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Mahalik S, Sharma A, Das DR, Mittra D, Mukherjee KJ. Co-expressing Leucine Responsive Regulatory protein (Lrp) enhances Recombinant L-Asparaginase-II production in Escherichia coli. J Biotechnol 2022; 351:99-108. [DOI: 10.1016/j.jbiotec.2022.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/27/2022]
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2
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Wang S, Tsao CY, Motabar D, Li J, Payne GF, Bentley WE. A Redox-Based Autoinduction Strategy to Facilitate Expression of 5xCys-Tagged Proteins for Electrobiofabrication. Front Microbiol 2021; 12:675729. [PMID: 34220759 PMCID: PMC8250426 DOI: 10.3389/fmicb.2021.675729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/13/2021] [Indexed: 01/17/2023] Open
Abstract
Biofabrication utilizes biological materials and biological means, or mimics thereof, for assembly. When interfaced with microelectronics, electrobiofabricated assemblies enable exquisite sensing and reporting capabilities. We recently demonstrated that thiolated polyethylene glycol (PEG-SH) could be oxidatively assembled into a thin disulfide crosslinked hydrogel at an electrode surface; with sufficient oxidation, extra sulfenic acid groups are made available for covalent, disulfide coupling to sulfhydryl groups of proteins or peptides. We intentionally introduced a polycysteine tag (5xCys-tag) consisting of five consecutive cysteine residues at the C-terminus of a Streptococcal protein G to enable its covalent coupling to an electroassembled PEG-SH film. We found, however, that its expression and purification from E. coli was difficult, owing to the extra cysteine residues. We developed a redox-based autoinduction methodology that greatly enhanced the yield, especially in the soluble fraction of E. coli extracts. The redox component involved the deletion of oxyRS, a global regulator of the oxidative stress response and the autoinduction component integrated a quorum sensing (QS) switch that keys the secreted QS autoinducer-2 to induction. Interestingly, both methods helped when independently employed and further, when used in combination (i.e., autodinduced oxyRS mutant) the results were best—we found the highest total yield and highest yield in the soluble fraction. We hypothesize that the production host was less prone to severe metabolic perturbations that might reduce yield or drive sequestration of the -tagged protein into inclusion bodies. We expect this methodology will be useful for the expression of many such Cys-tagged proteins, ultimately enabling a diverse array of functionalized devices.
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Affiliation(s)
- Sally Wang
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, United States.,Fischell Institute for Biomedical Devices, University of Maryland, College Park, College Park, MD, United States.,Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, College Park, MD, United States
| | - Chen-Yu Tsao
- Fischell Institute for Biomedical Devices, University of Maryland, College Park, College Park, MD, United States.,Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, College Park, MD, United States
| | - Dana Motabar
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, United States.,Fischell Institute for Biomedical Devices, University of Maryland, College Park, College Park, MD, United States.,Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, College Park, MD, United States
| | - Jinyang Li
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, United States.,Fischell Institute for Biomedical Devices, University of Maryland, College Park, College Park, MD, United States.,Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, College Park, MD, United States
| | - Gregory F Payne
- Fischell Institute for Biomedical Devices, University of Maryland, College Park, College Park, MD, United States.,Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, College Park, MD, United States
| | - William E Bentley
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, United States.,Fischell Institute for Biomedical Devices, University of Maryland, College Park, College Park, MD, United States.,Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, College Park, MD, United States
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3
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Süntar I, Çetinkaya S, Haydaroğlu ÜS, Habtemariam S. Bioproduction process of natural products and biopharmaceuticals: Biotechnological aspects. Biotechnol Adv 2021; 50:107768. [PMID: 33974980 DOI: 10.1016/j.biotechadv.2021.107768] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 02/07/2023]
Abstract
Decades of research have been put in place for developing sustainable routes of bioproduction of high commercial value natural products (NPs) on the global market. In the last few years alone, we have witnessed significant advances in the biotechnological production of NPs. The development of new methodologies has resulted in a better understanding of the metabolic flux within the organisms, which have driven manipulations to improve production of the target product. This was further realised due to the recent advances in the omics technologies such as genomics, transcriptomics, proteomics, metabolomics and secretomics, as well as systems and synthetic biology. Additionally, the combined application of novel engineering strategies has made possible avenues for enhancing the yield of these products in an efficient and economical way. Invention of high-throughput technologies such as next generation sequencing (NGS) and toolkits for genome editing Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9 (CRISPR/Cas9) have been the game changers and provided unprecedented opportunities to generate rationally designed synthetic circuits which can produce complex molecules. This review covers recent advances in the engineering of various hosts for the production of bioactive NPs and biopharmaceuticals. It also highlights general approaches and strategies to improve their biosynthesis with higher yields in a perspective of plants and microbes (bacteria, yeast and filamentous fungi). Although there are numerous reviews covering this topic on a selected species at a time, our approach herein is to give a comprehensive understanding about state-of-art technologies in different platforms of organisms.
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Affiliation(s)
- Ipek Süntar
- Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330 Etiler, Ankara, Turkey.
| | - Sümeyra Çetinkaya
- Biotechnology Research Center of Ministry of Agriculture and Forestry, 06330 Yenimahalle, Ankara, Turkey
| | - Ülkü Selcen Haydaroğlu
- Biotechnology Research Center of Ministry of Agriculture and Forestry, 06330 Yenimahalle, Ankara, Turkey
| | - Solomon Habtemariam
- Pharmacognosy Research Laboratories & Herbal Analysis Services UK, University of Greenwich, Chatham-Maritime, Kent ME4 4TB, United Kingdom
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4
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Hauk P, Stephens K, Virgile C, VanArsdale E, Pottash AE, Schardt JS, Jay SM, Sintim HO, Bentley WE. Homologous Quorum Sensing Regulatory Circuit: A Dual-Input Genetic Controller for Modulating Quorum Sensing-Mediated Protein Expression in E. coli. ACS Synth Biol 2020; 9:2692-2702. [PMID: 32822530 DOI: 10.1021/acssynbio.0c00179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We developed a hybrid synthetic circuit that co-opts the genetic regulation of the native bacterial quorum sensing autoinducer-2 and imposes an extra external controller for maintaining tightly controlled gene expression. This dual-input genetic controller was mathematically modeled and, by design, can be operated in three modes: a constitutive mode that enables consistent and high levels of expression; a tightly repressed mode in which there is very little background expression; and an inducible mode in which concentrations of two signals (arabinose and autoinducer-2) determine the net amplification of the gene(s)-of-interest. We demonstrate the utility of the circuit for the controlled expression of human granulocyte macrophage colony stimulating factor in an engineered probiotic E. coli. This dual-input genetic controller is the first homologous AI-2 quorum sensing circuit that has the ability to be operated in three different modes. We believe it has the potential for wide-ranging biotechnological applications due its versatile features.
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Affiliation(s)
- Pricila Hauk
- Institute for Bioscience and Biotechnology Research, College Park, Maryland 20742, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Kristina Stephens
- Institute for Bioscience and Biotechnology Research, College Park, Maryland 20742, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, Maryland 20742, United States
| | - Chelsea Virgile
- Institute for Bioscience and Biotechnology Research, College Park, Maryland 20742, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Eric VanArsdale
- Institute for Bioscience and Biotechnology Research, College Park, Maryland 20742, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, Maryland 20742, United States
| | - Alex Eli Pottash
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - John S. Schardt
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Steven M. Jay
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Herman O. Sintim
- Department of Chemistry and Institute for Drug Discovery, Purdue University, West Lafayette, Indiana 47907, United States
| | - William E. Bentley
- Institute for Bioscience and Biotechnology Research, College Park, Maryland 20742, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Institute for Biomedical Devices, University of Maryland, College Park, Maryland 20742, United States
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5
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Asif M, Imran M. Effect of Quorum Sensing Inhibitor Agents against Pseudomonas aeruginosa. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1068162020020041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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6
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Ge C, Sheng H, Chen X, Shen X, Sun X, Yan Y, Wang J, Yuan Q. Quorum Sensing System Used as a Tool in Metabolic Engineering. Biotechnol J 2020; 15:e1900360. [DOI: 10.1002/biot.201900360] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/07/2020] [Indexed: 12/29/2022]
Affiliation(s)
- Chang Ge
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Huakang Sheng
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Xin Chen
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Xiaolin Shen
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Xinxiao Sun
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Yajun Yan
- College of EngineeringThe University of Georgia Athens GA 30605 USA
| | - Jia Wang
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Qipeng Yuan
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
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Asif M, Imran M. Quorum Sensing Inhibition: Current Advances of the Natural Antimicrobial Agents. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1068162019060049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Quan Y, Meng F, Ma X, Song X, Liu X, Gao W, Dang Y, Meng Y, Cao M, Song C. Regulation of bacteria population behaviors by AI-2 "consumer cells" and "supplier cells". BMC Microbiol 2017; 17:198. [PMID: 28927379 PMCID: PMC5605969 DOI: 10.1186/s12866-017-1107-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 09/13/2017] [Indexed: 11/15/2022] Open
Abstract
Background Autoinducer-2 (AI-2) is a universal signal molecule and enables an individual bacteria to communicate with each other and ultimately control behaviors of the population. Harnessing the character of AI-2, two kinds of AI-2 “controller cells” (“consumer cells” and “supplier cells”) were designed to “reprogram” the behaviors of entire population. Results For the consumer cells, genes associated with the uptake and processing of AI-2, which includes LsrACDB, LsrFG, LsrK, were overexpressed in varying combinations. Four consumer cell strains were constructed: Escherichia coli MG1655 pLsrACDB (NK-C1), MG1655 pLsrACDBK (NK-C2), MG1655 pLsrACDBFG (NK-C3) and MG1655 pLsrACDBFGK (NK-C4). The key enzymes responsible for production of AI-2, LuxS and Mtn, were also overexpressed, yielding strains MG1655 pLuxS (NK-SU1), and MG1655 pLuxS-Mtn (NK-SU2). All the consumer cells could decrease the environmental AI-2 concentration. NK-C2 and NK-C4 were most effective in AI-2 uptake and inhibited biofilm formation. While suppliers can increase the environmental AI-2 concentration and NK-SU2 was most effective in supplying AI-2 and facilitated biofilm formation. Further, reporter strain, MG1655 pLGFP was constructed. The expression of green fluorescent protein (GFP) in reporter cells was initiated and guided by AI-2. Mixture of consumer cells and reporter cells suggest that consumer cells can decrease the AI-2 concentration. And the supplier cells were co-cultured with reporter cells, indicating that supplier cells can provide more AI-2 compared to the control. Conclusions The consumer cells and supplier cells could be used to regulate environmental AI-2 concentration and the biofilm formation. They can also modulate the AI-2 concentration when they were co-cultured with reporter cells. It can be envisioned that this system will become useful tools in synthetic biology and researching new antimicrobials. Electronic supplementary material The online version of this article (10.1186/s12866-017-1107-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yufen Quan
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Fankang Meng
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Xinyu Ma
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Xinhao Song
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Xiao Liu
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Weixia Gao
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Yulei Dang
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Yao Meng
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Mingfeng Cao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, 50011, USA
| | - Cunjiang Song
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Nankai University, Tianjin, 300071, China.
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Drachuk I, Harbaugh S, Geryak R, Kaplan DL, Tsukruk VV, Kelley-Loughnane N. Immobilization of Recombinant E. coli Cells in a Bacterial Cellulose–Silk Composite Matrix To Preserve Biological Function. ACS Biomater Sci Eng 2017; 3:2278-2292. [DOI: 10.1021/acsbiomaterials.7b00367] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Irina Drachuk
- UES Inc., 4401 Dayton-Xenia
Road, Dayton, Ohio 45432, United States
- Air Force Research Laboratory, 711th Human Performance Wing, Airmen Systems Directorate, 2510 Fifth Street, Wright-Patterson AFB, Dayton, Ohio 45433, United States
| | - Svetlana Harbaugh
- The Henry M. Jackson Foundation, 6720A Rockledge Drive, Bethesda, Maryland 20817, United States
- Air Force Research Laboratory, 711th Human Performance Wing, Airmen Systems Directorate, 2510 Fifth Street, Wright-Patterson AFB, Dayton, Ohio 45433, United States
| | - Ren Geryak
- School
of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - David L. Kaplan
- Department
of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Vladimir V. Tsukruk
- School
of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Nancy Kelley-Loughnane
- Air Force Research Laboratory, 711th Human Performance Wing, Airmen Systems Directorate, 2510 Fifth Street, Wright-Patterson AFB, Dayton, Ohio 45433, United States
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10
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Hauk P, Stephens K, Mckay R, Virgile CR, Ueda H, Ostermeier M, Ryu KS, Sintim HO, Bentley WE. Insightful directed evolution of Escherichia coli quorum sensing promoter region of the lsrACDBFG operon: a tool for synthetic biology systems and protein expression. Nucleic Acids Res 2016; 44:10515-10525. [PMID: 27915294 PMCID: PMC5137460 DOI: 10.1093/nar/gkw981] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 10/10/2016] [Accepted: 10/18/2016] [Indexed: 01/17/2023] Open
Abstract
Quorum sensing (QS) regulates many natural phenotypes (e.q. virulence, biofilm formation, antibiotic resistance), and its components, when incorporated into synthetic genetic circuits, enable user-directed phenotypes. We created a library of Escherichia coli lsr operon promoters using error-prone PCR (ePCR) and selected for promoters that provided E. coli with higher tetracycline resistance over the native promoter when placed upstream of the tet(C) gene. Among the fourteen clones identified, we found several mutations in the binding sites of QS repressor, LsrR. Using site-directed mutagenesis we restored all p-lsrR-box sites to the native sequence in order to maintain LsrR repression of the promoter, preserving the other mutations for analysis. Two promoter variants, EP01rec and EP14rec, were discovered exhibiting enhanced protein expression. In turn, these variants retained their ability to exhibit the LsrR-mediated QS switching activity. Their sequences suggest regulatory linkage between CytR (CRP repressor) and LsrR. These promoters improve upon the native system and exhibit advantages over synthetic QS promoters previously reported. Incorporation of these promoters will facilitate future applications of QS-regulation in synthetic biology and metabolic engineering.
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Affiliation(s)
- Pricila Hauk
- Institute for Bioscience and Biotechnology Research, College Park, MD, USA.,Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
| | - Kristina Stephens
- Institute for Bioscience and Biotechnology Research, College Park, MD, USA.,Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
| | - Ryan Mckay
- Institute for Bioscience and Biotechnology Research, College Park, MD, USA.,Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
| | - Chelsea Ryan Virgile
- Institute for Bioscience and Biotechnology Research, College Park, MD, USA.,Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
| | - Hana Ueda
- Department of Mathematics, University of Maryland, College Park, MD 20742, USA
| | - Marc Ostermeier
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Kyoung-Seok Ryu
- Protein Structure Group, Korea Basic Science Institute, 162 Yeongudangi-Ro, Ochang-Eup, Cheongju-Si, Chungcheongbuk-Do 363-883, South Korea
| | - Herman O Sintim
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - William E Bentley
- Institute for Bioscience and Biotechnology Research, College Park, MD, USA .,Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
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11
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Rational design of ‘controller cells’ to manipulate protein and phenotype expression. Metab Eng 2015; 30:61-68. [DOI: 10.1016/j.ymben.2015.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/17/2015] [Accepted: 04/01/2015] [Indexed: 01/03/2023]
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12
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Haigh R, Kumar B, Sandrini S, Freestone P. Mutation design and strain background influence the phenotype ofEscherichia coli luxSmutants. Mol Microbiol 2013; 88:951-69. [DOI: 10.1111/mmi.12237] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Richard Haigh
- Department of Genetics; University of Leicester; Leicester UK
| | - Brijesh Kumar
- Department of Infection, Immunity and Inflammation; University of Leicester; Leicester UK
| | - Sara Sandrini
- Department of Infection, Immunity and Inflammation; University of Leicester; Leicester UK
| | - Primrose Freestone
- Department of Infection, Immunity and Inflammation; University of Leicester; Leicester UK
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13
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Gao Q, Zheng D, Yuan Z. Substrate preference of 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidase inBurkholderia thailandensis. FEMS Microbiol Lett 2013. [DOI: 10.1111/1574-6968.12059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
| | - Dasheng Zheng
- Key Laboratory of Agricultural and Environmental Microbiology; Wuhan Institute of Virology; Chinese Academy of Sciences; Wuhan; China
| | - Zhiming Yuan
- Key Laboratory of Agricultural and Environmental Microbiology; Wuhan Institute of Virology; Chinese Academy of Sciences; Wuhan; China
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14
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Zhou K, Zou R, Stephanopoulos G, Too HP. Enhancing solubility of deoxyxylulose phosphate pathway enzymes for microbial isoprenoid production. Microb Cell Fact 2012; 11:148. [PMID: 23148661 PMCID: PMC3545872 DOI: 10.1186/1475-2859-11-148] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 11/07/2012] [Indexed: 12/02/2022] Open
Abstract
Background Recombinant proteins are routinely overexpressed in metabolic engineering. It is well known that some over-expressed heterologous recombinant enzymes are insoluble with little or no enzymatic activity. This study examined the solubility of over-expressed homologous enzymes of the deoxyxylulose phosphate pathway (DXP) and the impact of inclusion body formation on metabolic engineering of microbes. Results Four enzymes of this pathway (DXS, ISPG, ISPH and ISPA), but not all, were highly insoluble, regardless of the expression systems used. Insoluble dxs (the committed enzyme of DXP pathway) was found to be inactive. Expressions of fusion tags did not significantly improve the solubility of dxs. However, hypertonic media containing sorbitol, an osmolyte, successfully doubled the solubility of dxs, with the concomitant improvement in microbial production of the metabolite, DXP. Similarly, sorbitol significantly improved the production of soluble and functional ERG12, the committed enzyme in the mevalonate pathway. Conclusion This study demonstrated the unanticipated findings that some over-expressed homologous enzymes of the DXP pathway were highly insoluble, forming inclusion bodies, which affected metabolite formation. Sorbitol was found to increase both the solubility and function of some of these over-expressed enzymes, a strategy to increase the production of secondary metabolites.
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Affiliation(s)
- Kang Zhou
- Chemical and Pharmaceutical Engineering, Singapore-MIT Alliance, 4 Engineering Drive 3, Singapore, Singapore
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15
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luxS mutant regulation: quorum sensing impairment or methylation disorder? SENSORS 2012; 12:6155-75. [PMID: 22778636 PMCID: PMC3386735 DOI: 10.3390/s120506176] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 04/12/2012] [Accepted: 04/20/2012] [Indexed: 12/27/2022]
Abstract
AI-2–mediated quorum sensing has been identified in various bacteria, including both Gram-negative and Gram-positive species, and numerous phenotypes have been reported to be regulated by this mechanism, using the luxS-mutant strain. But the AI-2 production process confused this regulatory function; some considered this regulation as the result of a metabolic change, which refers to an important metabolic cycle named activated methyl cycle (AMC), caused by luxS-mutant simultaneously with the defect of AI-2. Herein we hypothesized that the quorum sensing system—not the metabolic aspect—is responsible for such a regulatory function. In this study, we constructed plasmids infused with sahH and induced protein expression in the luxS-mutant strain to make the quorum-sensing system and metabolic system independent. The biofilm-related genes were investigated by real-time polymerase chain reaction (PCR), and the results demonstrated that the quorum-sensing completed strain restored the gene expression of the defective strain, but the metabolically completed one did not. This evidence supported our hypothesis that the autoinducer-2-mediated, quorum-sensing system, not the AMC, was responsible for luxS mutant regulation.
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