1
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Liu Y, Chen L, Duan Y, Li R, Yang Z, Liu S, Li G. Recent progress and prospects for chain elongation of transforming biomass waste into medium-chain fatty acids. CHEMOSPHERE 2024; 355:141823. [PMID: 38552798 DOI: 10.1016/j.chemosphere.2024.141823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/18/2024] [Accepted: 03/26/2024] [Indexed: 04/06/2024]
Abstract
Chain elongation technology utilises microorganisms in anaerobic digestion to transform waste biomass into medium-chain fatty acids that have greater economic value. This innovative technology expands upon traditional anaerobic digestion methods, requiring abundant substrates that serve as electron donors and acceptors, and inoculating microorganisms with chain elongation functions. While this process may result in the production of by-products and elicit competitive responses, toxicity suppression of microorganisms by substrates and products remains a significant obstacle to the industrialisation of chain elongation technology. This study provides a comprehensive overview of existing research on widely employed electron donors and their synthetic reactions, competitive reactions, inoculum selection, toxicity inhibition of substrates and products, and increased chain elongation approaches. Additionally, it presents actionable recommendations for future research and development endeavours in this domain, intending to inspire and guide researchers in advancing the frontiers of chain elongation technology.
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Affiliation(s)
- Yuhao Liu
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China.
| | - Long Chen
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Yacong Duan
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Ruihua Li
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Ziyan Yang
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Shuli Liu
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Guoting Li
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
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2
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Liu Y, Duan Y, Chen L, Yang Z, Yang X, Liu S, Song G. Research on the Resource Recovery of Medium-Chain Fatty Acids from Municipal Sludge: Current State and Future Prospects. Microorganisms 2024; 12:680. [PMID: 38674623 PMCID: PMC11051992 DOI: 10.3390/microorganisms12040680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
The production of municipal sludge is steadily increasing in line with the production of sewage. A wealth of organic contaminants, including nutrients and energy, are present in municipal sludge. Anaerobic fermentation can be used to extract useful resources from sludge, producing hydrogen, methane, short-chain fatty acids, and, via further chain elongation, medium-chain fatty acids. By comparing the economic and use values of these retrieved resources, it is concluded that a high-value resource transformation of municipal sludge can be achieved via the production of medium-chain fatty acids using anaerobic fermentation, which is a hotspot for future research. In this study, the selection of the pretreatment method, the method of producing medium-chain fatty acids, the influence of the electron donor, and the technique used to enhance product synthesis in the anaerobic fermentation process are introduced in detail. The study outlines potential future research directions for medium-chain fatty acid production using municipal sludge. These acids could serve as a starting point for investigating other uses for municipal sludge.
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Affiliation(s)
- Yuhao Liu
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450046, China; (Y.D.); (L.C.); (Z.Y.); (X.Y.); (S.L.); (G.S.)
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3
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Tague N, Coriano-Ortiz C, Sheets MB, Dunlop MJ. Light-inducible protein degradation in E. coli with the LOVdeg tag. eLife 2024; 12:RP87303. [PMID: 38270583 PMCID: PMC10945698 DOI: 10.7554/elife.87303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
Molecular tools for optogenetic control allow for spatial and temporal regulation of cell behavior. In particular, light-controlled protein degradation is a valuable mechanism of regulation because it can be highly modular, used in tandem with other control mechanisms, and maintain functionality throughout growth phases. Here, we engineered LOVdeg, a tag that can be appended to a protein of interest for inducible degradation in Escherichia coli using blue light. We demonstrate the modularity of LOVdeg by using it to tag a range of proteins, including the LacI repressor, CRISPRa activator, and the AcrB efflux pump. Additionally, we demonstrate the utility of pairing the LOVdeg tag with existing optogenetic tools to enhance performance by developing a combined EL222 and LOVdeg system. Finally, we use the LOVdeg tag in a metabolic engineering application to demonstrate post-translational control of metabolism. Together, our results highlight the modularity and functionality of the LOVdeg tag system and introduce a powerful new tool for bacterial optogenetics.
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Affiliation(s)
- Nathan Tague
- Department of Biomedical Engineering, Boston UniversityBostonUnited States
- Biological Design Center, Boston UniversityBostonUnited States
| | - Cristian Coriano-Ortiz
- Department of Biomedical Engineering, Boston UniversityBostonUnited States
- Biological Design Center, Boston UniversityBostonUnited States
| | - Michael B Sheets
- Department of Biomedical Engineering, Boston UniversityBostonUnited States
- Biological Design Center, Boston UniversityBostonUnited States
| | - Mary J Dunlop
- Department of Biomedical Engineering, Boston UniversityBostonUnited States
- Biological Design Center, Boston UniversityBostonUnited States
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4
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Chen G, Wang R, Sun M, Chen J, Iyobosa E, Zhao J. Carbon dioxide reduction to high-value chemicals in microbial electrosynthesis system: Biological conversion and regulation strategies. CHEMOSPHERE 2023; 344:140251. [PMID: 37769909 DOI: 10.1016/j.chemosphere.2023.140251] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 10/03/2023]
Abstract
Large emissions of atmospheric carbon dioxide (CO2) are causing climatic and environmental problems. It is crucial to capture and utilize the excess CO2 through diverse methods, among which the microbial electrosynthesis (MES) system has become an attractive and promising technology to mitigate greenhouse effects while reducing CO2 to high-value chemicals. However, the biological conversion and metabolic pathways through microbial catalysis have not been clearly elucidated. This review first introduces the main acetogenic bacteria for CO2 reduction and extracellular electron transfer mechanisms in MES. It then intensively analyzes the CO2 bioconversion pathways and carbon chain elongation processes in MES, together with energy supply and utilization. The factors affecting MES performance, including physical, chemical, and biological aspects, are summarized, and the strategies to promote and regulate bioconversion in MES are explored. Finally, challenges and perspectives concerning microbial electrochemical carbon sequestration are proposed, and suggestions for future research are also provided. This review provides theoretical foundation and technical support for further development and industrial application of MES for CO2 reduction.
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Affiliation(s)
- Gaoxiang Chen
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
| | - Rongchang Wang
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China.
| | - Maoxin Sun
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
| | - Jie Chen
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
| | - Eheneden Iyobosa
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
| | - Jianfu Zhao
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
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5
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Tague N, Coriano-Ortiz C, Sheets MB, Dunlop MJ. Light inducible protein degradation in E. coli with the LOVdeg tag. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.25.530042. [PMID: 36865169 PMCID: PMC9980293 DOI: 10.1101/2023.02.25.530042] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Molecular tools for optogenetic control allow for spatial and temporal regulation of cell behavior. In particular, light controlled protein degradation is a valuable mechanism of regulation because it can be highly modular, used in tandem with other control mechanisms, and maintain functionality throughout growth phases. Here, we engineered LOVdeg, a tag that can be appended to a protein of interest for inducible degradation in Escherichia coli using blue light. We demonstrate the modularity of LOVdeg by using it to tag a range of proteins, including the LacI repressor, CRISPRa activator, and the AcrB efflux pump. Additionally, we demonstrate the utility of pairing the LOVdeg tag with existing optogenetic tools to enhance performance by developing a combined EL222 and LOVdeg system. Finally, we use the LOVdeg tag in a metabolic engineering application to demonstrate post-translational control of metabolism. Together, our results highlight the modularity and functionality of the LOVdeg tag system, and introduce a powerful new tool for bacterial optogenetics.
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6
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Guo H, Ji M, Du T, Xu W, Liu J, Bai R, Teng Z, Li T. Salt stress altered anaerobic microbial community and carbon metabolism characteristics: The trade-off between methanogenesis and chain elongation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 341:118111. [PMID: 37156025 DOI: 10.1016/j.jenvman.2023.118111] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/10/2023]
Abstract
Discharge of saline organic wastewater is increasing worldwide, yet how salt stress disrupts the microbial community's structure and metabolism in bioreactors has not been systematically investigated. The non-adapted anaerobic granular sludge was inoculated into wastewater with varying salt concentration (ranging from 0% to 5%) to examine the effects of salt stress on the structure and function of the anaerobic microbial community. Result indicated that salt stress had a significant impact on the metabolic function and community structure of the anaerobic granular sludge. Specifically, we observed a notable reduction in methane production in response to all salt stress treatments (r = -0.97, p < 0.01), while an unexpected increase in butyrate production (r = 0.91, p < 0.01) under moderate salt stress (1-3%) with ethanol and acetate as carbon sources. In addition, analysis of microbiome structures and networks demonstrated that as the degree of salt stress increased, the networks exhibited lower connectance and increased compartmentalization. The abundance of interaction partners (methanogenic archaea and syntrophic bacteria) decreased under salt stress. In contrast, the abundance of chain elongation bacteria, specifically Clostridium kluyveri, increased under moderate salt stress (1-3%). As a consequence, the microbial carbon metabolism patterns shifted from cooperative mode (methanogenesis) to independent mode (carbon chain elongation) under moderate salt stress. This study provides evidence that salt stress altered the anaerobic microbial community and carbon metabolism characteristics, and suggests potential guidance for steering the microbiota to promote resource conversion in saline organic wastewater treatment.
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Affiliation(s)
- Huiyuan Guo
- CAS Key Laboratory of Green Process and Engineering, Innovation Academy for Green Manufacture, National Engineering Research Center of Green Recycling for Strategic Metal Resources, Beijing Engineering Research Centre of Process Pollution Control, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Meina Ji
- CAS Key Laboratory of Green Process and Engineering, Innovation Academy for Green Manufacture, National Engineering Research Center of Green Recycling for Strategic Metal Resources, Beijing Engineering Research Centre of Process Pollution Control, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; Wuhan Institute of Technology, Wuhan, 430205, China
| | - Tianxiao Du
- CAS Key Laboratory of Green Process and Engineering, Innovation Academy for Green Manufacture, National Engineering Research Center of Green Recycling for Strategic Metal Resources, Beijing Engineering Research Centre of Process Pollution Control, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Weichao Xu
- CAS Key Laboratory of Green Process and Engineering, Innovation Academy for Green Manufacture, National Engineering Research Center of Green Recycling for Strategic Metal Resources, Beijing Engineering Research Centre of Process Pollution Control, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianwei Liu
- Beijing Research Center of Sustainable Urban Drainage System and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China
| | - Renbi Bai
- Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, 215009, China
| | - Zedong Teng
- CAS Key Laboratory of Green Process and Engineering, Innovation Academy for Green Manufacture, National Engineering Research Center of Green Recycling for Strategic Metal Resources, Beijing Engineering Research Centre of Process Pollution Control, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Tinggang Li
- CAS Key Laboratory of Green Process and Engineering, Innovation Academy for Green Manufacture, National Engineering Research Center of Green Recycling for Strategic Metal Resources, Beijing Engineering Research Centre of Process Pollution Control, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Ganjiang Innovation Academy, Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths, Chinese Academy of Sciences, Ganzhou, 341000, China.
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7
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Courtney DK, Su Y, Jacobson T, Khana D, Ailiani A, Amador-Noguez D, Pfleger BF. Relative Activities of the β-ketoacyl-CoA and Acyl-CoA Reductases Influence Product Profile and Flux in a Reversed β-Oxidation Pathway. ACS Catal 2023; 13:5914-5925. [PMID: 38094510 PMCID: PMC10718561 DOI: 10.1021/acscatal.3c00379] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
The β-Oxidation pathway, normally involved in the catabolism of fatty acids, can be functionally made to act as a fermentative, iterative, elongation pathway when driven by the activity of a trans-enoyl-CoA reductase. The terminal acyl-CoA reduction to alcohol can occur on substrates with varied chain lengths, leading to a broad distribution of fermentation products in vivo. Tight control of the average chain length and product profile is desirable as chain length greatly influences molecular properties and commercial value. Lacking a termination enzyme with a narrow chain length preference, we sought alternative factors that could influence the product profile and pathway flux in the iterative pathway. In this study, we reconstituted the reversed β-oxidation (R-βox) pathway in vitro with a purified tri-functional complex (FadBA) responsible for the thiolase, enoyl-CoA hydratase and hydroxyacyl-CoA dehydrogenase activities, a trans-enoyl-CoA reductase (TER), and an acyl-CoA reductase (ACR). Using this system, we determined the rate limiting step of the elongation cycle and demonstrated that by controlling the ratio of these three enzymes and the ratio of NADH and NADPH, we can influence the average chain length of the alcohol product profile.
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Affiliation(s)
- Dylan K. Courtney
- Department of Chemical and Biological Engineering, University of Wisconsin – Madison, Madison, WI, USA
| | - Yun Su
- Department of Chemical and Biological Engineering, University of Wisconsin – Madison, Madison, WI, USA
| | - Tyler Jacobson
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI, USA
| | - Daven Khana
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI, USA
| | - Aditya Ailiani
- Department of Biomedical Engineering, University of Wisconsin – Madison, Madison, WI, USA
| | | | - Brian F. Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin – Madison, Madison, WI, USA
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8
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Mains K, Fox JM. Ketosynthase mutants enable short-chain fatty acid biosynthesis in E. coli. Metab Eng 2023; 77:118-127. [PMID: 36963462 DOI: 10.1016/j.ymben.2023.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/16/2023] [Accepted: 03/20/2023] [Indexed: 03/26/2023]
Abstract
Cells build fatty acids in tightly regulated assembly lines, or fatty acid synthases (FASs), in which β-ketoacyl-acyl carrier protein (ACP) synthases (KSs) catalyze sequential carbon-carbon bond forming reactions that generate acyl-ACPs of varying lengths-precursors for a diverse set of lipids and oleochemicals. To date, most efforts to control fatty acid synthesis in engineered microbes have focused on modifying termination enzymes such as acyl-ACP thioesterases, which release free fatty acids from acyl-ACPs. Changes to the substrate specificity of KSs provide an alternative-and, perhaps, more generalizable-approach that focuses on controlling the acyl-ACPs available for downstream products. This study combines mutants of FabF and FabB, the two elongating KSs of the E. coli FAS, with in vitro and in vivo analyses to explore the use of KS mutants to control fatty acid synthesis. In vitro, single amino acid substitutions in the gating loop and acyl binding pocket of FabF shifted the product profiles of reconstituted FASs toward short chains and showed that KS mutants, alone, can cause large shifts in average length (i.e., 6.5-13.5). FabB, which is essential for unsaturated fatty acid synthesis, blunted this effect in vivo, but exogenously added cis-vaccenic acid (C18:1) enabled sufficient transcriptional repression of FabB to restore it. Strikingly, a single mutant of FabB afforded titers of octanoic acid as high as those generated by an engineered thioesterase. Findings indicate that fatty acid synthesis must be decoupled from microbial growth to resolve the influence of KS mutants on fatty acid profiles but show that these mutants offer a versatile approach for tuning FAS outputs.
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Affiliation(s)
- Kathryn Mains
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA
| | - Jerome M Fox
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA.
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9
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Wang K, Zhao W, Lin L, Wang T, Wei P, Ledesma-Amaro R, Zhang AH, Ji XJ. A robust soft sensor based on artificial neural network for monitoring microbial lipid fermentation processes using Yarrowia lipolytica. Biotechnol Bioeng 2023; 120:1015-1025. [PMID: 36522163 DOI: 10.1002/bit.28310] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Microbial oils produced by Yarrowia lipolytica offer an environmentally friendly and sustainable alternative to petroleum as well as traditional lipids from animals and plants. The accurate measurement of fermentation parameters, including the substrate concentration, dry cell weight, and lipid accumulation, is the foundation of process control, which is indispensable for industrial lipid production. However, it remains a great challenge to measure the complex parameters online during the lipid fermentation process, which is nonlinear, multivariate, and characterized by strong coupling. As a type of AI technology, the artificial neural network model is a powerful tool for handling extremely complex problems, and it can be employed to develop a soft sensor to monitor the microbial lipid fermentation process of Y. lipolytica. In this study, we first analyzed and emphasized the volume of sodium hydroxide and dissolved oxygen concentration as central parameters of the fermentation process. Then, a soft sensor based on a four-input artificial neural network model was developed, in which the input variables were fermentation time, dissolved oxygen concentration, initial glucose concentration, and additional volume of sodium hydroxide. This provides the possibility of online monitoring of dry cell weight, glucose concentration, and lipid production with high accuracy, which can be extended to similar fermentation processes characterized by the addition of bases or acids, as well as changes of the dissolved oxygen concentration.
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Affiliation(s)
- Kaifeng Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People's Republic of China
| | - Wenyang Zhao
- Institute of Network and Cloud Computing Technology, College of Computer Science and Technology, Nanjing Tech University, Nanjing, People's Republic of China
| | - Lu Lin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People's Republic of China
| | - Tianjing Wang
- Institute of Network and Cloud Computing Technology, College of Computer Science and Technology, Nanjing Tech University, Nanjing, People's Republic of China
| | - Ping Wei
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People's Republic of China
| | - Rodrigo Ledesma-Amaro
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London, UK
| | - Ai-Hui Zhang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
| | - Xiao-Jun Ji
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, People's Republic of China
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10
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Zhang Y, Bai J, Zuo J. Performance and mechanisms of medium-chain fatty acid production by anaerobic fermentation of food waste without external electron donors. BIORESOURCE TECHNOLOGY 2023; 374:128735. [PMID: 36781145 DOI: 10.1016/j.biortech.2023.128735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
This study performed a long-term operation to achieve efficient medium-chain fatty acids (MCFAs) production by anaerobic fermentation of food waste without external electron donors. The results show that total MCFAs reached the highest concentration of 29,886.10 mg COD/L, and n-caproate was the primary product, reaching the current maximum concentration of 28,191.66 mg COD/L. Microbial composition analysis demonstrated Lactobacillus, Bifidobacterium, Sporanaerobacter, and Caproiciproducens constituted the core community throughout the process. Metagenomic analysis suggested that two pathways, reverse β-oxidization (RBO) and fatty acid biosynthesis (FAB), were observed, and the FAB pathway was the main CE pathway. Unclassified_f_Ruminococcaceae and Limosilactobacillus were the main participants in the FAB pathway. This study is expected to provide new insights into MCFAs production from organic waste.
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Affiliation(s)
- Yanyan Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiazhe Bai
- Tsinghua Shenzhen International Graduate School, Shenzhen 518055, China
| | - Jiane Zuo
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Tsinghua Shenzhen International Graduate School, Shenzhen 518055, China.
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11
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Qin N, Li L, Wang Z, Shi S. Microbial production of odd-chain fatty acids. Biotechnol Bioeng 2023; 120:917-931. [PMID: 36522132 DOI: 10.1002/bit.28308] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 10/11/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Odd-chain fatty acids (OcFAs) and their derivatives have attracted much attention due to their beneficial physiological effects and their potential to be alternatives to advanced fuels. However, cells naturally produce even-chain fatty acids (EcFAs) with negligible OcFAs. In the process of biosynthesis of fatty acids (FAs), the acetyl-CoA serves as the starter unit for EcFAs, and propionyl-CoA works as the starter unit for OcFAs. The lack of sufficient propionyl-CoA, the precursor, is usually regarded as the main restriction for large-scale bioproduction of OcFAs. In recent years, synthetic biology strategies have been used to modify several microorganisms to produce more propionyl-CoA that would enable an efficient biosynthesis of OcFAs. This review discusses several reported and potential metabolic pathways for propionyl-CoA biosynthesis, followed by advances in engineering several cell factories for OcFAs production. Finally, trends and challenges of synthetic biology driven OcFAs production are discussed.
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Affiliation(s)
- Ning Qin
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Lingyun Li
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Zheng Wang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Shuobo Shi
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
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12
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Genome-wide CRISPRi screen identifies enhanced autolithotrophic phenotypes in acetogenic bacterium Eubacterium limosum. Proc Natl Acad Sci U S A 2023; 120:e2216244120. [PMID: 36716373 PMCID: PMC9963998 DOI: 10.1073/pnas.2216244120] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Acetogenic bacteria are a unique biocatalyst that highly promises to develop the sustainable bioconversion of carbon oxides (e.g., CO and CO2) into multicarbon biochemicals. Genotype-phenotype relationships are important for engineering their metabolic capability to enhance their biocatalytic performance; however, systemic investigation on the fitness contribution of individual gene has been limited. Here, we report genome-scale CRISPR interference screening using 41,939 guide RNAs designed from the E. limosum genome, one of the model acetogenic species, where all genes were targeted for transcriptional suppression. We investigated the fitness contributions of 96% of the total genes identified, revealing the gene fitness and essentiality for heterotrophic and autotrophic metabolisms. Our data show that the Wood-Ljungdahl pathway, membrane regeneration, membrane protein biosynthesis, and butyrate synthesis are essential for autotrophic acetogenesis in E. limosum. Furthermore, we discovered genes that are repression targets that unbiasedly increased autotrophic growth rates fourfold and acetoin production 1.5-fold compared to the wild-type strain under CO2-H2 conditions. These results provide insight for understanding acetogenic metabolism and genome engineering in acetogenic bacteria.
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13
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Zhou Y, Yu H, Tang Y, Chen R, Luo J, Shi C, Tang S, Li X, Shen X, Chen R, Zhang Y, Lu Y, Ye Z, Guo L, Ouyang B. Critical roles of mitochondrial fatty acid synthesis in tomato development and environmental response. PLANT PHYSIOLOGY 2022; 190:576-591. [PMID: 35640121 PMCID: PMC9434154 DOI: 10.1093/plphys/kiac255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/28/2022] [Indexed: 05/30/2023]
Abstract
Plant mitochondrial fatty acid synthesis (mtFAS) appears to be important in photorespiration based on the reverse genetics research from Arabidopsis (Arabidopsis thaliana) in recent years, but its roles in plant development have not been completely explored. Here, we identified a tomato (Solanum lycopersicum) mutant, fern-like, which displays pleiotropic phenotypes including dwarfism, yellowing, curly leaves, and increased axillary buds. Positional cloning and genetic and heterozygous complementation tests revealed that the underlying gene FERN encodes a 3-hydroxyl-ACP dehydratase enzyme involved in mtFAS. FERN was causally involved in tomato morphogenesis by affecting photorespiration, energy supply, and the homeostasis of reactive oxygen species. Based on lipidome data, FERN and the mtFAS pathway may modulate tomato development by influencing mitochondrial membrane lipid composition and other lipid metabolic pathways. These findings provide important insights into the roles and importance of mtFAS in tomato development.
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Affiliation(s)
- Yuhong Zhou
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Huiyang Yu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Yaping Tang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Rong Chen
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Jinying Luo
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Chunmei Shi
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Shan Tang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Xin Li
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Xinyan Shen
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Rongfeng Chen
- National Center for Occupational Safety and Health, NHC, Beijing 102308, China
| | - Yuyang Zhang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Yongen Lu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Zhibiao Ye
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Liang Guo
- Author for correspondence: (B.O.), (L.G.)
| | - Bo Ouyang
- Author for correspondence: (B.O.), (L.G.)
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Wang K, Shi TQ, Lin L, Wei P, Ledesma-Amaro R, Ji XJ. Engineering Yarrowia lipolytica to Produce Tailored Chain-Length Fatty Acids and Their Derivatives. ACS Synth Biol 2022; 11:2564-2577. [DOI: 10.1021/acssynbio.2c00305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Kaifeng Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People’s Republic of China
| | - Tian-Qiong Shi
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing 210046, People’s Republic of China
| | - Lu Lin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People’s Republic of China
| | - Ping Wei
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People’s Republic of China
| | - Rodrigo Ledesma-Amaro
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, United Kindom
| | - Xiao-Jun Ji
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People’s Republic of China
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15
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Muratovska N, Silva P, Pozdniakova T, Pereira H, Grey C, Johansson B, Carlquist M. Towards engineered yeast as production platform for capsaicinoids. Biotechnol Adv 2022; 59:107989. [PMID: 35623491 DOI: 10.1016/j.biotechadv.2022.107989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 12/23/2022]
Abstract
Capsaicinoids are bioactive alkaloids produced by the chili pepper fruit and are known to be the most potent agonists of the human pain receptor TRPV1 (Transient Receptor Potential Cation Channel Subfamily V Member 1). They are currently produced by extraction from chili pepper fruit or by chemical synthesis. Transfer of the biosynthetic route to a microbial host could enable more efficient capsaicinoid production by fermentation and may also enable the use of synthetic biology to create a diversity of new compounds with potentially improved properties. This review summarises the current state of the art on the biosynthesis of capsaicinoid precursors in baker's yeast, Saccharomyces cerevisiae, and discusses bioengineering strategies for achieving total synthesis from sugar.
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Affiliation(s)
- Nina Muratovska
- Division of Applied Microbiology, Lund University, Box 124, 221 00 Lund, Sweden
| | - Paulo Silva
- CBMA - Center of Molecular and Environmental Biology Engineering, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal
| | - Tatiana Pozdniakova
- CBMA - Center of Molecular and Environmental Biology Engineering, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal
| | - Humberto Pereira
- CBMA - Center of Molecular and Environmental Biology Engineering, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal
| | - Carl Grey
- Division of Biotechnology, Lund University, Box 118, SE-221 00 Lund, Sweden
| | - Björn Johansson
- CBMA - Center of Molecular and Environmental Biology Engineering, University of Minho, Campus de Gualtar, Braga 4710-057, Portugal.
| | - Magnus Carlquist
- Division of Applied Microbiology, Lund University, Box 124, 221 00 Lund, Sweden.
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16
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Fazili ABA, Shah AM, Zan X, Naz T, Nosheen S, Nazir Y, Ullah S, Zhang H, Song Y. Mucor circinelloides: a model organism for oleaginous fungi and its potential applications in bioactive lipid production. Microb Cell Fact 2022; 21:29. [PMID: 35227264 PMCID: PMC8883733 DOI: 10.1186/s12934-022-01758-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 02/10/2022] [Indexed: 11/10/2022] Open
Abstract
Microbial oils have gained massive attention because of their significant role in industrial applications. Currently plants and animals are the chief sources of medically and nutritionally important fatty acids. However, the ever-increasing global demand for polyunsaturated fatty acids (PUFAs) cannot be met by the existing sources. Therefore microbes, especially fungi, represent an important alternative source of microbial oils being investigated. Mucor circinelloides—an oleaginous filamentous fungus, came to the forefront because of its high efficiency in synthesizing and accumulating lipids, like γ-linolenic acid (GLA) in high quantity. Recently, mycelium of M. circinelloides has acquired substantial attraction towards it as it has been suggested as a convenient raw material source for the generation of biodiesel via lipid transformation. Although M. circinelloides accumulates lipids naturally, metabolic engineering is found to be important for substantial increase in their yields. Both modifications of existing pathways and re-formation of biosynthetic pathways in M. circinelloides have shown the potential to improve lipid levels. In this review, recent advances in various important metabolic aspects of M. circinelloides have been discussed. Furthermore, the potential applications of M. circinelloides in the fields of antioxidants, nutraceuticals, bioremediation, ethanol production, and carotenoids like beta carotene and astaxanthin having significant nutritional value are also deliberated.
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17
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Mains K, Peoples J, Fox JM. Kinetically guided, ratiometric tuning of fatty acid biosynthesis. Metab Eng 2021; 69:209-220. [PMID: 34826644 DOI: 10.1016/j.ymben.2021.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/29/2021] [Accepted: 11/21/2021] [Indexed: 11/29/2022]
Abstract
Cellular metabolism is a nonlinear reaction network in which dynamic shifts in enzyme concentration help regulate the flux of carbon to different products. Despite the apparent simplicity of these biochemical adjustments, their influence on metabolite biosynthesis tends to be context-dependent, difficult to predict, and challenging to exploit in metabolic engineering. This study combines a detailed kinetic model with a systematic set of in vitro and in vivo analyses to explore the use of enzyme concentration as a control parameter in fatty acid synthesis, an essential metabolic process with important applications in oleochemical production. Compositional analyses of a modeled and experimentally reconstituted fatty acid synthase (FAS) from Escherichia coli indicate that the concentration ratio of two native enzymes-a promiscuous thioesterase and a ketoacyl synthase-can tune the average length of fatty acids, an important design objective of engineered pathways. The influence of this ratio is sensitive to the concentrations of other FAS components, which can narrow or expand the range of accessible chain lengths. Inside the cell, simple changes in enzyme concentration can enhance product-specific titers by as much as 125-fold and elicit shifts in overall product profiles that rival those of thioesterase mutants. This work develops a kinetically guided approach for using ratiometric adjustments in enzyme concentration to control the product profiles of FAS systems and, broadly, provides a detailed framework for understanding how coordinated shifts in enzyme concentration can afford tight control over the outputs of nonlinear metabolic pathways.
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Affiliation(s)
- Kathryn Mains
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA
| | - Jackson Peoples
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA
| | - Jerome M Fox
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, CO, 80303, USA.
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18
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Wu Q, Jiang Y, Chen Y, Liu M, Bao X, Guo W. Opportunities and challenges in microbial medium chain fatty acids production from waste biomass. BIORESOURCE TECHNOLOGY 2021; 340:125633. [PMID: 34315125 DOI: 10.1016/j.biortech.2021.125633] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/16/2021] [Accepted: 07/17/2021] [Indexed: 06/13/2023]
Abstract
Medium chain fatty acids (MCFAs) that produced from affordable waste biomass via chain elongation (CE) technology are recognized as the potential alternatives to part fossil-derived chemicals, contributing to the sustainable development of economy and environment. The purpose of this review is to provide comprehensive analyses on the opportunities and challenges of MCFAs production and application. First, both two microbial MCFAs synthesis pathways of reverse β-oxidation and fatty acid biosynthesis were introduced/compared in detail to give readers a thorough understanding of the CE process, with the expectation of further boosting MCFAs production by well distinguishing them. Furthermore, the six key MCFAs production bottlenecks, corresponding research progresses, and possible solutions were analyzed. Five major MCFAs production strategies with their production mechanism, performances, and characteristics were also critically assessed. Additionally, the commercial production status was introduced, and future alternative production mode and research priorities were also recommended.
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Affiliation(s)
- Qinglian Wu
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Yong Jiang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Ying Chen
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Min Liu
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Xian Bao
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Wanqian Guo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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19
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Dynamic metabolic engineering of Escherichia coli improves fermentation for the production of pyruvate and its derivatives. J Biosci Bioeng 2021; 133:56-63. [PMID: 34674961 DOI: 10.1016/j.jbiosc.2021.09.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 11/23/2022]
Abstract
Pyruvate is a key intermediate that is involved in various synthetic metabolic pathways for microbial chemical and fuel production. It is widely used in the food, chemical, and pharmaceutical industries. However, the microbial production of pyruvate and its derivatives compete with microbial cell growth, as pyruvate is an important metabolic intermediate that serves as a hub for various endogenous metabolic pathways, including gluconeogenesis, amino acid synthesis, TCA cycle, and fatty acid biosynthesis. To achieve a more efficient bioprocess for the production of pyruvate and its derivatives, it is necessary to reduce the metabolic imbalance between cell growth and target chemical production. For this purpose, we devised a dynamic metabolic engineering strategy within an Escherichia coli model, in which a metabolic toggle switch (MTS) was employed to redirect metabolic flux from the endogenous pathway toward the target synthetic pathway. Through a combination of TCA cycle interruption through MTS and reduction of pyruvate consumption in endogenous pathways, we achieved a drastic improvement (163 mM, 26-fold) in pyruvate production. In addition, we demonstrated the redirection of metabolic flux from excess pyruvate toward isobutanol production. The final isobutanol production titer of the strain harboring MTS was 26% improved compared with that of the control strain.
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20
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Soma Y, Takahashi M, Fujiwara Y, Tomiyasu N, Goto M, Hanai T, Izumi Y, Bamba T. Quantitative metabolomics for dynamic metabolic engineering using stable isotope labeled internal standards mixture (SILIS). J Biosci Bioeng 2021; 133:46-55. [PMID: 34620543 DOI: 10.1016/j.jbiosc.2021.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 11/28/2022]
Abstract
The production of chemicals and fuels from renewable resources using engineered microbes is an attractive alternative for current fossil-dependent industries. Metabolic engineering has contributed to pathway engineering for the production of chemicals and fuels by various microorganisms. Recently, dynamic metabolic engineering harnessing synthetic biological tools has become a next-generation strategy in this field. The dynamic regulation of metabolic flux during fermentation optimizes metabolic states according to each fermentation stage such as cell growth phase and compound production phase. However, it is necessary to repeat the evaluation and redesign of the dynamic regulation system to achieve the practical use of engineered microbes. In this study, we performed quantitative metabolome analysis to investigate the effects of dynamic metabolic flux regulation on engineered Escherichia coli for γ-amino butyrate (GABA) fermentation. We prepared a stable isotope-labeled internal standard mixture (SILIS) for the stable isotope dilution method (SIDM), a mass spectrometry-based quantitative metabolome analysis method. We found multiple candidate bottlenecks for GABA production. Some metabolic reactions in the GABA production pathway should be engineered for further improvement in the direct GABA fermentation with dynamic metabolic engineering strategy.
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Affiliation(s)
- Yuki Soma
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Masatomo Takahashi
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yuri Fujiwara
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Noriyuki Tomiyasu
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Maiko Goto
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Taizo Hanai
- Laboratory for Synthetic Biology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, W5-729, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yoshihiro Izumi
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Takeshi Bamba
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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21
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Soma Y, Takahashi M, Fujiwara Y, Shinohara T, Izumi Y, Hanai T, Bamba T. Design of Synthetic Quorum Sensing Achieving Induction Timing-Independent Signal Stabilization for Dynamic Metabolic Engineering of E. coli. ACS Synth Biol 2021; 10:1384-1393. [PMID: 34106678 DOI: 10.1021/acssynbio.1c00008] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Dynamic metabolic engineering that harnesses synthetic biological tools is a next-generation strategy for microbial chemical and fuel production. We previously reported a synthetic quorum sensing system combined with a metabolic toggle switch (QS-MTS) in E. coli. It autonomously redirected endogenous metabolic flux toward the synthetic metabolic pathway and improved biofuel production. However, its functions and effects on host metabolism were attenuated by induction timing delay. Here, we redesigned the QS-MTS to stabilize QS signaling efficiency and metabolic regulation. We performed a metabolome analysis to clarify the effects of QS-MTS redesign on host metabolism. We compared the contributions of conventional and redesigned QS-MTS to fed-batch fermentation. The redesigned QS-MTS was more conducive than the conventional QS-MTS to long-term processes such as fed-batch fermentation. Here, we present a circuit redesign for metabolic flux control based on dynamic characteristic evaluation and metabolome analysis.
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Affiliation(s)
- Yuki Soma
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Masatomo Takahashi
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yuri Fujiwara
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Tamaki Shinohara
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yoshihiro Izumi
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Taizo Hanai
- Laboratory for Bioinformatics, Graduate School of Systems Lifesciences, Kyushu University, W5-729, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Takeshi Bamba
- Division of Metabolomics, Research Center for Transomics Medicine, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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22
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Enhancement of C6–C10 fatty acid ethyl esters production in Saccharomyces cerevisiae CA by metabolic engineering. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111496] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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23
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Mindrebo JT, Chen A, Kim WE, Re RN, Davis TD, Noel JP, Burkart MD. Structure and Mechanistic Analyses of the Gating Mechanism of Elongating Ketosynthases. ACS Catal 2021; 11:6787-6799. [DOI: 10.1021/acscatal.1c00745] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Jeffrey T. Mindrebo
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
- Jack H. Skirball Center for Chemical Biology and Proteomics, Salk Institute for Biological Studies, La Jolla, California 92037, United States
| | - Aochiu Chen
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Woojoo E. Kim
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Rebecca N. Re
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Tony D. Davis
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Joseph P. Noel
- Jack H. Skirball Center for Chemical Biology and Proteomics, Salk Institute for Biological Studies, La Jolla, California 92037, United States
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, California 92037, United States
| | - Michael D. Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
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24
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Martin-Pascual M, Batianis C, Bruinsma L, Asin-Garcia E, Garcia-Morales L, Weusthuis RA, van Kranenburg R, Martins Dos Santos VAP. A navigation guide of synthetic biology tools for Pseudomonas putida. Biotechnol Adv 2021; 49:107732. [PMID: 33785373 DOI: 10.1016/j.biotechadv.2021.107732] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 03/12/2021] [Accepted: 03/18/2021] [Indexed: 12/12/2022]
Abstract
Pseudomonas putida is a microbial chassis of huge potential for industrial and environmental biotechnology, owing to its remarkable metabolic versatility and ability to sustain difficult redox reactions and operational stresses, among other attractive characteristics. A wealth of genetic and in silico tools have been developed to enable the unravelling of its physiology and improvement of its performance. However, the rise of this microbe as a promising platform for biotechnological applications has resulted in diversification of tools and methods rather than standardization and convergence. As a consequence, multiple tools for the same purpose have been generated, whilst most of them have not been embraced by the scientific community, which has led to compartmentalization and inefficient use of resources. Inspired by this and by the substantial increase in popularity of P. putida, we aim herein to bring together and assess all currently available (wet and dry) synthetic biology tools specific for this microbe, focusing on the last 5 years. We provide information on the principles, functionality, advantages and limitations, with special focus on their use in metabolic engineering. Additionally, we compare the tool portfolio for P. putida with those for other bacterial chassis and discuss potential future directions for tool development. Therefore, this review is intended as a reference guide for experts and new 'users' of this promising chassis.
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Affiliation(s)
- Maria Martin-Pascual
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Christos Batianis
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Lyon Bruinsma
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Enrique Asin-Garcia
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Luis Garcia-Morales
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands
| | - Ruud A Weusthuis
- Bioprocess Engineering, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Richard van Kranenburg
- Corbion, Gorinchem 4206 AC, The Netherlands; Laboratory of Microbiology, Wageningen University & Research, Wageningen 6708 WE, the Netherlands
| | - Vitor A P Martins Dos Santos
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen 6708 WE, The Netherlands; LifeGlimmer GmbH, Berlin 12163, Germany.
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25
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Functional Analysis of an Acyltransferase-Like Domain from Polyunsaturated Fatty Acid Synthase in Thraustochytrium. Microorganisms 2021; 9:microorganisms9030626. [PMID: 33803061 PMCID: PMC8003026 DOI: 10.3390/microorganisms9030626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/15/2021] [Accepted: 03/15/2021] [Indexed: 12/19/2022] Open
Abstract
Biosynthesis of very long chain polyunsaturated fatty acids (VLCPUFA) such as docosahexaenoic acid (DHA, 22:6-4,7,10,13,16,19) and docosapentaenoic acid (DPA, 22:5-4,7,10,13,16) in protist Thraustochytrium is catalyzed by a polyunsaturated fatty acids (PUFA) synthase comprising three large subunits, each with multiple catalytic domains. This study used complementation test, in vitro assays, and functional expression to characterize an acyltransferase (AT)-like domain in Subunit-B of a PUFA synthase from Thraustochytrium. Complementation test in Escherichia coli showed that the AT-like domain could not restore the growth phenotype of a temperature-sensitive mutant (∆fabDts) defective in malonyl-CoA:ACP transacylase activity. In vitro assays showed that the AT-like domain possessed thioesterase activity towards a few acyl-CoAs tested where docosahexaenoyl-CoA (DHA-CoA) was the preferred substrate. Expression of this domain in an E. coli mutant (∆fadD) defective in acyl-CoA synthetase activity resulted in the increased accumulation of free fatty acids. Site-directed mutagenesis showed that the substitution of two putative active site residues, serine at 96 (S96) and histidine at 220 (H220), in the AT-like domain significantly reduced its activity towards DHA-CoA and accumulation of free fatty acids in the ∆fadD mutant. These results indicate that the AT-like domain of the PUFA synthase does not function as a malonyl-CoA:ACP transacylase, rather it functions as a thioesterase. It might catalyze the last step of the VLCPUFA biosynthesis by releasing freshly synthesized VLCPUFAs attached to ACP domains of the PUFA synthase in Thraustochytrium.
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26
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Shen H, Li C, He M, Huang Y, Wang J, Wang M, Yue B, Zhang X. Immune profiles of male giant panda (Ailuropoda melanoleuca) during the breeding season. BMC Genomics 2021; 22:143. [PMID: 33639852 PMCID: PMC7916315 DOI: 10.1186/s12864-021-07456-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 02/19/2021] [Indexed: 12/13/2022] Open
Abstract
Background The giant panda (Ailuropoda melanoleuca) is a threatened endemic Chinese species and a flagship species of national and global conservation concern. Life history theory proposes that reproduction and immunity can be mutually constraining and interrelated. Knowledge of immunity changes of male giant pandas during the breeding season is limited. Results Here, we researched peripheral blood gene expression profiles associated with immunity. Thirteen captive giant pandas, ranging from 9 to 11 years old, were divided into two groups based on their reproductive status. We identified 318 up-regulated DEGs and 43 down-regulated DEGs, which were enriched in 87 GO terms and 6 KEGG pathways. Additionally, we obtained 45 immune-related genes with altered expression, mostly up-regulated, and identified four hub genes HSPA4, SUGT1, SOD1, and IL1B in PPI analysis. These 45 genes were related to pattern recognition receptors, autophagy, peroxisome, proteasome, natural killer cell, antigen processing and presentation. SUGT1 and IL1B were related to pattern recognition receptors. HSP90AA1 was the most up-regulated gene and is a member of heat shock protein 90 family. HSP90 contributes to the translocation of extracellular antigen. KLRD1 encodes CD94, whose complex is an inhibitor of the cytotoxic activity of NK cells, was down-regulated. IGIP, which has the capability of inducing IgA production by B cells, was down-regulated, suggesting low concentration of IgA in male giant pandas. Our results suggest that most immune-related genes were up-regulated and more related to innate immune than adaptive immune. Conclusions Our results indicated that breeding male giant pandas presented an immunoenhancement in innate immunity, enhanced antigen presentation and processing in cellular immunity compared to non-breeding males. The humoral immunity of male giant pandas may show a tendency to decrease during the breeding season. This study will provide a foundation for further studies of immunity and reproduction in male giant pandas. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07456-x.
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Affiliation(s)
- Haibo Shen
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Science, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu, 610065, Sichuan, China
| | - Caiwu Li
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in The Giant Panda National Park, China Conservation and Research Center for the Giant Panda, Dujiangyan, 611830, Sichuan, PR China
| | - Ming He
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in The Giant Panda National Park, China Conservation and Research Center for the Giant Panda, Dujiangyan, 611830, Sichuan, PR China
| | - Yan Huang
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in The Giant Panda National Park, China Conservation and Research Center for the Giant Panda, Dujiangyan, 611830, Sichuan, PR China
| | - Jing Wang
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in The Giant Panda National Park, China Conservation and Research Center for the Giant Panda, Dujiangyan, 611830, Sichuan, PR China
| | - Minglei Wang
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in The Giant Panda National Park, China Conservation and Research Center for the Giant Panda, Dujiangyan, 611830, Sichuan, PR China
| | - Bisong Yue
- Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, College of Life Sciences, Sichuan University, Chengdu, 610064, PR China
| | - Xiuyue Zhang
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Science, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu, 610065, Sichuan, China.
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Valorization of CO2 through lithoautotrophic production of sustainable chemicals in Cupriavidus necator. Metab Eng 2020; 62:207-220. [DOI: 10.1016/j.ymben.2020.09.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 08/10/2020] [Accepted: 09/01/2020] [Indexed: 12/28/2022]
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Izadi P, Fontmorin JM, Godain A, Yu EH, Head IM. Parameters influencing the development of highly conductive and efficient biofilm during microbial electrosynthesis: the importance of applied potential and inorganic carbon source. NPJ Biofilms Microbiomes 2020; 6:40. [PMID: 33056998 PMCID: PMC7560852 DOI: 10.1038/s41522-020-00151-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 09/21/2020] [Indexed: 01/04/2023] Open
Abstract
Cathode-driven applications of bio-electrochemical systems (BESs) have the potential to transform CO2 into value-added chemicals using microorganisms. However, their commercialisation is limited as biocathodes in BESs are characterised by slow start-up and low efficiency. Understanding biosynthesis pathways, electron transfer mechanisms and the effect of operational variables on microbial electrosynthesis (MES) is of fundamental importance to advance these applications of a system that has the capacity to convert CO2 to organics and is potentially sustainable. In this work, we demonstrate that cathodic potential and inorganic carbon source are keys for the development of a dense and conductive biofilm that ensures high efficiency in the overall system. Applying the cathodic potential of -1.0 V vs. Ag/AgCl and providing only gaseous CO2 in our system, a dense biofilm dominated by Acetobacterium (ca. 50% of biofilm) was formed. The superior biofilm density was significantly correlated with a higher production yield of organic chemicals, particularly acetate. Together, a significant decrease in the H2 evolution overpotential (by 200 mV) and abundant nifH genes within the biofilm were observed. This can only be mechanistically explained if intracellular hydrogen production with direct electron uptake from the cathode via nitrogenase within bacterial cells is occurring in addition to the commonly observed extracellular H2 production. Indeed, the enzymatic activity within the biofilm accelerated the electron transfer. This was evidenced by an increase in the coulombic efficiency (ca. 69%) and a 10-fold decrease in the charge transfer resistance. This is the first report of such a significant decrease in the charge resistance via the development of a highly conductive biofilm during MES. The results highlight the fundamental importance of maintaining a highly active autotrophic Acetobacterium population through feeding CO2 in gaseous form, which its dominance in the biocathode leads to a higher efficiency of the system.
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Affiliation(s)
- Paniz Izadi
- School of Engineering, Newcastle University, Newcastle upon Tyne, UK
| | | | - Alexiane Godain
- School of Natural and Environmental Sciences, Newcastle upon Tyne, UK
| | - Eileen H Yu
- School of Engineering, Newcastle University, Newcastle upon Tyne, UK.
- Department of Chemical Engineering, Loughborough University, Loughborough, UK.
| | - Ian M Head
- School of Natural and Environmental Sciences, Newcastle upon Tyne, UK
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29
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Jawed K, Abdelaal AS, Koffas MAG, Yazdani SS. Improved Butanol Production Using FASII Pathway in E. coli. ACS Synth Biol 2020; 9:2390-2398. [PMID: 32813973 DOI: 10.1021/acssynbio.0c00154] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
n-Butanol is often considered a potential substitute for gasoline due to its physicochemical properties being closely related to those of gasoline. In this study, we extend our earlier work to convert endogenously producing butyrate via the FASII pathway using thioesterase TesBT to its corresponding alcohol, i.e., butanol. We first assembled pathway genes, i.e., car encoding carboxylic acid reductase from Mycobacterium marinum, sfp encoding phosphopantetheinyl transferase from Bacillus subtilis, and adh2 encoding alcohol dehydrogenase from S. cerevisiae, responsible for bioconversion of butyrate to butanol in three different configurations (Operon, Pseudo-Operon, and Monocistronic) to achieve optimum expression of each gene and compared with the clostridial solventogenic pathway for in vivo conversion of butyrate to butanol under aerobic conditions. An E. coli strain harboring car, sfp, and adh2 in pseudo-operon configuration was able to convert butyrate to butanol with 100% bioconversion efficiency when supplemented with 1 g/L of butyrate. Further, co-cultivation of an upstream strain (butyrate-producing) with a downstream strain (butyrate to butanol converting) at different inoculation ratios was investigated, and an optimized ratio of 1:4 (upstream strain: downstream strain) was found to produce ∼2 g/L butanol under fed-batch fermentation. Further, a mono-cultivation approach was applied by transforming a plasmid harboring tesBT gene into the downstream strain. This approach produced 0.42 g/L in a test tube and ∼2.9 g/L butanol under fed-batch fermentation. This is the first report where both mono- and co-cultivation approaches were tested and compared for butanol production, and butanol titers achieved using both strategies are the highest reported values in recombinant E. coli utilizing FASII pathway.
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Affiliation(s)
- Kamran Jawed
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, 110067 New Delhi, India
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Ali Samy Abdelaal
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, 110067 New Delhi, India
- Department of Genetics, Faculty of Agriculture, Damietta University, 34511 Damietta, Egypt
| | - Mattheos A. G. Koffas
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Syed Shams Yazdani
- Microbial Engineering Group, International Centre for Genetic Engineering and Biotechnology, 110067 New Delhi, India
- DBT-ICGEB Centre for Advanced Bioenergy Research, International Centre for Genetic Engineering and Biotechnology, 110067 New Delhi, India
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30
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A kinetic rationale for functional redundancy in fatty acid biosynthesis. Proc Natl Acad Sci U S A 2020; 117:23557-23564. [PMID: 32883882 DOI: 10.1073/pnas.2013924117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cells build fatty acids with biocatalytic assembly lines in which a subset of enzymes often exhibit overlapping activities (e.g., two enzymes catalyze one or more identical reactions). Although the discrete enzymes that make up fatty acid pathways are well characterized, the importance of catalytic overlap between them is poorly understood. We developed a detailed kinetic model of the fatty acid synthase (FAS) of Escherichia coli and paired that model with a fully reconstituted in vitro system to examine the capabilities afforded by functional redundancy in fatty acid synthesis. The model captures-and helps explain-the effects of experimental perturbations to FAS systems and provides a powerful tool for guiding experimental investigations of fatty acid assembly. Compositional analyses carried out in silico and in vitro indicate that FASs with multiple partially redundant enzymes enable tighter (i.e., more independent and/or broader range) control of distinct biochemical objectives-the total production, unsaturated fraction, and average length of fatty acids-than FASs with only a single multifunctional version of each enzyme (i.e., one enzyme with the catalytic capabilities of two partially redundant enzymes). Maximal production of unsaturated fatty acids, for example, requires a second dehydratase that is not essential for their synthesis. This work provides a kinetic, control-theoretic rationale for the inclusion of partially redundant enzymes in fatty acid pathways and supplies a valuable framework for carrying out detailed studies of FAS kinetics.
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Increased Accumulation of Medium-Chain Fatty Acids by Dynamic Degradation of Long-Chain Fatty Acids in Mucor circinelloides. Genes (Basel) 2020; 11:genes11080890. [PMID: 32764225 PMCID: PMC7464202 DOI: 10.3390/genes11080890] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 12/12/2022] Open
Abstract
Concerns about global warming, fossil-fuel depletion, food security, and human health have promoted metabolic engineers to develop tools/strategies to overproduce microbial functional oils directly from renewable resources. Medium-chain fatty acids (MCFAs, C8–C12) have been shown to be important sources due to their diverse biotechnological importance, providing benefits ranging from functional lipids to uses in bio-fuel production. However, oleaginous microbes do not carry native pathways for the production of MCFAs, and therefore, diverse approaches have been adapted to compensate for the requirements of industrial demand. Mucor circinelloides is a promising organism for lipid production (15–36% cell dry weight; CDW) and the investigation of mechanisms of lipid accumulation; however, it mostly produces long-chain fatty acids (LCFAs). To address this challenge, we genetically modified strain M. circinelloides MU758, first by integrating heterologous acyl-ACP thioesterase (TE) into fatty acid synthase (FAS) complex and subsequently by modifying the β-oxidation pathway by disrupting the acyl-CoA oxidase (ACOX) and/or acyl-CoA thioesterase (ACOT) genes with a preference for medium-chain acyl-CoAs, to elevate the yield of MCFAs. The resultant mutant strains (M-1, M-2, and M-3, respectively) showed a significant increase in lipid production in comparison to the wild-type strain (WT). MCFAs in M-1 (47.45%) was sharply increased compared to the wild type strain (2.25%), and it was further increased in M-2 (60.09%) suggesting a negative role of ACOX in MCFAs production. However, MCFAs in M-3 were much decreased compared to M-1,suggesting a positive role of ACOT in MCFAs production. The M-2 strain showed maximum lipid productivity (~1800 milligram per liter per day or mg/L.d) and MCFAs productivity (~1100 mg/L.d). Taken together, this study elaborates on how the combination of two multidimensional approaches, TE gene over-expression and modification of the β-oxidation pathway via substantial knockout of specific ACOX gene, significantly increased the production of MCFAs. This synergistic approach ultimately offers a novel opportunity for synthetic/industrial biologists to increase the content of MCFAs.
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Venkateswar Reddy M, Kumar G, Mohanakrishna G, Shobana S, Al-Raoush RI. Review on the production of medium and small chain fatty acids through waste valorization and CO 2 fixation. BIORESOURCE TECHNOLOGY 2020; 309:123400. [PMID: 32371319 DOI: 10.1016/j.biortech.2020.123400] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 06/11/2023]
Abstract
The developing approaches in the recovery of resources from biowastes for the production of renewable value-added products and fuels, using microbial cultures as bio-catalyst have now became promising aspect. In the path of anaerobic digestion, the microorganisms are assisting transformation of a complex organic feedstock/waste to biomass and biogas. This potentiality consequently leads to the production of intermediate precursors of renewable value-added products. Particularly, a set of anaerobic pathways in the fermentation process, yields small-chain fatty acids (SCFA), and medium-chain fatty acids (MCFA) via chain elongation pathways from waste valorization and CO2 fixation. This review focuses on the production of SCFA and MCFA from CO2, synthetic substrates and waste materials. Moreover, the review introduces the metabolic engineering of Escherichia coli and Saccharomyces cerevisiae for SCFAs/MCFAs production. Furtherly, it concludes that future critical research might target progress of this promising approach as a valorization of complex organic wastes.
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Affiliation(s)
- M Venkateswar Reddy
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms Universität, Corrensstr. 3, 48149 Münster, Germany
| | - Gopalakrishnan Kumar
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Gunda Mohanakrishna
- Department of Civil and Architectural Engineering, College of Engineering, Qatar University, P O Box 2713, Doha, Qatar.
| | - Sutha Shobana
- Department of Chemistry & Research Centre, Mohamed Sathak Engineering College, Kilakarai, 623 806 Ramanathapuram, Tamil Nadu, India
| | - Riyadh I Al-Raoush
- Department of Civil and Architectural Engineering, College of Engineering, Qatar University, P O Box 2713, Doha, Qatar
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Baumschlager A, Rullan M, Khammash M. Exploiting natural chemical photosensitivity of anhydrotetracycline and tetracycline for dynamic and setpoint chemo-optogenetic control. Nat Commun 2020; 11:3834. [PMID: 32737309 PMCID: PMC7395757 DOI: 10.1038/s41467-020-17677-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 07/02/2020] [Indexed: 01/02/2023] Open
Abstract
The transcriptional inducer anhydrotetracycline (aTc) and the bacteriostatic antibiotic tetracycline (Tc) are commonly used in all fields of biology for control of transcription or translation. A drawback of these and other small molecule inducers is the difficulty of their removal from cell cultures, limiting their application for dynamic control. Here, we describe a simple method to overcome this limitation, and show that the natural photosensitivity of aTc/Tc can be exploited to turn them into highly predictable optogenetic transcriptional- and growth-regulators. This new optogenetic class uniquely features both dynamic and setpoint control which act via population-memory adjustable through opto-chemical modulation. We demonstrate this method by applying it for dynamic gene expression control and for enhancing the performance of an existing optogenetic system. We then expand the utility of the aTc system by constructing a new chemical bandpass filter that increases its aTc response range. The simplicity of our method enables scientists and biotechnologists to use their existing systems employing aTc/Tc for dynamic optogenetic experiments without genetic modification.
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Affiliation(s)
- Armin Baumschlager
- Department of Biosystems Science and Engineering (D-BSSE), ETH-Zürich, Mattenstrasse 26, 4058, Basel, Switzerland
| | - Marc Rullan
- Department of Biosystems Science and Engineering (D-BSSE), ETH-Zürich, Mattenstrasse 26, 4058, Basel, Switzerland
| | - Mustafa Khammash
- Department of Biosystems Science and Engineering (D-BSSE), ETH-Zürich, Mattenstrasse 26, 4058, Basel, Switzerland.
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34
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Wang L, Chen L, Yang S, Tan X. Photosynthetic Conversion of Carbon Dioxide to Oleochemicals by Cyanobacteria: Recent Advances and Future Perspectives. Front Microbiol 2020; 11:634. [PMID: 32362881 PMCID: PMC7181335 DOI: 10.3389/fmicb.2020.00634] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 03/20/2020] [Indexed: 11/21/2022] Open
Abstract
Sustainable production of biofuels and biochemicals has been broadly accepted as a solution to lower carbon dioxide emissions. Besides being used as lubricants or detergents, oleochemicals are also attractive biofuels as they are compatible with existing transport infrastructures. Cyanobacteria are autotrophic prokaryotes possessing photosynthetic abilities with mature genetic manipulation systems. Through the introduction of exogenous or the modification of intrinsic metabolic pathways, cyanobacteria have been engineered to produce various bio-chemicals and biofuels over the past decade. In this review, we specifically summarize recent progress on photosynthetic production of fatty acids, fatty alcohols, fatty alk(a/e)nes, and fatty acid esters by genetically engineered cyanobacteria. We also summarize recent reports on fatty acid and lipid metabolisms of cyanobacteria and provide perspectives for economic cyanobacterial oleochemical production in the future.
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Affiliation(s)
- Li Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, School of Life Sciences, Hubei University, Wuhan, China
| | - Liyuan Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, School of Life Sciences, Hubei University, Wuhan, China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, School of Life Sciences, Hubei University, Wuhan, China
| | - Xiaoming Tan
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, School of Life Sciences, Hubei University, Wuhan, China
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35
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Zhang Q, Hou Z, Ma Q, Mo X, Sun Q, Tan M, Xia L, Lin G, Yang M, Zhang Y, Xu Q, Li Y, Chen N, Xie X. CRISPRi-Based Dynamic Control of Carbon Flow for Efficient N-Acetyl Glucosamine Production and Its Metabolomic Effects in Escherichia coli. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:3203-3213. [PMID: 32101421 DOI: 10.1021/acs.jafc.9b07896] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Carbon competition between cell growth and product synthesis is the bottleneck in efficient N-acetyl glucosamine (GlcNAc) production in microbial cell factories. In this study, a xylose-induced T7 RNA polymerase-PT7 promoter system was introduced in Escherichia coli W3110 to control the GlcNAc synthesis. Meanwhile, an arabinose-induced CRISPR interference (CRISPRi) system was applied to adjust cell growth by attenuating the transcription of key growth-related genes. By designing proper sgRNAs, followed by elaborate adjustment of the addition time and concentration of the two inducers, the carbon flux between cell growth and GlcNAc synthesis was precisely redistributed. Comparative metabolomics analysis results confirmed that the repression of pfkA and zwf significantly attenuated the TCA cycle and the synthesis of related amino acids, saving more carbon for the GlcNAc synthesis. Finally, the simultaneous repression of pfkA and zwf in strain GLA-14 increased the GlcNAc titer by 47.6% compared with that in E. coli without the CRISPRi system in a shake flask. GLA-14 could produce 90.9 g/L GlcNAc within 40 h in a 5 L bioreactor, with a high productivity of 2.27 g/L/h. This dynamic strategy for rebalancing cell growth and product synthesis could be applied in the fermentative production of other chemicals derived from precursors synthesized via central carbon metabolism.
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Affiliation(s)
- Quanwei Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Zhengjie Hou
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Qian Ma
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin 300457, China
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin 300457, China
| | - Xiaolin Mo
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Quanwei Sun
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Miao Tan
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Li Xia
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Gaoyang Lin
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Mengya Yang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Ying Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Qingyang Xu
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin 300457, China
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin 300457, China
| | - Yanjun Li
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin 300457, China
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin 300457, China
| | - Ning Chen
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin 300457, China
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin 300457, China
| | - Xixian Xie
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin 300457, China
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin 300457, China
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36
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Multidimensional engineering of Saccharomyces cerevisiae for efficient synthesis of medium-chain fatty acids. Nat Catal 2020. [DOI: 10.1038/s41929-019-0409-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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37
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Kim SG, Noh MH, Lim HG, Jang S, Jang S, Koffas MAG, Jung GY. Molecular parts and genetic circuits for metabolic engineering of microorganisms. FEMS Microbiol Lett 2019; 365:5059574. [PMID: 30052915 DOI: 10.1093/femsle/fny187] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 07/24/2018] [Indexed: 12/17/2022] Open
Abstract
Microbial conversion of biomass into value-added biochemicals is a highly sustainable process compared to petroleum-based production. In this regard, microorganisms have been engineered via simple overexpression or deletion of metabolic genes to facilitate the production. However, the producer microorganisms require complex regulatory circuits to maximize productivity and performance. To address this issue, diverse genetic circuits have been developed that allow cells to minimize their metabolic burden, overcome metabolic imbalances and respond to a dynamically changing environment. In this review, we briefly explain the basic strategy for constructing genetic circuits by assembling molecular parts such as input, operation and output modules. Next, we describe recent applications of the circuits in the metabolic engineering of microorganisms to improve biochemical production. Beyond those achievements, genetic circuits will facilitate more innovative approaches to future strain development through mining and engineering new genetic elements and improving the complexity of genetic circuit design.
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Affiliation(s)
- Seong Gyeong Kim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Myung Hyun Noh
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Hyun Gyu Lim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Sungho Jang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Sungyeon Jang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Mattheos A G Koffas
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy 12180, USA
| | - Gyoo Yeol Jung
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
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Chacón MG, Kendrick EG, Leak DJ. Engineering Escherichia coli for the production of butyl octanoate from endogenous octanoyl-CoA. PeerJ 2019; 7:e6971. [PMID: 31304053 PMCID: PMC6610577 DOI: 10.7717/peerj.6971] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 04/18/2019] [Indexed: 11/20/2022] Open
Abstract
Medium chain esters produced from fruits and flowering plants have a number of commercial applications including use as flavour and fragrance ingredients, biofuels, and in pharmaceutical formulations. These esters are typically made via the activity of an alcohol acyl transferase (AAT) enzyme which catalyses the condensation of an alcohol and an acyl-CoA. Developing a microbial platform for medium chain ester production using AAT activity presents several obstacles, including the low product specificity of these enzymes for the desired ester and/or low endogenous substrate availability. In this study, we engineered Escherichia coli for the production of butyl octanoate from endogenously produced octanoyl-CoA. This was achieved through rational protein engineering of an AAT enzyme from Actinidia chinensis for improved octanoyl-CoA substrate specificity and metabolic engineering of E. coli fatty acid metabolism for increased endogenous octanoyl-CoA availability. This resulted in accumulation of 3.3 + 0.1 mg/L butyl octanoate as the sole product from E. coli after 48 h. This study represents a preliminary examination of the feasibility of developing E. coli platforms for the synthesis single medium chain esters from endogenous fatty acids.
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Affiliation(s)
- Micaela G Chacón
- Department of Biology and Biochemistry, University of Bath, Bath, England
| | | | - David J Leak
- Department of Biology and Biochemistry, University of Bath, Bath, England
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39
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Heil CS, Wehrheim SS, Paithankar KS, Grininger M. Fatty Acid Biosynthesis: Chain‐Length Regulation and Control. Chembiochem 2019; 20:2298-2321. [DOI: 10.1002/cbic.201800809] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/20/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Christina S. Heil
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - S. Sophia Wehrheim
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - Karthik S. Paithankar
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - Martin Grininger
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
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40
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Optimization of Diverse Carbon Sources and Cultivation Conditions for Enhanced Growth and Lipid and Medium-Chain Fatty Acid (MCFA) Production by Mucor circinelloides. FERMENTATION-BASEL 2019. [DOI: 10.3390/fermentation5020035] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Keywords: Mucor circinelloides; microbial lipids; medium-chain fatty acids; culture optimization
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Yan Q, Pfleger BF. Revisiting metabolic engineering strategies for microbial synthesis of oleochemicals. Metab Eng 2019; 58:35-46. [PMID: 31022535 DOI: 10.1016/j.ymben.2019.04.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/20/2019] [Accepted: 04/21/2019] [Indexed: 02/06/2023]
Abstract
Microbial production of oleochemicals from renewable feedstocks remains an attractive route to produce high-energy density, liquid transportation fuels and high-value chemical products. Metabolic engineering strategies have been applied to demonstrate production of a wide range of oleochemicals, including free fatty acids, fatty alcohols, esters, olefins, alkanes, ketones, and polyesters in both bacteria and yeast. The majority of these demonstrations synthesized products containing long-chain fatty acids. These successes motivated additional effort to produce analogous molecules comprised of medium-chain fatty acids, molecules that are less common in natural oils and therefore of higher commercial value. Substantial progress has been made towards producing a subset of these chemicals, but significant work remains for most. The other primary challenge to producing oleochemicals in microbes is improving the performance, in terms of yield, rate, and titer, of biocatalysts such that economic large-scale processes are feasible. Common metabolic engineering strategies include blocking pathways that compete with synthesis of oleochemical building blocks and/or consume products, pulling flux through pathways by removing regulatory signals, pushing flux into biosynthesis by overexpressing rate-limiting enzymes, and engineering cells to tolerate the presence of oleochemical products. In this review, we describe the basic fundamentals of oleochemical synthesis and summarize advances since 2013 towards improving performance of heterotrophic microbial cell factories.
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Affiliation(s)
- Qiang Yan
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Brian F Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Wisconsin-Madison, Madison, WI 53706, United States; Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706, United States.
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Engineering of Fatty Acid Synthases (FASs) to Boost the Production of Medium-Chain Fatty Acids (MCFAs) in Mucor circinelloides. Int J Mol Sci 2019; 20:ijms20030786. [PMID: 30759801 PMCID: PMC6387429 DOI: 10.3390/ijms20030786] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/06/2019] [Accepted: 02/09/2019] [Indexed: 02/06/2023] Open
Abstract
Increasing energy demands and health-related concerns worldwide have motivated researchers to adopt diverse strategies to improve medium-chain fatty acid (MCFA) biosynthesis for use in the functional food and aviation industries. The abundance of naturally produced MCFAs from botanical sources (i.e., coconut fruit/seeds and palm tree) has been observed to be insufficient compared with the various microorganisms used to cope with industrial demands. Mucor circinelloides is one of many promising microorganisms; it exhibits diverse biotechnological importance ranging from the production of functional lipids to applications in the manufacture of bio-fuel. Thus, research was conducted to acquire the desired elevated amounts of MCFAs (i.e., C8–C12) from metabolically engineered strains of M. circinelloides M65. To achieve this goal, four different acyl-acyl carrier protein (ACP) thioesterase (TE)-encoding genes exhibiting a substrate preference for medium-chain acyl-ACP molecules were expressed in M. circinelloides M65, resulting in the generation of C8–C12 fatty acids. Among all the engineered strains, M65-TE-03 and M65-TE-04 demonstrated the highest production of non-native C8–C10 and C12 fatty acids, respectively, in comparison to the control. These recombinant strains biosynthesized MCFAs de novo within the range from 28 to 46% (i.e., 1.14 to 2.77 g/L) of total cell lipids. Moreover, the reduction in chain length eventually resulted in a 1.5–1.75-fold increase in total lipid productivity in the engineered strains. The MCFAs were also found to be integrated into all lipid classes. This work illustrates how the integration of heterologous enzymes in M. circinelloides can offer a novel opportunity to edit the fatty acid synthases (FAS) complex, resulting in increased production of microbial MFCAs.
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Microbial Production of Fatty Acid via Metabolic Engineering and Synthetic Biology. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-018-0374-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Tong X, Oh EK, Lee BH, Lee JK. Production of long-chain free fatty acids from metabolically engineered Rhodobacter sphaeroides heterologously producing periplasmic phospholipase A2 in dodecane-overlaid two-phase culture. Microb Cell Fact 2019; 18:20. [PMID: 30704481 PMCID: PMC6357386 DOI: 10.1186/s12934-019-1070-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 01/22/2019] [Indexed: 12/03/2022] Open
Abstract
Background Long-chain free fatty acids (FFAs) are a type of backbone molecule that can react with alcohol to produce biodiesels. Various microorganisms have become potent producers of FFAs. Efforts have focused on increasing metabolic flux to the synthesis of either neutral fat or fatty acyl intermediates attached to acyl carrier protein (ACP), which are the source of FFAs. Membrane lipids are also a source of FFAs. As an alternative way of producing FFAs, exogenous phospholipase may be used after heterologous production and localization in the periplasmic space. In this work, we examined whether Rhodobacter sphaeroides, which forms an intracytoplasmic membrane, can be used for long-chain FFA production using phospholipase. Results The recombinant R. sphaeroides strain Rs-A2, which heterologously produces Arabidopsis thaliana phospholipase A2 (PLA2) in the periplasm, excretes FFAs during growth. FFA productivity under photoheterotrophic conditions is higher than that observed under aerobic or semiaerobic conditions. When the biosynthetic enzymes for FA (β-ketoacyl-ACP synthase, FabH) and phosphatidate (1-acyl-sn-glycerol-3-phosphate acyltransferase, PlsC) were overproduced in Rs-A2, the FFA productivity of the resulting strain Rs-HCA2 was elevated, and the FFAs produced mainly consisted of long-chain FAs of cis-vaccenate, stearate, and palmitate in an approximately equimolar ratio. The high-cell-density culture of Rs-HCA2 with DMSO in two-phase culture with dodecane resulted in an increase of overall carbon substrate consumption, which subsequently leads to a large increase in FFA productivity of up to 2.0 g L−1 day−1. Overexpression of the genes encoding phosphate acyltransferase (PlsX) and glycerol-3-phosphate acyltransferase (PlsY), which catalyze the biosynthetic steps immediately upstream from PlsC, in Rs-HCA2 generated Rs-HXYCA2, which grew faster than Rs-HCA2 and showed an FFA productivity of 2.8 g L−1 day−1 with an FFA titer of 8.5 g L−1. Conclusion We showed that long-chain FFAs can be produced from metabolically engineered R. sphaeroides heterologously producing PLA2 in the periplasm. The FFA productivity was greatly increased by high-cell-density culture in two-phase culture with dodecane. This approach provides highly competitive productivity of long-chain FFAs by R. sphaeroides compared with other bacteria. This method may be applied to FFA production by other photosynthetic bacteria with similar differentiated membrane systems. Electronic supplementary material The online version of this article (10.1186/s12934-019-1070-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaomeng Tong
- Department of Life Science, Sogang University, Mapo, Shinsu 1, Seoul, 121-742, South Korea
| | - Eun Kyoung Oh
- Department of Life Science, Sogang University, Mapo, Shinsu 1, Seoul, 121-742, South Korea
| | - Byeong-Ha Lee
- Department of Life Science, Sogang University, Mapo, Shinsu 1, Seoul, 121-742, South Korea
| | - Jeong K Lee
- Department of Life Science, Sogang University, Mapo, Shinsu 1, Seoul, 121-742, South Korea.
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Abstract
Biocatalytic systems (e.g., multienzyme pathways or complexes) enable the conversion of simple sugars into complex products under ambient conditions and, thus, represent promising platforms for the synthesis of renewable fuels and chemicals. Unfortunately, to date, many of these systems have proven difficult to engineer without a detailed understanding of the kinetic relationships that regulate the concerted action of their constituent enzymes. This study develops a mechanistic kinetic model of the fatty acid synthase (FAS) of Escherichia coli and uses that model to determine how different FAS components work together to control the production of free fatty acids-precursors to a wide range of oleochemicals. Perturbational analyses indicate that the modification or overexpression of a single FAS component can depress fatty acid production (a commonly observed phenomenon) by sequestering the proteins with which it interacts and/or by depleting common substrate pools. Compositional studies, in turn, suggest that simple changes in the ratios of FAS components can alter the average length of fatty acids but show that specialized enzymes (i.e., highly specific ketoacyl synthases or thioesterases) are required for narrow product profiles. Intriguingly, a sensitivity analysis indicates that two components primarily influence-and, thus, enable fine control over-total production, but suggests that the enzymes that regulate product profile are more broadly influential. Findings thus reveal the general importance of kinetic considerations in efforts to engineer fatty acid biosynthesis and provide strategies-and a kinetic model-for incorporating those considerations into FAS designs.
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Affiliation(s)
- Sophia Ruppe
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303, United States
| | - Jerome M. Fox
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303, United States
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Hernández Lozada NJ, Lai RY, Simmons TR, Thomas KA, Chowdhury R, Maranas CD, Pfleger BF. Highly Active C 8-Acyl-ACP Thioesterase Variant Isolated by a Synthetic Selection Strategy. ACS Synth Biol 2018; 7:2205-2215. [PMID: 30064208 DOI: 10.1021/acssynbio.8b00215] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Microbial metabolism is an attractive route for producing medium chain length fatty acids, e.g., octanoic acid, used in the oleochemical industry. One challenge to this strategy is the lack of enzymes that are both highly active in a microbial host and selective toward substrates with desired chain length. Of the many steps in fatty acid biosynthesis, the thioesterase is the most widely used enzyme for controlling chain length. Thioesterases hydrolyze the thioester bond between fatty acids and the acyl-carrier protein (ACP) or coenzyme A (CoA) cofactor. The functional role of thioesterases varies between organisms ( i.e., bacteria vs plant) and therefore so do the substrate specificities. As a result, microbial biocatalysts that utilize a heterologous thioesterase either produce high titers of fatty acids with mixed chain lengths or low titers of products with a narrow chain length distribution. To search for highly active enzymes that selectively hydrolyze octanoyl-ACP, we developed a genetic selection based on the lipoic acid requirement of Escherichia coli. We used the selection to identify variants in a randomly mutagenized library of the C8-specific Cuphea palustris FatB1 thioesterase. After optimizing expression of the thioesterase, E. coli cultures produced 1.7 g/L of octanoic acid with >90% specificity from a single chromosomal copy of this thioesterase. In vitro studies confirmed the mutant thioesterase possessed a 15-fold increase in kcat compared to its native sequence. The high level of specific activity allowed for low levels of expression while maintaining fatty acid titer. The low expression requirement will allow metabolic engineers to use more cellular resources to address other limitations in the pathway and maximize overall productivity.
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Affiliation(s)
- Néstor J. Hernández Lozada
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Rung-Yi Lai
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Trevor R. Simmons
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Kelsey A. Thomas
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Ratul Chowdhury
- Department of Chemical Engineering, Pennsylvania State University, 158 Fenske Laboratory, University Park, Pennsylvania 16802, United States
| | - Costas D. Maranas
- Department of Chemical Engineering, Pennsylvania State University, 158 Fenske Laboratory, University Park, Pennsylvania 16802, United States
| | - Brian F. Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin−Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
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Lessons in Membrane Engineering for Octanoic Acid Production from Environmental Escherichia coli Isolates. Appl Environ Microbiol 2018; 84:AEM.01285-18. [PMID: 30030228 DOI: 10.1128/aem.01285-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 07/10/2018] [Indexed: 01/01/2023] Open
Abstract
Fermentative production of many attractive biorenewable fuels and chemicals is limited by product toxicity in the form of damage to the microbial cell membrane. Metabolic engineering of the production organism can help mitigate this problem, but there is a need for identification and prioritization of the most effective engineering targets. Here, we use a set of previously characterized environmental Escherichia coli isolates with high tolerance and production of octanoic acid, a model membrane-damaging biorenewable product, as a case study for identifying and prioritizing membrane engineering strategies. This characterization identified differences in the membrane lipid composition, fluidity, integrity, and cell surface hydrophobicity from those of the lab strain MG1655. Consistent with previous publications, decreased membrane fluidity was associated with increased fatty acid production ability. Maintenance of high membrane integrity or longer membrane lipids seemed to be of less importance than fluidity. Cell surface hydrophobicity was also directly associated with fatty acid production titers, with the strength of this association demonstrated by plasmid-based expression of the multiple stress resistance outer membrane protein BhsA. This expression of bhsA was effective in altering hydrophobicity, but the direction and magnitude of the change differed between strains. Thus, additional strategies are needed to reliably engineer cell surface hydrophobicity. This work demonstrates the ability of environmental microbiological studies to impact the metabolic engineering design-build-test-learn cycle and possibly increase the economic viability of fermentative bioprocesses.IMPORTANCE The production of bulk fuels and chemicals in a bio-based fermentation process requires high product titers. This is often difficult to achieve, because many of the target molecules damage the membrane of the microbial cell factory. Engineering the composition of the membrane in order to decrease its vulnerability to this damage has proven to be an effective strategy for improving bioproduction, but additional strategies and engineering targets are needed. Here, we studied a small set of environmental Escherichia coli isolates that have higher production titers of octanoic acid, a model biorenewable chemical, than those of the lab strain MG1655. We found that membrane fluidity and cell surface hydrophobicity are strongly associated with improved octanoic acid production. Fewer genetic modification strategies have been demonstrated for tuning hydrophobicity relative to fluidity, leading to the conclusion that there is a need for expanding hydrophobicity engineering strategies in E. coli.
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Tan Z, Clomburg JM, Gonzalez R. Synthetic Pathway for the Production of Olivetolic Acid in Escherichia coli. ACS Synth Biol 2018; 7:1886-1896. [PMID: 29976061 DOI: 10.1021/acssynbio.8b00075] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Type III polyketide synthases (PKS IIIs) contribute to the synthesis of many economically important natural products, most of which are currently produced by direct extraction from plants or through chemical synthesis. Olivetolic acid (OLA) is a plant secondary metabolite sourced from PKS III catalysis, which along with its prenylated derivatives has various pharmacological activities. To demonstrate the potential for microbial cell factories to circumvent limitations of plant extraction or chemical synthesis for OLA, here we utilize a synthetic approach to engineer Escherichia coli for the production of OLA. In vitro characterization of polyketide synthase and cyclase enzymes, OLA synthase and OLA cyclase, respectively, validated their requirement as enzymatic components of the OLA pathway and confirmed the ability for these eukaryotic enzymes to be functionally expressed in E. coli. This served as a platform for the combinatorial expression of these enzymes with auxiliary enzymes aimed at increasing the supply of hexanoyl-CoA and malonyl-CoA as starting and extender units, respectively. Through combining OLA synthase and OLA cyclase expression with the required modules of a β-oxidation reversal for hexanoyl-CoA generation, we demonstrate the in vivo synthesis of olivetolic acid from a single carbon source. The integration of additional auxiliary enzymes to increase hexanoyl-CoA and malonyl-CoA, along with evaluation of varying fermentation conditions enabled the synthesis of 80 mg/L OLA. This is the first report of OLA production in E. coli, adding a new example to the repertoire of valuable compounds synthesized in this industrial workhorse.
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Affiliation(s)
- Zaigao Tan
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - James M. Clomburg
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Ramon Gonzalez
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
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Motwalli O, Essack M, Salhi A, Hanks J, Mijakovic I, Bajic VB. BioPS: System for screening and assessment of biofuel-production potential of cyanobacteria. PLoS One 2018; 13:e0202002. [PMID: 30096176 PMCID: PMC6086437 DOI: 10.1371/journal.pone.0202002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 07/26/2018] [Indexed: 01/03/2023] Open
Abstract
Background Cyanobacteria are one of the target groups of organisms explored for production of free fatty acids (FFAs) as biofuel precursors. Experimental evaluation of cyanobacterial potential for FFA production is costly and time consuming. Thus, computational approaches for comparing and ranking cyanobacterial strains for their potential to produce biofuel based on the characteristics of their predicted proteomes can be of great importance. Results To enable such comparison and ranking, and to assist biotechnology developers and researchers in selecting strains more likely to be successfully engineered for the FFA production, we developed the Biofuel Producer Screen (BioPS) platform (http://www.cbrc.kaust.edu.sa/biops). BioPS relies on the estimation of the predicted proteome makeup of cyanobacterial strains to produce and secrete FFAs, based on the analysis of well-studied cyanobacterial strains with known FFA production profiles. The system links results back to various external repositories such as KEGG, UniProt and GOLD, making it easier for users to explore additional related information. Conclusion To our knowledge, BioPS is the first tool that screens and evaluates cyanobacterial strains for their potential to produce and secrete FFAs based on strain’s predicted proteome characteristics, and rank strains based on that assessment. We believe that the availability of such a platform (comprising both a prediction tool and a repository of pre-evaluated stains) would be of interest to biofuel researchers. The BioPS system will be updated annually with information obtained from newly sequenced cyanobacterial genomes as they become available, as well as with new genes that impact FFA production or secretion.
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Affiliation(s)
- Olaa Motwalli
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Thuwal, Kingdom of Saudi Arabia
- Saudi Electronic University (SEU), College of Computing and Informatics, Madinah, Kingdom of Saudi Arabia
| | - Magbubah Essack
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Thuwal, Kingdom of Saudi Arabia
| | - Adil Salhi
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Thuwal, Kingdom of Saudi Arabia
| | - John Hanks
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Thuwal, Kingdom of Saudi Arabia
| | - Ivan Mijakovic
- Chalmers University of Technology, Division of Systems & Synthetic Biology, Department of Biology and Biological Engineering, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Vladimir B. Bajic
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Thuwal, Kingdom of Saudi Arabia
- * E-mail:
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Maury J, Kannan S, Jensen NB, Öberg FK, Kildegaard KR, Forster J, Nielsen J, Workman CT, Borodina I. Glucose-Dependent Promoters for Dynamic Regulation of Metabolic Pathways. Front Bioeng Biotechnol 2018; 6:63. [PMID: 29872655 PMCID: PMC5972318 DOI: 10.3389/fbioe.2018.00063] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 04/30/2018] [Indexed: 11/13/2022] Open
Abstract
For an industrial fermentation process, it can be advantageous to decouple cell growth from product formation. This decoupling would allow for the rapid accumulation of biomass without inhibition from product formation, after which the fermentation can be switched to a mode where cells would grow minimally and primarily act as catalysts to convert substrate into desired product. The switch in fermentation mode should preferably be accomplished without the addition of expensive inducers. A common cell factory Saccharomyces cerevisiae is a Crabtree-positive yeast and is typically fermented at industrial scale under glucose-limited conditions to avoid the formation of ethanol. In this work, we aimed to identify and characterize promoters that depend on glucose concentration for use as dynamic control elements. Through analysis of mRNA data of S. cerevisiae grown in chemostats under glucose excess or limitation, we identified 34 candidate promoters that strongly responded to glucose presence or absence. These promoters were characterized in small-scale batch and fed-batch cultivations using a quickly maturing rapidly degrading green fluorescent protein yEGFP3-Cln2PEST as a reporter. Expressing 3-hydroxypropionic acid (3HP) pathway from a set of selected regulated promoters allowed for suppression of 3HP production during glucose-excess phase of a batch cultivation with subsequent activation in glucose-limiting conditions. Regulating the 3HP pathway by the ICL1 promoter resulted in 70% improvement of 3HP titer in comparison to PGK1 promoter.
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Affiliation(s)
- Jérôme Maury
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Soumya Kannan
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Niels B Jensen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Fredrik K Öberg
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Kanchana R Kildegaard
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Jochen Forster
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Jens Nielsen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Christopher T Workman
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Irina Borodina
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
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