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Zhao X, Yu H, Liang Q, Zhou J, Li J, Du G, Chen J. Stepwise Optimization of Inducible Expression System for the Functional Secretion of Horseradish Peroxidase in Saccharomyces cerevisiae. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:4059-4068. [PMID: 36821527 DOI: 10.1021/acs.jafc.2c09117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Horseradish peroxidase (HRP) is a plant-derived glycoprotein that can be developed as a food additive to cross-link proteins or biopolymers. Although Saccharomyces cerevisiae has advantages in the production of food-grade HRP, the low expressional level and inefficient secretion hindered its application values. After comparing the effects of constitutive and inducible expression on cell growth, the strength of HRP expression was roughly tuned by replacing core regions of the promoter in the GAL80-knockout strain and further finely tuned by terminator screening. Additionally, the most suitable signal peptide was selected, and the pre-peptide with pro-peptides was modified to balance the transport of HRP in the endoplasmic reticulum. The extracellular HRP activity of the best strain reached 13 506 U/L at the fermenter level, 330-fold higher than the previous result of 41 U/L in S. cerevisiae. The strategy can be applied to alleviate the inhibition of cell growth caused by the expression of toxic proteins and improve their secretion.
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Affiliation(s)
- Xinrui Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Haibo Yu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Qingfeng Liang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jianghua Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Guocheng Du
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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2
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Rajkumar AS, Özdemir E, Lis AV, Schneider K, Qin J, Jensen MK, Keasling JD. Engineered Reversal of Function in Glycolytic Yeast Promoters. ACS Synth Biol 2019; 8:1462-1468. [PMID: 31051075 DOI: 10.1021/acssynbio.9b00027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Promoters are key components of cell factory design, allowing precise expression of genes in a heterologous pathway. Several commonly used promoters in yeast cell factories belong to glycolytic genes, highly expressed in actively growing yeast when glucose is used as a carbon source. However, their expression can be suboptimal when alternate carbon sources are used, or if there is a need to decouple growth from production. Hence, there is a need for alternate promoters for different carbon sources and production schemes. In this work, we demonstrate a reversal of regulatory function in two glycolytic yeast promoters by replacing glycolytic regulatory elements with ones induced by the diauxic shift. We observe a shift in induction from glucose-rich to glucose-poor medium without loss of regulatory activity, and strong ethanol induction. Applications of these promoters were validated for expression of the vanillin biosynthetic pathway, reaching production of vanillin comparable to pathway designs using strong constitutive promoters.
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Affiliation(s)
- Arun S. Rajkumar
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Emre Özdemir
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Alicia V. Lis
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Konstantin Schneider
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Jiufu Qin
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Michael K. Jensen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Jay D. Keasling
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94704, United States
- Department of Chemical and Biomolecular Engineering & Department of Bioengineering, University of California, Berkeley, California 94720-1462, United States
- Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institutes of Advanced Technologies, Shenzhen, China
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3
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Liu Q, Yu T, Campbell K, Nielsen J, Chen Y. Modular Pathway Rewiring of Yeast for Amino Acid Production. Methods Enzymol 2018; 608:417-439. [PMID: 30173772 DOI: 10.1016/bs.mie.2018.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Amino acids find various applications in biotechnology in view of their importance in the food, feed, pharmaceutical, and personal care industries as nutrients, additives, and drugs, respectively. For the large-scale production of amino acids, microbial cell factories are widely used and the development of amino acid-producing strains has mainly focused on prokaryotes Corynebacterium glutamicum and Escherichia coli. However, the eukaryote Saccharomyces cerevisiae is becoming an even more appealing microbial host for production of amino acids and derivatives because of its superior molecular and physiological features, such as amenable to genetic engineering and high tolerance to harsh conditions. To transform S. cerevisiae into an industrial amino acid production platform, the highly coordinated and multiple layers regulation in its amino acid metabolism should be relieved and reconstituted to optimize the metabolic flux toward synthesis of target products. This chapter describes principles, strategies, and applications of modular pathway rewiring in yeast using the engineering of l-ornithine metabolism as a paradigm. Additionally, detailed protocols for in vitro module construction and CRISPR/Cas-mediated pathway assembly are provided.
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Affiliation(s)
- Quanli Liu
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden
| | - Tao Yu
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden
| | - Kate Campbell
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark.
| | - Yun Chen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden; Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden
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4
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MiYA, an efficient machine-learning workflow in conjunction with the YeastFab assembly strategy for combinatorial optimization of heterologous metabolic pathways in Saccharomyces cerevisiae. Metab Eng 2018; 47:294-302. [DOI: 10.1016/j.ymben.2018.03.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/20/2018] [Accepted: 03/31/2018] [Indexed: 11/20/2022]
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5
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Qian Y, Huang HH, Jiménez JI, Del Vecchio D. Resource Competition Shapes the Response of Genetic Circuits. ACS Synth Biol 2017; 6:1263-1272. [PMID: 28350160 DOI: 10.1021/acssynbio.6b00361] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A common approach to design genetic circuits is to compose gene expression cassettes together. While appealing, this modular approach is challenged by the fact that expression of each gene depends on the availability of transcriptional/translational resources, which is in turn determined by the presence of other genes in the circuit. This raises the question of how competition for resources by different genes affects a circuit's behavior. Here, we create a library of genetic activation cascades in E. coli bacteria, where we explicitly tune the resource demand by each gene. We develop a general Hill-function-based model that incorporates resource competition effects through resource demand coefficients. These coefficients lead to nonregulatory interactions among genes that reshape the circuit's behavior. For the activation cascade, such interactions result in surprising biphasic or monotonically decreasing responses. Finally, we use resource demand coefficients to guide the choice of ribosome binding site and DNA copy number to restore the cascade's intended monotonically increasing response. Our results demonstrate how unintended circuit's behavior arises from resource competition and provide a model-guided methodology to minimize the resulting effects.
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Affiliation(s)
- Yili Qian
- Department
of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Hsin-Ho Huang
- Department
of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - José I. Jiménez
- Department
of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Faculty
of Health of Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, U.K
| | - Domitilla Del Vecchio
- Department
of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Synthetic
Biology Center, Massachusetts Institute of Technology, 500 Technology
Square, Cambridge, Massachusetts 02139, United States
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6
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Chen X, Gao C, Guo L, Hu G, Luo Q, Liu J, Nielsen J, Chen J, Liu L. DCEO Biotechnology: Tools To Design, Construct, Evaluate, and Optimize the Metabolic Pathway for Biosynthesis of Chemicals. Chem Rev 2017; 118:4-72. [DOI: 10.1021/acs.chemrev.6b00804] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Xiulai Chen
- State
Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key
Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Cong Gao
- State
Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key
Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Liang Guo
- State
Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key
Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Guipeng Hu
- State
Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key
Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Qiuling Luo
- State
Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key
Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Jia Liu
- State
Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key
Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Jens Nielsen
- Department
of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE-412 96, Sweden
- Novo
Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK2800 Lyngby, Denmark
| | - Jian Chen
- State
Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key
Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Liming Liu
- State
Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Department
of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE-412 96, Sweden
- Key
Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
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7
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Zargar A, Quan DN, Abutaleb N, Choi E, Terrell JL, Payne GF, Bentley WE. Constructing "quantized quorums" to guide emergent phenotypes through quorum quenching capsules. Biotechnol Bioeng 2016; 114:407-415. [PMID: 27543759 DOI: 10.1002/bit.26080] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 08/17/2016] [Indexed: 11/10/2022]
Abstract
Microbial cells have for many years been engineered to facilitate efficient production of biologics, chemicals, and other compounds. As the "metabolic" burden of synthetic genetic components can impair cell performance, microbial consortia are being developed to piece together specialized subpopulations that collectively produce desired products. Their use, however, has been limited by the inability to control their composition and function. One approach to leverage advantages of the division of labor within consortia is to link microbial subpopulations together through quorum sensing (QS) molecules. Previously, we directed the assembly of "quantized quorums," microbial subpopulations that are parsed through QS activation, by the exogenous addition of QS signal molecules to QS synthase mutants. In this work, we develop a more facile and general platform for creating "quantized quorums." Moreover, the methodology is not restricted to QS-mutant populations. We constructed quorum quenching capsules that partition QS-mediated phenotypes into discrete subpopulations. This compartmentalization guides QS subpopulations in a dose-dependent manner, parsing cell populations into activated or deactivated groups. The capsular "devices" consist of polyelectrolyte alginate-chitosan beads that encapsulate high-efficiency (HE) "controller cells" that, in turn, provide rapid uptake of the QS signal molecule AI-2 from culture fluids. In this methodology, instead of adding AI-2 to parse QS-mutants into subpopulations, we engineered cells to encapsulate them into compartments, and they serve to deplete AI-2 from wild-type populations. These encapsulated bacteria therefore, provide orthogonal control of population composition while allowing only minimal interaction with the product-producing cell population or consortia. We envision that compartmentalized control of QS should have applications in both metabolic engineering and human disease. Biotechnol. Bioeng. 2017;114: 407-415. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Amin Zargar
- Institute for Bioscience and Biotechnology Research (IBBR), University of Maryland, 5115 Plant Sciences Building, College Park, Maryland 20742.,Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - David N Quan
- Institute for Bioscience and Biotechnology Research (IBBR), University of Maryland, 5115 Plant Sciences Building, College Park, Maryland 20742.,Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - Nadia Abutaleb
- Institute for Bioscience and Biotechnology Research (IBBR), University of Maryland, 5115 Plant Sciences Building, College Park, Maryland 20742.,Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - Erica Choi
- Institute for Bioscience and Biotechnology Research (IBBR), University of Maryland, 5115 Plant Sciences Building, College Park, Maryland 20742.,Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - Jessica L Terrell
- Institute for Bioscience and Biotechnology Research (IBBR), University of Maryland, 5115 Plant Sciences Building, College Park, Maryland 20742.,Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - Gregory F Payne
- Institute for Bioscience and Biotechnology Research (IBBR), University of Maryland, 5115 Plant Sciences Building, College Park, Maryland 20742.,Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - William E Bentley
- Institute for Bioscience and Biotechnology Research (IBBR), University of Maryland, 5115 Plant Sciences Building, College Park, Maryland 20742.,Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
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8
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Zargar A, Quan DN, Bentley WE. Enhancing Intercellular Coordination: Rewiring Quorum Sensing Networks for Increased Protein Expression through Autonomous Induction. ACS Synth Biol 2016; 5:923-8. [PMID: 27267750 DOI: 10.1021/acssynbio.5b00261] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
While inducing agents are often used to redirect resources from growth and proliferation toward product outputs, they can be prohibitively expensive on the industrial scale. Previously, we developed an autonomously guided protein production system based on the rewiring of E. coli's native quorum sensing (QS) signal transduction cascade. Self-secreted autoinducer, AI-2, accumulated over time and actuated recombinant gene expression-its design, co-opting the collective nature of QS-mediated behavior. We recently demonstrated that desynchronization of autoinduced intercellular feedback leads to bimodality in QS activation. In this work, we developed a new QS-enabled system with enhanced feedback to reduce cell heterogeneity. This narrows the population distribution of protein expression, leading to significant per cell and overall increases in productivity. We believe directed engineering of cell populations and/or cell consortia will offer many such opportunities in future bioprocessing applications.
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Affiliation(s)
- Amin Zargar
- Institute
for Bioscience and Biotechnology Research (IBBR), University of Maryland, College
Park, Maryland 20742, United States
- Fischell
Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - David N. Quan
- Institute
for Bioscience and Biotechnology Research (IBBR), University of Maryland, College
Park, Maryland 20742, United States
- Fischell
Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - William E. Bentley
- Institute
for Bioscience and Biotechnology Research (IBBR), University of Maryland, College
Park, Maryland 20742, United States
- Fischell
Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
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9
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Marchand N, Collins CH. Synthetic Quorum Sensing and Cell-Cell Communication in Gram-Positive Bacillus megaterium. ACS Synth Biol 2016. [PMID: 26203497 DOI: 10.1021/acssynbio.5b00099] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The components of natural quorum-sensing (QS) systems can be used to engineer synthetic communication systems that regulate gene expression in response to chemical signals. We have used the machinery from the peptide-based agr QS system from Staphylococcus aureus to engineer a synthetic QS system in Bacillus megaterium to enable autoinduction of a target gene at high cell densities. Growth and gene expression from these synthetic QS cells were characterized in both complex and minimal media. We also split the signal production and sensing components between two strains of B. megaterium to produce sender and receiver cells and characterized the resulting communication in liquid media and on semisolid agar. The system described in this work represents the first synthetic QS and cell-cell communication system that has been engineered to function in a Gram-positive host, and it has the potential to enable the generation of dynamic gene regulatory networks in B. megaterium and other Gram-positive organisms.
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Affiliation(s)
- Nicholas Marchand
- Department of Chemical and Biological Engineering, ‡Center for Biotechnology
and Interdisciplinary
Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States
| | - Cynthia H. Collins
- Department of Chemical and Biological Engineering, ‡Center for Biotechnology
and Interdisciplinary
Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States
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10
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Tan SZ, Manchester S, Prather KLJ. Controlling Central Carbon Metabolism for Improved Pathway Yields in Saccharomyces cerevisiae. ACS Synth Biol 2016; 5:116-24. [PMID: 26544022 DOI: 10.1021/acssynbio.5b00164] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Engineering control of metabolic pathways is important to improving product titers and yields. Traditional methods such as overexpressing pathway enzymes and deleting competing ones are restricted by the interdependence of metabolic reactions and the finite nature of cellular resources. Here, we developed a metabolite valve that controls glycolytic flux through central carbon metabolism in Saccharomyces cerevisiae. In a Hexokinase 2 and Glucokinase 1 deleted strain (hxk2Δglk1Δ), glucose flux was diverted away from glycolysis and into a model pathway, gluconate, by controlling the transcription of Hexokinase 1 with the tetracycline transactivator protein (tTA). A maximum 10-fold decrease in hexokinase activity resulted in a 50-fold increase in gluconate yields, from 0.7% to 36% mol/mol of glucose. The reduction in glucose flux resulted in a significant decrease in ethanol byproduction that extended to semianaerobic conditions, as shown in the production of isobutanol. This proof-of-concept is one of the first demonstrations in S. cerevisiae of dynamic redirection of glucose from glycolysis and into a heterologous pathway.
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Affiliation(s)
- Sue Zanne Tan
- Department of Chemical Engineering, ‡MIT Center for Integrative Synthetic
Biology, §Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Shawn Manchester
- Department of Chemical Engineering, ‡MIT Center for Integrative Synthetic
Biology, §Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Kristala L. J. Prather
- Department of Chemical Engineering, ‡MIT Center for Integrative Synthetic
Biology, §Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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11
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Alcohol Selectivity in a Synthetic Thermophilic n-Butanol Pathway Is Driven by Biocatalytic and Thermostability Characteristics of Constituent Enzymes. Appl Environ Microbiol 2015; 81:7187-200. [PMID: 26253677 DOI: 10.1128/aem.02028-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 07/29/2015] [Indexed: 02/06/2023] Open
Abstract
n-Butanol is generated as a natural product of metabolism by several microorganisms, but almost all grow at mesophilic temperatures. A synthetic pathway for n-butanol production from acetyl coenzyme A (acetyl-CoA) that functioned at 70°C was assembled in vitro from enzymes recruited from thermophilic bacteria to inform efforts for engineering butanol production into thermophilic hosts. Recombinant versions of eight thermophilic enzymes (β-ketothiolase [Thl], 3-hydroxybutyryl-CoA dehydrogenase [Hbd], and 3-hydroxybutyryl-CoA dehydratase [Crt] from Caldanaerobacter subterraneus subsp. tengcongensis; trans-2-enoyl-CoA reductase [Ter] from Spirochaeta thermophila; bifunctional acetaldehyde dehydrogenase/alcohol dehydrogenase [AdhE] from Clostridium thermocellum; and AdhE, aldehyde dehydrogenase [Bad], and butanol dehydrogenase [Bdh] from Thermoanaerobacter sp. strain X514) were utilized to examine three possible pathways for n-butanol. These pathways differed in the two steps required to convert butyryl-CoA to n-butanol: Thl-Hbd-Crt-Ter-AdhE (C. thermocellum), Thl-Hbd-Crt-Ter-AdhE (Thermoanaerobacter X514), and Thl-Hbd-Crt-Ter-Bad-Bdh. n-Butanol was produced at 70°C, but with different amounts of ethanol as a coproduct, because of the broad substrate specificities of AdhE, Bad, and Bdh. A reaction kinetics model, validated via comparison to in vitro experiments, was used to determine relative enzyme ratios needed to maximize n-butanol production. By using large relative amounts of Thl and Hbd and small amounts of Bad and Bdh, >70% conversion to n-butanol was observed in vitro, but with a 60% decrease in the predicted pathway flux. With more-selective hypothetical versions of Bad and Bdh, >70% conversion to n-butanol is predicted, with a 19% increase in pathway flux. Thus, more-selective thermophilic versions of Bad, Bdh, and AdhE are needed to fully exploit biocatalytic n-butanol production at elevated temperatures.
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12
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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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13
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Multivariate modular metabolic engineering for pathway and strain optimization. Curr Opin Biotechnol 2014; 29:156-62. [PMID: 24927371 DOI: 10.1016/j.copbio.2014.05.005] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 05/19/2014] [Indexed: 12/21/2022]
Abstract
Despite the potential in utilizing microbial fermentation for chemical production, the field of industrial biotechnology still lacks a standard, universally applicable principle for strain optimization. A key challenge has been in finding and applying effective ways to address metabolic flux imbalances. Strategies based on rational design require significant a priori knowledge and often fail to take a holistic view of cellular metabolism. Combinatorial approaches enable more global searches but require a high-throughput screen. Here, we present the recent advances and promises of a novel approach to metabolic pathway and strain optimization called multivariate modular metabolic engineering (MMME). In this technique, key enzymes are organized into distinct modules and simultaneously varied based on expression to balance flux through a pathway. Because of its simplicity and broad applicability, MMME has the potential to systematize and revolutionize the field of metabolic engineering and industrial biotechnology.
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14
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Production of bulk chemicals via novel metabolic pathways in microorganisms. Biotechnol Adv 2012; 31:925-35. [PMID: 23280013 DOI: 10.1016/j.biotechadv.2012.12.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 12/09/2012] [Accepted: 12/23/2012] [Indexed: 02/05/2023]
Abstract
Metabolic engineering has been playing important roles in developing high performance microorganisms capable of producing various chemicals and materials from renewable biomass in a sustainable manner. Synthetic and systems biology are also contributing significantly to the creation of novel pathways and the whole cell-wide optimization of metabolic performance, respectively. In order to expand the spectrum of chemicals that can be produced biotechnologically, it is necessary to broaden the metabolic capacities of microorganisms. Expanding the metabolic pathways for biosynthesizing the target chemicals requires not only the enumeration of a series of known enzymes, but also the identification of biochemical gaps whose corresponding enzymes might not actually exist in nature; this issue is the focus of this paper. First, pathway prediction tools, effectively combining reactions that lead to the production of a target chemical, are analyzed in terms of logics representing chemical information, and designing and ranking the proposed metabolic pathways. Then, several approaches for potentially filling in the gaps of the novel metabolic pathway are suggested along with relevant examples, including the use of promiscuous enzymes that flexibly utilize different substrates, design of novel enzymes for non-natural reactions, and exploration of hypothetical proteins. Finally, strain optimization by systems metabolic engineering in the context of novel metabolic pathways constructed is briefly described. It is hoped that this review paper will provide logical ways of efficiently utilizing 'big' biological data to design and develop novel metabolic pathways for the production of various bulk chemicals that are currently produced from fossil resources.
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Induction of gene expression in bacteria at optimal growth temperatures. Appl Microbiol Biotechnol 2012; 97:5423-31. [PMID: 23271670 DOI: 10.1007/s00253-012-4633-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 11/29/2012] [Accepted: 12/01/2012] [Indexed: 10/27/2022]
Abstract
Traditional temperature-sensitive systems use either heat shock (40-42 °C) or cold shock (15-23 °C) to induce gene expression at temperatures that are not the optimal temperature for host cell growth (37 °C). This impacts the overall productivity and yield by disturbing cell growth and cellular metabolism. Here, we have developed a new system which controls gene expression in Escherichia coli at more permissive temperatures. The temperature-sensitive cI857-P L system and the classic lacI-P lacO system were connected in series to control the gene of interest. When the culture temperature was lowered, the thermolabile cI857 repressor was activated and blocked the expression of lacI from P L. Subsequently, the decrease of LacI derepressed the expression of gene of interest from P lacO . Using a green fluorescent protein marker, we demonstrated that (1) gene expression was tightly regulated at 42 °C and strongly induced by lowering temperature to 25-37 °C; (2) different levels of gene expression can be induced by varying culture temperature; and (3) gene expression after induction was sustained until the end of the log phase. We then applied this system in the biosynthesis of acetoin and demonstrated that high yield and production could be achieved using temperature induction. The ability to express proteins at optimal growth temperatures without chemical inducers is advantageous for large-scale and industrial fermentations.
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Bioengineering of carbon fixation, biofuels, and biochemicals in cyanobacteria and plants. J Biotechnol 2012; 162:134-47. [PMID: 22677697 DOI: 10.1016/j.jbiotec.2012.05.006] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/15/2012] [Accepted: 05/21/2012] [Indexed: 11/23/2022]
Abstract
Development of sustainable energy is a pivotal step towards solutions for today's global challenges, including mitigating the progression of climate change and reducing dependence on fossil fuels. Biofuels derived from agricultural crops have already been commercialized. However the impacts on environmental sustainability and food supply have raised ethical questions about the current practices. Cyanobacteria have attracted interest as an alternative means for sustainable energy productions. Being aquatic photoautotrophs they can be cultivated in non-arable lands and do not compete for land for food production. Their rich genetic resources offer means to engineer metabolic pathways for synthesis of valuable bio-based products. Currently the major obstacle in industrial-scale exploitation of cyanobacteria as the economically sustainable production hosts is low yields. Much effort has been made to improve the carbon fixation and manipulating the carbon allocation in cyanobacteria and their evolutionary photosynthetic relatives, algae and plants. This review aims at providing an overview of the recent progress in the bioengineering of carbon fixation and allocation in cyanobacteria; wherever relevant, the progress made in plants and algae is also discussed as an inspiration for future application in cyanobacteria.
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Abstract
Metabolism is a highly interconnected web of chemical reactions that power life. Though the stoichiometry of metabolism is well understood, the multidimensional aspects of metabolic regulation in time and space remain difficult to define, model and engineer. Complex metabolic conversions can be performed by multiple species working cooperatively and exchanging metabolites via structured networks of organisms and resources. Within cells, metabolism is spatially regulated via sequestration in subcellular compartments and through the assembly of multienzyme complexes. Metabolic engineering and synthetic biology have had success in engineering metabolism in the first and second dimensions, designing linear metabolic pathways and channeling metabolic flux. More recently, engineering of the third dimension has improved output of engineered pathways through isolation and organization of multicell and multienzyme complexes. This review highlights natural and synthetic examples of three-dimensional metabolism both inter- and intracellularly, offering tools and perspectives for biological design.
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Systems metabolic engineering of microorganisms for natural and non-natural chemicals. Nat Chem Biol 2012; 8:536-46. [PMID: 22596205 DOI: 10.1038/nchembio.970] [Citation(s) in RCA: 507] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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