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Wu T, Jiang J, Zhang H, Liu J, Ruan H. Transcending membrane barriers: advances in membrane engineering to enhance the production capacity of microbial cell factories. Microb Cell Fact 2024; 23:154. [PMID: 38796463 PMCID: PMC11128114 DOI: 10.1186/s12934-024-02436-8] [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: 03/15/2024] [Accepted: 05/21/2024] [Indexed: 05/28/2024] Open
Abstract
Microbial cell factories serve as pivotal platforms for the production of high-value natural products, which tend to accumulate on the cell membrane due to their hydrophobic properties. However, the limited space of the cell membrane presents a bottleneck for the accumulation of these products. To enhance the production of intracellular natural products and alleviate the burden on the cell membrane caused by product accumulation, researchers have implemented various membrane engineering strategies. These strategies involve modifying the membrane components and structures of microbial cell factories to achieve efficient accumulation of target products. This review summarizes recent advances in the application of membrane engineering technologies in microbial cell factories, providing case studies involving Escherichia coli and yeast. Through these strategies, researchers have not only improved the tolerance of cells but also optimized intracellular storage space, significantly enhancing the production efficiency of natural products. This article aims to provide scientific evidence and references for further enhancing the efficiency of similar cell factories.
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Affiliation(s)
- Tao Wu
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China.
| | - Jingjing Jiang
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China
| | - Hongyang Zhang
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China
| | - Jiazhi Liu
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China
| | - Haihua Ruan
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China.
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2
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Wang JM, Cao YJ, Men X, Zhang HB. Construction of a grpE-based plasmid addiction system in Escherichia coli and its application in phloroglucinol biosynthesis. J Appl Microbiol 2024; 135:lxae116. [PMID: 38724452 DOI: 10.1093/jambio/lxae116] [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: 01/17/2024] [Revised: 03/15/2024] [Accepted: 05/08/2024] [Indexed: 05/24/2024]
Abstract
AIM Biotechnical processes in Escherichia coli often operate with artificial plasmids. However, these bioprocesses frequently encounter plasmid loss. To ensure stable expression of heterologous genes in E. coli BL21(DE3), a novel plasmid addiction system (PAS) was developed. METHODS AND RESULTS This PAS employed an essential gene grpE encoding a cochaperone in the DnaK-DnaJ-GrpE chaperone system as the selection marker, which represented a chromosomal ΔgrpE mutant harboring episomal expression plasmids that carry supplementary grpE alleles to restore the deficiency. To demonstrate the feasibility of this system, it was implemented in phloroglucinol (PG) biosynthesis, manifesting improved host tolerance to PG and increased PG production. Specifically, PG titer significantly improved from 0.78 ± 0.02 to 1.34 ± 0.04 g l-1, representing a 71.8% increase in shake-flask fermentation. In fed-batch fermentation, the titer increased from 3.71 ± 0.11 to 4.54 ± 0.10 g l-1, showing a 22.4% increase. RNA sequencing and transcriptome analysis revealed that the improvements were attributed to grpE overexpression and upregulation of various protective chaperones and the biotin acetyl-CoA carboxylase ligase coding gene birA. CONCLUSION This novel PAS could be regarded as a typical example of nonanabolite- and nonmetabolite-related PAS. It effectively promoted plasmid maintenance in the host, improved tolerance to PG, and increased the titer of this compound.
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Affiliation(s)
- Ji-Ming Wang
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 26601, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- School of Health Management, Hengxing University, Qingdao 266100, China
| | - Yu-Jin Cao
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 26601, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Xiao Men
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 26601, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
| | - Hai-Bo Zhang
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 26601, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
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3
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Zhou H, Jia S, Gao Y, Li X, Lin Y, Yang F, Ni K. Characterization of phyllosphere endophytic lactic acid bacteria reveals a potential novel route to enhance silage fermentation quality. Commun Biol 2024; 7:117. [PMID: 38253824 PMCID: PMC10803313 DOI: 10.1038/s42003-024-05816-3] [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: 08/04/2023] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
The naturally attached phyllosphere microbiota play a crucial role in plant-derived fermentation, but the structure and function of phyllosphere endophytes remain largely unidentified. Here, we reveal the diversity, specificity, and functionality of phyllosphere endophytes in alfalfa (Medicago sativa L.) through combining typical microbial culture, high-throughput sequencing, and genomic comparative analysis. In comparison to phyllosphere bacteria (PB), the fermentation of alfalfa solely with endophytes (EN) enhances the fermentation characteristics, primarily due to the dominance of specific lactic acid bacteria (LAB) such as Lactiplantibacillus, Weissella, and Pediococcus. The inoculant with selected endophytic LAB strains also enhances the fermentation quality compared to epiphytic LAB treatment. Especially, one key endophytic LAB named Pediococcus pentosaceus EN5 shows enrichment of genes related to the mannose phosphotransferase system (Man-PTS) and carbohydrate-metabolizing enzymes and higher utilization of carbohydrates. Representing phyllosphere, endophytic LAB shows great potential of promoting ensiling and provides a novel direction for developing microbial inoculant.
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Affiliation(s)
- Hongzhang Zhou
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Shangang Jia
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Yu Gao
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Xiaomei Li
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Yanli Lin
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Fuyu Yang
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China
- College of Animal Science, Guizhou University, Guiyang, 550025, China
| | - Kuikui Ni
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100193, China.
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4
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Gao S, Liao Y, He H, Yang H, Yang X, Xu S, Wang X, Chen K, Ouyang P. Advance of tolerance engineering on microbes for industrial production. Synth Syst Biotechnol 2023; 8:697-707. [PMID: 38025766 PMCID: PMC10656194 DOI: 10.1016/j.synbio.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Industrial microbes have become the core of biological manufacturing, which utilized as the cell factory for production of plenty of chemicals, fuels and medicine. However, the challenge that the extreme stress conditions exist in production is unavoidable for cell factory. Consequently, to enhance robustness of the chassis cell lays the foundation for development of bio-manufacturing. Currently, the researches on cell tolerance covered various aspects, involving reshaping regulatory network, cell membrane modification and other stress response. In fact, the strategies employed to improve cell robustness could be summarized into two directions, irrational engineering and rational engineering. In this review, the metabolic engineering technologies on enhancement of microbe tolerance to industrial conditions are summarized. Meanwhile, the novel thoughts emerged with the development of biological instruments and synthetic biology are discussed.
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Affiliation(s)
- Siyuan Gao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Yang Liao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Hao He
- Petrochemical Research Institute of PetroChina Co. Ltd., Beijing, 102206, China
| | - Huiling Yang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Xuewei Yang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Sheng Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Xin Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Kequan Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Pingkai Ouyang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
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5
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Re A, Mazzoli R. Current progress on engineering microbial strains and consortia for production of cellulosic butanol through consolidated bioprocessing. Microb Biotechnol 2022; 16:238-261. [PMID: 36168663 PMCID: PMC9871528 DOI: 10.1111/1751-7915.14148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/01/2022] [Accepted: 09/07/2022] [Indexed: 01/27/2023] Open
Abstract
In the last decades, fermentative production of n-butanol has regained substantial interest mainly owing to its use as drop-in-fuel. The use of lignocellulose as an alternative to traditional acetone-butanol-ethanol fermentation feedstocks (starchy biomass and molasses) can significantly increase the economic competitiveness of biobutanol over production from non-renewable sources (petroleum). However, the low cost of lignocellulose is offset by its high recalcitrance to biodegradation which generally requires chemical-physical pre-treatment and multiple bioreactor-based processes. The development of consolidated processing (i.e., single-pot fermentation) can dramatically reduce lignocellulose fermentation costs and promote its industrial application. Here, strategies for developing microbial strains and consortia that feature both efficient (hemi)cellulose depolymerization and butanol production will be depicted, that is, rational metabolic engineering of native (hemi)cellulolytic or native butanol-producing or other suitable microorganisms; protoplast fusion of (hemi)cellulolytic and butanol-producing strains; and co-culture of (hemi)cellulolytic and butanol-producing microbes. Irrespective of the fermentation feedstock, biobutanol production is inherently limited by the severe toxicity of this solvent that challenges process economic viability. Hence, an overview of strategies for developing butanol hypertolerant strains will be provided.
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Affiliation(s)
- Angela Re
- Centre for Sustainable Future TechnologiesFondazione Istituto Italiano di TecnologiaTorinoItaly,Department of Applied Science and TechnologyPolitecnico di TorinoTurinItaly
| | - Roberto Mazzoli
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems BiologyUniversity of TorinoTorinoItaly
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6
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Sun Q, Gao S, Yu S, Zheng P, Zhou J. Production of (2S)-sakuranetin from (2S)-naringenin in Escherichia coli by strengthening methylation process and cell resistance. Synth Syst Biotechnol 2022; 7:1117-1125. [PMID: 36017331 PMCID: PMC9399173 DOI: 10.1016/j.synbio.2022.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/15/2022] Open
Abstract
(2S)-Sakuranetin is a 7-O-methylflavonoid that has anticancer, antiviral, and antimicrobial activities. Methylation process is involved in biosynthesizing (2S)-sakuranetin from (2S)-naringenin, in which S-adenosylmethionine (SAM) serves as the methyl donor. In this study, after methyl donor and substrate inhibition were identified as limiting factors for (2S)-sakuranetin biosynthesis, an efficient (2S)-sakuranetin-producing strain was constructed by enhancing methyl donor supply and cell tolerance to (2S)-naringenin. Firstly, PfOMT3 from Perilla frutescens was selected as the optimal flavonoid 7-O-methyltransferase (F7-OMT) for the conversion of (2S)-naringenin to (2S)-sakuranetin. Then, the methylation process was upregulated by regulating pyridoxal 5′-phosphate (PLP) content, key enzymes in methionine synthesis pathway, and the availability of ATP. Furthermore, genes that can enhance cell resistance to (2S)-naringenin were identified from molecular chaperones and sRNAs. Finally, by optimizing the fermentation process, 681.44 mg/L of (2S)-sakuranetin was obtained in 250-mL shake flasks. The titer of (2S)-sakuranetin reached 2642.38 mg/L in a 5-L bioreactor, which is the highest titer ever reported. This work demonstrates the importance of cofactor PLP in methylation process, and provides insights to biosynthesize other O-methylated flavonoids efficiently in E. coli.
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Affiliation(s)
- Qiumeng Sun
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Song Gao
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Shiqin Yu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Pu Zheng
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Corresponding author. School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.
| | - Jingwen Zhou
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Corresponding author. Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.
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7
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Engineering E. coli to synthesize butanol. Biochem Soc Trans 2022; 50:867-876. [PMID: 35356968 DOI: 10.1042/bst20211009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 02/22/2022] [Accepted: 03/15/2022] [Indexed: 11/17/2022]
Abstract
Biobutanol is gaining much attention as a potential biofuel due to its superior properties over ethanol. Butanol has been naturally produced via acetone-butanol-ethanol (ABE) fermentation by many Clostridium species, which are not very user-friendly bacteria. Therefore, to improve butanol titers and yield, various butanol synthesis pathways have been engineered in Escherichia coli, a much more robust and convenient host than Clostridium species. This review mainly focuses on the biosynthesis of n-butanol in engineered E. coli with an emphasis on efficient enzymes for butanol production in E. coli, butanol competing pathways, and genome engineering of E. coli for butanol production. In addition, the use of alternate strategies for butanol biosynthesis/enhancement, alternate substrates for the low cost of butanol production, and genetic improvement for butanol tolerance in E. coli have also been discussed.
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8
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How to outwit nature: Omics insight into butanol tolerance. Biotechnol Adv 2020; 46:107658. [PMID: 33220435 DOI: 10.1016/j.biotechadv.2020.107658] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 12/16/2022]
Abstract
The energy crisis, depletion of oil reserves, and global climate changes are pressing problems of developed societies. One possibility to counteract that is microbial production of butanol, a promising new fuel and alternative to many petrochemical reagents. However, the high butanol toxicity to all known microbial species is the main obstacle to its industrial implementation. The present state of the art review aims to expound the recent advances in modern omics approaches to resolving this insurmountable to date problem of low butanol tolerance. Genomics, transcriptomics, and proteomics show that butanol tolerance is a complex phenomenon affecting multiple genes and their expression. Efflux pumps, stress and multidrug response, membrane transport, and redox-related genes are indicated as being most important during butanol challenge, in addition to fine-tuning of global regulators of transcription (Spo0A, GntR), which may further improve tolerance. Lipidomics shows that the alterations in membrane composition (saturated lipids and plasmalogen increase) are very much species-specific and butanol-related. Glycomics discloses the pleiotropic effect of CcpA, the role of alternative sugar transport, and the production of exopolysaccharides as alternative routes to overcoming butanol stress. Unfortunately, the strain that simultaneously syntheses and tolerates butanol in concentrations that allow its commercialization has not yet been discovered or produced. Omics insight will allow the purposeful increase of butanol tolerance in natural and engineered producers and the effective heterologous expression of synthetic butanol pathways in strains hereditary butanol-resistant up to 3.2 - 4.9% (w/v). Future breakthrough can be achieved by a detailed study of the membrane proteome, of which 21% are proteins with unknown functions.
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9
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Xu G, Xiao L, Wu A, Han R, Ni Y. Enhancing n-Butanol Tolerance of Escherichia coli by Overexpressing of Stress-Responsive Molecular Chaperones. Appl Biochem Biotechnol 2020; 193:257-270. [PMID: 32929579 DOI: 10.1007/s12010-020-03417-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/23/2020] [Indexed: 12/14/2022]
Abstract
Microbial tolerance to organic solvents is critical for efficient production of biofuels. In this study, n-butanol tolerance of Escherichia coli JM109 was improved by overexpressing of genes encoding stress-responsive small RNA-regulator, RNA chaperone, and molecular chaperone. Gene rpoS, coding for sigma S subunit of RNA polymerase, was the most efficient in improving n-butanol tolerance of E. coli. The highest OD600 and the specific growth rate of JM109/pQE80L-rpoS reached 1.692 and 0.144 h-1 respectively at 1.0% (v/v) n-butanol. Double and triple expression of molecular chaperones rpoS, secB, and groS were conducted and optimized. Recombinant strains JM109/pQE80L-secB-rpoS and JM109/pQE80L-groS-secB-rpoS exhibited the highest n-butanol tolerance, with specific growth rates of 0.164 and 0.165 h-1, respectively. Membrane integrity, potentials, and cell morphology analyses demonstrated the high viability of JM109/pQE80L-groS-secB-rpoS. This study provides guidance on employing various molecular chaperones for enhancing the tolerance of E. coli against n-butanol.
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Affiliation(s)
- Guochao Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Lin Xiao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Anning Wu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Ruizhi Han
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Ye Ni
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
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10
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Liang L, Liu R, Freed EF, Eckert CA. Synthetic Biology and Metabolic Engineering Employing Escherichia coli for C2-C6 Bioalcohol Production. Front Bioeng Biotechnol 2020; 8:710. [PMID: 32719784 PMCID: PMC7347752 DOI: 10.3389/fbioe.2020.00710] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/08/2020] [Indexed: 12/18/2022] Open
Abstract
Biofuel production from renewable and sustainable resources is playing an increasingly important role within the fuel industry. Among biofuels, bioethanol has been most widely used as an additive for gasoline. Higher alcohols can be blended at a higher volume compared to ethanol and generate lower greenhouse gas (GHG) emissions without a need to change current fuel infrastructures. Thus, these fuels have the potential to replace fossil fuels in support of more environmentally friendly processes. This review summarizes the efforts to enhance bioalcohol production in engineered Escherichia coli over the last 5 years and analyzes the current challenges for increasing productivities for industrial applications.
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Affiliation(s)
- Liya Liang
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, United States
| | - Rongming Liu
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, United States
| | - Emily F. Freed
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, United States
| | - Carrie A. Eckert
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, United States
- National Renewable Energy Laboratory, Golden, CO, United States
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11
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Engineering microbial cell morphology and membrane homeostasis toward industrial applications. Curr Opin Biotechnol 2020; 66:18-26. [PMID: 32569960 DOI: 10.1016/j.copbio.2020.05.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/25/2020] [Accepted: 05/12/2020] [Indexed: 01/03/2023]
Abstract
Microbial cell factory performance is significantly affected by the cell morphology and membrane homeostasis. It is important to ensure that cell factories are able to regulate cell morphology and maintain membrane homeostasis. Cell morphology can be controlled by regulating the formation of elongasomes and divisomes, which change the shapes of cells from rods to fibers, large spheres, or mini-cells. Membrane homeostasis can also be controlled by regulating the homeostasis of membrane lipids and proteins, thereby improving the robustness of microbes in toxic environments. In the present review, we discuss promising developments in cell morphology and membrane homeostasis engineering that have improved microbial cell factory performance.
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12
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Ferreira S, Pereira R, Wahl SA, Rocha I. Metabolic engineering strategies for butanol production in Escherichia coli. Biotechnol Bioeng 2020; 117:2571-2587. [PMID: 32374413 DOI: 10.1002/bit.27377] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 04/03/2020] [Accepted: 05/04/2020] [Indexed: 11/06/2022]
Abstract
The global market of butanol is increasing due to its growing applications as solvent, flavoring agent, and chemical precursor of several other compounds. Recently, the superior properties of n-butanol as a biofuel over ethanol have stimulated even more interest. (Bio)butanol is natively produced together with ethanol and acetone by Clostridium species through acetone-butanol-ethanol fermentation, at noncompetitive, low titers compared to petrochemical production. Different butanol production pathways have been expressed in Escherichia coli, a more accessible host compared to Clostridium species, to improve butanol titers and rates. The bioproduction of butanol is here reviewed from a historical and theoretical perspective. All tested rational metabolic engineering strategies in E. coli to increase butanol titers are reviewed: manipulation of central carbon metabolism, elimination of competing pathways, cofactor balancing, development of new pathways, expression of homologous enzymes, consumption of different substrates, and molecular biology strategies. The progress in the field of metabolic modeling and pathway generation algorithms and their potential application to butanol production are also summarized here. The main goals are to gather all the strategies, evaluate the respective progress obtained, identify, and exploit the outstanding challenges.
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Affiliation(s)
- Sofia Ferreira
- CEB-Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-NOVA), Oeiras, Portugal
| | - Rui Pereira
- SilicoLife Lda, Braga, Portugal.,Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - S A Wahl
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Isabel Rocha
- CEB-Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB-NOVA), Oeiras, Portugal
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