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Wang Y, Liu F, Lu X, Zong H, Zhuge B. Regulatory mechanisms and cell membrane properties of Candida glycerinogenes differ under 2-phenylethanol addition or fermentation conditions. Biotechnol J 2024; 19:e2300181. [PMID: 37840403 DOI: 10.1002/biot.202300181] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 10/03/2023] [Accepted: 10/06/2023] [Indexed: 10/17/2023]
Abstract
The biosynthesis of 2-phenylethanol (2-PE) at high yields and titers is often limited by its toxicity. In this study, we describe the molecular mechanisms of 2-PE tolerance in the multi-stress tolerant industrial yeast, Candida glycerinogenes. They were different under 2-PE addition or fermentation conditions. After extracellular addition of 2-PE, C. glycerinogenes cells became rounder and bigger, which reduced specific surface area. However, during 2-PE fermentation C. glycerinogenes cells were smaller, which increased specific surface area. Other differences in the tolerance mechanisms were studied by analyzing the composition and molecular parameters of the cell membrane. Extracellular 2-PE stress resulted in down-regulation of transcriptional expression of unsaturated fatty acid synthesis genes. This raised the proportion of saturated fatty acids in the cell membrane, which increased rigidity of the cell membrane and reduced 2-PE entry to the cell. However, intracellular 2-PE stress resulted in up-regulation of transcriptional expression of unsaturated fatty acid synthesis genes, and increased the proportion of unsaturated fatty acids in the cell membrane; this in turn enhanced flexibility of the cell membrane which accelerated efflux of 2-PE. These contrasting mechanisms are mediated by transcriptional factors Hog1 and Swi5. Under 2-PE addition, C. glycerinogenes activated Hog1 and repressed Swi5 to upregulate erg5 and erg4 expression, which increased cell membrane rigidity and resisted 2-PE import. During 2-PE fermentation, C. glycerinogenes activated Hog1 and repressed Swi5 to upregulate 2-PE transporter proteins cdr1 and Acyl-CoA desaturase 1 ole1 to increase 2-PE export, thus reducing 2-PE intracellular toxicity. The results provide new insights into 2-PE tolerance mechanisms at the cell membrane level and suggest a novel strategy to improve 2-PE production by engineering anti-stress genes.
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Affiliation(s)
- Yuqin Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- School of Grain Science and Technology, Jiangsu University of Science and Technology, Zhenjiang, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Fang Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xinyao Lu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Hong Zong
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Bin Zhuge
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Research Centre of Industrial Microbiology, School of Biotechnology, Jiangnan University, Wuxi, China
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2
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Tanniche I, Nazem-Bokaee H, Scherr DM, Schlemmer S, Senger RS. A novel synthetic sRNA promoting protein overexpression in cell-free systems. Biotechnol Prog 2023; 39:e3324. [PMID: 36651906 DOI: 10.1002/btpr.3324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/31/2022] [Accepted: 01/11/2023] [Indexed: 01/19/2023]
Abstract
Bacterial small RNAs (sRNAs) that regulate gene expression have been engineered for uses in synthetic biology and metabolic engineering. Here, we designed a novel non-Hfq-dependent sRNA scaffold that uses a modifiable 20 nucleotide antisense binding region to target mRNAs selectively and influence protein expression. The system was developed for regulation of a fluorescent reporter in vivo using Escherichia coli, but the system was found to be more responsive and produced statistically significant results when applied to protein synthesis using in vitro cell-free systems (CFS). Antisense binding sequences were designed to target not only translation initiation regions but various secondary structures in the reporter mRNA. Targeting a high-energy stem loop structure and the 3' end of mRNA yielded protein expression knock-downs that approached 70%. Notably, targeting a low-energy stem structure near a potential RNase E binding site led to a statistically significant 65% increase in protein expression (p < 0.05). These results were not obtainable in vivo, and the underlying mechanism was translated from the reporter system to achieve better than 75% increase in recombinant diaphorase expression in a CFS. It is possible the designs developed here can be applied to improve/regulate expression of other proteins in a CFS.
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Affiliation(s)
- Imen Tanniche
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
- School of Plant & Environmental Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Hadi Nazem-Bokaee
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
- CSIRO, Black Mountain Science & Innovation Park, Canberra, Australia
| | - David M Scherr
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
| | - Sara Schlemmer
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia, USA
| | - Ryan S Senger
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia, USA
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3
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Rodrigues JS, Bourgade B, Galle KR, Lindberg P. Mapping competitive pathways to terpenoid biosynthesis in Synechocystis sp. PCC 6803 using an antisense RNA synthetic tool. Microb Cell Fact 2023; 22:35. [PMID: 36823631 PMCID: PMC9951418 DOI: 10.1186/s12934-023-02040-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/10/2023] [Indexed: 02/25/2023] Open
Abstract
BACKGROUND Synechocystis sp. PCC 6803 utilizes pyruvate and glyceraldehyde 3-phosphate via the methylerythritol 4-phosphate (MEP) pathway for the biosynthesis of terpenoids. Considering the deep connection of the MEP pathway to the central carbon metabolism, and the low carbon partitioning towards terpenoid biosynthesis, significant changes in the metabolic network are required to increase cyanobacterial production of terpenoids. RESULTS We used the Hfq-MicC antisense RNA regulatory tool, under control of the nickel-inducible PnrsB promoter, to target 12 different genes involved in terpenoid biosynthesis, central carbon metabolism, amino acid biosynthesis and ATP production, and evaluated the changes in the performance of an isoprene-producing cyanobacterial strain. Six candidate targets showed a positive effect on isoprene production: three genes involved in terpenoid biosynthesis (crtE, chlP and thiG), two involved in amino acid biosynthesis (ilvG and ccmA) and one involved in sugar catabolism (gpi). The same strategy was applied to interfere with different parts of the terpenoid biosynthetic pathway in a bisabolene-producing strain. Increased bisabolene production was observed not only when interfering with chlorophyll a biosynthesis, but also with carotenogenesis. CONCLUSIONS We demonstrated that the Hfq-MicC synthetic tool can be used to evaluate the effects of gene knockdown on heterologous terpenoid production, despite the need for further optimization of the technique. Possible targets for future engineering of Synechocystis aiming at improved terpenoid microbial production were identified.
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Affiliation(s)
- João S. Rodrigues
- grid.8993.b0000 0004 1936 9457Department of Chemistry – Ångström, Uppsala University, Uppsala, Sweden
| | - Barbara Bourgade
- grid.8993.b0000 0004 1936 9457Department of Chemistry – Ångström, Uppsala University, Uppsala, Sweden
| | - Karen R. Galle
- grid.8993.b0000 0004 1936 9457Department of Chemistry – Ångström, Uppsala University, Uppsala, Sweden ,grid.5808.50000 0001 1503 7226Faculty of Sciences, University of Porto, Porto, Portugal
| | - Pia Lindberg
- Department of Chemistry - Ångström, Uppsala University, Uppsala, Sweden.
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Tellechea-Luzardo J, Stiebritz MT, Carbonell P. Transcription factor-based biosensors for screening and dynamic regulation. Front Bioeng Biotechnol 2023; 11:1118702. [PMID: 36814719 PMCID: PMC9939652 DOI: 10.3389/fbioe.2023.1118702] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/26/2023] [Indexed: 02/09/2023] Open
Abstract
Advances in synthetic biology and genetic engineering are bringing into the spotlight a wide range of bio-based applications that demand better sensing and control of biological behaviours. Transcription factor (TF)-based biosensors are promising tools that can be used to detect several types of chemical compounds and elicit a response according to the desired application. However, the wider use of this type of device is still hindered by several challenges, which can be addressed by increasing the current metabolite-activated transcription factor knowledge base, developing better methods to identify new transcription factors, and improving the overall workflow for the design of novel biosensor circuits. These improvements are particularly important in the bioproduction field, where researchers need better biosensor-based approaches for screening production-strains and precise dynamic regulation strategies. In this work, we summarize what is currently known about transcription factor-based biosensors, discuss recent experimental and computational approaches targeted at their modification and improvement, and suggest possible future research directions based on two applications: bioproduction screening and dynamic regulation of genetic circuits.
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Affiliation(s)
- Jonathan Tellechea-Luzardo
- Institute of Industrial Control Systems and Computing (AI2), Universitat Politècnica de València (UPV), Valencia, Spain
| | - Martin T. Stiebritz
- Institute of Industrial Control Systems and Computing (AI2), Universitat Politècnica de València (UPV), Valencia, Spain
| | - Pablo Carbonell
- Institute of Industrial Control Systems and Computing (AI2), Universitat Politècnica de València (UPV), Valencia, Spain
- Institute for Integrative Systems Biology I2SysBio, Universitat de València-CSIC, Paterna, Spain
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5
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Li J, Yi F, Chen G, Pan F, Yang Y, Shu M, Chen Z, Zhang Z, Mei X, Zhong W. Function Enhancement of a Metabolic Module via Endogenous Promoter Replacement for Pseudomonas sp. JY-Q to Degrade Nicotine in Tobacco Waste Treatment. Appl Biochem Biotechnol 2021; 193:2793-2805. [PMID: 34061306 DOI: 10.1007/s12010-021-03566-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 04/08/2021] [Indexed: 12/17/2022]
Abstract
Nicotine-degrading Pseudomonas sp. JY-Q is a preferred strain utilized in reconstituted tobacco process for tobacco waste treatment. However, its efficiency of nicotine metabolism still requires to be improved via genomic technology such as promoter engineering based on genomic information. Concerning upstream module of nicotine metabolic pathway, we found that two homologous genes of nicotine dehydrogenase (nicA2 and nox) coexisted in strain JY-Q. However, the transcriptional amount of nox was 20-fold higher than that of nicA2. Thus, the nicA2 expression required improvement. Combinatorial displacement was accomplished for two predicted endogenous promoters, named as PnicA2 and Pnox for nicA2 and nox, respectively. The mutant with Pnox as the promoters for both nicA2 and nox exhibited the best nicotine metabolic capacity which increased by 66% compared to the wild type. These results suggested that endogenous promoter replacement is also feasible for function improvement of metabolic modules and strain enhancement of biodegradation capacity to meet real environment demand.
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Affiliation(s)
- Jun Li
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Fengmei Yi
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Guoqing Chen
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Fanda Pan
- Technology Center, China Tobacco Zhejiang Industrial Co., Ltd., Hangzhou, 310009, China
| | - Yang Yang
- Technology Center, China Tobacco Zhejiang Industrial Co., Ltd., Hangzhou, 310009, China.
| | - Ming Shu
- Technology Center, China Tobacco Zhejiang Industrial Co., Ltd., Hangzhou, 310009, China
| | - Zeyu Chen
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Zeling Zhang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Xiaotong Mei
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, China
| | - Weihong Zhong
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, China.
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6
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You J, Yang C, Pan X, Hu M, Du Y, Osire T, Yang T, Rao Z. Metabolic engineering of Bacillus subtilis for enhancing riboflavin production by alleviating dissolved oxygen limitation. BIORESOURCE TECHNOLOGY 2021; 333:125228. [PMID: 33957462 DOI: 10.1016/j.biortech.2021.125228] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/23/2021] [Accepted: 04/25/2021] [Indexed: 06/12/2023]
Abstract
Riboflavin, an essential vitamin for animals, is used widely in the pharmaceutical industry and as a food and feed additive. The microbial synthesis of riboflavin requires a large amount of oxygen, which limits the industrial-scale production of the vitamin. In this study, a metabolic engineering strategy based on transcriptome analysis was identified as effective in increasing riboflavin production. First, transcriptional profiling revealed that hypoxia affects purine, and nitrogen metabolism. Next, the precursor supply pool was increased by purR knockout and tnrA and glnR knockdown to balance intracellular nitrogen metabolism. Finally, increased oxygen utilization was achieved by dynamically regulating vgb. Fed-batch fermentation of the engineered strain in a 5-liter bioreactor produced 10.71 g/l riboflavin, a 45.51% higher yield than that obtained with Bacillus subtilis RF1. The metabolic engineering strategy described herein is useful for alleviating the oxygen limitation of bacterial strains used for the industrial production of riboflavin and related products.
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Affiliation(s)
- Jiajia You
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Chen Yang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xuewei Pan
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Mengkai Hu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yuxuan Du
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Tolbert Osire
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Taowei Yang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
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7
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Roux C, Etienne TA, Hajnsdorf E, Ropers D, Carpousis AJ, Cocaign-Bousquet M, Girbal L. The essential role of mRNA degradation in understanding and engineering E. coli metabolism. Biotechnol Adv 2021; 54:107805. [PMID: 34302931 DOI: 10.1016/j.biotechadv.2021.107805] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/28/2021] [Accepted: 07/14/2021] [Indexed: 11/17/2022]
Abstract
Metabolic engineering strategies are crucial for the development of bacterial cell factories with improved performance. Until now, optimal metabolic networks have been designed based on systems biology approaches integrating large-scale data on the steady-state concentrations of mRNA, protein and metabolites, sometimes with dynamic data on fluxes, but rarely with any information on mRNA degradation. In this review, we compile growing evidence that mRNA degradation is a key regulatory level in E. coli that metabolic engineering strategies should take into account. We first discuss how mRNA degradation interacts with transcription and translation, two other gene expression processes, to balance transcription regulation and remove poorly translated mRNAs. The many reciprocal interactions between mRNA degradation and metabolism are also highlighted: metabolic activity can be controlled by changes in mRNA degradation and in return, the activity of the mRNA degradation machinery is controlled by metabolic factors. The mathematical models of the crosstalk between mRNA degradation dynamics and other cellular processes are presented and discussed with a view towards novel mRNA degradation-based metabolic engineering strategies. We show finally that mRNA degradation-based strategies have already successfully been applied to improve heterologous protein synthesis. Overall, this review underlines how important mRNA degradation is in regulating E. coli metabolism and identifies mRNA degradation as a key target for innovative metabolic engineering strategies in biotechnology.
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Affiliation(s)
- Charlotte Roux
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France; UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Thibault A Etienne
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France; Univ. Grenoble Alpes, Inria, 38000 Grenoble, France.
| | - Eliane Hajnsdorf
- UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | | | - A J Carpousis
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France; LMGM, Université de Toulouse, CNRS, UPS, CBI, 31062 Toulouse, France.
| | | | - Laurence Girbal
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France.
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8
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Lozano Terol G, Gallego-Jara J, Sola Martínez RA, Martínez Vivancos A, Cánovas Díaz M, de Diego Puente T. Impact of the Expression System on Recombinant Protein Production in Escherichia coli BL21. Front Microbiol 2021; 12:682001. [PMID: 34234760 PMCID: PMC8257044 DOI: 10.3389/fmicb.2021.682001] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/18/2021] [Indexed: 12/13/2022] Open
Abstract
Recombinant protein production for medical, academic, or industrial applications is essential for our current life. Recombinant proteins are obtained mainly through microbial fermentation, with Escherichia coli being the host most used. In spite of that, some problems are associated with the production of recombinant proteins in E. coli, such as the formation of inclusion bodies, the metabolic burden, or the inefficient translocation/transport system of expressed proteins. Optimizing transcription of heterologous genes is essential to avoid these drawbacks and develop competitive biotechnological processes. Here, expression of YFP reporter protein is evaluated under the control of four promoters of different strength (PT7lac, Ptrc, Ptac, and PBAD) and two different replication origins (high copy number pMB1′ and low copy number p15A). In addition, the study has been carried out with the E. coli BL21 wt and the ackA mutant strain growing in a rich medium with glucose or glycerol as carbon sources. Results showed that metabolic burden associated with transcription and translation of foreign genes involves a decrease in recombinant protein expression. It is necessary to find a balance between plasmid copy number and promoter strength to maximize soluble recombinant protein expression. The results obtained represent an important advance on the most suitable expression system to improve both the quantity and quality of recombinant proteins in bioproduction engineering.
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Affiliation(s)
- Gema Lozano Terol
- Department of Biochemistry and Molecular Biology and Immunology (B), Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Murcia, Spain
| | - Julia Gallego-Jara
- Department of Biochemistry and Molecular Biology and Immunology (B), Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Murcia, Spain
| | - Rosa Alba Sola Martínez
- Department of Biochemistry and Molecular Biology and Immunology (B), Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Murcia, Spain
| | - Adrián Martínez Vivancos
- Department of Biochemistry and Molecular Biology and Immunology (B), Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Murcia, Spain
| | - Manuel Cánovas Díaz
- Department of Biochemistry and Molecular Biology and Immunology (B), Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Murcia, Spain
| | - Teresa de Diego Puente
- Department of Biochemistry and Molecular Biology and Immunology (B), Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence "Campus Mare Nostrum", Murcia, Spain
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9
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Vo PNL, Lee HM, Ren J, Na D. Optimized expression of Hfq protein increases Escherichia coli growth. J Biol Eng 2021; 15:7. [PMID: 33602295 PMCID: PMC7890833 DOI: 10.1186/s13036-021-00260-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 02/09/2021] [Indexed: 12/23/2022] Open
Abstract
Escherichia coli is a widely used platform for metabolic engineering due to its fast growth and well-established engineering techniques. However, there has been a demand for faster-growing E. coli for higher production of desired substances. Here, to increase the growth of E. coli cells, we optimized the expression level of Hfq protein, which plays an essential role in stress responses. Six variants of the hfq gene with a different ribosome binding site sequence and thereby a different expression level were constructed. When the Hfq expression level was optimized in DH5α, its growth rate was increased by 12.1% and its cell density was also increased by 4.5%. RNA-seq and network analyses revealed the upregulation of stress response genes and metabolic genes, which increases the tolerance against pH changes. When the same strategy was applied to five other E. coli strains (BL21 (DE3), JM109, TOP10, W3110, and MG1655), all their growth rates were increased by 18-94% but not all their densities were increased (- 12 - + 32%). In conclusion, the Hfq expression optimization can increase cell growth rate and probably their cell densities as well. Since the hfq gene is highly conserved across bacterial species, the same strategy could be applied to other bacterial species to construct faster-growing strains.
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Affiliation(s)
- Phuong N L Vo
- Department of Biomedical Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Hyang-Mi Lee
- Department of Biomedical Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Jun Ren
- Department of Biomedical Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Dokyun Na
- Department of Biomedical Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea.
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10
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Ahangarzadeh S, Moghimi H, Bandehpour M, Ranjbari J. Acetate Kinase a Antisense Delivery by PAMAM Dendrimer for Decreasing Acetate Production and Increasing the Production of Recombinant Albumin in E. coli. IRANIAN JOURNAL OF BIOTECHNOLOGY 2021; 19:e2617. [PMID: 34179192 PMCID: PMC8217542 DOI: 10.30498/ijb.2021.2617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Background: Acetate accumulation in the culture medium is known as an inhibitor in recombinant protein production in Escherichia coli.
Various approaches have been proposed and evaluated to overcome this challenge and reduce the concentration of acetate.
In this study, we examined the effect of acetate kinase A antisense on acetate production rate in E. coli We also used
PAMAM dendrimers as a suitable delivery agent for antisense transformation into E. coli host cell. Objective: This study aimed to decrease acetate production as a by-product using an antisense-dendrimer complex to increase mass cell and subsequently recombinant Albumin production in E. coli. Materials and Methods: Here, to study the effect of this treatment on recombinant protein production, we used pET22b/HAS construct. The ackA gene expression was inhibited by designed antisense to reduce acetate concentration in culture medium. AckA antisense was transferred to E. coli by PAMAM dendrimer. Finally, ackA expression and recombinant Albumin production were evaluated Real-Time PCR and densitometry, respectively. Results: Our data showed, designed antisense lead to reduction of acetate kinase gene expression and subsequently acetate concentration in
the culture medium. Finally, acetate concentration reduction and cell mass increase result in enhanced recombinant Alb production in
the treated group (1.25 mg.mL-1) compare to the control group ( 0.59 mg.mL-1). Conclusions: Reduction of acetate in E. coli fermentation process decreased the recombinant Alb production following cell
growth and cell mass increase. In the current study, we showed that an antisense can be a useful tool for ackA gene expression reduction.
Also, we noted that PAMAM dendrimer could be a proper delivery agent for oligonucleotide antisense transformation into bacterial cells.
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Affiliation(s)
- Shahrzad Ahangarzadeh
- Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hamidreza Moghimi
- Department of Pharmaceutics, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mojgan Bandehpour
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Javad Ranjbari
- Medical Nanotechnology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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11
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Immobilization of genetically engineered whole-cell biocatalysts with periplasmic carbonic anhydrase in polyurethane foam for enzymatic CO2 capture and utilization. J CO2 UTIL 2020. [DOI: 10.1016/j.jcou.2020.101172] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Kim SY, Kim KW, Kwon YM, Kim JYH. mCherry Protein as an In Vivo Quantitative Reporter of Gene Expression in the Chloroplast of Chlamydomonas reinhardtii. Mol Biotechnol 2020; 62:297-305. [PMID: 32185599 DOI: 10.1007/s12033-020-00249-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Microalgal chloroplasts have a substantial potential as a sustainable alternative to conventional hosts for recombinant protein production, due to their photosynthetic ability. However, realization of microalgal chloroplast as a platform for the production of recombinant proteins has suffered from difficulties in genetic manipulation and development of molecular tools, including reporter proteins. Here, we investigated the suitability of a fluorescent protein, mCherry, as a reporter for quantitative in vivo monitoring of gene expression in the chloroplast of Chlamydomonas reinhardtii. By analyzing cell growth, the fluorescence intensity of a mCherry-expressing strain, as well as auto-fluorescence, under different photoautotrophic culture conditions, we demonstrated a strong correlation between the fluorescence intensity of mCherry expressed in the chloroplast and its protein expression level. In addition, we found that the supply of CO2 and light energy can be an important factor for the synthesis of recombinant proteins in the microalgal chloroplast. Our results identified mCherry as a reliable and quantitative reporter for the study of gene expression in chloroplasts, which is essential for the biotechnological application of microalgal chloroplasts and for improved production of valuable recombinant proteins.
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Affiliation(s)
- Sun Young Kim
- Department of Applied Research, National Marine Biodiversity Institute of Korea, Jangsan-ro 101-75, Seocheon-gun, Chungcheongnam-do, 33662, South Korea
| | - Kyung Woo Kim
- Department of Applied Research, National Marine Biodiversity Institute of Korea, Jangsan-ro 101-75, Seocheon-gun, Chungcheongnam-do, 33662, South Korea
| | - Yong Min Kwon
- Department of Applied Research, National Marine Biodiversity Institute of Korea, Jangsan-ro 101-75, Seocheon-gun, Chungcheongnam-do, 33662, South Korea
| | - Jaoon Young Hwan Kim
- Department of Applied Research, National Marine Biodiversity Institute of Korea, Jangsan-ro 101-75, Seocheon-gun, Chungcheongnam-do, 33662, South Korea.
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13
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Lozano Terol G, Gallego-Jara J, Sola Martínez RA, Cánovas Díaz M, de Diego Puente T. Engineering protein production by rationally choosing a carbon and nitrogen source using E. coli BL21 acetate metabolism knockout strains. Microb Cell Fact 2019; 18:151. [PMID: 31484572 PMCID: PMC6724240 DOI: 10.1186/s12934-019-1202-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/29/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Escherichia coli (E. coli) is a bacteria that is widely employed in many industries for the production of high interest bio-products such as recombinant proteins. Nevertheless, the use of E. coli for recombinant protein production may entail some disadvantages such as acetate overflow. Acetate is accumulated under some culture conditions, involves a decrease in biomass and recombinant protein production, and its metabolism is related to protein lysine acetylation. Thereby, the carbon and nitrogen sources employed are relevant factors in cell host metabolism, and the study of the central metabolism of E. coli and its regulation is essential for optimizing the production of biomass and recombinant proteins. In this study, our aim was to find the most favourable conditions for carrying out recombinant protein production in E. coli BL21 using two different approaches, namely, manipulation of the culture media composition and the deletion of genes involved in acetate metabolism and Nε-lysine acetylation. RESULTS We evaluated protein overexpression in E. coli BL21 wt and five mutant strains involved in acetate metabolism (Δacs, ΔackA and Δpta) and lysine acetylation (ΔpatZ and ΔcobB) grown in minimal medium M9 (inorganic ammonium nitrogen source) and in complex TB7 medium (peptide-based nitrogen source) supplemented with glucose (PTS carbon source) or glycerol (non-PTS carbon source). We observed a dependence of recombinant protein production on acetate metabolism and the carbon and nitrogen source employed. The use of complex medium supplemented with glycerol as a carbon source entails an increase in protein production and an efficient use of resources, since is a sub-product of biodiesel synthesis. Furthermore, the deletion of the ackA gene results in a fivefold increase in protein production with respect to the wt strain and a reduction in acetate accumulation. CONCLUSION The results showed that the use of diverse carbon and nitrogen sources and acetate metabolism knockout strains can redirect E. coli carbon fluxes to different pathways and affect the final yield of the recombinant protein bioprocess. Thereby, we obtained a fivefold increase in protein production and an efficient use of the resources employing the most suitable strain and culture conditions.
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Affiliation(s)
- Gema Lozano Terol
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Julia Gallego-Jara
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain.
| | - Rosa Alba Sola Martínez
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Manuel Cánovas Díaz
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Teresa de Diego Puente
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain.
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14
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Advances in engineered trans-acting regulatory RNAs and their application in bacterial genome engineering. J Ind Microbiol Biotechnol 2019; 46:819-830. [PMID: 30887255 DOI: 10.1007/s10295-019-02160-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 03/05/2019] [Indexed: 12/15/2022]
Abstract
Small noncoding RNAs, a large class of ancient posttranscriptional regulators, are increasingly recognized and utilized as key modulators of gene expression in a broad range of microorganisms. Owing to their small molecular size and the central role of Watson-Crick base pairing in defining their interactions, structure and function, numerous diverse types of trans-acting RNA regulators that are functional at the DNA, mRNA and protein levels have been experimentally characterized. It has become increasingly clear that most small RNAs play critical regulatory roles in many processes and are, therefore, considered to be powerful tools for genetic engineering and synthetic biology. The trans-acting regulatory RNAs accelerate this ability to establish potential framework for genetic engineering and genome-scale engineering, which allows RNA structure characterization, easier to design and model compared to DNA or protein-based systems. In this review, we summarize recent advances in engineered trans-acting regulatory RNAs that are used in bacterial genome-scale engineering and in novel cellular capabilities as well as their implementation in wide range of biotechnological, biological and medical applications.
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Wang M, Yu H, Shen Z. Antisense RNA-Based Strategy for Enhancing Surfactin Production in Bacillus subtilis TS1726 via Overexpression of the Unconventional Biotin Carboxylase II To Enhance ACCase Activity. ACS Synth Biol 2019; 8:251-256. [PMID: 30702274 DOI: 10.1021/acssynbio.8b00459] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The antisense RNA (asRNA) strategy is commonly used to block protein expression and downregulate the contents of metabolites in several microorganisms. Here, we show that the asRNA strategy can also be used to block gfp expression in Bacillus subtilis TS1726, which could further be utilized in the identification of new genes and functions. Via application of this strategy, biotin carboxylase II encoded by yngH (GeneID 939474) was identified to play a more significant role in maintaining acetyl-CoA carboxylase (ACCase) activity and enhancing surfactin synthesis compared to those of other ACCase subunits. The yngH gene was then overexpressed in the engineered strain B. subtilis TS1726(yngH). The surfactin titer of TS1726(yngH) increased to 13.37 g/L in a flask culture, representing a 43% increase compared to that of parental strain TS1726. This strategy opens the door to achieving large-scale production and broad application of surfactin.
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Affiliation(s)
- Miaomiao Wang
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China
- Key Laboratory of Industrial Biocatalysis (Tsinghua University), Ministry of Education, Beijing 100084, P. R. China
| | - Huimin Yu
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China
- Key Laboratory of Industrial Biocatalysis (Tsinghua University), Ministry of Education, Beijing 100084, P. R. China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, P. R. China
| | - Zhongyao Shen
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China
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16
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Peters G, Maertens J, Lammertyn J, De Mey M. Exploring of the feature space of de novo developed post-transcriptional riboregulators. PLoS Comput Biol 2018; 14:e1006170. [PMID: 30118473 PMCID: PMC6114898 DOI: 10.1371/journal.pcbi.1006170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 08/29/2018] [Accepted: 04/30/2018] [Indexed: 11/23/2022] Open
Abstract
Metabolic engineering increasingly depends upon RNA technology to customly rewire the metabolism to maximize production. To this end, pure riboregulators allow dynamic gene repression without the need of a potentially burdensome coexpressed protein like typical Hfq binding small RNAs and clustered regularly interspaced short palindromic repeats technology. Despite this clear advantage, no clear general design principles are available to de novo develop repressing riboregulators, limiting the availability and the reliable development of these type of riboregulators. Here, to overcome this lack of knowledge on the functionality of repressing riboregulators, translation inhibiting RNAs are developed from scratch. These de novo developed riboregulators explore features related to thermodynamical and structural factors previously attributed to translation initiation modulation. In total, 12 structural and thermodynamic features were defined of which six features were retained after removing correlations from an in silico generated riboregulator library. From this translation inhibiting RNA library, 18 riboregulators were selected using a experimental design and subsequently constructed and co-expressed with two target untranslated regions to link the translation inhibiting RNA features to functionality. The pure riboregulators in the design of experiments showed repression down to 6% of the original protein expression levels, which could only be partially explained by a ordinary least squares regression model. To allow reliable forward engineering, a partial least squares regression model was constructed and validated to link the properties of translation inhibiting RNA riboregulators to gene repression. In this model both structural and thermodynamic features were important for efficient gene repression by pure riboregulators. This approach enables a more reliable de novo forward engineering of effective pure riboregulators, which further expands the RNA toolbox for gene expression modulation. To allow reliable forward engineering of microbial cell factories, various metabolic engineering efforts rely on RNA-based technology. As such, programmable riboregulators allow dynamic control over gene expression. However, no clear design principles exist for de novo developed repressing riboregulators, which limits their applicability. Here, various engineering principles are identified and computationally explored. Subsequently, various design criteria are used in an experimental design, which were explored in an in vivo study. This resulted in a regression model that enables a more reliable computational design of repression small RNAs.
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Affiliation(s)
- Gert Peters
- Centre for Synthetic Biology, Ghent University, Ghent, Belgium
| | - Jo Maertens
- Centre for Synthetic Biology, Ghent University, Ghent, Belgium
| | | | - Marjan De Mey
- Centre for Synthetic Biology, Ghent University, Ghent, Belgium
- * E-mail:
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17
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Kuczyńska-Wiśnik D, Moruno-Algara M, Stojowska-Swędrzyńska K, Laskowska E. The effect of protein acetylation on the formation and processing of inclusion bodies and endogenous protein aggregates in Escherichia coli cells. Microb Cell Fact 2016; 15:189. [PMID: 27832787 PMCID: PMC5105262 DOI: 10.1186/s12934-016-0590-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/03/2016] [Indexed: 12/21/2022] Open
Abstract
Background Acetylation of lysine residues is a reversible post-translational modification conserved from bacteria to humans. Several recent studies have revealed hundreds of lysine-acetylated proteins in various bacteria; however, the physiological role of these modifications remains largely unknown. Since lysine acetylation changes the size and charge of proteins and thereby may affect their conformation, we assumed that lysine acetylation can stimulate aggregation of proteins, especially for overproduced recombinant proteins that form inclusion bodies. Results To verify this assumption, we used Escherichia coli strains that overproduce aggregation-prone VP1GFP protein. We found that in ΔackA-pta cells, which display diminished protein acetylation, inclusion bodies were formed with a delay and processed faster than in the wild-type cells. Moreover, in ΔackA-pta cells, inclusion bodies exhibited significantly increased specific GFP fluorescence. In CobB deacetylase-deficient cells, in which protein acetylation was enhanced, the formation of inclusion bodies was increased and their processing was significantly inhibited. Similar results were obtained with regard to endogenous protein aggregates formed during the late stationary phase in ΔackA-pta and ΔcobB cells. Conclusions Our studies revealed that protein acetylation affected the aggregation of endogenous E. coli proteins and the yield, solubility, and biological activity of a model recombinant protein. In general, decreased lysine acetylation inhibited the formation of protein aggregates, whereas increased lysine acetylation stabilized protein aggregates. These findings should be considered during the designing of efficient strategies for the production of recombinant proteins in E. coli cells. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0590-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dorota Kuczyńska-Wiśnik
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland
| | - María Moruno-Algara
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland
| | - Karolina Stojowska-Swędrzyńska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland
| | - Ewa Laskowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland.
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Westbrook AW, Moo-Young M, Chou CP. Development of a CRISPR-Cas9 Tool Kit for Comprehensive Engineering of Bacillus subtilis. Appl Environ Microbiol 2016; 82:4876-95. [PMID: 27260361 PMCID: PMC4968543 DOI: 10.1128/aem.01159-16] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 05/19/2016] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED The establishment of a clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 system for strain construction in Bacillus subtilis is essential for its progression toward industrial utility. Here we outline the development of a CRISPR-Cas9 tool kit for comprehensive genetic engineering in B. subtilis In addition to site-specific mutation and gene insertion, our approach enables continuous genome editing and multiplexing and is extended to CRISPR interference (CRISPRi) for transcriptional modulation. Our tool kit employs chromosomal expression of Cas9 and chromosomal transcription of guide RNAs (gRNAs) using a gRNA transcription cassette and counterselectable gRNA delivery vectors. Our design obviates the need for multicopy plasmids, which can be unstable and impede cell viability. Efficiencies of up to 100% and 85% were obtained for single and double gene mutations, respectively. Also, a 2.9-kb hyaluronic acid (HA) biosynthetic operon was chromosomally inserted with an efficiency of 69%. Furthermore, repression of a heterologous reporter gene was achieved, demonstrating the versatility of the tool kit. The performance of our tool kit is comparable with those of systems developed for Escherichia coli and Saccharomyces cerevisiae, which rely on replicating vectors to implement CRISPR-Cas9 machinery. IMPORTANCE In this paper, as the first approach, we report implementation of the CRISPR-Cas9 system in Bacillus subtilis, which is recognized as a valuable host system for biomanufacturing. The study enables comprehensive engineering of B. subtilis strains with virtually any desired genotypes/phenotypes and biochemical properties for extensive industrial application.
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Affiliation(s)
- Adam W Westbrook
- Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Murray Moo-Young
- Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - C Perry Chou
- Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada
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19
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Jabarivelisdeh B, Waldherr S. Improving Bioprocess Productivity Using Constraint-Based Models in a Dynamic Optimization Scheme. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.ifacol.2016.12.133] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Peters G, Coussement P, Maertens J, Lammertyn J, De Mey M. Putting RNA to work: Translating RNA fundamentals into biotechnological engineering practice. Biotechnol Adv 2015; 33:1829-44. [PMID: 26514597 DOI: 10.1016/j.biotechadv.2015.10.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/13/2015] [Accepted: 10/22/2015] [Indexed: 11/19/2022]
Abstract
Synthetic biology, in close concert with systems biology, is revolutionizing the field of metabolic engineering by providing novel tools and technologies to rationally, in a standardized way, reroute metabolism with a view to optimally converting renewable resources into a broad range of bio-products, bio-materials and bio-energy. Increasingly, these novel synthetic biology tools are exploiting the extensive programmable nature of RNA, vis-à-vis DNA- and protein-based devices, to rationally design standardized, composable, and orthogonal parts, which can be scaled and tuned promptly and at will. This review gives an extensive overview of the recently developed parts and tools for i) modulating gene expression ii) building genetic circuits iii) detecting molecules, iv) reporting cellular processes and v) building RNA nanostructures. These parts and tools are becoming necessary armamentarium for contemporary metabolic engineering. Furthermore, the design criteria, technological challenges, and recent metabolic engineering success stories of the use of RNA devices are highlighted. Finally, the future trends in transforming metabolism through RNA engineering are critically evaluated and summarized.
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Affiliation(s)
- Gert Peters
- Centre of Expertise Industrial Biotechnology and Biocatalysis, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Pieter Coussement
- Centre of Expertise Industrial Biotechnology and Biocatalysis, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Jo Maertens
- Centre of Expertise Industrial Biotechnology and Biocatalysis, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Jeroen Lammertyn
- BIOSYST-MeBioS, KU Leuven, Willem de Croylaan 42, 3001 Louvain, Belgium
| | - Marjan De Mey
- Centre of Expertise Industrial Biotechnology and Biocatalysis, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
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21
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Reduction of foaming and enhancement of ascomycin production in rational Streptomyces hygroscopicus fermentation. Chin J Chem Eng 2015. [DOI: 10.1016/j.cjche.2014.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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22
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Impact of deletion of the genes encoding acetate kinase on production of L-tryptophan by Escherichia coli. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1103-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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23
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Chaudhary AK, Na D, Lee EY. Rapid and high-throughput construction of microbial cell-factories with regulatory noncoding RNAs. Biotechnol Adv 2015; 33:914-30. [PMID: 26027891 DOI: 10.1016/j.biotechadv.2015.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/27/2015] [Accepted: 05/27/2015] [Indexed: 12/11/2022]
Abstract
Due to global crises such as pollution and depletion of fossil fuels, sustainable technologies based on microbial cell-factories have been garnering great interest as an alternative to chemical factories. The development of microbial cell-factories is imperative in cutting down the overall manufacturing cost. Thus, diverse metabolic engineering strategies and engineering tools have been established to obtain a preferred genotype and phenotype displaying superior productivity. However, these tools are limited to only a handful of genes with permanent modification of a genome and significant labor costs, and this is one of the bottlenecks associated with biofactory construction. Therefore, a groundbreaking rapid and high-throughput engineering tool is needed for efficient construction of microbial cell-factories. During the last decade, copious small noncoding RNAs (ncRNAs) have been discovered in bacteria. These are involved in substantial regulatory roles like transcriptional and post-transcriptional gene regulation by modulating mRNA elongation, stability, or translational efficiency. Because of their vulnerability, ncRNAs can be used as another layer of conditional control over gene expression without modifying chromosomal sequences, and hence would be a promising high-throughput tool for metabolic engineering. Here, we review successful design principles and applications of ncRNAs for high-throughput metabolic engineering or physiological studies of diverse industrially important microorganisms.
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Affiliation(s)
- Amit Kumar Chaudhary
- Department of Chemical Engineering, Kyung Hee University, Gyeonggi-do 446-701, Republic of Korea
| | - Dokyun Na
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea.
| | - Eun Yeol Lee
- Department of Chemical Engineering, Kyung Hee University, Gyeonggi-do 446-701, Republic of Korea.
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24
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Brockman IM, Prather KLJ. Dynamic metabolic engineering: New strategies for developing responsive cell factories. Biotechnol J 2015; 10:1360-9. [PMID: 25868062 DOI: 10.1002/biot.201400422] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/02/2015] [Accepted: 03/15/2015] [Indexed: 12/22/2022]
Abstract
Metabolic engineering strategies have enabled improvements in yield and titer for a variety of valuable small molecules produced naturally in microorganisms, as well as those produced via heterologous pathways. Typically, the approaches have been focused on up- and downregulation of genes to redistribute steady-state pathway fluxes, but more recently a number of groups have developed strategies for dynamic regulation, which allows rebalancing of fluxes according to changing conditions in the cell or the fermentation medium. This review highlights some of the recently published work related to dynamic metabolic engineering strategies and explores how advances in high-throughput screening and synthetic biology can support development of new dynamic systems. Dynamic gene expression profiles allow trade-offs between growth and production to be better managed and can help avoid build-up of undesired intermediates. The implementation is more complex relative to static control, but advances in screening techniques and DNA synthesis will continue to drive innovation in this field.
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Affiliation(s)
- Irene M Brockman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kristala L J Prather
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
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25
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Krivoruchko A, Zhang Y, Siewers V, Chen Y, Nielsen J. Microbial acetyl-CoA metabolism and metabolic engineering. Metab Eng 2014; 28:28-42. [PMID: 25485951 DOI: 10.1016/j.ymben.2014.11.009] [Citation(s) in RCA: 222] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 11/25/2014] [Accepted: 11/26/2014] [Indexed: 12/23/2022]
Abstract
Recent concerns over the sustainability of petrochemical-based processes for production of desired chemicals have fueled research into alternative modes of production. Metabolic engineering of microbial cell factories such as Saccharomyces cerevisiae and Escherichia coli offers a sustainable and flexible alternative for the production of various molecules. Acetyl-CoA is a key molecule in microbial central carbon metabolism and is involved in a variety of cellular processes. In addition, it functions as a precursor for many molecules of biotechnological relevance. Therefore, much interest exists in engineering the metabolism around the acetyl-CoA pools in cells in order to increase product titers. Here we provide an overview of the acetyl-CoA metabolism in eukaryotic and prokaryotic microbes (with a focus on S. cerevisiae and E. coli), with an emphasis on reactions involved in the production and consumption of acetyl-CoA. In addition, we review various strategies that have been used to increase acetyl-CoA production in these microbes.
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Affiliation(s)
- Anastasia Krivoruchko
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Yiming Zhang
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Verena Siewers
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Yun Chen
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Jens Nielsen
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
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Morshedi D, Aliakbari F, Nouri HR, Lotfinia M, Fallahi J. Using small molecules as a new challenge to redirect metabolic pathway. 3 Biotech 2014; 4:513-522. [PMID: 28324386 PMCID: PMC4162896 DOI: 10.1007/s13205-013-0185-6] [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: 08/22/2013] [Accepted: 11/09/2013] [Indexed: 11/26/2022] Open
Abstract
The presence of acetate in the bacterial medium leads to a reduction in the growth rate of cells and recombinant protein production. In this study, three compounds including propionic acid, lithium chloride and butyric acid were added to the medium which decreased acetate levels and enhanced recombinant protein production (alpha-synuclein). In fact, propionic acid and lithium chloride are both known as acetate kinase inhibitors. The results obtained in the case of butyric acid were similar to those of the two other compounds indicating that butyric acid may act through a mechanism similar to propionic acid and lithium chloride. Consequently, it was shown that the presence of each of these supplements (5–200 μM) increased recombinant alpha-synuclein production and cell density by approximately 10–15 %. HPLC analysis showed that the levels of acetate in the media containing the supplements were considerably less than those of the control. Furthermore, pH values remained almost constant in the supplemented cultures. Growing the bacteria at lower temperatures (25 °C) indicated that the positive effects of these supplements were not as effective as at higher temperatures (37 °C), presumably due to the adequate balance between oxygen and carbon consumption. This study can confirm the viewpoint regarding the harmful effects of acetate on the recombinant protein production and cell density. Besides, such methods represent easy and complementary ways to increase target recombinant protein production without negatively affecting host cell density, and requiring complex genetic manipulation.
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Affiliation(s)
- Dina Morshedi
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran.
| | - Farhang Aliakbari
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
- Department of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran
| | - Hamid Reza Nouri
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
| | - Majid Lotfinia
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran
| | - Jafar Fallahi
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
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27
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Fine-Tuning of the Fatty Acid Pathway by Synthetic Antisense RNA for Enhanced (2S)-Naringenin Production from l-Tyrosine in Escherichia coli. Appl Environ Microbiol 2014; 80:7283-92. [PMID: 25239896 DOI: 10.1128/aem.02411-14] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/12/2014] [Indexed: 12/26/2022] Open
Abstract
Malonyl coenzyme A (malonyl-CoA) is an important precursor for the synthesis of natural products, such as polyketides and flavonoids. The majority of this cofactor often is consumed for producing fatty acids and phospholipids, leaving only a small amount of cellular malonyl-CoA available for producing the target compound. The tuning of malonyl-CoA into heterologous pathways yields significant phenotypic effects, such as growth retardation and even cell death. In this study, fine-tuning of the fatty acid pathway in Escherichia coli with antisense RNA (asRNA) to balance the demands on malonyl-CoA for target-product synthesis and cell health was proposed. To establish an efficient asRNA system, the relationship between sequence and function for asRNA was explored. It was demonstrated that the gene-silencing effect of asRNA could be tuned by directing asRNA to different positions in the 5'-UTR (untranslated region) of the target gene. Based on this principle, the activity of asRNA was quantitatively tailored to balance the need for malonyl-CoA in cell growth and the production of the main flavonoid precursor, (2S)-naringenin. Appropriate inhibitory efficiency of the anti-fabB/fabF asRNA improved the production titer by 431% (391 mg/liter). Therefore, the strategy presented in this study provided a useful tool for the fine-tuning of endogenous gene expression in bacteria.
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Bakhtiari N, Mirshahi M, Babaeipour V, Maghsoudi N, Tahzibi A. Down Regulation of ackA-pta Pathway in Escherichia coli BL21 (DE3): A Step Toward Optimized Recombinant Protein Expression System. Jundishapur J Microbiol 2014; 7:e8990. [PMID: 25147677 PMCID: PMC4138692 DOI: 10.5812/jjm.8990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 12/01/2012] [Accepted: 02/19/2013] [Indexed: 01/27/2023] Open
Abstract
Background: One of the most important problems in production of recombinant protein is to attain over-expression of the target gene and high cell density. In such conditions, the secondary metabolites of bacteria become toxic for the medium and cause cells to die. One of these aforementioned metabolites is acetate, which enormously accumulated in the medium, so that both cell and protein yields are affected. Objectives: To overcome this problem, several strategies applied. In this research we used antisense RNA strategy, where the transcription of phosphotransacetylase (PTA) and acetate kinase (ACK), two acetate pathway key enzymes, could be controlled, which led to reduced acetate production. Materials and Methods: In order to achieve this, recombinant plasmid harboring antisense sequences targeting both of pta and ackA was assembled, after transfecting to the cells, its effects on the cell growth and acetate accumulation in the minimal media was assessed and compared with the control, the plasmid without antisense cassette, in presence and absence of IPTG in Escherichia coli BL21 (DE3). Results: It was observed that the mentioned strategy partially affect the growth and amount of excreted acetate in comparison with the control. In addition it was found that high down-regulation of the acetate production pathway reduces the growth rate of E. coli BL21 (DE3). Conclusions: The study principally proved the importance of this strategy in acetate excretion control.
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Affiliation(s)
- Nahid Bakhtiari
- Biochemistry Department, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, IR Iran
| | - Manouchehr Mirshahi
- Biochemistry Department, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, IR Iran
| | - Valiollah Babaeipour
- Department of Bioscience and Biotechnology, Malek Ashtar University of Technology, Tehran, IR Iran
- Corresponding author: Valiollah Babaeipour, Department of Bioscience and Biotechnology, Malek Ashtar University of Technology, Tehran, IR Iran. Tel: +98-2122974614; Fax: +98-2122974614, E-mail:
| | - Nader Maghsoudi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran
| | - Abbas Tahzibi
- Food and Drug Organization, Ministry of Health of Iran, Tehran, IR Iran
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Nakashima N, Miyazaki K. Bacterial cellular engineering by genome editing and gene silencing. Int J Mol Sci 2014; 15:2773-93. [PMID: 24552876 PMCID: PMC3958881 DOI: 10.3390/ijms15022773] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 01/27/2014] [Accepted: 01/28/2014] [Indexed: 12/18/2022] Open
Abstract
Genome editing is an important technology for bacterial cellular engineering, which is commonly conducted by homologous recombination-based procedures, including gene knockout (disruption), knock-in (insertion), and allelic exchange. In addition, some new recombination-independent approaches have emerged that utilize catalytic RNAs, artificial nucleases, nucleic acid analogs, and peptide nucleic acids. Apart from these methods, which directly modify the genomic structure, an alternative approach is to conditionally modify the gene expression profile at the posttranscriptional level without altering the genomes. This is performed by expressing antisense RNAs to knock down (silence) target mRNAs in vivo. This review describes the features and recent advances on methods used in genomic engineering and silencing technologies that are advantageously used for bacterial cellular engineering.
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Affiliation(s)
- Nobutaka Nakashima
- Bioproduction Research Institute, National Institute of Advanced Industrial Sciences and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
| | - Kentaro Miyazaki
- Bioproduction Research Institute, National Institute of Advanced Industrial Sciences and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
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Kang Z, Zhang C, Zhang J, Jin P, Zhang J, Du G, Chen J. Small RNA regulators in bacteria: powerful tools for metabolic engineering and synthetic biology. Appl Microbiol Biotechnol 2014; 98:3413-24. [DOI: 10.1007/s00253-014-5569-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 01/22/2014] [Accepted: 01/23/2014] [Indexed: 12/17/2022]
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Solomon KV, Sanders TM, Prather KL. A dynamic metabolite valve for the control of central carbon metabolism. Metab Eng 2012; 14:661-71. [DOI: 10.1016/j.ymben.2012.08.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Revised: 08/22/2012] [Accepted: 08/26/2012] [Indexed: 11/26/2022]
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Metabolic responses to recombinant bioprocesses in Escherichia coli. J Biotechnol 2012; 164:396-408. [PMID: 23022453 DOI: 10.1016/j.jbiotec.2012.08.026] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 07/09/2012] [Accepted: 08/08/2012] [Indexed: 01/13/2023]
Abstract
Escherichia coli has been widely used for the production of recombinant proteins. However, the unbalances between host metabolism and recombinant biosynthesis continue to hamper the efficiency of these recombinant bioprocesses. The additional drainage of biosynthetic precursors toward recombinant processes burdens severely the metabolism of cells that, ultimately, elicits a series of stress responses, reducing biomass growth and recombinant protein production. Several strategies to overcome these metabolic limitations have been implemented; however, in most cases, improvements in recombinant protein expression were achieved at the expense of biomass growth arrest, which significantly hampers the efficiency of recombinant bioprocesses. With the advent of high throughput techniques and modelling approaches that provide a system-level understanding of the cellular systems, it is now expected that new advances in recombinant bioprocesses are achieved. By providing means to deal with these systems, our understanding on the metabolic behaviour of recombinant cells will advance and can be further explored to the design of suitable hosts and more efficient and cost-effective bioprocesses. Here, we review the major metabolic responses associated with recombinant processes and the engineering strategies relevant to overcome these stresses. Moreover, the advantages of applying systems levels engineering strategies to enhance recombinant protein production in E. coli cells are discussed and future perspectives on the advances of mathematical modelling approaches to study these systems are exposed.
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Recent advances in engineering the central carbon metabolism of industrially important bacteria. Microb Cell Fact 2012; 11:50. [PMID: 22545791 PMCID: PMC3461431 DOI: 10.1186/1475-2859-11-50] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 04/30/2012] [Indexed: 01/19/2023] Open
Abstract
This paper gives an overview of the recent advances in engineering the central carbon metabolism of the industrially important bacteria Escherichia coli, Bacillus subtilis, Corynobacterium glutamicum, Streptomyces spp., Lactococcus lactis and other lactic acid bacteria. All of them are established producers of important classes of products, e.g. proteins, amino acids, organic acids, antibiotics, high-value metabolites for the food industry and also, promising producers of a large number of industrially or therapeutically important chemicals. Optimization of existing or introduction of new cellular processes in these microorganisms is often achieved through manipulation of targets that reside at major points of central metabolic pathways, such as glycolysis, gluconeogenesis, the pentose phosphate pathway and the tricarboxylic acid cycle with the glyoxylate shunt. Based on the huge progress made in recent years in biochemical, genetic and regulatory studies, new fascinating engineering approaches aim at ensuring an optimal carbon and energy flow within central metabolism in order to achieve optimized metabolite production.
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Sharma V, Yamamura A, Yokobayashi Y. Engineering artificial small RNAs for conditional gene silencing in Escherichia coli. ACS Synth Biol 2012; 1:6-13. [PMID: 23651005 DOI: 10.1021/sb200001q] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
It has become increasingly evident that noncoding small RNAs (sRNAs) play a significant and global role in bacterial gene regulation. A majority of the trans-acting sRNAs in bacteria interact with the 5' untranslated region (UTR) and/or the translation initiation region of the targeted mRNAs via imperfect base pairing, resulting in reduced translation efficiency and/or mRNA stability. Additionally, bacterial sRNAs often contain distinct scaffolds that recruit RNA chaperones such as Hfq to facilitate gene regulation. In this study, we describe a strategy to engineer artificial sRNAs that can regulate desired endogenous genes in Escherichia coli. Using a fluorescent reporter gene that was translationally fused to a native 5' mRNA leader sequence, active artificial sRNAs were screened from libraries in which natural sRNA scaffolds were fused to a randomized antisense domain. Artificial sRNAs that posttranscriptionally repress two endogenous genes ompF and fliC were isolated and characterized. We anticipate that the artificial sRNAs will be useful for dynamic control and fine-tuning of endogenous gene expression in bacteria for applications in synthetic biology.
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Affiliation(s)
- Vandana Sharma
- Department of Biomedical Engineering, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, United States
| | - Asami Yamamura
- Department of Biomedical Engineering, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, United States
| | - Yohei Yokobayashi
- Department of Biomedical Engineering, University of California, Davis, 451 Health Sciences Drive, Davis, California 95616, United States
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Son YJ, Phue JN, Trinh LB, Lee SJ, Shiloach J. The role of Cra in regulating acetate excretion and osmotic tolerance in E. coli K-12 and E. coli B at high density growth. Microb Cell Fact 2011; 10:52. [PMID: 21718532 PMCID: PMC3146397 DOI: 10.1186/1475-2859-10-52] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 06/30/2011] [Indexed: 11/26/2022] Open
Abstract
Background E. coli B (BL21), unlike E.coli K-12 (JM109) is insensitive to glucose concentration and, therefore, grows faster and produces less acetate than E. coli K-12, especially when growing to high cell densities at high glucose concentration. By performing genomic analysis, it was demonstrated that the cause of this difference in sensitivity to the glucose concentration is the result of the differences in the central carbon metabolism activity. We hypothesized that the global transcription regulator Cra (FruR) is constitutively expressed in E. coli B and may be responsible for the different behaviour of the two strains. To investigate this possibility and better understand the function of Cra in the two strains, cra - negative E. coli B (BL21) and E. coli K-12 (JM109) were prepared and their growth behaviour and gene expression at high glucose were evaluated using microarray and real-time PCR. Results The deletion of the cra gene in E. coli B (BL21) minimally affected the growth and maximal acetate accumulation, while the deletion of the same gene in E.coli K-12 (JM109) caused the cells to stop growing as soon as acetate concentration reached 6.6 g/L and the media conductivity reached 21 mS/cm. ppsA (gluconeogenesis gene), aceBA (the glyoxylate shunt genes) and poxB (the acetate producing gene) were down-regulated in both strains, while acs (acetate uptake gene) was down-regulated only in E.coli B (BL21). These transcriptional differences had little effect on acetate and pyruvate production. Additionally, it was found that the lower growth of E. coli K-12 (JM109) strain was the result of transcription inhibition of the osmoprotectant producing bet operon (betABT). Conclusions The transcriptional changes caused by the deletion of cra gene did not affect the activity of the central carbon metabolism, suggesting that Cra does not act alone; rather it interacts with other pleiotropic regulators to create a network of metabolic effects. An unexpected outcome of this work is the finding that cra deletion caused transcription inhibition of the bet operon in E. coli K-12 (JM109) but did not affect this operon transcription in E. coli B (BL21). This property, together with the insensitivity to high glucose concentrations, makes this the E. coli B (BL21) strain more resistant to environmental changes.
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Affiliation(s)
- Young-Jin Son
- Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases/ NIH, Bethesda, MD 20892, USA
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Solomon KV, Prather KLJ. The zero-sum game of pathway optimization: emerging paradigms for tuning gene expression. Biotechnol J 2011; 6:1064-70. [PMID: 21695787 DOI: 10.1002/biot.201100086] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 04/30/2011] [Accepted: 05/09/2011] [Indexed: 12/20/2022]
Abstract
With increasing price volatility and growing awareness of the lack of sustainability of traditional chemical synthesis, microbial chemical production has been tapped as a promising renewable alternative for the generation of diverse, stereospecific compounds. Nonetheless, many attempts to generate them are not yet economically viable. Due to the zero-sum nature of microbial resources, traditional strategies of pathway optimization are attaining minimal returns. This result is in part a consequence of the gross changes in host physiology resulting from such efforts and underscores the need for more precise and subtle forms of gene modulation. In this review, we describe alternative strategies and emerging paradigms to address this problem and highlight potential solutions from the emerging field of synthetic biology.
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Affiliation(s)
- Kevin V Solomon
- Department of Chemical Engineering, Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, MA, USA
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Abstract
Antisense RNAs encoded on the DNA strand opposite another gene have the potential to form extensive base-pairing interactions with the corresponding sense RNA. Unlike other smaller regulatory RNAs in bacteria, antisense RNAs range in size from tens to thousands of nucleotides. The numbers of antisense RNAs reported for different bacteria vary extensively, but hundreds have been suggested in some species. If all of these reported antisense RNAs are expressed at levels sufficient to regulate the genes encoded opposite them, antisense RNAs could significantly impact gene expression in bacteria. Here, we review the evidence for these RNA regulators and describe what is known about the functions and mechanisms of action for some of these RNAs. Important considerations for future research as well as potential applications are also discussed.
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Affiliation(s)
- Maureen Kiley Thomason
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland 20892-5430, USA.
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Carnes AE, Luke JM, Vincent JM, Schukar A, Anderson S, Hodgson CP, Williams JA. Plasmid DNA fermentation strain and process-specific effects on vector yield, quality, and transgene expression. Biotechnol Bioeng 2010; 108:354-63. [DOI: 10.1002/bit.22936] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Oddone GM, Mills DA, Block DE. Dual inducible expression of recombinant GFP and targeted antisense RNA in Lactococcus lactis. Plasmid 2009; 62:108-18. [DOI: 10.1016/j.plasmid.2009.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 06/04/2009] [Accepted: 06/04/2009] [Indexed: 12/21/2022]
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40
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Nakashima N, Tamura T. Conditional gene silencing of multiple genes with antisense RNAs and generation of a mutator strain of Escherichia coli. Nucleic Acids Res 2009; 37:e103. [PMID: 19515932 PMCID: PMC2731896 DOI: 10.1093/nar/gkp498] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
In this study, we describe a method of simultaneous conditional gene silencing of up to four genes in Escherichia coli by using antisense RNAs. We used antisense RNAs with paired termini, which carried flanking inverted repeats to create paired double-stranded RNA termini; these RNAs have been proven to have high silencing efficacy. To express antisense RNAs, we constructed four IPTG-inducible vectors carrying different but compatible replication origins. When the lacZ antisense RNA was expressed using these vectors, lacZ expression was successfully silenced by all the vectors, but the expression level of the antisense RNA and silencing efficacy differed depending on the used vectors. All the vectors were co-transformable; the antisense RNAs against lacZ, ackA, pta and pepN were co-expressed, and silencing of all the target genes was confirmed. Furthermore, when antisense RNAs were targeted to the mutator genes mutS, mutD (dnaQ) and ndk, which are involved in DNA replication or DNA mismatch repair, spontaneous mutation frequencies increased over 2000-fold. The resulting mutator strain is useful for random mutagenesis of plasmids. The method provides a robust tool for investigating functional relationships between multiple genes or altering cell phenotypes for biotechnological and industrial applications.
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Affiliation(s)
- Nobutaka Nakashima
- Proteolysis and Protein Turnover Research Group, Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology, Sapporo 062-8517, Japan.
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Anesiadis N, Cluett WR, Mahadevan R. Dynamic metabolic engineering for increasing bioprocess productivity. Metab Eng 2008; 10:255-66. [DOI: 10.1016/j.ymben.2008.06.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Revised: 06/11/2008] [Accepted: 06/12/2008] [Indexed: 10/21/2022]
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Impact of dissolved oxygen concentration on some key parameters and production of rhG-CSF in batch fermentation. J Ind Microbiol Biotechnol 2008; 35:991-1000. [DOI: 10.1007/s10295-008-0374-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Accepted: 05/12/2008] [Indexed: 10/22/2022]
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Rasmussen LCV, Sperling-Petersen HU, Mortensen KK. Hitting bacteria at the heart of the central dogma: sequence-specific inhibition. Microb Cell Fact 2007; 6:24. [PMID: 17692125 PMCID: PMC1995221 DOI: 10.1186/1475-2859-6-24] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Accepted: 08/10/2007] [Indexed: 12/16/2022] Open
Abstract
An important objective in developing new drugs is the achievement of high specificity to maximize curing effect and minimize side-effects, and high specificity is an integral part of the antisense approach. The antisense techniques have been extensively developed from the application of simple long, regular antisense RNA (asRNA) molecules to highly modified versions conferring resistance to nucleases, stability of hybrid formation and other beneficial characteristics, though still preserving the specificity of the original nucleic acids. These new and improved second- and third-generation antisense molecules have shown promising results. The first antisense drug has been approved and more are in clinical trials. However, these antisense drugs are mainly designed for the treatment of different human cancers and other human diseases. Applying antisense gene silencing and exploiting RNA interference (RNAi) are highly developed approaches in many eukaryotic systems. But in bacteria RNAi is absent, and gene silencing by antisense compounds is not nearly as well developed, despite its great potential and the intriguing possibility of applying antisense molecules in the fight against multiresistant bacteria. Recent breakthrough and current status on the development of antisense gene silencing in bacteria including especially phosphorothioate oligonucleotides (PS-ODNs), peptide nucleic acids (PNAs) and phosphorodiamidate morpholino oligomers (PMOs) will be presented in this review.
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Affiliation(s)
| | - Hans Uffe Sperling-Petersen
- Laboratory of BioDesign, Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10 C, DK-8000 Aarhus C, Denmark
| | - Kim Kusk Mortensen
- Laboratory of BioDesign, Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10 C, DK-8000 Aarhus C, Denmark
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Wittmann C, Weber J, Betiku E, Krömer J, Böhm D, Rinas U. Response of fluxome and metabolome to temperature-induced recombinant protein synthesis in Escherichia coli. J Biotechnol 2007; 132:375-84. [PMID: 17689798 DOI: 10.1016/j.jbiotec.2007.07.495] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 06/07/2007] [Accepted: 07/03/2007] [Indexed: 10/23/2022]
Abstract
The response of the central carbon metabolism of Escherichia coli to temperature-induced recombinant production of human fibroblast growth factor was studied on the level of metabolic fluxes and intracellular metabolite levels. During production, E. coli TG1:plambdaFGFB, carrying a plasmid encoded gene for the recombinant product, revealed stress related characteristics such as decreased growth rate and biomass yield and enhanced by-product excretion (acetate, pyruvate, lactate). With the onset of production, the adenylate energy charge dropped from 0.85 to 0.60, indicating the occurrence of a severe energy limitation. This triggered an increase of the glycolytic flux which, however, was not sufficient to compensate for the increased ATP demand. The activation of the glycolytic flux was also indicated by the readjustment of glycolytic pool sizes leading to an increased driving force for the reaction catalyzed by phosphofructokinase. Moreover, fluxes through the TCA cycle, into the pentose phosphate pathway and into anabolic pathways decreased significantly. The strong increase of flux into overflow pathways, especially towards acetate was most likely caused by a flux redirection from pyruvate dehydrogenase to pyruvate oxidase. The glyoxylate shunt, not active during growth, was the dominating anaplerotic pathway during production. Together with pyruvate oxidase and acetyl CoA synthase this pathway could function as a metabolic by-pass to overcome the limitation in the junction between glycolysis and TCA cycle and partly recycle the acetate formed back into the metabolism.
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Chou CP. Engineering cell physiology to enhance recombinant protein production in Escherichia coli. Appl Microbiol Biotechnol 2007; 76:521-32. [PMID: 17571257 DOI: 10.1007/s00253-007-1039-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 05/08/2007] [Accepted: 05/21/2007] [Indexed: 11/26/2022]
Abstract
The advent of recombinant DNA technology has revolutionized the strategies for protein production. Due to the well-characterized genome and a variety of mature tools available for genetic manipulation, Escherichia coli is still the most common workhorse for recombinant protein production. However, the culture for industrial applications often presents E. coli cells with a growth condition that is significantly different from their natural inhabiting environment in the gastrointestinal tract, resulting in deterioration in cell physiology and limitation in cell's productivity. It has been recognized that innovative design of genetically engineered strains can highly increase the bioprocess yield with minimum investment on the capital and operating costs. Nevertheless, most of these genetic manipulations, by which traits are implanted into the workhorse through recombinant DNA technology, for enhancing recombinant protein productivity often translate into the challenges that deteriorate cell physiology or even jeopardize cell survival. An in-depth understanding of these challenges and their corresponding cellular response at the molecular level becomes crucial for developing superior strains that are more physiologically adaptive to the production environment to improve culture productivity. With the accumulated knowledge in cell physiology, whose importance to gene overexpression was to some extent undervalued previously, this review is intended to focus on the recent biotechnological advancement in engineering cell physiology to enhance recombinant protein production in E. coli.
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Affiliation(s)
- C Perry Chou
- Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada, N2L 3G1.
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Kemmer C, Neubauer P. Antisense RNA based down-regulation of RNaseE in E. coli. Microb Cell Fact 2006; 5:38. [PMID: 17164000 PMCID: PMC1716169 DOI: 10.1186/1475-2859-5-38] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2006] [Accepted: 12/12/2006] [Indexed: 11/10/2022] Open
Abstract
Background Messenger RNA decay is an important mechanism for controlling gene expression in all organisms. The rate of the mRNA degradation directly affects the steady state concentration of mRNAs and therefore influences the protein synthesis. RNaseE has a key importance for the general mRNA decay in E.coli. While RNaseE initiates the degradation of most mRNAs in E.coli, it is likely that the enzyme is also responsible for the degradation of recombinant RNAs. As RNaseE is essential for cell viability and knockout mutants cannot be cultured, we investigated the possibility for a down-regulation of the intracellular level of RNaseE by antisense RNAs. During this study, an antisense RNA based approach could be established which revealed a strong reduction of the intracellular level of RNaseE in E.coli. Results Despite the autoregulation of rne mRNA by its gene product, significant antisense downregulation of RNaseE is possible. The expression of antisense RNAs did not effect the cell growth negatively. The amount of antisense RNA was monitored quantitatively by a fluorescence based sandwich hybridisation assay. Induction by anhydrotetracycline was followed by a 25-fold increase of the detectable antisense RNA molecules per cell. The antisense RNA level was maintained above 400 molecules per cell until the stationary phase, which caused the level of expressed antisense RNAs to decrease markedly. Western blot experiments revealed the strongest reduction in the RNaseE protein level 90 min after antisense RNA induction. The cellular level of RNaseE could be decreased to 35% of the wild type level. When the growth entered the stationary phase, the RNaseE level was maintained still at 50 to 60% of the wild type level. Conclusion In difference to eukaryotic cells, where the RNAi technology is widely used, this technology is rather unexplored in bacteria, although different natural systems use antisense RNA-based silencing, and a few studies have earlier indicated the potential of this technology also in prokaryotes. Our results show that even complicated self-regulatory systems such as RNaseE may be controlled by antisense RNA technology, indicating that systems based on antisense RNA expression may have a potential for controlling detrimental factors with plasmid-based constructs in arbitrary strains while maintaining their beneficial characteristics. The study also proved that the RNA sandwich hybridisation technique is directly applicable to quantify small RNA molecules in crude cell extracts, which may have a broader application potential as a monitoring tool in RNA inhibition applications.
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Affiliation(s)
- Christian Kemmer
- Bioprocess Engineering Laboratory, Department of Process and Environmental Engineering and Biocenter Oulu, P. O. Box 4300, University of Oulu, FIN-90014 Oulu, Finland
| | - Peter Neubauer
- Bioprocess Engineering Laboratory, Department of Process and Environmental Engineering and Biocenter Oulu, P. O. Box 4300, University of Oulu, FIN-90014 Oulu, Finland
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Eiteman MA, Altman E. Overcoming acetate in Escherichia coli recombinant protein fermentations. Trends Biotechnol 2006; 24:530-6. [PMID: 16971006 DOI: 10.1016/j.tibtech.2006.09.001] [Citation(s) in RCA: 261] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 08/04/2006] [Accepted: 09/01/2006] [Indexed: 11/18/2022]
Abstract
Escherichia coli is the organism of choice for the expression of a wide variety of recombinant proteins for therapeutic, diagnostic and industrial applications. E. coli generates acetic acid (acetate) as an undesirable by-product that has several negative effects on protein production. Various strategies have been developed to limit acetate accumulation or reduce its negative effects to increase the productivity of recombinant proteins. This article reviews recent strategies for reducing or eliminating acetate, including approaches that optimize the protein production process as well as those that involve modifying the host organism itself.
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Affiliation(s)
- Mark A Eiteman
- Center for Molecular BioEngineering, University of Georgia, Athens, GA 30602, USA
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Nakashima N, Tamura T, Good L. Paired termini stabilize antisense RNAs and enhance conditional gene silencing in Escherichia coli. Nucleic Acids Res 2006; 34:e138. [PMID: 17062631 PMCID: PMC1635301 DOI: 10.1093/nar/gkl697] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Reliable methods for conditional gene silencing in bacteria have been elusive. To improve silencing by expressed antisense RNAs (asRNAs), we systematically altered several design parameters and targeted multiple reporter and essential genes in Escherichia coli. A paired termini (PT) design, where flanking inverted repeats create paired dsRNA termini, proved effective. PTasRNAs targeted against the ackA gene within the acetate kinase-phosphotransacetylase operon (ackA-pta) triggered target mRNA decay and a 78% reduction in AckA activity with high genetic penetrance. PTasRNAs are abundant and stable and function through an RNase III independent mechanism that requires a large stoichiometric excess of asRNA. Conditional ackA silencing reduced carbon flux to acetate and increased heterologous gene expression. The PT design also improved silencing of the essential fabI gene. Full anti-fabI PTasRNA induction prevented growth and partial induction sensitized cells to a FabI inhibitor. PTasRNAs have potential for functional genomics, antimicrobial discovery and metabolic flux control.
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Affiliation(s)
- Nobutaka Nakashima
- Department of Cell and Molecular Biology, Programme for Genomics and Bioinformatics, Karolinska InstituteBerzelius väg 35, 171 77 Stockholm, Sweden
- Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology (AIST)2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, 062-8517 Sapporo, Japan
| | - Tomohiro Tamura
- Research Institute of Genome-based Biofactory, National Institute of Advanced Industrial Science and Technology (AIST)2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, 062-8517 Sapporo, Japan
- Laboratory of Molecular Environmental Microbiology, Graduate School of Agriculture, Hokkaido UniversityKita-9, Nishi-9, Kita-ku, 060-8589 Sapporo, Japan
| | - Liam Good
- Department of Cell and Molecular Biology, Programme for Genomics and Bioinformatics, Karolinska InstituteBerzelius väg 35, 171 77 Stockholm, Sweden
- To whom correspondence should be addressed. Tel: +46 8 5248 6385, Fax: +46 8 32 39 50;
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Guapillo MR, Márquez MA, Benítez-Hess ML, Alvarez-Salas LM. A bacterial reporter system for the evaluation of antisense oligodeoxynucleotides directed against human papillomavirus type 16 (HPV-16). Arch Med Res 2006; 37:584-92. [PMID: 16740427 DOI: 10.1016/j.arcmed.2005.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 11/21/2005] [Indexed: 10/24/2022]
Abstract
BACKGROUND Antisense oligodeoxynucleotides (AS-ODNs) are a promising alternative for the cure of many diseases because of their in vivo specificity and stability. However, AS-ODNs have a strong dependence on the target mRNA structure making necessary extensive in vivo testing. There is, therefore, a need to develop assays to rapidly evaluate in vivo ODN performance. METHODS We report a simple and inexpensive bacterial reporter system for the rapid in vivo evaluation of AS-ODNs directed against human papillomavirus type 16 (HPV-16) based on the destruction of a chimeric CFP mRNA using the reported HPV-16 nt 410-445 target. RESULTS In vitro RNaseH assays confirmed target RNA accessibility after AS-ODN treatment. Expression of CFP in Escherichia coli BL21(DE3) with pGST-TSd2-CFP plasmid containing HPV-16 nt 410-445 target linked to CFP was blocked by transformed antisense PS-ODNs but not by two different scrambled ODN controls. CONCLUSIONS A correlation was observed between bacterial CFP downregulation with the HPV-16 E6/E7 mRNA downregulation and the inhibition of anchorage-independent growth of HPV-16 containing cells suggesting that inhibition of HPV-16 E6/E7 expression by AS-ODNs directed against 410-445 target in cervical tumor cells can be tested in bacterial models.
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Affiliation(s)
- Mario R Guapillo
- Laboratorio de Terapia Génetica, Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados, México, D.F., México
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