs) that have a wide range of applications in chemical industries. Using direct precursors of 15 target SCPAs determined by the above strategy, Streptomyces viridifaciens vlmD encoding valine decarboxylase is examined as a proof-of-concept promiscuous enzyme both in vitro and in vivo for generating SCPAs from their precursors. Escherichia coli expressing the heterologous vlmD produces 10 SCPAs by feeding their direct precursors. Furthermore, metabolically engineered E. coli strains are developed to produce representative SCPAs from glucose, including the one producing 10.67 g L-1 of iso-butylamine by fed-batch culture. This study presents the strategy of systematically designing biosynthetic pathways for the production of a group of related chemicals as demonstrated by multiple SCPAs as examples.
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Affiliation(s)
- Dong In Kim
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering, KAIST Institute for BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, Daejeon, 34141, Republic of Korea
| | - Tong Un Chae
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering, KAIST Institute for BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, Daejeon, 34141, Republic of Korea
| | - Hyun Uk Kim
- Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, Daejeon, 34141, Republic of Korea
- Systems Biology and Medicine Laboratory, Department of Chemical and Biomolecular Engineering, KAIST, Daejeon, 34141, Republic of Korea
- KAIST Institute for Artificial Intelligence, BioProcess Engineering Research Center and BioInformatics Research Center, KAIST, Daejeon, 34141, Republic of Korea
| | - Woo Dae Jang
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering, KAIST Institute for BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, Daejeon, 34141, Republic of Korea
| | - Sang Yup Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering, KAIST Institute for BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
- Systems Metabolic Engineering and Systems Healthcare Cross-Generation Collaborative Laboratory, KAIST, Daejeon, 34141, Republic of Korea.
- KAIST Institute for Artificial Intelligence, BioProcess Engineering Research Center and BioInformatics Research Center, KAIST, Daejeon, 34141, Republic of Korea.
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176
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Adegboye MF, Ojuederie OB, Talia PM, Babalola OO. Bioprospecting of microbial strains for biofuel production: metabolic engineering, applications, and challenges. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:5. [PMID: 33407786 PMCID: PMC7788794 DOI: 10.1186/s13068-020-01853-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 12/09/2020] [Indexed: 05/17/2023]
Abstract
The issues of global warming, coupled with fossil fuel depletion, have undoubtedly led to renewed interest in other sources of commercial fuels. The search for renewable fuels has motivated research into the biological degradation of lignocellulosic biomass feedstock to produce biofuels such as bioethanol, biodiesel, and biohydrogen. The model strain for biofuel production needs the capability to utilize a high amount of substrate, transportation of sugar through fast and deregulated pathways, ability to tolerate inhibitory compounds and end products, and increased metabolic fluxes to produce an improved fermentation product. Engineering microbes might be a great approach to produce biofuel from lignocellulosic biomass by exploiting metabolic pathways economically. Metabolic engineering is an advanced technology for the construction of highly effective microbial cell factories and a key component for the next-generation bioeconomy. It has been extensively used to redirect the biosynthetic pathway to produce desired products in several native or engineered hosts. A wide range of novel compounds has been manufactured through engineering metabolic pathways or endogenous metabolism optimizations by metabolic engineers. This review is focused on the potential utilization of engineered strains to produce biofuel and gives prospects for improvement in metabolic engineering for new strain development using advanced technologies.
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Affiliation(s)
- Mobolaji Felicia Adegboye
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, Private Bag X2046, 2735, South Africa
| | - Omena Bernard Ojuederie
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, Private Bag X2046, 2735, South Africa
- Department of Biological Sciences, Faculty of Science, Kings University, Ode-Omu, PMB 555, Osun State, Nigeria
| | - Paola M Talia
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA CICVyA, CNIA, INTA Castelar, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, 1686) Hurlingham, Provincia de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas Y Tecnológicas (CONICET), Buenos Aires, Provincia de Buenos Aires, Argentina
| | - Olubukola Oluranti Babalola
- Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, Private Bag X2046, 2735, South Africa.
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177
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Acedos MG, de la Torre I, Santos VE, García-Ochoa F, García JL, Galán B. Modulating redox metabolism to improve isobutanol production in Shimwellia blattae. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:8. [PMID: 33407735 PMCID: PMC7789792 DOI: 10.1186/s13068-020-01862-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/17/2020] [Indexed: 05/04/2023]
Abstract
BACKGROUND Isobutanol is a candidate to replace gasoline from fossil resources. This higher alcohol can be produced from sugars using genetically modified microorganisms. Shimwellia blattae (p424IbPSO) is a robust strain resistant to high concentration of isobutanol that can achieve a high production rate of this alcohol. Nevertheless, this strain, like most strains developed for isobutanol production, has some limitations in its metabolic pathway. Isobutanol production under anaerobic conditions leads to a depletion of NADPH, which is necessary for two enzymes in the metabolic pathway. In this work, two independent approaches have been studied to mitigate the co-substrates imbalance: (i) using a NADH-dependent alcohol dehydrogenase to reduce the NADPH dependence of the pathway and (ii) using a transhydrogenase to increase NADPH level. RESULTS The addition of the NADH-dependent alcohol dehydrogenase from Lactococcus lactis (AdhA) to S. blattae (p424IbPSO) resulted in a 19.3% higher isobutanol production. The recombinant strain S. blattae (p424IbPSO, pIZpntAB) harboring the PntAB transhydrogenase produced 39.0% more isobutanol than the original strain, reaching 5.98 g L-1 of isobutanol. In both strains, we observed a significant decrease in the yields of by-products such as lactic acid or ethanol. CONCLUSIONS The isobutanol biosynthesis pathway in S. blattae (p424IbPSO) uses the endogenous NADPH-dependent alcohol dehydrogenase YqhD to complete the pathway. The addition of NADH-dependent AdhA leads to a reduction in the consumption of NADPH that is a bottleneck of the pathway. The higher consumption of NADH by AdhA reduces the availability of NADH required for the transformation of pyruvate into lactic acid and ethanol. On the other hand, the expression of PntAB from E. coli increases the availability of NADPH for IlvC and YqhD and at the same time reduces the availability of NADH and thus, the production of lactic acid and ethanol. In this work it is shown how the expression of AdhA and PntAB enzymes in Shimwellia blattae increases yield from 11.9% to 14.4% and 16.4%, respectively.
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Affiliation(s)
- Miguel G Acedos
- Chemical and Materials Engineering Department, Chemical Sciences School, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Isabel de la Torre
- Chemical and Materials Engineering Department, Chemical Sciences School, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Victoria E Santos
- Chemical and Materials Engineering Department, Chemical Sciences School, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Félix García-Ochoa
- Chemical and Materials Engineering Department, Chemical Sciences School, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - José L García
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas, CSIC, 28040, Madrid, Spain
| | - Beatriz Galán
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas, CSIC, 28040, Madrid, Spain.
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178
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Fang Y, Zhang S, Wang J, Yin L, Zhang H, Wang Z, Song J, Hu X, Wang X. Metabolic Detoxification of 2-Oxobutyrate by Remodeling Escherichia coli Acetate Bypass. Metabolites 2021; 11:metabo11010030. [PMID: 33406667 PMCID: PMC7824062 DOI: 10.3390/metabo11010030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 12/03/2022] Open
Abstract
2-Oxobutyrate (2-OBA), as a toxic metabolic intermediate, generally arrests the cell growth of most microorganisms and blocks the biosynthesis of target metabolites. In this study, we demonstrated that using the acetate bypass to replace the pyruvate dehydrogenase complex (PDHc) in Escherichia coli could recharge the intracellular acetyl-CoA pool to alleviate the metabolic toxicity of 2-OBA. Furthermore, based on the crystal structure of pyruvate oxidase (PoxB), two candidate residues in the substrate-binding pocket of PoxB were predicted by computational simulation. Site-directed saturation mutagenesis was performed to attenuate 2-OBA-binding affinity, and one of the variants, PoxBF112W, exhibited a 20-fold activity ratio of pyruvate/2-OBA in substrate selectivity. PoxBF112W was employed to remodel the acetate bypass in E. coli, resulting in l-threonine (a precursor of 2-OBA) biosynthesis with minimal inhibition from 2-OBA. After metabolic detoxification of 2-OBA, the supplies of intracellular acetyl-CoA and NADPH (nicotinamide adenine dinucleotide phosphate) used for l-threonine biosynthesis were restored. Therefore, 2-OBA is the substitute for pyruvate to engage in enzymatic reactions and disturbs pyruvate metabolism. Our study makes a straightforward explanation of the 2-OBA toxicity mechanism and gives an effective approach for its metabolic detoxification.
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Affiliation(s)
- Yu Fang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Shuyan Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Jianli Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Lianghong Yin
- Zhejiang Provincial Key Laboratory of Resources Protection and Innovation of Traditional Chinese Medicine, Zhejiang A&F University, Hangzhou 311300, China;
| | - Hailing Zhang
- Department of Biological Engineering, College of Life Science, Yantai University, Yantai 264005, China;
| | - Zhen Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Jie Song
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
- Correspondence: ; Tel./Fax: +86-510-85329239
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179
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Carruthers DN, Saleski TE, Scholz SA, Lin XN. Random Chromosomal Integration and Screening Yields E. coli K-12 Derivatives Capable of Efficient Sucrose Utilization. ACS Synth Biol 2020; 9:3311-3321. [PMID: 33236893 DOI: 10.1021/acssynbio.0c00392] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Chromosomal expression of heterologous genes offers stability and maintenance advantages over episomal expression, yet remains difficult to optimize through site-specific integration. The challenge has in large part been due to the variability of chromosomal gene expression, which has only recently been shown to be affected by multiple factors, including the local genomic context. In this work we utilize Tn5 transposase to randomly integrate a three-gene csc operon encoding nonphosphotransferase sucrose catabolism into the E. coli K-12 chromosome. Isolates from the transposon library yielded a range of growth rates on sucrose as the sole carbon source, including some that were comparable to that of E. coli K-12 on glucose (μmax = 0.70 ± 0.03 h-1). Narrowness of the growth rate distributions and faster growth compared to plasmids indicate that efficient csc expression is attainable. Furthermore, enhanced growth rate upon transduction into strains that underwent adaptive laboratory evolution indicate that sucrose catabolism is not limiting to cellular growth. We also show that transduction of a csc fast-growth locus into an isobutanol production strain yields high titer (7.56 ± 0.25 g/L) on sucrose as the sole carbon source. Our results demonstrate that random integration is an effective strategy for optimizing heterologous expression within the context of cellular metabolism for both fast growth and biochemical production phenotypes.
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Affiliation(s)
- David N. Carruthers
- Chemical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Tatyana E. Saleski
- Chemical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Scott A. Scholz
- Department of Biochemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xiaoxia Nina Lin
- Chemical Engineering Department, University of Michigan, Ann Arbor, Michigan 48109, United States
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180
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Zhang L, Liu Z, Deng Q, Sang Y, Dong K, Ren J, Qu X. Nature‐Inspired Construction of MOF@COF Nanozyme with Active Sites in Tailored Microenvironment and Pseudopodia‐Like Surface for Enhanced Bacterial Inhibition. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202012487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Lu Zhang
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Chinese Academy of Sciences Beijing 100039 China
| | - Zhengwei Liu
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Chinese Academy of Sciences Beijing 100039 China
| | - Qingqing Deng
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Science and Technology of China Hefei Anhui 230026 China
| | - Yanjuan Sang
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Science and Technology of China Hefei Anhui 230026 China
| | - Kai Dong
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
| | - Jinsong Ren
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Chinese Academy of Sciences Beijing 100039 China
- University of Science and Technology of China Hefei Anhui 230026 China
| | - Xiaogang Qu
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Chinese Academy of Sciences Beijing 100039 China
- University of Science and Technology of China Hefei Anhui 230026 China
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181
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Zhang L, Liu Z, Deng Q, Sang Y, Dong K, Ren J, Qu X. Nature‐Inspired Construction of MOF@COF Nanozyme with Active Sites in Tailored Microenvironment and Pseudopodia‐Like Surface for Enhanced Bacterial Inhibition. Angew Chem Int Ed Engl 2020; 60:3469-3474. [DOI: 10.1002/anie.202012487] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Lu Zhang
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Chinese Academy of Sciences Beijing 100039 China
| | - Zhengwei Liu
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Chinese Academy of Sciences Beijing 100039 China
| | - Qingqing Deng
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Science and Technology of China Hefei Anhui 230026 China
| | - Yanjuan Sang
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Science and Technology of China Hefei Anhui 230026 China
| | - Kai Dong
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
| | - Jinsong Ren
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Chinese Academy of Sciences Beijing 100039 China
- University of Science and Technology of China Hefei Anhui 230026 China
| | - Xiaogang Qu
- State Key Laboratory of Rare Earth Resource Utilization and Laboratory of Chemical Biology Changchun Institute of Applied Chemistry Chinese Academy of Science Changchun Jilin 130022 P. R. China
- University of Chinese Academy of Sciences Beijing 100039 China
- University of Science and Technology of China Hefei Anhui 230026 China
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182
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Choi KR, Jiao S, Lee SY. Metabolic engineering strategies toward production of biofuels. Curr Opin Chem Biol 2020; 59:1-14. [DOI: 10.1016/j.cbpa.2020.02.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 10/24/2022]
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183
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Pfeifer K, Ergal İ, Koller M, Basen M, Schuster B, Rittmann SKMR. Archaea Biotechnology. Biotechnol Adv 2020; 47:107668. [PMID: 33271237 DOI: 10.1016/j.biotechadv.2020.107668] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022]
Abstract
Archaea are a domain of prokaryotic organisms with intriguing physiological characteristics and ecological importance. In Microbial Biotechnology, archaea are historically overshadowed by bacteria and eukaryotes in terms of public awareness, industrial application, and scientific studies, although their biochemical and physiological properties show a vast potential for a wide range of biotechnological applications. Today, the majority of microbial cell factories utilized for the production of value-added and high value compounds on an industrial scale are bacterial, fungal or algae based. Nevertheless, archaea are becoming ever more relevant for biotechnology as their cultivation and genetic systems improve. Some of the main advantages of archaeal cell factories are the ability to cultivate many of these often extremophilic organisms under non-sterile conditions, and to utilize inexpensive feedstocks often toxic to other microorganisms, thus drastically reducing cultivation costs. Currently, the only commercially available products of archaeal cell factories are bacterioruberin, squalene, bacteriorhodopsin and diether-/tetraether-lipids, all of which are produced utilizing halophiles. Other archaeal products, such as carotenoids and biohydrogen, as well as polyhydroxyalkanoates and methane are in early to advanced development stages, respectively. The aim of this review is to provide an overview of the current state of Archaea Biotechnology by describing the actual state of research and development as well as the industrial utilization of archaeal cell factories, their role and their potential in the future of sustainable bioprocessing, and to illustrate their physiological and biotechnological potential.
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Affiliation(s)
- Kevin Pfeifer
- Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, Universität Wien, Wien, Austria; Institute of Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Wien, Austria
| | - İpek Ergal
- Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, Universität Wien, Wien, Austria
| | - Martin Koller
- Office of Research Management and Service, c/o Institute of Chemistry, University of Graz, Austria
| | - Mirko Basen
- Microbial Physiology Group, Division of Microbiology, Institute of Biological Sciences, University of Rostock, Rostock, Germany
| | - Bernhard Schuster
- Institute of Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Wien, Austria
| | - Simon K-M R Rittmann
- Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, Universität Wien, Wien, Austria.
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184
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Solid/gas biocatalysis for aroma production: An alternative process of white biotechnology. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107767] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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185
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Biorefinery: The Production of Isobutanol from Biomass Feedstocks. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10228222] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Environmental issues have prompted the vigorous development of biorefineries that use agricultural waste and other biomass feedstock as raw materials. However, most current biorefinery products are cellulosic ethanol. There is an urgent need for biorefineries to expand into new bioproducts. Isobutanol is an important bulk chemical with properties that are close to gasoline, making it a very promising biofuel. The use of microorganisms to produce isobutanol has been extensively studied, but there is still a considerable gap to achieving the industrial production of isobutanol from biomass. This review summarizes current metabolic engineering strategies that have been applied to biomass isobutanol production and recent advances in the production of isobutanol from different biomass feedstocks.
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186
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Glutaric acid production by systems metabolic engineering of an l-lysine-overproducing Corynebacterium glutamicum. Proc Natl Acad Sci U S A 2020; 117:30328-30334. [PMID: 33199604 DOI: 10.1073/pnas.2017483117] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
There is increasing industrial demand for five-carbon platform chemicals, particularly glutaric acid, a widely used building block chemical for the synthesis of polyesters and polyamides. Here we report the development of an efficient glutaric acid microbial producer by systems metabolic engineering of an l-lysine-overproducing Corynebacterium glutamicum BE strain. Based on our previous study, an optimal synthetic metabolic pathway comprising Pseudomonas putida l-lysine monooxygenase (davB) and 5-aminovaleramide amidohydrolase (davA) genes and C. glutamicum 4-aminobutyrate aminotransferase (gabT) and succinate-semialdehyde dehydrogenase (gabD) genes, was introduced into the C. glutamicum BE strain. Through system-wide analyses including genome-scale metabolic simulation, comparative transcriptome analysis, and flux response analysis, 11 target genes to be manipulated were identified and expressed at desired levels to increase the supply of direct precursor l-lysine and reduce precursor loss. A glutaric acid exporter encoded by ynfM was discovered and overexpressed to further enhance glutaric acid production. Fermentation conditions, including oxygen transfer rate, batch-phase glucose level, and nutrient feeding strategy, were optimized for the efficient production of glutaric acid. Fed-batch culture of the final engineered strain produced 105.3 g/L of glutaric acid in 69 h without any byproduct. The strategies of metabolic engineering and fermentation optimization described here will be useful for developing engineered microorganisms for the high-level bio-based production of other chemicals of interest to industry.
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187
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Wang Y, Zhang Z, Lu X, Zong H, Zhuge B. Genetic engineering of an industrial yeast Candida glycerinogenes for efficient production of 2-phenylethanol. Appl Microbiol Biotechnol 2020; 104:10481-10491. [PMID: 33180170 DOI: 10.1007/s00253-020-10991-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/23/2020] [Accepted: 10/31/2020] [Indexed: 10/23/2022]
Abstract
Microbial cell factories offer an economic approach for synthesizing "natural'" aromatic flavor compounds. During their fermentation process, the inefficient synthesis pathway and product cytotoxicity are the major barriers to the high-level production. This study combined metabolic engineering and tolerance engineering strategies to maximize the valuable rose-smell 2-phenylethanol (2-PE) production in Candida glycerinogenes, a GRAS diploid industrial yeast. Firstly, 2-PE metabolic networks involved in Ehrlich pathway were stepwise rewired using metabolic engineering, including the following: (1) overexpressing L-phenylalanine permease Aap9 enhanced precursor uptake; (2) overexpressing enzymes (aminotransferase Aro9 and decarboxylase Aro10) of Ehrlich pathway increased catalytic efficiency; and (3) disrupting the formation of by-product phenylacetate catalyzed by Ald2 and Ald3 maximized the metabolic flux toward 2-PE. Then, tolerance engineering was applied by overexpression of a stress-inducible gene SLC1 in the metabolically engineered strain to further enhance 2-PE production. Combining these two approaches finally resulted in 5.0 g/L 2-PE in shake flasks, with productivity reaching 0.21 g/L/h, which were increased by 38.9% and 177% compared with those of the non-engineered strain, respectively. The 2-PE yield of this engineered strain was 0.71 g/g L-phenylalanine, corresponding to 95.9% of theoretical yield. This study provides a reference to efficiently engineering of microbial cell factories for other valuable aromatic compounds. KEY POINTS: • Metabolic engineering improved 2-PE biosynthesis. • Tolerance engineering alleviated product inhibition, contributing to 2-PE production. • The best strain produced 5.0 g/L 2-PE with 0.959 mol/mol yield and high productivity.
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Affiliation(s)
- Yuqin Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zhongyuan Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xinyao Lu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China. .,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China. .,Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China.
| | - Hong Zong
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Bin Zhuge
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China. .,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China. .,Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China.
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188
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Wang J, Huang C, Guo K, Ma L, Meng X, Wang N, Huo YX. Converting Escherichia coli MG1655 into a chemical overproducer through inactivating defense system against exogenous DNA. Synth Syst Biotechnol 2020; 5:333-342. [PMID: 33102829 PMCID: PMC7568196 DOI: 10.1016/j.synbio.2020.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 09/30/2020] [Accepted: 10/09/2020] [Indexed: 01/05/2023] Open
Abstract
Escherichia coli strain K-12 MG1655 has been proposed as an appropriate host strain for industrial production. However, the direct application of this strain suffers from the transformation inefficiency and plasmid instability. Herein, we conducted genetic modifications at a serial of loci of MG1655 genome, generating a robust and universal host strain JW128 with higher transformation efficiency and plasmid stability that can be used to efficiently produce desired chemicals after introducing the corresponding synthetic pathways. Using JW128 as the host, the titer of isobutanol reached 5.76 g/L in shake-flask fermentation, and the titer of lycopene reached 1.91 g/L in test-tube fermentation, 40-fold and 5-fold higher than that of original MG1655, respectively. These results demonstrated JW128 is a promising chassis for high-level production of value-added chemicals.
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Affiliation(s)
- Jingge Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Sciences, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, China
- SIP-UCLA Institute for Technology Advancement, 10 Yueliangwan Road, Suzhou Industrial Park, Suzhou, 215123, China
| | - Chaoyong Huang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Sciences, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, China
| | - Kai Guo
- Biology Institute, Shandong Province Key Laboratory for Biosensors, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250103, China
| | - Lianjie Ma
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Sciences, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, China
| | - Xiangyu Meng
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Sciences, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, China
| | - Ning Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Sciences, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, China
- Corresponding author.
| | - Yi-Xin Huo
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Sciences, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, China
- SIP-UCLA Institute for Technology Advancement, 10 Yueliangwan Road, Suzhou Industrial Park, Suzhou, 215123, China
- Corresponding author. Key Laboratory of Molecular Medicine and Biotherapy, School of Life Sciences, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, China.
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Abstract
Biocatalysts provide a number of advantages such as high selectivity, the ability to operate under mild reaction conditions and availability from renewable resources that are of interest in the development of bioreactors for applications in the pharmaceutical and other sectors. The use of oxidoreductases in biocatalytic reactors is primarily focused on the use of NAD(P)-dependent enzymes, with the recycling of the cofactor occurring via an additional enzymatic system. The use of electrochemically based systems has been limited. This review focuses on the development of electrochemically based biocatalytic reactors. The mechanisms of mediated and direct electron transfer together with methods of immobilising enzymes are briefly reviewed. The use of electrochemically based batch and flow reactors is reviewed in detail with a focus on recent developments in the use of high surface area electrodes, enzyme engineering and enzyme cascades. A future perspective on electrochemically based bioreactors is presented.
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190
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Novak K, Baar J, Freitag P, Pflügl S. Metabolic engineering of Escherichia coli W for isobutanol production on chemically defined medium and cheese whey as alternative raw material. J Ind Microbiol Biotechnol 2020; 47:1117-1132. [PMID: 33068182 PMCID: PMC7728641 DOI: 10.1007/s10295-020-02319-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 10/03/2020] [Indexed: 11/28/2022]
Abstract
The aim of this study was to establish isobutanol production on chemically defined medium in Escherichia coli. By individually expressing each gene of the pathway, we constructed a plasmid library for isobutanol production. Strain screening on chemically defined medium showed successful production in the robust E. coli W strain, and expression vector IB 4 was selected as the most promising construct due to its high isobutanol yields and efficient substrate uptake. The investigation of different aeration strategies in combination with strain improvement and the implementation of a pulsed fed-batch were key for the development of an efficient production process. E. coli W ΔldhA ΔadhE Δpta ΔfrdA enabled aerobic isobutanol production at 38% of the theoretical maximum. Use of cheese whey as raw material resulted in longer process stability, which allowed production of 20 g l−1 isobutanol. Demonstrating isobutanol production on both chemically defined medium and a residual waste stream, this study provides valuable information for further development of industrially relevant isobutanol production processes.
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Affiliation(s)
- Katharina Novak
- Institute for Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060, Vienna, Austria
| | - Juliane Baar
- Institute for Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060, Vienna, Austria
| | - Philipp Freitag
- Institute for Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060, Vienna, Austria
| | - Stefan Pflügl
- Institute for Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Gumpendorfer Straße 1a, 1060, Vienna, Austria.
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191
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Xu Y, Zhou D, Luo R, Yang X, Wang B, Xiong X, Shen W, Wang D, Wang Q. Metabolic engineering of Escherichia coli for polyamides monomer δ-valerolactam production from feedstock lysine. Appl Microbiol Biotechnol 2020; 104:9965-9977. [PMID: 33064187 DOI: 10.1007/s00253-020-10939-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 09/06/2020] [Accepted: 10/01/2020] [Indexed: 01/03/2023]
Abstract
Nylon 5 and nylon 6,5 are recently explored as new commercial polyamides, of which the monomer includes δ-valerolactam. In this study, a novel catalytic activity of lysine 2-monooxygenase (DavB) was explored to produce δ-valerolactam from L-pipecolic acid (L-PA), functioning as oxidative decarboxylase on a cyclic compound. Recombinant Escherichia coli BS01 strain expressing DavB from Pseudomonas putida could synthesize δ-valerolactam from L-pipecolic acid with a concentration of 90.3 mg/L. Through the co-expression of recombinant apoptosis-inducing protein (rAIP) from Scomber japonicus, glucose dehydrogenase (GDH) from Bacillus subtilis, Δ1-piperideine-2-carboxylae reductase (DpkA) from P. putida and lysine permease (LysP) from E. coli with DavB, δ-valerolactam was produced with the highest concentration of 242 mg/L. α-Dioxygenases (αDox) from Oryza sativa could act as a similar catalyst on L-pipecolic acid. A novel δ-valerolactam synthesis pathway was constructed entirely via microbial conversion from feedstock lysine in this study. Our system has great potential in the development of a bio-nylon production process. KEY POINTS: • DavB performs as an oxidative decarboxylase on L-PA with substrate promiscuity. • Strain with rAIP, GDH, DpkA, LysP, and DavB coexpression could produce δ-valerolactam. • This is the first time to obtain valerolactam entirely via biosynthesis from lysine.
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Affiliation(s)
- Yanqin Xu
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, Chongqing University, Chongqing, 401331, People's Republic of China
| | - Dan Zhou
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, Chongqing University, Chongqing, 401331, People's Republic of China
| | - Ruoshi Luo
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, Chongqing University, Chongqing, 401331, People's Republic of China
| | - Xizhi Yang
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, Chongqing University, Chongqing, 401331, People's Republic of China
| | - Baosheng Wang
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, Chongqing University, Chongqing, 401331, People's Republic of China
| | - Xiaochao Xiong
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, 99164-6120, USA
| | - Weifeng Shen
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, Chongqing University, Chongqing, 401331, People's Republic of China
| | - Dan Wang
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Key Laboratory of Chemical Process for Clean Energy and Resource Utilization, Chongqing University, Chongqing, 401331, People's Republic of China.
| | - Qinhong Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
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192
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Thompson MG, Incha MR, Pearson AN, Schmidt M, Sharpless WA, Eiben CB, Cruz-Morales P, Blake-Hedges JM, Liu Y, Adams CA, Haushalter RW, Krishna RN, Lichtner P, Blank LM, Mukhopadhyay A, Deutschbauer AM, Shih PM, Keasling JD. Fatty Acid and Alcohol Metabolism in Pseudomonas putida: Functional Analysis Using Random Barcode Transposon Sequencing. Appl Environ Microbiol 2020; 86:e01665-20. [PMID: 32826213 PMCID: PMC7580535 DOI: 10.1128/aem.01665-20] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022] Open
Abstract
With its ability to catabolize a wide variety of carbon sources and a growing engineering toolkit, Pseudomonas putida KT2440 is emerging as an important chassis organism for metabolic engineering. Despite advances in our understanding of the organism, many gaps remain in our knowledge of the genetic basis of its metabolic capabilities. The gaps are particularly noticeable in our understanding of both fatty acid and alcohol catabolism, where many paralogs putatively coding for similar enzymes coexist, making biochemical assignment via sequence homology difficult. To rapidly assign function to the enzymes responsible for these metabolisms, we leveraged random barcode transposon sequencing (RB-Tn-Seq). Global fitness analyses of transposon libraries grown on 13 fatty acids and 10 alcohols produced strong phenotypes for hundreds of genes. Fitness data from mutant pools grown on fatty acids of varying chain lengths indicated specific enzyme substrate preferences and enabled us to hypothesize that DUF1302/DUF1329 family proteins potentially function as esterases. From the data, we also postulate catabolic routes for the two biogasoline molecules isoprenol and isopentanol, which are catabolized via leucine metabolism after initial oxidation and activation with coenzyme A (CoA). Because fatty acids and alcohols may serve as both feedstocks and final products of metabolic-engineering efforts, the fitness data presented here will help guide future genomic modifications toward higher titers, rates, and yields.IMPORTANCE To engineer novel metabolic pathways into P. putida, a comprehensive understanding of the genetic basis of its versatile metabolism is essential. Here, we provide functional evidence for the putative roles of hundreds of genes involved in the fatty acid and alcohol metabolism of the bacterium. These data provide a framework facilitating precise genetic changes to prevent product degradation and to channel the flux of specific pathway intermediates as desired.
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Affiliation(s)
- Mitchell G Thompson
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Plant Biology, University of California, Davis, California, USA
| | - Matthew R Incha
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| | - Allison N Pearson
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| | - Matthias Schmidt
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - William A Sharpless
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Christopher B Eiben
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Joint Program in Bioengineering, University of California, Berkeley, California, USA
| | - Pablo Cruz-Morales
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Centro de Biotecnología FEMSA, Instituto Tecnológico y de Estudios Superiores de Monterrey, Monterrey, México
| | - Jacquelyn M Blake-Hedges
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Yuzhong Liu
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Catharine A Adams
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Robert W Haushalter
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Rohith N Krishna
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Patrick Lichtner
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Lars M Blank
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Aindrila Mukhopadhyay
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Adam M Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Patrick M Shih
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Plant Biology, University of California, Davis, California, USA
- Environmental and Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Jay D Keasling
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Joint Program in Bioengineering, University of California, Berkeley, California, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, USA
- Institute for Quantitative Biosciences, University of California, Berkeley, California, USA
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
- Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institutes for Advanced Technologies, Shenzhen, China
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193
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Wohlgemuth R. Biocatalysis - Key enabling tools from biocatalytic one-step and multi-step reactions to biocatalytic total synthesis. N Biotechnol 2020; 60:113-123. [PMID: 33045418 DOI: 10.1016/j.nbt.2020.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 07/07/2020] [Accepted: 08/31/2020] [Indexed: 12/20/2022]
Abstract
In the area of human-made innovations to improve the quality of life, biocatalysis has already had a great impact and contributed enormously to a growing number of catalytic transformations aimed at the detection and analysis of compounds, the bioconversion of starting materials and the preparation of target compounds at any scale, from laboratory small scale to industrial large scale. The key enabling tools which have been developed in biocatalysis over the last decades also provide great opportunities for further development and numerous applications in various sectors of the global bioeconomy. Systems biocatalysis is a modular, bottom-up approach to designing the architecture of enzyme-catalyzed reaction steps in a synthetic route from starting materials to target molecules. The integration of biocatalysis and sustainable chemistry in vitro aims at ideal conversions with high molecular economy and their intensification. Retrosynthetic analysis in the chemical and biological domain has been a valuable tool for target-oriented synthesis while, on the other hand, diversity-oriented synthesis builds on forward-looking analysis. Bioinformatic tools for rapid identification of the required enzyme functions, efficient enzyme production systems, as well as generalized bioprocess design tools, are important for rapid prototyping of the biocatalytic reactions. The tools for enzyme engineering and the reaction engineering of each enzyme-catalyzed one-step reaction are also valuable for coupling reactions. The tools to overcome interaction issues with other components or enzymes are of great interest in designing multi-step reactions as well as in biocatalytic total synthesis.
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Affiliation(s)
- Roland Wohlgemuth
- Institute of Molecular and Industrial Biotechnology, Lodz University of Technology, Lodz, Poland; Swiss Coordination Committee on Biotechnology (SKB), Nordstrasse 15, 8021 Zürich, Switzerland.
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194
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Yang Y, Zhang Z, Lu X, Gu J, Wang Y, Yao Y, Liao X, Shi J, Lye G, Baganz F, Hao J. Production of 2,3-dihydroxyisovalerate by Enterobacter cloacae. Enzyme Microb Technol 2020; 140:109650. [PMID: 32912674 DOI: 10.1016/j.enzmictec.2020.109650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 08/05/2020] [Accepted: 08/10/2020] [Indexed: 01/09/2023]
Abstract
2,3-Dihydroxyisovalerate is an intermediate of the valine synthesis pathway. However, neither natural microorganisms nor valine producing engineered strains have been reported yet to produce this chemical. Based on the 2,3-butanediol synthesis pathway, a biological route of 2,3-dihydroxyisovalerate production was developed using a budA and ilvD disrupted Klebsiella pneumoniae strain in our previous research. We hypothesised, that other 2,3-butanediol producing bacteria could be used for 2,3-dihydroxyisovalerate production. Here a budA disrupted Enterobacter cloacae was constructed, and this strain exhibited a high 2,3-dihydroxyisovalerate producing ability. Disruption of ilvD in E. cloacae ΔbudA further increased 2,3-dihydroxyisovalerate level. The disruption of budA, encoding an acetolactate decarboxylase, resulted in the acetolactate synthesized in the 2,3-butanediol synthesis pathway to flow into the valine synthesis pathway. The additional disruption of ilvD, encoding a dihydroxy acid dehydratase, prevented the 2,3-dihydroxyisovalerate to be further metabolized in the valine synthesis pathway. Thus, the disruption of both budA and ilvD in 2,3-butanediol producing strains might be an universal strategy for 2,3-dihydroxyisovalerate accumulation. After optimization of the medium components and culture parameters 31.2 g/L of 2,3-dihydroxyisovalerate was obtained with a productivity of 0.41 g/L h and a substrate conversion ratio of 0.56 mol/mol glucose in a fed-batch fermentation. This approach provides an economic way for 2,3-dihydroxyisovalerate production.
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Affiliation(s)
- Yang Yang
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, PR China; School of Life Science, Shanghai University, Shanghai 200444, PR China
| | - Zhongxi Zhang
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, PR China; School of Life Science, Shanghai University, Shanghai 200444, PR China
| | - Xiyang Lu
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, PR China
| | - Jinjie Gu
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Yike Wang
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, PR China; School of Life Science, Shanghai University, Shanghai 200444, PR China
| | - Yao Yao
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Xianyan Liao
- School of Life Science, Shanghai University, Shanghai 200444, PR China
| | - Jiping Shi
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, PR China; School of Life Science and Technology, ShanghaiTech University, PR China
| | - Gary Lye
- Department of Biochemical Engineering, University College London, Gordon Street, London WC1H 0AH, UK
| | - Frank Baganz
- Department of Biochemical Engineering, University College London, Gordon Street, London WC1H 0AH, UK.
| | - Jian Hao
- Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai, 201210, PR China; Department of Biochemical Engineering, University College London, Gordon Street, London WC1H 0AH, UK.
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195
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Roulet J, Galván V, Lara J, Salazar MO, Cholich V, Gramajo H, Arabolaza A. Modification of PapA5 acyltransferase substrate selectivity for optimization of short-chain alcohol-derived multimethyl-branched ester production in Escherichia coli. Appl Microbiol Biotechnol 2020; 104:8705-8718. [PMID: 32910267 DOI: 10.1007/s00253-020-10872-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/10/2020] [Accepted: 08/31/2020] [Indexed: 11/30/2022]
Abstract
Plant waxes are interesting substitutes of fossil-derived compounds; however, their limited sources and narrow structural diversity prompted the development of microbial platforms to produce esters with novel chemical structures and properties. One successful strategy was the heterologous expression of the mycocerosic polyketide synthase-based biosynthetic pathway (MAS-PKS, PapA5 and FadD28 enzymes) from Mycobacterium tuberculosis in Escherichia coli. This recombinant strain has the ability to produce a broad spectrum of multimethyl-branched long-chain esters (MBE) with novel chemical structures and high oxidation stability. However, one limitation of this microbial platform was the low yields obtained for MBE derived of short-chain alcohols. In an attempt to improve the titers of the short-chain alcohol-derived MBE, we focused on the PapA5 acyltransferase-enzyme that catalyzes the ester formation reaction. Specific amino acid residues located in the two-substrate recognition channels of this enzyme were identified, rationally mutated, and the corresponding mutants characterized both in vivo and in vitro. The phenylalanine located at 331 position in PapA5 (F331) was found to be a key residue that when substituted by other bulky and aromatic or bulky and polar amino acid residues (F331W, F331Y or F331H), gave rise to PapA5 mutants with improved bioconversion efficiency; showing in average, 2.5 higher yields of short-chain alcohol-derived MBE compared with the wild-type enzyme. Furthermore, two alternative pathways for synthetizing ethanol were engineered into the MBE producer microorganism, allowing de novo production of ethanol-derived MBE at levels comparable with those obtained by the external supply of this alcohol. KEY POINTS: • Mutation in channel 2 changes PapA5 acyltransferase bioconversion efficiency. • Improved production of short-chain alcohol derived multimethyl-branched esters. • Establishing ethanologenic pathways for de novo production of ethanol derived MBE. • Characterization of a novel phenylethanol-derived MBE.
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Affiliation(s)
- Julia Roulet
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Virginia Galván
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Julia Lara
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Mario O Salazar
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Valeria Cholich
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Hugo Gramajo
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina. .,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina.
| | - Ana Arabolaza
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina. .,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina.
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196
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Optogenetic control of the lac operon for bacterial chemical and protein production. Nat Chem Biol 2020; 17:71-79. [PMID: 32895498 DOI: 10.1038/s41589-020-0639-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 07/31/2020] [Indexed: 12/24/2022]
Abstract
Control of the lac operon with isopropyl β-D-1-thiogalactopyranoside (IPTG) has been used to regulate gene expression in Escherichia coli for countless applications, including metabolic engineering and recombinant protein production. However, optogenetics offers unique capabilities, such as easy tunability, reversibility, dynamic induction strength and spatial control, that are difficult to obtain with chemical inducers. We have developed a series of circuits for optogenetic regulation of the lac operon, which we call OptoLAC, to control gene expression from various IPTG-inducible promoters using only blue light. Applying them to metabolic engineering improves mevalonate and isobutanol production by 24% and 27% respectively, compared to IPTG induction, in light-controlled fermentations scalable to at least two-litre bioreactors. Furthermore, OptoLAC circuits enable control of recombinant protein production, reaching yields comparable to IPTG induction but with easier tunability of expression. OptoLAC circuits are potentially useful to confer light control over other cell functions originally designed to be IPTG-inducible.
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197
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198
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Isobutanol production freed from biological limits using synthetic biochemistry. Nat Commun 2020; 11:4292. [PMID: 32855421 PMCID: PMC7453195 DOI: 10.1038/s41467-020-18124-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/07/2020] [Indexed: 11/09/2022] Open
Abstract
Cost competitive conversion of biomass-derived sugars into biofuel will require high yields, high volumetric productivities and high titers. Suitable production parameters are hard to achieve in cell-based systems because of the need to maintain life processes. As a result, next-generation biofuel production in engineered microbes has yet to match the stringent cost targets set by petroleum fuels. Removing the constraints imposed by having to maintain cell viability might facilitate improved production metrics. Here, we report a cell-free system in a bioreactor with continuous product removal that produces isobutanol from glucose at a maximum productivity of 4 g L−1 h−1, a titer of 275 g L−1 and 95% yield over the course of nearly 5 days. These production metrics exceed even the highly developed ethanol fermentation process. Our results suggest that moving beyond cells has the potential to expand what is possible for bio-based chemical production. A cell free or synthetic biochemistry approach offers a way to circumvent the many constraints of living cells. Here, the authors demonstrate, via enzyme and process enhancements, the production of isobutanol with the metrics exceeding highly developed ethanol fermentation.
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199
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Huang C, Guo L, Wang J, Wang N, Huo YX. Efficient long fragment editing technique enables large-scale and scarless bacterial genome engineering. Appl Microbiol Biotechnol 2020; 104:7943-7956. [PMID: 32794018 DOI: 10.1007/s00253-020-10819-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/20/2020] [Accepted: 08/05/2020] [Indexed: 11/24/2022]
Abstract
Bacteria are versatile living systems that enhance our understanding of nature and enable biosynthesis of valuable chemicals. Long fragment editing techniques are of great importance for accelerating bacterial genome engineering to obtain desirable and genetically stable strains. However, the existing genome editing methods cannot meet the needs of engineers. We herein report an efficient long fragment editing method for large-scale and scarless genome engineering in Escherichia coli. The method enabled us to insert DNA fragments up to 12 kb into the genome and to delete DNA fragments up to 186.7 kb from the genome, with positive rates over 95%. We applied this method for E. coli genome simplification, resulting in 12 individual deletion mutants and four cumulative deletion mutants. The simplest genome lost a total of 370.6 kb of DNA sequence containing 364 open reading frames. Additionally, we applied this technique to metabolic engineering and obtained a genetically stable plasmid-independent isobutanol production strain that produced 1.3 g/L isobutanol via shake-flask fermentation. These results suggest that the method is a powerful genome engineering tool, highlighting its potential to be applied in synthetic biology and metabolic engineering. KEY POINTS: • This article reports an efficient genome engineering tool for E. coli. • The tool is advantageous for the manipulations of long DNA fragments. • The tool has been successfully applied for genome simplification. • The tool has been successfully applied for metabolic engineering.
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Affiliation(s)
- Chaoyong Huang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.,SIP-UCLA Institute for Technology Advancement, Suzhou, 215123, China
| | - Liwei Guo
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Jingge Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Ning Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Yi-Xin Huo
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China. .,SIP-UCLA Institute for Technology Advancement, Suzhou, 215123, China.
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Rubinstein GM, Lipscomb GL, Williams-Rhaesa AM, Schut GJ, Kelly RM, Adams MWW. Engineering the cellulolytic extreme thermophile Caldicellulosiruptor bescii to reduce carboxylic acids to alcohols using plant biomass as the energy source. J Ind Microbiol Biotechnol 2020; 47:585-597. [PMID: 32783103 DOI: 10.1007/s10295-020-02299-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/27/2020] [Indexed: 01/13/2023]
Abstract
Caldicellulosiruptor bescii is the most thermophilic cellulolytic organism yet identified (Topt 78 °C). It grows on untreated plant biomass and has an established genetic system thereby making it a promising microbial platform for lignocellulose conversion to bio-products. Here, we investigated the ability of engineered C. bescii to generate alcohols from carboxylic acids. Expression of aldehyde ferredoxin oxidoreductase (aor from Pyrococcus furiosus) and alcohol dehydrogenase (adhA from Thermoanaerobacter sp. X514) enabled C. bescii to generate ethanol from crystalline cellulose and from biomass by reducing the acetate produced by fermentation. Deletion of lactate dehydrogenase in a strain expressing the AOR-Adh pathway increased ethanol production. Engineered strains also converted exogenously supplied organic acids (isobutyrate and n-caproate) to the corresponding alcohol (isobutanol and hexanol) using both crystalline cellulose and switchgrass as sources of reductant for alcohol production. This is the first instance of an acid to alcohol conversion pathway in a cellulolytic microbe.
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Affiliation(s)
- Gabriel M Rubinstein
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Gina L Lipscomb
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | | | - Gerrit J Schut
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Robert M Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA.
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