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Adams J, Clark DS. Techno-Economic Assessment of Electromicrobial Production of n-Butanol from Air-Captured CO 2. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:7302-7313. [PMID: 38621294 PMCID: PMC11064224 DOI: 10.1021/acs.est.3c08748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 03/29/2024] [Accepted: 04/02/2024] [Indexed: 04/17/2024]
Abstract
Electromicrobial production (EMP), where electrochemically generated substrates (e.g., H2) are used as energy sources for microbial processes, has garnered significant interest as a method of producing fuels and other value-added chemicals from CO2. Combining these processes with direct air capture (DAC) has the potential to enable a truly circular carbon economy. Here, we analyze the economics of a hypothetical system that combines adsorbent-based DAC with EMP to produce n-butanol, a potential replacement for fossil fuels. First-principles-based modeling is used to predict the performance of the DAC and bioprocess components. A process model is then developed to map material and energy flows, and a techno-economic assessment is performed to determine the minimum fuel selling price. Beyond assessing a specific set of conditions, this analytical framework provides a tool to reveal potential pathways toward the economic viability of this process. We show that an EMP system utilizing an engineered knallgas bacterium can achieve butanol production costs of <$6/gal ($1.58/L) if a set of optimistic assumptions can be realized.
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Affiliation(s)
- Jeremy
David Adams
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Douglas S. Clark
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- Molecular
Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
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2
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Pearson AN, Incha MR, Ho CN, Schmidt M, Roberts JB, Nava AA, Keasling JD. Characterization and Diversification of AraC/XylS Family Regulators Guided by Transposon Sequencing. ACS Synth Biol 2024; 13:206-219. [PMID: 38113125 DOI: 10.1021/acssynbio.3c00441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
In this study, we explored the development of engineered inducible systems. Publicly available data from previous transposon sequencing assays were used to identify regulators of metabolism in Pseudomonas putida KT2440. For AraC family regulators (AFRs) represented in these data, we posited AFR/promoter/inducer groupings. Twelve promoters were characterized for a response to their proposed inducers in P. putida, and the resultant data were used to create and test nine two-plasmid sensor systems in Escherichia coli. Several of these were further developed into a palette of single-plasmid inducible systems. From these experiments, we observed an unreported inducer response from a previously characterized AFR, demonstrated that the addition of a P. putida transporter improved the sensor dynamics of an AFR in E. coli, and identified an uncharacterized AFR with a novel potential inducer specificity. Finally, targeted mutations in an AFR, informed by structural predictions, enabled the further diversification of these inducible plasmids.
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Affiliation(s)
- Allison N Pearson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Matthew R Incha
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Cindy N Ho
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Matthias Schmidt
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology-ABBt, RWTH Aachen University, Aachen 52062, Germany
| | - Jacob B Roberts
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint Program in Bioengineering, University of California, Berkeley/San Francisco, California 94720, United States
| | - Alberto A Nava
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Jay D Keasling
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint Program in Bioengineering, University of California, Berkeley/San Francisco, California 94720, United States
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
- Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, United States
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby 2800, Denmark
- Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institutes for Advanced Technologies, Shenzhen 518055, China
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3
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Rondthaler S, Sarker B, Howitz N, Shah I, Andrews LB. Toolbox of Characterized Genetic Parts for Staphylococcus aureus. ACS Synth Biol 2024; 13:103-118. [PMID: 38064657 PMCID: PMC10805105 DOI: 10.1021/acssynbio.3c00325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 10/06/2023] [Accepted: 10/10/2023] [Indexed: 01/23/2024]
Abstract
Staphylococcus aureus is an important clinical bacterium prevalent in human-associated microbiomes and the cause of many diseases. However, S. aureus has been intractable to synthetic biology approaches due to limited characterized genetic parts for this nonmodel Gram-positive bacterium. Moreover, genetic manipulation of S. aureus has relied on cumbersome and inefficient cloning strategies. Here, we report the first standardized genetic parts toolbox for S. aureus, which includes characterized promoters, ribosome binding sites, terminators, and plasmid replicons from a variety of bacteria for precise control of gene expression. We established a standard relative expression unit (REU) for S. aureus using a plasmid reference and characterized genetic parts in standardized REUs using S. aureus ATCC 12600. We constructed promoter and terminator part plasmids that are compatible with an efficient Type IIS DNA assembly strategy to effectively build multipart DNA constructs. A library of 24 constitutive promoters was built and characterized in S. aureus, which showed a 380-fold activity range. This promoter library was also assayed in Bacillus subtilis (122-fold activity range) to demonstrate the transferability of the constitutive promoters between these Gram-positive bacteria. By applying an iterative design-build-test-learn cycle, we demonstrated the use of our toolbox for the rational design and engineering of a tetracycline sensor in S. aureus using the PXyl-TetO aTc-inducible promoter that achieved 25.8-fold induction. This toolbox greatly expands the growing number of genetic parts for Gram-positive bacteria and will allow researchers to leverage synthetic biology approaches to study and engineer cellular processes in S. aureus.
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Affiliation(s)
- Stephen
N. Rondthaler
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Biprodev Sarker
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Nathaniel Howitz
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Ishita Shah
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Lauren B. Andrews
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
- Molecular
and Cellular Biology Graduate Program, University
of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
- Biotechnology
Training Program, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
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4
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Mishra S, Perkovich PM, Mitchell WP, Venkataraman M, Pfleger BF. Expanding the synthetic biology toolbox of Cupriavidus necator for establishing fatty acid production. J Ind Microbiol Biotechnol 2024; 51:kuae008. [PMID: 38366943 PMCID: PMC10926325 DOI: 10.1093/jimb/kuae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 02/15/2024] [Indexed: 02/19/2024]
Abstract
The Gram-negative betaproteobacterium Cupriavidus necator is a chemolithotroph that can convert carbon dioxide into biomass. Cupriavidus necator has been engineered to produce a variety of high-value chemicals in the past. However, there is still a lack of a well-characterized toolbox for gene expression and genome engineering. Development and optimization of biosynthetic pathways in metabolically engineered microorganisms necessitates control of gene expression via functional genetic elements such as promoters, ribosome binding sites (RBSs), and codon optimization. In this work, a set of inducible and constitutive promoters were validated and characterized in C. necator, and a library of RBSs was designed and tested to show a 50-fold range of expression for green fluorescent protein (gfp). The effect of codon optimization on gene expression in C. necator was studied by expressing gfp and mCherry genes with varied codon-adaptation indices and was validated by expressing codon-optimized variants of a C12-specific fatty acid thioesterase to produce dodecanoic acid. We discuss further hurdles that will need to be overcome for C. necator to be widely used for biosynthetic processes.
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Affiliation(s)
- Shivangi Mishra
- Department of Chemical and Biological Engineering, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Paul M Perkovich
- Department of Chemical and Biological Engineering, University of Wisconsin–Madison, Madison, WI 53706, USA
| | | | - Maya Venkataraman
- Department of Chemical and Biological Engineering, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Brian F Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin–Madison, Madison, WI 53706, USA
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Kurt E, Qin J, Williams A, Zhao Y, Xie D. Perspectives for Using CO 2 as a Feedstock for Biomanufacturing of Fuels and Chemicals. Bioengineering (Basel) 2023; 10:1357. [PMID: 38135948 PMCID: PMC10740661 DOI: 10.3390/bioengineering10121357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/20/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023] Open
Abstract
Microbial cell factories offer an eco-friendly alternative for transforming raw materials into commercially valuable products because of their reduced carbon impact compared to conventional industrial procedures. These systems often depend on lignocellulosic feedstocks, mainly pentose and hexose sugars. One major hurdle when utilizing these sugars, especially glucose, is balancing carbon allocation to satisfy energy, cofactor, and other essential component needs for cellular proliferation while maintaining a robust yield. Nearly half or more of this carbon is inevitably lost as CO2 during the biosynthesis of regular metabolic necessities. This loss lowers the production yield and compromises the benefit of reducing greenhouse gas emissions-a fundamental advantage of biomanufacturing. This review paper posits the perspectives of using CO2 from the atmosphere, industrial wastes, or the exhausted gases generated in microbial fermentation as a feedstock for biomanufacturing. Achieving the carbon-neutral or -negative goals is addressed under two main strategies. The one-step strategy uses novel metabolic pathway design and engineering approaches to directly fix the CO2 toward the synthesis of the desired products. Due to the limitation of the yield and efficiency in one-step fixation, the two-step strategy aims to integrate firstly the electrochemical conversion of the exhausted CO2 into C1/C2 products such as formate, methanol, acetate, and ethanol, and a second fermentation process to utilize the CO2-derived C1/C2 chemicals or co-utilize C5/C6 sugars and C1/C2 chemicals for product formation. The potential and challenges of using CO2 as a feedstock for future biomanufacturing of fuels and chemicals are also discussed.
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Affiliation(s)
- Elif Kurt
- Department of Chemical Engineering, University of Massachusetts, Lowell, MA 01854, USA; (E.K.); (J.Q.); (A.W.)
| | - Jiansong Qin
- Department of Chemical Engineering, University of Massachusetts, Lowell, MA 01854, USA; (E.K.); (J.Q.); (A.W.)
| | - Alexandria Williams
- Department of Chemical Engineering, University of Massachusetts, Lowell, MA 01854, USA; (E.K.); (J.Q.); (A.W.)
| | - Youbo Zhao
- Physical Sciences Inc., 20 New England Business Ctr., Andover, MA 01810, USA;
| | - Dongming Xie
- Department of Chemical Engineering, University of Massachusetts, Lowell, MA 01854, USA; (E.K.); (J.Q.); (A.W.)
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Sydow A, Becker L, Lombard E, Ulber R, Guillouet SE, Holtmann D. Autotrophic Production of the Sesquiterpene α-Humulene with Cupriavidus necator in a Controlled Bioreactor. Bioengineering (Basel) 2023; 10:1194. [PMID: 37892924 PMCID: PMC10603880 DOI: 10.3390/bioengineering10101194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 10/07/2023] [Accepted: 10/08/2023] [Indexed: 10/29/2023] Open
Abstract
Cupriavidus necator is a facultative chemolithotrophic organism that grows under both heterotrophic and autotrophic conditions. It is becoming increasingly important due to its ability to convert CO2 into industrially valuable chemicals. To translate the potential of C. necator into technical applications, it is necessary to optimize and scale up production processes. A previous proof-of-principle study showed that C. necator can be used for the de novo production of the terpene α-humulene from CO2 up to concentrations of 11 mg L-1 in septum flasks. However, an increase in final product titer and space-time yield will be necessary to establish an economically viable industrial process. To ensure optimized growth and production conditions, the application of an improved process design in a gas bioreactor with the control of pH, dissolved oxygen and temperature including a controlled gas supply was investigated. In the controlled gas bioreactor, the concentration of α-humulene was improved by a factor of 6.6 and the space-time yield was improved by a factor of 13.2. These results represent an important step toward the autotrophic production of high-value chemicals from CO2. In addition, the in situ product removal of α-humulene was investigated and important indications of the critical logP value were obtained, which was in the range of 3.0-4.2.
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Affiliation(s)
- Anne Sydow
- Industrial Biotechnology, DECHEMA Research Institute, Theodor Heuss Allee 25, 60486 Frankfurt, Germany
| | - Lucas Becker
- Bioprocess Intensification, Institute of Bioprocess Engineering and Pharmaceutical Technology, Technische Hochschule Mittelhessen, Wiesenstrasse 14, 35390 Giessen, Germany
| | - Eric Lombard
- TBI, Université de Toulouse, National Institute of Applied Sciences (INSA), 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Roland Ulber
- Institute of Bioprocess Engineering, University of Kaiserslautern-Landau, Gottlieb-Daimler-Straße 49, 67663 Kaiserslautern, Germany
| | - Stephane E. Guillouet
- TBI, Université de Toulouse, National Institute of Applied Sciences (INSA), 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Dirk Holtmann
- Bioprocess Intensification, Institute of Bioprocess Engineering and Pharmaceutical Technology, Technische Hochschule Mittelhessen, Wiesenstrasse 14, 35390 Giessen, Germany
- Institute of Process Engineering in Life Sciences, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131 Karlsruhe, Germany
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7
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Wang T, Zhang J, Wei L, Zhao D, Bi C, Liu Q, Xu N, Liu J. Developing a PAM-Flexible CRISPR-Mediated Dual-Deaminase Base Editor to Regulate Extracellular Electron Transport in Shewanella oneidensis. ACS Synth Biol 2023; 12:1727-1738. [PMID: 37212667 DOI: 10.1021/acssynbio.3c00045] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Shewanella oneidensis MR-1 is a promising electroactive microorganism in environmental bioremediation, bioenergy generation, and bioproduct synthesis. Accelerating the extracellular electron transfer (EET) pathway that enables efficient electron exchange between microbes and extracellular substances is critical for improving its electrochemical properties. However, the potential genomic engineering strategies for enhancing EET capabilities are still limited. Here, we developed a clustered regularly interspaced short palindromic repeats (CRISPR)-mediated dual-deaminase base editing system, named in situ protospacer-adjacent motif (PAM)-flexible dual base editing regulatory system (iSpider), for precise and high-throughput genomic manipulation. The iSpider enabled simultaneous C-to-T and A-to-G conversions with high diversity and efficiency in S. oneidensis. By weakening DNA glycosylase-based repair pathway and tethering two copies of adenosine deaminase, the A-to-G editing efficiency was obviously improved. As a proof-of-concept study, the iSpider was adapted to achieve multiplexed base editing for the regulation of the riboflavin biosynthesis pathway, and the optimized strain showed an approximately three-fold increase in riboflavin production. Moreover, the iSpider was also applied to evolve the performance of an inner membrane component CymA implicated in EET, and one beneficial mutant facilitating electron transfer could be rapidly identified. Taken together, our study demonstrates that the iSpider allows efficient base editing in a PAM-flexible manner, providing insights into the design of novel genomic tools for Shewanella engineering.
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Affiliation(s)
- Tailin Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jiwei Zhang
- School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Liang Wei
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
| | - Dongdong Zhao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
| | - Changhao Bi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
| | - Qingdai Liu
- School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Ning Xu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
| | - Jun Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
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Pearson AN, Thompson MG, Kirkpatrick LD, Ho C, Vuu KM, Waldburger LM, Keasling JD, Shih PM. The pGinger Family of Expression Plasmids. Microbiol Spectr 2023; 11:e0037323. [PMID: 37212656 PMCID: PMC10269703 DOI: 10.1128/spectrum.00373-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/09/2023] [Indexed: 05/23/2023] Open
Abstract
The pGinger suite of expression plasmids comprises 43 plasmids that will enable precise constitutive and inducible gene expression in a wide range of Gram-negative bacterial species. Constitutive vectors are composed of 16 synthetic constitutive promoters upstream of red fluorescent protein (RFP), with a broad-host-range BBR1 origin and a kanamycin resistance marker. The family also has seven inducible systems (Jungle Express, Psal/NahR, Pm/XylS, Prha/RhaS, LacO1/LacI, LacUV5/LacI, and Ptet/TetR) controlling RFP expression on BBR1/kanamycin plasmid backbones. For four of these inducible systems (Jungle Express, Psal/NahR, LacO1/LacI, and Ptet/TetR), we created variants that utilize the RK2 origin and spectinomycin or gentamicin selection. Relevant RFP expression and growth data have been collected in the model bacterium Escherichia coli as well as Pseudomonas putida. All pGinger vectors are available via the Joint BioEnergy Institute (JBEI) Public Registry. IMPORTANCE Metabolic engineering and synthetic biology are predicated on the precise control of gene expression. As synthetic biology expands beyond model organisms, more tools will be required that function robustly in a wide range of bacterial hosts. The pGinger family of plasmids constitutes 43 plasmids that will enable both constitutive and inducible gene expression in a wide range of nonmodel Proteobacteria.
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Affiliation(s)
- Allison N. Pearson
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
| | - Mitchell G. Thompson
- Joint BioEnergy Institute, Emeryville, California, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Liam D. Kirkpatrick
- Joint BioEnergy Institute, Emeryville, California, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Cindy Ho
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Khanh M. Vuu
- Joint BioEnergy Institute, Emeryville, California, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Lucas M. Waldburger
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Bioengineering, University of California, Berkeley, California, USA
| | - Jay D. Keasling
- Joint BioEnergy Institute, Emeryville, California, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, USA
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
- Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institutes for Advanced Technologies, Shenzhen, China
| | - Patrick M. Shih
- Joint BioEnergy Institute, Emeryville, California, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Innovative Genomics Institute, University of California, Berkeley, California, USA
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9
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Adams JD, Sander KB, Criddle CS, Arkin AP, Clark DS. Engineering osmolysis susceptibility in Cupriavidus necator and Escherichia coli for recovery of intracellular products. Microb Cell Fact 2023; 22:69. [PMID: 37046248 PMCID: PMC10091555 DOI: 10.1186/s12934-023-02064-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/16/2023] [Indexed: 04/14/2023] Open
Abstract
BACKGROUND Intracellular biomacromolecules, such as industrial enzymes and biopolymers, represent an important class of bio-derived products obtained from bacterial hosts. A common key step in the downstream separation of these biomolecules is lysis of the bacterial cell wall to effect release of cytoplasmic contents. Cell lysis is typically achieved either through mechanical disruption or reagent-based methods, which introduce issues of energy demand, material needs, high costs, and scaling problems. Osmolysis, a cell lysis method that relies on hypoosmotic downshock upon resuspension of cells in distilled water, has been applied for bioseparation of intracellular products from extreme halophiles and mammalian cells. However, most industrial bacterial strains are non-halotolerant and relatively resistant to hypoosmotic cell lysis. RESULTS To overcome this limitation, we developed two strategies to increase the susceptibility of non-halotolerant hosts to osmolysis using Cupriavidus necator, a strain often used in electromicrobial production, as a prototypical strain. In one strategy, C. necator was evolved to increase its halotolerance from 1.5% to 3.25% (w/v) NaCl through adaptive laboratory evolution, and genes potentially responsible for this phenotypic change were identified by whole genome sequencing. The evolved halotolerant strain experienced an osmolytic efficiency of 47% in distilled water following growth in 3% (w/v) NaCl. In a second strategy, the cells were made susceptible to osmolysis by knocking out the large-conductance mechanosensitive channel (mscL) gene in C. necator. When these strategies were combined by knocking out the mscL gene from the evolved halotolerant strain, greater than 90% osmolytic efficiency was observed upon osmotic downshock. A modified version of this strategy was applied to E. coli BL21 by deleting the mscL and mscS (small-conductance mechanosensitive channel) genes. When grown in medium with 4% NaCl and subsequently resuspended in distilled water, this engineered strain experienced 75% cell lysis, although decreases in cell growth rate due to higher salt concentrations were observed. CONCLUSIONS Our strategy is shown to be a simple and effective way to lyse cells for the purification of intracellular biomacromolecules and may be applicable in many bacteria used for bioproduction.
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Affiliation(s)
- Jeremy David Adams
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
| | - Kyle B Sander
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Craig S Criddle
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Adam P Arkin
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Douglas S Clark
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.
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10
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Yu X, Catanescu CO, Bird RE, Satagopan S, Baum ZJ, Lotti Diaz LM, Zhou QA. Trends in Research and Development for CO 2 Capture and Sequestration. ACS OMEGA 2023; 8:11643-11664. [PMID: 37033841 PMCID: PMC10077574 DOI: 10.1021/acsomega.2c05070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 03/03/2023] [Indexed: 06/19/2023]
Abstract
Technological and medical advances over the past few decades epitomize human capabilities. However, the increased life expectancies and concomitant land-use changes have significantly contributed to the release of ∼830 gigatons of CO2 into the atmosphere over the last three decades, an amount comparable to the prior two and a half centuries of CO2 emissions. The United Nations has adopted a pledge to achieve "net zero", i.e., yearly removing as much CO2 from the atmosphere as the amount emitted due to human activities, by the year 2050. Attaining this goal will require a concerted effort by scientists, policy makers, and industries all around the globe. The development of novel materials on industrial scales to selectively remove CO2 from mixtures of gases makes it possible to mitigate CO2 emissions using a multipronged approach. Broadly, the CO2 present in the atmosphere can be captured using materials and processes for biological, chemical, and geological technologies that can sequester CO2 while also reducing our dependence on fossil-fuel reserves. In this review, we used the curated literature available in the CAS Content Collection to present a systematic analysis of the various approaches taken by scientists and industrialists to restore carbon balance in the environment. Our analysis highlights the latest trends alongside the associated challenges.
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11
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Calvey CH, Sànchez I Nogué V, White AM, Kneucker CM, Woodworth SP, Alt HM, Eckert CA, Johnson CW. Improving growth of Cupriavidus necator H16 on formate using adaptive laboratory evolution-informed engineering. Metab Eng 2023; 75:78-90. [PMID: 36368470 DOI: 10.1016/j.ymben.2022.10.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 10/28/2022] [Accepted: 10/30/2022] [Indexed: 11/11/2022]
Abstract
Conversion of CO2 to value-added products presents an opportunity to reduce GHG emissions while generating revenue. Formate, which can be generated by the electrochemical reduction of CO2, has been proposed as a promising intermediate compound for microbial upgrading. Here we present progress towards improving the soil bacterium Cupriavidus necator H16, which is capable of growing on formate as its sole source of carbon and energy using the Calvin-Benson-Bassham (CBB) cycle, as a host for formate utilization. Using adaptive laboratory evolution, we generated several isolates that exhibited faster growth rates on formate. The genomes of these isolates were sequenced, and resulting mutations were systematically reintroduced by metabolic engineering, to identify those that improved growth. The metabolic impact of several mutations was investigated further using RNA-seq transcriptomics. We found that deletion of a transcriptional regulator implicated in quorum sensing, PhcA, reduced expression of several operons and led to improved growth on formate. Growth was also improved by deleting large genomic regions present on the extrachromosomal megaplasmid pHG1, particularly two hydrogenase operons and the megaplasmid CBB operon, one of two copies present in the genome. Based on these findings, we generated a rationally engineered ΔphcA and megaplasmid-deficient strain that exhibited a 24% faster maximum growth rate on formate. Moreover, this strain achieved a 7% growth rate improvement on succinate and a 19% increase on fructose, demonstrating the broad utility of microbial genome reduction. This strain has the potential to serve as an improved microbial chassis for biological conversion of formate to value-added products.
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Affiliation(s)
- Christopher H Calvey
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Violeta Sànchez I Nogué
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Aleena M White
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Colin M Kneucker
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Sean P Woodworth
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Hannah M Alt
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Carrie A Eckert
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Christopher W Johnson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
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12
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Valencia LE, Incha MR, Schmidt M, Pearson AN, Thompson MG, Roberts JB, Mehling M, Yin K, Sun N, Oka A, Shih PM, Blank LM, Gladden J, Keasling JD. Engineering Pseudomonas putida KT2440 for chain length tailored free fatty acid and oleochemical production. Commun Biol 2022; 5:1363. [PMID: 36509863 PMCID: PMC9744835 DOI: 10.1038/s42003-022-04336-2] [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: 10/14/2022] [Accepted: 12/02/2022] [Indexed: 12/15/2022] Open
Abstract
Despite advances in understanding the metabolism of Pseudomonas putida KT2440, a promising bacterial host for producing valuable chemicals from plant-derived feedstocks, a strain capable of producing free fatty acid-derived chemicals has not been developed. Guided by functional genomics, we engineered P. putida to produce medium- and long-chain free fatty acids (FFAs) to titers of up to 670 mg/L. Additionally, by taking advantage of the varying substrate preferences of paralogous native fatty acyl-CoA ligases, we employed a strategy to control FFA chain length that resulted in a P. putida strain specialized in producing medium-chain FFAs. Finally, we demonstrate the production of oleochemicals in these strains by synthesizing medium-chain fatty acid methyl esters, compounds useful as biodiesel blending agents, in various media including sorghum hydrolysate at titers greater than 300 mg/L. This work paves the road to produce high-value oleochemicals and biofuels from cheap feedstocks, such as plant biomass, using this host.
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Affiliation(s)
- Luis E. Valencia
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Bioengineering, University of California, Berkeley, CA 94720 USA
| | - Matthew R. Incha
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
| | - Matthias Schmidt
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.1957.a0000 0001 0728 696XInstitute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Allison N. Pearson
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
| | - Mitchell G. Thompson
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | - Jacob B. Roberts
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Bioengineering, University of California, Berkeley, CA 94720 USA
| | - Marina Mehling
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Kevin Yin
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
| | - Ning Sun
- grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,Advanced Biofuels and Bioproducts Process Demonstration Unit, Emeryville, CA 94608 USA
| | - Asun Oka
- grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,Advanced Biofuels and Bioproducts Process Demonstration Unit, Emeryville, CA 94608 USA
| | - Patrick M. Shih
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA ,grid.184769.50000 0001 2231 4551Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | - Lars M. Blank
- grid.1957.a0000 0001 0728 696XInstitute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - John Gladden
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.474523.30000000403888279Biomanufacturing and Biomaterials Department, Sandia National Laboratories, Livermore, CA 94550 USA
| | - Jay D. Keasling
- grid.451372.60000 0004 0407 8980Joint BioEnergy Institute, Emeryville, CA 94608 USA ,grid.184769.50000 0001 2231 4551Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Bioengineering, University of California, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Chemical & Biomolecular Engineering, University of California, Berkeley, CA 94720 USA ,grid.5170.30000 0001 2181 8870Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark ,Center for Synthetic Biochemistry, Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technologies, Shenzhen, China
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13
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Baumschabl M, Ata Ö, Mitic BM, Lutz L, Gassler T, Troyer C, Hann S, Mattanovich D. Conversion of CO 2 into organic acids by engineered autotrophic yeast. Proc Natl Acad Sci U S A 2022; 119:e2211827119. [PMID: 36383601 PMCID: PMC9704707 DOI: 10.1073/pnas.2211827119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 10/13/2022] [Indexed: 10/23/2023] Open
Abstract
The increase of CO2 emissions due to human activity is one of the preeminent reasons for the present climate crisis. In addition, considering the increasing demand for renewable resources, the upcycling of CO2 as a feedstock gains an extensive importance to establish CO2-neutral or CO2-negative industrial processes independent of agricultural resources. Here we assess whether synthetic autotrophic Komagataella phaffii (Pichia pastoris) can be used as a platform for value-added chemicals using CO2 as a feedstock by integrating the heterologous genes for lactic and itaconic acid synthesis. 13C labeling experiments proved that the resulting strains are able to produce organic acids via the assimilation of CO2 as a sole carbon source. Further engineering attempts to prevent the lactic acid consumption increased the titers to 600 mg L-1, while balancing the expression of key genes and modifying screening conditions led to 2 g L-1 itaconic acid. Bioreactor cultivations suggest that a fine-tuning on CO2 uptake and oxygen demand of the cells is essential to reach a higher productivity. We believe that through further metabolic and process engineering, the resulting engineered strain can become a promising host for the production of value-added bulk chemicals by microbial assimilation of CO2, to support sustainability of industrial bioprocesses.
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Affiliation(s)
- Michael Baumschabl
- Austrian Centre of Industrial Biotechnology (ACIB), Vienna, 1190, Austria
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
| | - Özge Ata
- Austrian Centre of Industrial Biotechnology (ACIB), Vienna, 1190, Austria
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
| | - Bernd M. Mitic
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
- Department of Chemistry, Institute of Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
| | - Lisa Lutz
- Austrian Centre of Industrial Biotechnology (ACIB), Vienna, 1190, Austria
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
| | - Thomas Gassler
- Austrian Centre of Industrial Biotechnology (ACIB), Vienna, 1190, Austria
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
- Present address: Institute of Microbiology, ETH Zurich, Zurich, 8093, Switzerland
| | - Christina Troyer
- Department of Chemistry, Institute of Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
| | - Stephan Hann
- Austrian Centre of Industrial Biotechnology (ACIB), Vienna, 1190, Austria
- Department of Chemistry, Institute of Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
| | - Diethard Mattanovich
- Austrian Centre of Industrial Biotechnology (ACIB), Vienna, 1190, Austria
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria
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14
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Turco F, Garavaglia M, Van Houdt R, Hill P, Rawson FJ, Kovacs K. Synthetic Biology Toolbox, Including a Single-Plasmid CRISPR-Cas9 System to Biologically Engineer the Electrogenic, Metal-Resistant Bacterium Cupriavidus metallidurans CH34. ACS Synth Biol 2022; 11:3617-3628. [PMID: 36278822 PMCID: PMC9680026 DOI: 10.1021/acssynbio.2c00130] [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] [Indexed: 01/27/2023]
Abstract
Cupriavidus metallidurans CH34 exhibits extraordinary metabolic versatility, including chemolithoautotrophic growth; degradation of BTEX (benzene, toluene, ethylbenzene, xylene); high resistance to numerous metals; biomineralization of gold, platinum, silver, and uranium; and accumulation of polyhydroxybutyrate (PHB). These qualities make it a valuable host for biotechnological applications such as bioremediation, bioprocessing, and the generation of bioelectricity in microbial fuel cells (MFCs). However, the lack of genetic tools for strain development and studying its fundamental physiology represents a bottleneck to boosting its commercial applications. In this study, inducible and constitutive promoter libraries were built and characterized, providing the first comprehensive list of biological parts that can be used to regulate protein expression and optimize the CRISPR-Cas9 genome editing tools for this host. A single-plasmid CRISPR-Cas9 system that can be delivered by both conjugation and electroporation was developed, and its efficiency was demonstrated by successfully targeting the pyrE locus. The CRISPR-Cas9 system was next used to target candidate genes encoding type IV pili, hypothesized by us to be involved in extracellular electron transfer (EET) in this organism. Single and double deletion strains (ΔpilA, ΔpilE, and ΔpilAE) were successfully generated. Additionally, the CRISPR-Cas9 tool was validated for constructing genomic insertions (ΔpilAE::gfp and ΔpilAE::λPrgfp). Finally, as type IV pili are believed to play an important role in extracellular electron transfer to solid surfaces, C. metallidurans CH34 ΔpilAE was further studied by means of cyclic voltammetry using disposable screen-printed carbon electrodes. Under these conditions, we demonstrated that C. metallidurans CH34 could generate extracellular currents; however, no difference in the intensity of the current peaks was found in the ΔpilAE double deletion strain when compared to the wild type. This finding suggests that the deleted type IV pili candidate genes are not involved in extracellular electron transfer under these conditions. Nevertheless, these experiments revealed the presence of different redox centers likely to be involved in both mediated electron transfer (MET) and direct electron transfer (DET), the first interpretation of extracellular electron transfer mechanisms in C. metallidurans CH34.
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Affiliation(s)
- Federico Turco
- School of Pharmacy,
Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Marco Garavaglia
- BBSRC/EPSRC Synthetic Biology Research
Centre, School of Life Sciences, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Rob Van Houdt
- Microbiology Unit, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400 Mol, Belgium
| | - Phil Hill
- School
of Biosciences, The University of Nottingham, Sutton Bonington Campus, Leicestershire LE12 5RD, United Kingdom
| | - Frankie J. Rawson
- Bioelectronics Laboratory, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Katalin Kovacs
- Division of Molecular Therapeutics and Formulations,
School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom,
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15
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Kim S, Jang YJ, Gong G, Lee SM, Um Y, Kim KH, Ko JK. Engineering Cupriavidus necator H16 for enhanced lithoautotrophic poly(3-hydroxybutyrate) production from CO 2. Microb Cell Fact 2022; 21:231. [PMCID: PMC9636797 DOI: 10.1186/s12934-022-01962-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022] Open
Abstract
Background A representative hydrogen-oxidizing bacterium Cupriavidus necator H16 has attracted much attention as hosts to recycle carbon dioxide (CO2) into a biodegradable polymer, poly(R)-3-hydroxybutyrate (PHB). Although C. necator H16 has been used as a model PHB producer, the PHB production rate from CO2 is still too low for commercialization. Results Here, we engineer the carbon fixation metabolism to improve CO2 utilization and increase PHB production. We explore the possibilities to enhance the lithoautotrophic cell growth and PHB production by introducing additional copies of transcriptional regulators involved in Calvin Benson Bassham (CBB) cycle. Both cbbR and regA-overexpressing strains showed the positive phenotypes for 11% increased biomass accumulation and 28% increased PHB production. The transcriptional changes of key genes involved in CO2—fixing metabolism and PHB production were investigated. Conclusions The global transcriptional regulator RegA plays an important role in the regulation of carbon fixation and shows the possibility to improve autotrophic cell growth and PHB accumulation by increasing its expression level. This work represents another step forward in better understanding and improving the lithoautotrophic PHB production by C. necator H16. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01962-7.
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Affiliation(s)
- Soyoung Kim
- grid.35541.360000000121053345Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
| | - Yong Jae Jang
- grid.35541.360000000121053345Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
| | - Gyeongtaek Gong
- grid.35541.360000000121053345Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea ,grid.412786.e0000 0004 1791 8264Division of Energy and Environment Technology, KIST School, University of Science and Technology, Seoul, 02792 Republic of Korea
| | - Sun-Mi Lee
- grid.35541.360000000121053345Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea ,grid.412786.e0000 0004 1791 8264Division of Energy and Environment Technology, KIST School, University of Science and Technology, Seoul, 02792 Republic of Korea
| | - Youngsoon Um
- grid.35541.360000000121053345Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea ,grid.412786.e0000 0004 1791 8264Division of Energy and Environment Technology, KIST School, University of Science and Technology, Seoul, 02792 Republic of Korea
| | - Kyoung Heon Kim
- grid.222754.40000 0001 0840 2678Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 Republic of Korea
| | - Ja Kyong Ko
- grid.35541.360000000121053345Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea ,grid.412786.e0000 0004 1791 8264Division of Energy and Environment Technology, KIST School, University of Science and Technology, Seoul, 02792 Republic of Korea
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16
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Salinas A, McGregor C, Irorere V, Arenas-López C, Bommareddy RR, Winzer K, Minton NP, Kovács K. Metabolic engineering of Cupriavidus necator H16 for heterotrophic and autotrophic production of 3-hydroxypropionic acid. Metab Eng 2022; 74:178-190. [DOI: 10.1016/j.ymben.2022.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/29/2022] [Accepted: 10/30/2022] [Indexed: 11/06/2022]
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17
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De Wannemaeker L, Bervoets I, De Mey M. Unlocking the bacterial domain for industrial biotechnology applications using universal parts and tools. Biotechnol Adv 2022; 60:108028. [PMID: 36031082 DOI: 10.1016/j.biotechadv.2022.108028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 07/29/2022] [Accepted: 08/16/2022] [Indexed: 11/02/2022]
Abstract
Synthetic biology can play a major role in the development of sustainable industrial biotechnology processes. However, the development of economically viable production processes is currently hampered by the limited availability of host organisms that can be engineered for a specific production process. To date, standard hosts such as Escherichia coli and Saccharomyces cerevisiae are often used as starting points for process development since parts and tools allowing their engineering are readily available. However, their suboptimal metabolic background or impaired performance at industrial scale for a desired production process, can result in increased costs associated with process development and/or disappointing production titres. Building a universal and portable gene expression system allowing genetic engineering of hosts across the bacterial domain would unlock the bacterial domain for industrial biotechnology applications in a highly standardized manner and doing so, render industrial biotechnology processes more competitive compared to the current polluting chemical processes. This review gives an overview of a selection of bacterial hosts highly interesting for industrial biotechnology based on both their metabolic and process optimization properties. Moreover, the requirements and progress made so far to enable universal, standardized, and portable gene expression across the bacterial domain is discussed.
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Affiliation(s)
- Lien De Wannemaeker
- Centre for Synthetic Biology (CSB), Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Indra Bervoets
- Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Marjan De Mey
- Centre for Synthetic Biology (CSB), Ghent University, Coupure links 653, 9000 Ghent, Belgium.
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18
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Immethun CM, Kathol M, Changa T, Saha R. Synthetic Biology Tool Development Advances Predictable Gene Expression in the Metabolically Versatile Soil Bacterium Rhodopseudomonas palustris. Front Bioeng Biotechnol 2022; 10:800734. [PMID: 35372317 PMCID: PMC8966681 DOI: 10.3389/fbioe.2022.800734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
Harnessing the unique biochemical capabilities of non-model microorganisms would expand the array of biomanufacturing substrates, process conditions, and products. There are non-model microorganisms that fix nitrogen and carbon dioxide, derive energy from light, catabolize methane and lignin-derived aromatics, are tolerant to physiochemical stresses and harsh environmental conditions, store lipids in large quantities, and produce hydrogen. Model microorganisms often only break down simple sugars and require low stress conditions, but they have been engineered for the sustainable manufacture of numerous products, such as fragrances, pharmaceuticals, cosmetics, surfactants, and specialty chemicals, often by using tools from synthetic biology. Transferring complex pathways has proven to be exceedingly difficult, as the cofactors, cellular conditions, and energy sources necessary for this pathway to function may not be present in the host organism. Utilization of unique biochemical capabilities could also be achieved by engineering the host; although, synthetic biology tools developed for model microbes often do not perform as designed in other microorganisms. The metabolically versatile Rhodopseudomonas palustris CGA009, a purple non-sulfur bacterium, catabolizes aromatic compounds derived from lignin in both aerobic and anaerobic conditions and can use light, inorganic, and organic compounds for its source of energy. R. palustris utilizes three nitrogenase isozymes to fulfill its nitrogen requirements while also generating hydrogen. Furthermore, the bacterium produces two forms of RuBisCo in response to carbon dioxide/bicarbonate availability. While this potential chassis harbors many beneficial traits, stable heterologous gene expression has been problematic due to its intrinsic resistance to many antibiotics and the lack of synthetic biology parts investigated in this microbe. To address these problems, we have characterized gene expression and plasmid maintenance for different selection markers, started a synthetic biology toolbox specifically for the photosynthetic R. palustris, including origins of replication, fluorescent reporters, terminators, and 5′ untranslated regions, and employed the microbe’s endogenous plasmid for exogenous protein production. This work provides essential synthetic biology tools for engineering R. palustris’ many unique biochemical processes and has helped define the principles for expressing heterologous genes in this promising microbe through a methodology that could be applied to other non-model microorganisms.
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19
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Nitrogen Metabolism in Pseudomonas putida: Functional Analysis Using Random Barcode Transposon Sequencing. Appl Environ Microbiol 2022; 88:e0243021. [PMID: 35285712 DOI: 10.1128/aem.02430-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas putida KT2440 has long been studied for its diverse and robust metabolisms, yet many genes and proteins imparting these growth capacities remain uncharacterized. Using pooled mutant fitness assays, we identified genes and proteins involved in the assimilation of 52 different nitrogen containing compounds. To assay amino acid biosynthesis, 19 amino acid drop-out conditions were also tested. From these 71 conditions, significant fitness phenotypes were elicited in 672 different genes including 100 transcriptional regulators and 112 transport-related proteins. We divide these conditions into 6 classes, and propose assimilatory pathways for the compounds based on this wealth of genetic data. To complement these data, we characterize the substrate range of three promiscuous aminotransferases relevant to metabolic engineering efforts in vitro. Furthermore, we examine the specificity of five transcriptional regulators, explaining some fitness data results and exploring their potential to be developed into useful synthetic biology tools. In addition, we use manifold learning to create an interactive visualization tool for interpreting our BarSeq data, which will improve the accessibility and utility of this work to other researchers. IMPORTANCE Understanding the genetic basis of P. putida's diverse metabolism is imperative for us to reach its full potential as a host for metabolic engineering. Many target molecules of the bioeconomy and their precursors contain nitrogen. This study provides functional evidence linking hundreds of genes to their roles in the metabolism of nitrogenous compounds, and provides an interactive tool for visualizing these data. We further characterize several aminotransferases, lactamases, and regulators, which are of particular interest for metabolic engineering.
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20
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Chen Y, Fang L, Ying X, Cheng M, Wang L, Sun P, Zhang Z, Shi L, Cao Y, Song H. Development of Whole Genome-Scale Base Editing Toolbox to Promote Efficiency of Extracellular Electron Transfer in Shewanella oneidensis MR-1. Adv Biol (Weinh) 2022; 6:e2101296. [PMID: 35182055 DOI: 10.1002/adbi.202101296] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/18/2022] [Indexed: 11/06/2022]
Abstract
Shewanella oneidensis MR-1, as a model electroactive microorganism (EAM) for extracellular electron transfer (EET) study, plays a key role in advancing practical applications of bio-electrochemical systems (BES). Efficient genome-level manipulation tools are vital to promote EET efficiency; thus, a powerful and rapid base editing toolbox in S. oneidensis MR-1 is developed. Firstly a CRISPR/dCas9-AID base editor that shows a relatively narrow editing window restricted to the "-20 to -16" range upstream of the protospacer adjacent motif (PAM) is constructed. Cas9 is also confined by its native PAM requirement, NGG. Then to expand the editable scope, the sgRNA and the Cas-protein to broaden the editing window to "-22 to -9" upstream of the PAM are engineered, and the PAM field to NNN is opened up. Consequently, the coverage of the editable gene is expanded from 89% to nearly 100% in S. oneidensis MR-1. This whole genome-scale cytidine deaminase-based base editing toolbox (WGcBE) is applied to regulate the cell length and the biofilm morphology, which enhances the EET efficiency by 6.7-fold. WGcBE enables an efficient deactivation of genes with full genome coverage, which would contribute to the in-depth and multi-faceted EET study in Shewanella.
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Affiliation(s)
- Yaru Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Lixia Fang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Xiang Ying
- College of Intelligence and Computing, Tianjin University, Tianjin, 300072, China
| | - Meijie Cheng
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Lin Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Panxing Sun
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Zhaoyu Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China
| | - Liang Shi
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geosciences in Wuhan, Wuhan, Hubei, 430074, China
| | - Yingxiu Cao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Hao Song
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
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21
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Hanko EKR, Sherlock G, Minton NP, Malys N. Biosensor-informed engineering of Cupriavidus necator H16 for autotrophic D-mannitol production. Metab Eng 2022; 72:24-34. [PMID: 35149227 DOI: 10.1016/j.ymben.2022.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 02/07/2022] [Accepted: 02/07/2022] [Indexed: 01/26/2023]
Abstract
Cupriavidus necator H16 is one of the most researched carbon dioxide (CO2)-fixing bacteria. It can store carbon in form of the polymer polyhydroxybutyrate and generate energy by aerobic hydrogen oxidation under lithoautotrophic conditions, making C. necator an ideal chassis for the biological production of value-added compounds from waste gases. Despite its immense potential, however, the experimental evidence of C. necator utilisation for autotrophic biosynthesis of chemicals is limited. Here, we genetically engineered C. necator for the high-level de novo biosynthesis of the industrially relevant sugar alcohol mannitol directly from Calvin-Benson-Bassham (CBB) cycle intermediates. To identify optimal mannitol production conditions in C. necator, a mannitol-responsive biosensor was applied for screening of mono- and bifunctional mannitol 1-phosphate dehydrogenases (MtlDs) and mannitol 1-phosphate phosphatases (M1Ps). We found that MtlD/M1P from brown alga Ectocarpus siliculosus performed overall the best under heterotrophic growth conditions and was selected to be chromosomally integrated. Consequently, autotrophic fermentation of recombinant C. necator yielded up to 3.9 g/L mannitol, representing a substantial improvement over mannitol biosynthesis using recombinant cyanobacteria. Importantly, we demonstrate that at the onset of stationary growth phase nearly 100% of carbon can be directed from the CBB cycle into mannitol through the glyceraldehyde 3-phosphate and fructose 6-phosphate intermediates. This study highlights for the first time the potential of C. necator to generate sugar alcohols from CO2 utilising precursors derived from the CBB cycle.
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Affiliation(s)
- Erik K R Hanko
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom; Present address: Manchester Centre for Fine and Speciality Chemicals (SYNBIOCHEM), Manchester Institute of Biotechnology, University of Manchester, Manchester, M1 7DN, United Kingdom
| | - Gillian Sherlock
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Naglis Malys
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom.
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22
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Abel AJ, Hilzinger JM, Arkin AP, Clark DS. Systems-informed genome mining for electroautotrophic microbial production. Bioelectrochemistry 2022; 145:108054. [DOI: 10.1016/j.bioelechem.2022.108054] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/15/2021] [Accepted: 01/06/2022] [Indexed: 01/09/2023]
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23
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Tsai ST, Cheng WJ, Zhang QX, Yeh YC. Gold-Specific Biosensor for Monitoring Wastewater Using Genetically Engineered Cupriavidus metallidurans CH34. ACS Synth Biol 2021; 10:3576-3582. [PMID: 34860511 DOI: 10.1021/acssynbio.1c00520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Transcription factor-based whole-cell biosensors have recently become promising alternatives to conventional analytical methods due to their advantage of simplicity, cost-effectiveness, and environmental friendliness. In this study, we used genetic engineering to develop a whole-cell biosensor based on the activation of promoters by CupR via interactions with gold ions, leading to the expression of reporter genes that yield output signals. Altering the promoter sequences was shown to significantly improve the performance of the biosensor strain in terms of gold-specificity. The detection sensitivity of our engineered strains was 42-fold higher than that of wild-type strains. The linear range of the purposed sensor was 125-1000 nM with a limit of detection at 46.5 nM. The effectiveness of the sensor strain was verified in wastewater samples.
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Affiliation(s)
- Ssu-Tzu Tsai
- Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan
| | - Wen-Jui Cheng
- Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan
| | - Qian-Xian Zhang
- Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan
| | - Yi-Chun Yeh
- Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan
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24
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Boy C, Lesage J, Alfenore S, Guillouet SE, Gorret N. Investigation of the robustness of Cupriavidus necator engineered strains during fed-batch cultures. AMB Express 2021; 11:151. [PMID: 34783891 PMCID: PMC8595445 DOI: 10.1186/s13568-021-01307-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 11/10/2022] Open
Abstract
It is of major interest to ensure stable and performant microbial bioprocesses, therefore maintaining high strain robustness is one of the major future challenges in industrial microbiology. Strain robustness can be defined as the persistence of genotypic and/or phenotypic traits in a system. In this work, robustness of an engineered strain is defined as plasmid expression stability, cultivability, membrane integrity and macroscopic cell behavior and was assessed in response to implementations of sugar feeding strategies (pulses and continuous) and two plasmid stabilization systems (kanamycin resistance and Post-Segregational Killing hok/sok). Fed-batch bioreactor cultures, relevant mode to reach high cell densities and higher cell generation number, were implemented to investigate the robustness of C. necator engineered strains. Host cells bore a recombinant plasmid encoding for a plasmid expression level monitoring system, based on eGFP fluorescence quantified by flow cytometry. We first showed that well-controlled continuous feeding in comparison to a pulse-based feeding allowed a better carbon use for protein synthesis (avoiding organic acid excretion), a lower heterogeneity of the plasmid expression and a lower cell permeabilization. Moreover, the plasmid stabilization system Post-Segregational Killing hok/sok, an autonomous system independent on external addition of compounds, showed the best ability to maintain plasmid expression level stability insuring a greater population homogeneity in the culture. Therefore, in the case of engineered C. necator, the PSK system hok/sok appears to be a relevant and an efficient alternative to antibiotic resistance system for selection pressure, especially, in the case of bioprocess development for economic and environmental reasons.
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25
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Wendisch VF, Kosec G, Heux S, Brautaset T. Aerobic Utilization of Methanol for Microbial Growth and Production. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2021; 180:169-212. [PMID: 34761324 DOI: 10.1007/10_2021_177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Methanol is a reduced one-carbon (C1) compound. It supports growth of aerobic methylotrophs that gain ATP from reduced redox equivalents by respiratory phosphorylation in their electron transport chains. Notably, linear oxidation of methanol to carbon dioxide may yield three reduced redox equivalents if methanol oxidation is NAD-dependent as, e.g., in Bacillus methanolicus. Methanol has a higher degree of reduction per carbon than glucose (6 vs. 4), and thus, lends itself as an ideal carbon source for microbial production of reduced target compounds. However, C-C bond formation in the RuMP or serine cycle, a prerequisite for production of larger molecules, requires ATP and/or reduced redox equivalents. Moreover, heat dissipation and a high demand for oxygen during catabolic oxidation of methanol may pose challenges for fermentation processes. In this chapter, we summarize metabolic pathways for aerobic methanol utilization, aerobic methylotrophs as industrial production hosts, strain engineering, and methanol bioreactor processes. In addition, we provide technological and market outlooks.
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Affiliation(s)
- Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology and CeBiTec, Bielefeld University, Bielefeld, Germany.
| | | | - Stéphanie Heux
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Trygve Brautaset
- Department of Biotechnology and Food Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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26
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Pan H, Wang J, Wu H, Li Z, Lian J. Synthetic biology toolkit for engineering Cupriviadus necator H16 as a platform for CO 2 valorization. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:212. [PMID: 34736496 PMCID: PMC8570001 DOI: 10.1186/s13068-021-02063-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 10/25/2021] [Indexed: 06/09/2023]
Abstract
BACKGROUND CO2 valorization is one of the effective methods to solve current environmental and energy problems, in which microbial electrosynthesis (MES) system has proved feasible and efficient. Cupriviadus necator (Ralstonia eutropha) H16, a model chemolithoautotroph, is a microbe of choice for CO2 conversion, especially with the ability to be employed in MES due to the presence of genes encoding [NiFe]-hydrogenases and all the Calvin-Benson-Basham cycle enzymes. The CO2 valorization strategy will make sense because the required hydrogen can be produced from renewable electricity independently of fossil fuels. MAIN BODY In this review, synthetic biology toolkit for C. necator H16, including genetic engineering vectors, heterologous gene expression elements, platform strain and genome engineering, and transformation strategies, is firstly summarized. Then, the review discusses how to apply these tools to make C. necator H16 an efficient cell factory for converting CO2 to value-added products, with the examples of alcohols, fatty acids, and terpenoids. The review is concluded with the limitation of current genetic tools and perspectives on the development of more efficient and convenient methods as well as the extensive applications of C. necator H16. CONCLUSIONS Great progress has been made on genetic engineering toolkit and synthetic biology applications of C. necator H16. Nevertheless, more efforts are expected in the near future to engineer C. necator H16 as efficient cell factories for the conversion of CO2 to value-added products.
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Affiliation(s)
- Haojie Pan
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jia Wang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Haoliang Wu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Zhongjian Li
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China.
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27
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Gauttam R, Mukhopadhyay A, Simmons BA, Singer SW. Development of dual-inducible duet-expression vectors for tunable gene expression control and CRISPR interference-based gene repression in Pseudomonas putida KT2440. Microb Biotechnol 2021; 14:2659-2678. [PMID: 34009716 PMCID: PMC8601191 DOI: 10.1111/1751-7915.13832] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/29/2021] [Indexed: 12/16/2022] Open
Abstract
The development of P. putida as an industrial host requires a sophisticated molecular toolbox for strain improvement, including vectors for gene expression and repression. To augment existing expression plasmids for metabolic engineering, we developed a series of dual-inducible duet-expression vectors for P. putida KT2440. A number of inducible promoters (Plac , Ptac , PtetR/tetA and Pbad ) were used in different combinations to differentially regulate the expression of individual genes. Protein expression was evaluated by measuring the fluorescence of reporter proteins (GFP and RFP). Our experiments demonstrated the use of compatible plasmids, a useful approach to coexpress multiple genes in P. putida KT2440. These duet vectors were modified to generate a fully inducible CRISPR interference system using two catalytically inactive Cas9 variants from S. pasteurianus (dCas9) and S. pyogenes (spdCas9). The utility of developed CRISPRi system(s) was demonstrated by repressing the expression of nine conditionally essential genes, resulting in growth impairment and prolonged lag phase for P. putida KT2440 growth on glucose. Furthermore, the system was shown to be tightly regulated, tunable and to provide a simple way to identify essential genes with an observable phenotype.
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Affiliation(s)
- Rahul Gauttam
- The Joint BioEnergy InstituteEmeryvilleCAUSA
- Biological Systems and Engineering DivisionLawrence Berkeley National LaboratoryBerkeleyCAUSA
| | - Aindrila Mukhopadhyay
- The Joint BioEnergy InstituteEmeryvilleCAUSA
- Biological Systems and Engineering DivisionLawrence Berkeley National LaboratoryBerkeleyCAUSA
| | - Blake A. Simmons
- The Joint BioEnergy InstituteEmeryvilleCAUSA
- Biological Systems and Engineering DivisionLawrence Berkeley National LaboratoryBerkeleyCAUSA
| | - Steven W. Singer
- The Joint BioEnergy InstituteEmeryvilleCAUSA
- Biological Systems and Engineering DivisionLawrence Berkeley National LaboratoryBerkeleyCAUSA
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28
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Ehsaan M, Baker J, Kovács K, Malys N, Minton NP. The pMTL70000 modular, plasmid vector series for strain engineering in Cupriavidus necator H16. J Microbiol Methods 2021; 189:106323. [PMID: 34506812 PMCID: PMC8482281 DOI: 10.1016/j.mimet.2021.106323] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/06/2021] [Accepted: 09/06/2021] [Indexed: 11/06/2022]
Abstract
Cupriavidus necator H16 can convert CO2 into industrial chemicals and fuels. To facilitate its engineering, we designed, built and tested the pMTL70000 modular plasmids comprising standardised Cupriavidus and E. coli replicons, selectable markers and application specific modules. Plasmids were characterised in terms of transmissibility, stability, copy number and compatibility. A standardised, modular vector system for engineering Cupriavidus necator H16. An improved procedure for DNA transfer by electroporation. Vectors characterised in terms of segregational stability, copy number and compatibility.
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Affiliation(s)
- Muhammad Ehsaan
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Jonathan Baker
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Katalin Kovács
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Naglis Malys
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, United Kingdom.
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29
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Improved Dynamic Range of a Rhamnose-Inducible Promoter for Gene Expression in Burkholderia spp. Appl Environ Microbiol 2021; 87:e0064721. [PMID: 34190606 DOI: 10.1128/aem.00647-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A diverse genetic toolkit is critical for understanding bacterial physiology and genotype-phenotype relationships. Inducible promoter systems are an integral part of this toolkit. In Burkholderia and related species, the l-rhamnose-inducible promoter is among the first choices due to its tight control and the lack of viable alternatives. To improve upon its maximum activity and dynamic range, we explored the effect of promoter system modifications in Burkholderia cenocepacia with a LacZ-based reporter. By combining the bacteriophage T7 gene 10 stem-loop and engineered rhaI transcription factor-binding sites, we obtained a rhamnose-inducible system with a 6.5-fold and 3.0-fold increases in maximum activity and dynamic range, respectively, compared to the native promoter. We then added the modified promoter system to pSCrhaB2 and pSC201, common genetic tools used for plasmid-based and chromosome-based gene expression, respectively, in Burkholderia, creating pSCrhaB2plus and pSC201plus. We demonstrated the utility of pSCrhaB2plus for gene expression in B. thailandensis, B. multivorans, and B. vietnamiensis and used pSC201plus to control highly expressed essential genes from the chromosome of B. cenocepacia. The utility of the modified system was demonstrated as we recovered viable mutants to control ftsZ, rpoBC, and rpsF, whereas the unmodified promoter was unable to control rpsF. The modified expression system allowed control of an essential gene depletion phenotype at lower levels of l-rhamnose, the inducer. pSCRhaB2plus and pSC201plus are expected to be valuable additions to the genetic toolkit for Burkholderia and related species. IMPORTANCE Species of Burkholderia are dually recognized as being of attractive biotechnological potential but also opportunistic pathogens for immunocompromised individuals. Understanding the genotype-phenotype relationship is critical for synthetic biology approaches in Burkholderia to disentangle pathogenic from beneficial traits. A diverse genetic toolkit, including inducible promoters, is the foundation for these investigations. Thus, we sought to improve on the commonly used rhamnose-inducible promoter system. Our modifications resulted in both higher levels of heterologous protein expression and broader control over highly expressed essential genes in B. cenocepacia. The significance of our work is in expanding the genetic toolkit to enable more comprehensive studies into Burkholderia and related bacteria.
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30
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Azubuike CC, Gatehouse AMR, Howard TP. pCAT vectors overcome inefficient electroporation of Cupriavidus necator H16. N Biotechnol 2021; 65:20-30. [PMID: 34333160 DOI: 10.1016/j.nbt.2021.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/06/2021] [Accepted: 07/24/2021] [Indexed: 10/20/2022]
Abstract
Cupriavidus necator H16 is a chemolithoautotroph with a range of industrial biotechnological applications. Advanced metabolic engineering in the bacterium, however, is impeded by low transformation efficiency, making it difficult to introduce and screen new genetic functions rapidly. This study systematically characterized the broad host range plasmids pBHR1, pBBR1MCS-2 and pKT230 used frequently for C. necator engineering. Kanamycin resistance cassette (KanR) and a truncated sequence of the replication origin (Rep) are contributing factors to C. necator low electroporation transformation efficiency. Consequently, a series of modular minimal plasmids, named pCAT, were constructed. pCAT vectors transform C. necator H16 with a > 3000-fold higher efficiency (up to 107 CFU/μg DNA) compared to control plasmids. Further, pCAT vectors are highly stable, expressing reporter proteins over several days of serial cultivation in the absence of selection pressure. Finally, they can be assembled rapidly from PCR or synthesized DNA fragments, and restriction-ligation reactions can be efficiently electroporated directly into C. necator, circumventing the requirement to use Escherichia coli for plasmid maintenance or propagation. This study demonstrates that an understanding of the behaviour of the constituent parts of plasmids in a host is key to efficient propagation of genetic information, while offering new methods for engineering a bacterium with desirable industrial biotechnological features.
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Affiliation(s)
- Christopher C Azubuike
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle-upon-Tyne, NE1 7RX, United Kingdom; Department of Microbiology, Faculty of Science, University of Port Harcourt, East-West Road, P.M.B. 5323, Choba, Port Harcourt, Rivers State, Nigeria
| | - Angharad M R Gatehouse
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle-upon-Tyne, NE1 7RX, United Kingdom
| | - Thomas P Howard
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle-upon-Tyne, NE1 7RX, United Kingdom.
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31
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Schuster LA, Reisch CR. A plasmid toolbox for controlled gene expression across the Proteobacteria. Nucleic Acids Res 2021; 49:7189-7202. [PMID: 34125913 PMCID: PMC8266580 DOI: 10.1093/nar/gkab496] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/19/2021] [Accepted: 05/24/2021] [Indexed: 11/16/2022] Open
Abstract
Controlled gene expression is fundamental for the study of gene function and our ability to engineer bacteria. However, there is currently no easy-to-use genetics toolbox that enables controlled gene expression in a wide range of diverse species. To facilitate the development of genetics systems in a fast, easy, and standardized manner, we constructed and tested a plasmid assembly toolbox that will enable the identification of well-regulated promoters in many Proteobacteria and potentially beyond. Each plasmid is composed of four categories of genetic parts (i) the origin of replication, (ii) resistance marker, (iii) promoter-regulator and (iv) reporter. The plasmids can be efficiently assembled using ligation-independent cloning, and any gene of interest can be easily inserted in place of the reporter. We tested this toolbox in nine different Proteobacteria and identified regulated promoters with over fifty-fold induction range in eight of these bacteria. We also constructed variant libraries that enabled the identification of promoter-regulators with varied expression levels and increased inducible fold change relative to the original promoter. A selection of over 50 plasmids, which contain all of the toolbox's genetic parts, are available for community use and will enable easy construction and testing of genetics systems in both model and non-model bacteria.
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Affiliation(s)
- Layla A Schuster
- Dept. of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32603, USA
| | - Christopher R Reisch
- Dept. of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32603, USA
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32
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Panich J, Fong B, Singer SW. Metabolic Engineering of Cupriavidus necator H16 for Sustainable Biofuels from CO 2. Trends Biotechnol 2021; 39:412-424. [PMID: 33518389 DOI: 10.1016/j.tibtech.2021.01.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 02/08/2023]
Abstract
Decelerating global warming is one of the predominant challenges of our time and will require conversion of CO2 to usable products and commodity chemicals. Of particular interest is the production of fuels, because the transportation sector is a major source of CO2 emissions. Here, we review recent technological advances in metabolic engineering of the hydrogen-oxidizing bacterium Cupriavidus necator H16, a chemolithotroph that naturally consumes CO2 to generate biomass. We discuss recent successes in biofuel production using this organism, and the implementation of electrolysis/artificial photosynthesis approaches that enable growth of C. necator using renewable electricity and CO2. Last, we discuss prospects of improving the nonoptimal growth of C. necator in ambient concentrations of CO2.
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Affiliation(s)
- Justin Panich
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Bonnie Fong
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Steven W Singer
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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33
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Riley LA, Guss AM. Approaches to genetic tool development for rapid domestication of non-model microorganisms. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:30. [PMID: 33494801 PMCID: PMC7830746 DOI: 10.1186/s13068-020-01872-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/30/2020] [Indexed: 05/04/2023]
Abstract
Non-model microorganisms often possess complex phenotypes that could be important for the future of biofuel and chemical production. They have received significant interest the last several years, but advancement is still slow due to the lack of a robust genetic toolbox in most organisms. Typically, "domestication" of a new non-model microorganism has been done on an ad hoc basis, and historically, it can take years to develop transformation and basic genetic tools. Here, we review the barriers and solutions to rapid development of genetic transformation tools in new hosts, with a major focus on Restriction-Modification systems, which are a well-known and significant barrier to efficient transformation. We further explore the tools and approaches used for efficient gene deletion, DNA insertion, and heterologous gene expression. Finally, more advanced and high-throughput tools are now being developed in diverse non-model microbes, paving the way for rapid and multiplexed genome engineering for biotechnology.
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Affiliation(s)
- Lauren A Riley
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Bredesen Center, University of Tennessee, Knoxville, TN, 37996, USA
| | - Adam M Guss
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
- Bredesen Center, University of Tennessee, Knoxville, TN, 37996, USA.
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34
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Li Z, Xin X, Xiong B, Zhao D, Zhang X, Bi C. Engineering the Calvin-Benson-Bassham cycle and hydrogen utilization pathway of Ralstonia eutropha for improved autotrophic growth and polyhydroxybutyrate production. Microb Cell Fact 2020; 19:228. [PMID: 33308236 PMCID: PMC7733298 DOI: 10.1186/s12934-020-01494-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 12/05/2020] [Indexed: 12/24/2022] Open
Abstract
Background CO2 is fixed by all living organisms with an autotrophic metabolism, among which the Calvin–Benson–Bassham (CBB) cycle is the most important and widespread carbon fixation pathway. Thus, studying and engineering the CBB cycle with the associated energy providing pathways to increase the CO2 fixation efficiency of cells is an important subject of biological research with significant application potential. Results In this work, the autotrophic microbe Ralstonia eutropha (Cupriavidus necator) was selected as a research platform for CBB cycle optimization engineering. By knocking out either CBB operon genes on the operon or mega-plasmid of R. eutropha, we found that both CBB operons were active and contributed almost equally to the carbon fixation process. With similar knock-out experiments, we found both soluble and membrane-bound hydrogenases (SH and MBH), belonging to the energy providing hydrogenase module, were functional during autotrophic growth of R. eutropha. SH played a more significant role. By introducing a heterologous cyanobacterial RuBisCO with the endogenous GroES/EL chaperone system(A quality control systems for proteins consisting of molecular chaperones and proteases, which prevent protein aggregation by either refolding or degrading misfolded proteins) and RbcX(A chaperone in the folding of Rubisco), the culture OD600 of engineered strain increased 89.2% after 72 h of autotrophic growth, although the difference was decreased at 96 h, indicating cyanobacterial RuBisCO with a higher activity was functional in R. eutropha and lead to improved growth in comparison to the host specific enzyme. Meanwhile, expression of hydrogenases was optimized by modulating the expression of MBH and SH, which could further increase the R. eutropha H16 culture OD600 to 93.4% at 72 h. Moreover, the autotrophic yield of its major industrially relevant product, polyhydroxybutyrate (PHB), was increased by 99.7%. Conclusions To our best knowledge, this is the first report of successfully engineering the CBB pathway and hydrogenases of R. eutropha for improved activity, and is one of only a few cases where the efficiency of CO2 assimilation pathway was improved. Our work demonstrates that R. eutropha is a useful platform for studying and engineering the CBB for applications.
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Affiliation(s)
- Zhongkang Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Xiuqing Xin
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Bin Xiong
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Dongdong Zhao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Xueli Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
| | - Changhao Bi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
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Passarini MRZ, E Silva TR, Bernal SPF, Cecchet NL, Sartoratto A, Boroski M, Duarte AWF, Ottoni JR, Rosa LH, de Oliveira VM. Undecane production by cold-adapted bacteria from Antarctica. Extremophiles 2020; 24:863-873. [PMID: 32944821 DOI: 10.1007/s00792-020-01200-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/03/2020] [Indexed: 11/27/2022]
Abstract
In the last decades, efforts to reduce the use of fossil fuels have increased the search for alternative sustainable sources of renewable energy. In this scenario, hydrocarbons derived from fatty acids are among the compounds that have been drawing attention. The intracellular production of hydrocarbons by bacteria derived from cold environments such as the Antarctic continent is currently poorly investigated, as extremophilic microorganisms provide a great range of metabolic capabilities and may represent a key tool in the production of biofuels. The aim of this study was to explore the ability of bacterial cells derived from extreme environments to produce hydrocarbons with potential for further use as biofuels. Seven bacteria isolated from Antarctic samples were evaluated for hydrocarbon production using GC-MS approaches. Two isolates, identified as Arthrobacter livingstonensis 593 and Pseudoalteromonas arctica 628, were able to produce the hydrocarbon undecane (CH3-(CH2)9-CH3) in concentrations of 1.39 mg L-1 and 1.81 mg L-1, respectively. Results from the present work encourage further research focusing on the optimization of hydrocarbon production by the isolates identified as producers, which may be used in further aircraft biofuel production. This is the first report on the production of the undecane compound by bacteria isolated from waterlogged soil and sponge from Antarctica.
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Affiliation(s)
- Michel Rodrigo Zambrano Passarini
- UNILA-Universidade Federal da Integração Latino-Americana. Laboratório de Biotecnologia Ambiental, Av. Tarquínio Joslin dos Santos, 1000-Jd Universitário, Foz do Iguaçu, PR, 85870-650, Brazil.
| | - Tiago Rodrigues E Silva
- CPQBA/UNICAMP-Divisão de Recursos Microbianos, Rua Alexandre Caselatto 999, Vila Betel, CP 6171, Campinas, SP, 13083-970, Brazil
| | - Suzan Prado Fernandes Bernal
- UNILA-Universidade Federal da Integração Latino-Americana. Laboratório de Biotecnologia Ambiental, Av. Tarquínio Joslin dos Santos, 1000-Jd Universitário, Foz do Iguaçu, PR, 85870-650, Brazil
| | - Nathália Luana Cecchet
- UNILA-Universidade Federal da Integração Latino-Americana. Laboratório de Biotecnologia Ambiental, Av. Tarquínio Joslin dos Santos, 1000-Jd Universitário, Foz do Iguaçu, PR, 85870-650, Brazil
| | - Adilson Sartoratto
- CPQBA/UNICAMP-Divisão de Química Orgânica e Farmacêutica, Rua Alexandre Caselatto 999, Vila Betel, CP 6171, Campinas, SP, 13083-970, Brazil
| | - Marcela Boroski
- UNILA-Universidade Federal da Integração Latino-Americana. Laboratório de Química, Av. Tancredo Neves 6731- Conjunto B, Foz do Iguaçu, PR, 85867-970, Brazil
| | - Alysson Wagner Fernandes Duarte
- UFAL-Universidade Federal de Alagoas, Av. Manoel Severino Barbosa-Rodovia AL-115, Bom Sucesso, Arapiraca, AL, 57309-005, Brazil
| | - Júlia Ronzella Ottoni
- UDC-Centro Universitário Dinâmica das Cataratas, Rua Castelo Branco, 349, Centro, Foz do Iguaçu, PR, Brazil
| | - Luiz Henrique Rosa
- UFMG-Departamento de Microbiologia, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Valéria Maia de Oliveira
- CPQBA/UNICAMP-Divisão de Recursos Microbianos, Rua Alexandre Caselatto 999, Vila Betel, CP 6171, Campinas, SP, 13083-970, Brazil
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Applying Statistical Design of Experiments To Understanding the Effect of Growth Medium Components on Cupriavidus necator H16 Growth. Appl Environ Microbiol 2020; 86:AEM.00705-20. [PMID: 32561588 PMCID: PMC7440812 DOI: 10.1128/aem.00705-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/31/2020] [Indexed: 01/06/2023] Open
Abstract
Chemically defined media (CDM) for cultivation of C. necator vary in components and compositions. This lack of consensus makes it difficult to optimize new processes for the bacterium. This study employed statistical design of experiments (DOE) to understand how basic components of defined media affect C. necator growth. Our growth model predicts that C. necator can be cultivated to high cell density with components held at low concentrations, arguing that CDM for large-scale cultivation of the bacterium for industrial purposes will be economically competitive. Although existing CDM for the bacterium are without amino acids, addition of a few amino acids to growth medium shortened lag phase of growth. The interactions highlighted by our growth model show how factors can interact with each other during a process to positively or negatively affect process output. This approach is efficient, relying on few well-structured experimental runs to gain maximum information on a biological process, growth. Cupriavidus necator H16 is gaining significant attention as a microbial chassis for range of biotechnological applications. While the bacterium is a major producer of bioplastics, its lithoautotrophic and versatile metabolic capabilities make the bacterium a promising microbial chassis for biofuels and chemicals using renewable resources. It remains necessary to develop appropriate experimental resources to permit controlled bioengineering and system optimization of this microbe. In this study, we employed statistical design of experiments to gain understanding of the impact of components of defined media on C. necator growth and built a model that can predict the bacterium’s cell density based on medium components. This highlighted medium components, and interaction between components, having the most effect on growth: fructose, amino acids, trace elements, CaCl2, and Na2HPO4 contributed significantly to growth (t values of <−1.65 or >1.65); copper and histidine were found to interact and must be balanced for robust growth. Our model was experimentally validated and found to correlate well (r2 = 0.85). Model validation at large culture scales showed correlations between our model-predicted growth ranks and experimentally determined ranks at 100 ml in shake flasks (ρ = 0.87) and 1 liter in a bioreactor (ρ = 0.90). Our approach provides valuable and quantifiable insights on the impact of medium components on cell growth and can be applied to model other C. necator responses that are crucial for its deployment as a microbial chassis. This approach can be extended to other nonmodel microbes of medical and industrial biotechnological importance. IMPORTANCE Chemically defined media (CDM) for cultivation of C. necator vary in components and compositions. This lack of consensus makes it difficult to optimize new processes for the bacterium. This study employed statistical design of experiments (DOE) to understand how basic components of defined media affect C. necator growth. Our growth model predicts that C. necator can be cultivated to high cell density with components held at low concentrations, arguing that CDM for large-scale cultivation of the bacterium for industrial purposes will be economically competitive. Although existing CDM for the bacterium are without amino acids, addition of a few amino acids to growth medium shortened lag phase of growth. The interactions highlighted by our growth model show how factors can interact with each other during a process to positively or negatively affect process output. This approach is efficient, relying on few well-structured experimental runs to gain maximum information on a biological process, growth.
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Gauttam R, Mukhopadhyay A, Singer SW. Construction of a novel dual-inducible duet-expression system for gene (over)expression in Pseudomonas putida. Plasmid 2020; 110:102514. [PMID: 32504628 DOI: 10.1016/j.plasmid.2020.102514] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/01/2020] [Accepted: 04/16/2020] [Indexed: 02/07/2023]
Abstract
Pseudomonas putida is a widely used host for metabolic engineering and synthetic biology. However, the use of P. putida has been hampered by the availability of a limited set of expression vectors for producing heterologous proteins. To widen the scope of expression vectors for gene co-expression studies, a previously established dual-inducible expression vector pRG_Duet2 developed for Corynebacterium glutamicum has been modified for use in P. putida. This expression vector, named pRGPDuo2, harbors two origins of replication, colE1 for replication in E. coli and pRO1600 for replication in P. putida. Two multiple cloning sites (MCS1 and MCS2) in pRGPDuo2 are individually controlled by inducible promoters Ptac or PtetR/tetA. Functional validation of pRGPDuo2 was confirmed by the co-expression of genes for the fluorescent proteins namely, superfolder green fluorescent protein (sfGFP), and red fluorescent protein (RFP). Moreover, the strength of the fluorescence signal was dependent on the inducer concentrations present in the culture medium. The expression vector pRGPDuo2 is an attractive addition to the existing repertoire of expression plasmids for expression profiling and adds to the tools available for P. putida metabolic engineering.
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Affiliation(s)
- Rahul Gauttam
- The Joint BioEnergy Institute, Emeryville, CA, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Aindrila Mukhopadhyay
- The Joint BioEnergy Institute, Emeryville, CA, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Steven W Singer
- The Joint BioEnergy Institute, Emeryville, CA, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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Pander B, Mortimer Z, Woods C, McGregor C, Dempster A, Thomas L, Maliepaard J, Mansfield R, Rowe P, Krabben P. Hydrogen oxidising bacteria for production of single‐cell protein and other food and feed ingredients. ENGINEERING BIOLOGY 2020; 4:21-24. [PMID: 36970394 PMCID: PMC9996702 DOI: 10.1049/enb.2020.0005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/04/2020] [Indexed: 11/19/2022] Open
Abstract
Using hydrogen oxidising bacteria to produce protein and other food and feed ingredients is a form of industrial biotechnology that is gaining traction. The technology fixes carbon dioxide into products without the light requirements of agriculture and biotech that rely on primary producers such as plants and algae while promising higher growth rates, drastically less land, fresh water, and mineral requirements. The significant body of scientific knowledge on hydrogen oxidising bacteria continues to grow and genetic engineering tools are well developed for specific species. The scale-up success of other types of gas- fermentation using carbon monoxide or methane has paved the way for scale-up of a process that uses a mix of hydrogen, oxygen, and carbon dioxide to produce bacteria as a food and feed ingredients in a highly sustainable fashion.
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Affiliation(s)
| | - Zahara Mortimer
- School of Lifesciences University of Nottingham Nottingham UK
| | - Craig Woods
- Deep Branch Biotechnology Ltd Nottingham UK
- School of Lifesciences University of Nottingham Nottingham UK
| | - Callum McGregor
- Deep Branch Biotechnology Ltd Nottingham UK
- School of Lifesciences University of Nottingham Nottingham UK
| | - Andrew Dempster
- School of Lifesciences University of Nottingham Nottingham UK
| | | | - Joshua Maliepaard
- Deep Branch Biotechnology Ltd Nottingham UK
- Leiden Academic Centre for Drug Research University of Leiden Leiden The Netherlands
| | - Robert Mansfield
- Deep Branch Biotechnology Ltd Nottingham UK
- School of Lifesciences University of Nottingham Nottingham UK
| | - Peter Rowe
- Deep Branch Biotechnology Ltd Nottingham UK
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Incha MR, Thompson MG, Blake-Hedges JM, Liu Y, Pearson AN, Schmidt M, Gin JW, Petzold CJ, Deutschbauer AM, Keasling JD. Leveraging host metabolism for bisdemethoxycurcumin production in Pseudomonas putida. Metab Eng Commun 2020; 10:e00119. [PMID: 32280587 PMCID: PMC7136493 DOI: 10.1016/j.mec.2019.e00119] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023] Open
Abstract
Pseudomonas putida is a saprophytic bacterium with robust metabolisms and strong solvent tolerance making it an attractive host for metabolic engineering and bioremediation. Due to its diverse carbon metabolisms, its genome encodes an array of proteins and enzymes that can be readily applied to produce valuable products. In this work we sought to identify design principles and bottlenecks in the production of type III polyketide synthase (T3PKS)-derived compounds in P. putida. T3PKS products are widely used as nutraceuticals and medicines and often require aromatic starter units, such as coumaroyl-CoA, which is also an intermediate in the native coumarate catabolic pathway of P. putida. Using a randomly barcoded transposon mutant (RB-TnSeq) library, we assayed gene functions for a large portion of aromatic catabolism, confirmed known pathways, and proposed new annotations for two aromatic transporters. The 1,3,6,8-tetrahydroxynapthalene synthase of Streptomyces coelicolor (RppA), a microbial T3PKS, was then used to rapidly assay growth conditions for increased T3PKS product accumulation. The feruloyl/coumaroyl CoA synthetase (Fcs) of P. putida was used to supply coumaroyl-CoA for the curcuminoid synthase (CUS) of Oryza sativa, a plant T3PKS. We identified that accumulation of coumaroyl-CoA in this pathway results in extended growth lag times in P. putida. Deletion of the second step in coumarate catabolism, the enoyl-CoA hydratase-lyase (Ech), resulted in increased production of the type III polyketide bisdemethoxycurcumin.
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Affiliation(s)
- Matthew R. Incha
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Mitchell G. Thompson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Jacquelyn M. Blake-Hedges
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Yuzhong Liu
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Allison N. Pearson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Matthias Schmidt
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jennifer W. Gin
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Christopher J. Petzold
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Adam M. Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jay D. Keasling
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
- Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institutes for Advanced Technologies, Shenzhen, China
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Hu M, Xiong B, Li Z, Liu L, Li S, Zhang C, Zhang X, Bi C. A novel gene expression system for Ralstonia eutropha based on the T7 promoter. BMC Microbiol 2020; 20:121. [PMID: 32429840 PMCID: PMC7236105 DOI: 10.1186/s12866-020-01812-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023] Open
Abstract
Background Ralstonia eutropha (syn. Cupriavidus necator) is a model microorganism for studying metabolism of polyhydroxyalkanoates (PHAs) and a potential chassis for protein expression due to various advantages. Although current plasmid systems of R. eutropha provide a basic platform for gene expression, the performance of the expression-inducing systems is still limited. In addition, the sizes of the cloned genes are limited due to the large sizes of the plasmid backbones. Results In this study, an R. eutropha T7 expression system was established by integrating a T7 RNA polymerase gene driven by the PBAD promoter into the genome of R. eutropha, as well as adding a T7 promoter into a pBBR1-derived plasmid for gene expression. In addition, the essential DNA sequence necessary for pBBR1 plasmid replication was identified, and the redundant parts were deleted reducing the expression plasmid size to 3392 bp, which improved the electroporation efficiency about 4 times. As a result, the highest expression level of RFP was enhanced, and the L-arabinose concentration for expression induction was decreased 20 times. Conclusions The R. eutropha T7 expression system provides an efficient platform for protein production and synthetic biology applications.
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Affiliation(s)
- Muzi Hu
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, People's Republic of China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Bin Xiong
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Zhongkang Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Li Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Siwei Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Chunzhi Zhang
- School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, People's Republic of China
| | - Xueli Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China
| | - Changhao Bi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
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Plasmid expression level heterogeneity monitoring via heterologous eGFP production at the single-cell level in Cupriavidus necator. Appl Microbiol Biotechnol 2020; 104:5899-5914. [PMID: 32358761 DOI: 10.1007/s00253-020-10616-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 10/24/2022]
Abstract
A methodology for plasmid expression level monitoring of eGFP expression suitable for dynamic processes was assessed during fermentation. This technique was based on the expression of a fluorescent biosensor (eGFP) encoded on a recombinant plasmid coupled to single-cell analysis. Fluorescence intensity at single-cell level was measured by flow cytometry. We demonstrated that promoter evaluation based on single-cell analysis versus classic global analysis brings valuable insights. Single-cell analysis pointed out the fact that intrinsic fluorescence increased with the strength of the promoter up to a threshold. Beyond that, cell permeability increases to excrete the fluorescent protein in the medium. The metabolic load due to the increase in the eGFP production in the case of strong constitutive promoters leads to slower growth kinetics compared with plasmid-free cells. With the strain Cupriavidus necator Re2133, growth rate losses were measured from 3% with the weak constitutive promoter Plac to 56% with the strong constitutive promoter Pj5. Through this work, it seems crucial to find a compromise between the fluorescence intensity in single cells and the metabolic load; in our conditions, the best compromise found was the weak promoter Plac. The plasmid expression level monitoring method was tested in the presence of a heterogeneous population induced by plasmid-curing methods. For all the identified subpopulations, the plasmid expression level heterogeneity was significantly detected at the level of fluorescence intensity in single cells. After cell sorting, growth rate and cultivability were assessed for each subpopulation. In conclusion, this eGFP biosensor makes it possible to follow the variations in the level of plasmid expression under conditions of population heterogeneity.Key Points•Development of a plasmid expression level monitoring method at the single-cell level by flow cytometry.•Promoter evaluation by single-cell analysis: cell heterogeneity and strain robustness.•Reporter system optimization for efficient subpopulation detection in pure cultures.
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Wiltschi B, Cernava T, Dennig A, Galindo Casas M, Geier M, Gruber S, Haberbauer M, Heidinger P, Herrero Acero E, Kratzer R, Luley-Goedl C, Müller CA, Pitzer J, Ribitsch D, Sauer M, Schmölzer K, Schnitzhofer W, Sensen CW, Soh J, Steiner K, Winkler CK, Winkler M, Wriessnegger T. Enzymes revolutionize the bioproduction of value-added compounds: From enzyme discovery to special applications. Biotechnol Adv 2020; 40:107520. [DOI: 10.1016/j.biotechadv.2020.107520] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 10/18/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022]
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Liow LT, Go MK, Chang MW, Yew WS. Toolkit Development for Cyanogenic and Gold Biorecovery Chassis Chromobacterium violaceum. ACS Synth Biol 2020; 9:953-961. [PMID: 32160465 DOI: 10.1021/acssynbio.0c00064] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Chromobacterium violaceum has been of interest recently due to its cyanogenic ability and its potential role in environmental sustainability via the biorecovery of gold from electronic waste. However, as with many nonmodel bacteria, there are limited genetic tools to implement the use of this Gram-negative chassis in synthetic biology. We propose a system that involves assaying spontaneous antibiotic resistances and using broad host range vectors to develop episomal vectors for nonmodel Gram-negative bacteria. These developed vectors can subsequently be used to characterize inducible promoters for gene expressions and implementing CRISPRi to inhibit endogenous gene expression for further studies. Here, we developed the first episomal genetic toolkit for C. violaceum consisting of two origins of replication, three antibiotic resistance genes, and four inducible promoter systems. We examined the occurrences of spontaneous resistances of the bacterium to the chosen selection markers to prevent incidences of false positives. We also tested broad host range vectors from four different incompatibility groups and characterized four inducible promoter systems, which potentially can be applied in other Gram-negative nonmodel bacteria. CRISPRi was also implemented to inhibit violacein pigment production in C. violaceum. This systematic toolkit will aid future genetic circuitry building in this chassis and other nonmodel bacteria for synthetic biology and biotechnological applications.
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Affiliation(s)
- Lu Ting Liow
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, 117597, Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation, Centre for Life Sciences, 28 Medical Drive, 117456, Singapore
| | - Maybelle Kho Go
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, 117597, Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation, Centre for Life Sciences, 28 Medical Drive, 117456, Singapore
| | - Matthew Wook Chang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, 117597, Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation, Centre for Life Sciences, 28 Medical Drive, 117456, Singapore
| | - Wen Shan Yew
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, 117597, Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation, Centre for Life Sciences, 28 Medical Drive, 117456, Singapore
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Chu N, Liang Q, Jiang Y, Zeng RJ. Microbial electrochemical platform for the production of renewable fuels and chemicals. Biosens Bioelectron 2020; 150:111922. [DOI: 10.1016/j.bios.2019.111922] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/23/2019] [Accepted: 11/25/2019] [Indexed: 12/01/2022]
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Thompson MG, Pearson AN, Barajas JF, Cruz-Morales P, Sedaghatian N, Costello Z, Garber ME, Incha MR, Valencia LE, Baidoo EEK, Martin HG, Mukhopadhyay A, Keasling JD. Identification, Characterization, and Application of a Highly Sensitive Lactam Biosensor from Pseudomonas putida. ACS Synth Biol 2020; 9:53-62. [PMID: 31841635 DOI: 10.1021/acssynbio.9b00292] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Caprolactam is an important polymer precursor to nylon traditionally derived from petroleum and produced on a scale of 5 million tons per year. Current biological pathways for the production of caprolactam are inefficient with titers not exceeding 2 mg/L, necessitating novel pathways for its production. As development of novel metabolic routes often require thousands of designs and result in low product titers, a highly sensitive biosensor for the final product has the potential to rapidly speed up development times. Here we report a highly sensitive biosensor for valerolactam and caprolactam from Pseudomonas putida KT2440 which is >1000× more sensitive to an exogenous ligand than previously reported sensors. Manipulating the expression of the sensor oplR (PP_3516) substantially altered the sensing parameters, with various vectors showing Kd values ranging from 700 nM (79.1 μg/L) to 1.2 mM (135.6 mg/L). Our most sensitive construct was able to detect in vivo production of caprolactam above background at ∼6 μg/L. The high sensitivity and range of OplR is a powerful tool toward the development of novel routes to the biological synthesis of caprolactam.
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Affiliation(s)
- Mitchell G. Thompson
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Allison N. Pearson
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jesus F. Barajas
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Energy Agile BioFoundry, Emeryville, California 94608, United States
| | - Pablo Cruz-Morales
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Centro de Biotecnologia FEMSA, Instituto Tecnologico y de Estudios superiores de Monterrey, Monterrey, 64849, Mexico
| | - Nima Sedaghatian
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Zak Costello
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Energy Agile BioFoundry, Emeryville, California 94608, United States
| | - Megan E. Garber
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Comparative Biochemistry Graduate Group, University of California, Berkeley, California United States
| | - Matthew R. Incha
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Luis E. Valencia
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint Program in Bioengineering, University of California, Berkeley/San Francisco, California 94720, United States
| | - Edward E. K. Baidoo
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Hector Garcia Martin
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Energy Agile BioFoundry, Emeryville, California 94608, United States
- BCAM, Basque Center for Applied Mathematics, Bilbao, Spain
| | - Aindrila Mukhopadhyay
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Comparative Biochemistry Graduate Group, University of California, Berkeley, California United States
| | - Jay D. Keasling
- Joint BioEnergy Institute, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint Program in Bioengineering, University of California, Berkeley/San Francisco, California 94720, United States
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
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Tremblay PL, Xu M, Chen Y, Zhang T. Nonmetallic Abiotic-Biological Hybrid Photocatalyst for Visible Water Splitting and Carbon Dioxide Reduction. iScience 2019; 23:100784. [PMID: 31962238 PMCID: PMC6971392 DOI: 10.1016/j.isci.2019.100784] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/22/2019] [Accepted: 12/12/2019] [Indexed: 12/14/2022] Open
Abstract
Both artificial photosystems and natural photosynthesis have not reached their full potential for the sustainable conversion of solar energy into specific chemicals. A promising approach is hybrid photosynthesis combining efficient, non-toxic, and low-cost abiotic photocatalysts capable of water splitting with metabolically versatile non-photosynthetic microbes. Here, we report the development of a water-splitting enzymatic photocatalyst made of graphitic carbon nitride (g-C3N4) coupled with H2O2-degrading catalase and its utilization for hybrid photosynthesis with the non-photosynthetic bacterium Ralstonia eutropha for bioplastic production. The g-C3N4-catalase system has an excellent solar-to-hydrogen efficiency of 3.4% with a H2 evolution rate up to 55.72 μmol h−1 while evolving O2 stoichiometrically. The hybrid photosynthesis system built with the water-spitting g-C3N4-catalase photocatalyst doubles the production of the bioplastic polyhydroxybutyrate by R. eutropha from CO2 and increases it by 1.84-fold from fructose. These results illustrate how synergy between abiotic non-metallic photocatalyst, enzyme, and bacteria can augment solar-to-multicarbon chemical conversion. H2O2-degrading enzymes from R. eutropha enable visible-light water splitting by C3N4 C3N4 coupled with bovine catalase has a solar-to-hydrogen efficiency of 3.4% C3N4-catalase increases CO2 conversion into bioplastic under light by R. eutropha Heterotrophic bioplastic production by R. eutropha is also improved by C3N4-catalase
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Affiliation(s)
- Pier-Luc Tremblay
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, PR China; School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, PR China
| | - Mengying Xu
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, PR China; School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, PR China; School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, PR China
| | - Yiming Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China
| | - Tian Zhang
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, PR China; School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, PR China; School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, PR China.
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Thompson MG, Costello Z, Hummel NFC, Cruz-Morales P, Blake-Hedges JM, Krishna RN, Skyrud W, Pearson AN, Incha MR, Shih PM, Garcia-Martin H, Keasling JD. Robust Characterization of Two Distinct Glutarate Sensing Transcription Factors of Pseudomonas putida l-Lysine Metabolism. ACS Synth Biol 2019; 8:2385-2396. [PMID: 31518500 DOI: 10.1021/acssynbio.9b00255] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A significant bottleneck in synthetic biology involves screening large genetically encoded libraries for desirable phenotypes such as chemical production. However, transcription factor-based biosensors can be leveraged to screen thousands of genetic designs for optimal chemical production in engineered microbes. In this study we characterize two glutarate sensing transcription factors (CsiR and GcdR) from Pseudomonas putida. The genomic contexts of csiR homologues were analyzed, and their DNA binding sites were bioinformatically predicted. Both CsiR and GcdR were purified and shown to bind upstream of their coding sequencing in vitro. CsiR was shown to dissociate from DNA in vitro when exogenous glutarate was added, confirming that it acts as a genetic repressor. Both transcription factors and cognate promoters were then cloned into broad host range vectors to create two glutarate biosensors. Their respective sensing performance features were characterized, and more sensitive derivatives of the GcdR biosensor were created by manipulating the expression of the transcription factor. Sensor vectors were then reintroduced into P. putida and evaluated for their ability to respond to glutarate and various lysine metabolites. Additionally, we developed a novel mathematical approach to describe the usable range of detection for genetically encoded biosensors, which may be broadly useful in future efforts to better characterize biosensor performance.
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Affiliation(s)
- Mitchell G. Thompson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Zak Costello
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- DOE Agile BioFoundry, Emeryville, California 94608, United States
| | - Niklas F. C. Hummel
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Department of Plant Biology, University of California, Davis, Davis, California 95616, United States
| | - Pablo Cruz-Morales
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Centro de Biotecnologia FEMSA, Instituto Tecnologico y de Estudios Superiores de Monterrey, 64849 Monterrey, Mexico
| | - Jacquelyn M. Blake-Hedges
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Rohith N. Krishna
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Will Skyrud
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Allison N. Pearson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Matthew R. Incha
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Patrick M. Shih
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Department of Plant Biology, University of California, Davis, Davis, California 95616, United States
| | - Hector Garcia-Martin
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- DOE Agile BioFoundry, Emeryville, California 94608, United States
- BCAM, Basque Center for Applied Mathematics, 48009 Bilbao, Spain
| | - Jay D. Keasling
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Joint Program in Bioengineering, University of California, Berkeley, California 94720, United States
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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48
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Thompson MG, Valencia LE, Blake-Hedges JM, Cruz-Morales P, Velasquez AE, Pearson AN, Sermeno LN, Sharpless WA, Benites VT, Chen Y, Baidoo EEK, Petzold CJ, Deutschbauer AM, Keasling JD. Omics-driven identification and elimination of valerolactam catabolism in Pseudomonas putida KT2440 for increased product titer. Metab Eng Commun 2019; 9:e00098. [PMID: 31720214 PMCID: PMC6838509 DOI: 10.1016/j.mec.2019.e00098] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/13/2019] [Accepted: 08/08/2019] [Indexed: 12/25/2022] Open
Abstract
Pseudomonas putida is a promising bacterial chassis for metabolic engineering given its ability to metabolize a wide array of carbon sources, especially aromatic compounds derived from lignin. However, this omnivorous metabolism can also be a hindrance when it can naturally metabolize products produced from engineered pathways. Herein we show that P. putida is able to use valerolactam as a sole carbon source, as well as degrade caprolactam. Lactams represent important nylon precursors, and are produced in quantities exceeding one million tons per year (Zhang et al., 2017). To better understand this metabolism we use a combination of Random Barcode Transposon Sequencing (RB-TnSeq) and shotgun proteomics to identify the oplBA locus as the likely responsible amide hydrolase that initiates valerolactam catabolism. Deletion of the oplBA genes prevented P. putida from growing on valerolactam, prevented the degradation of valerolactam in rich media, and dramatically reduced caprolactam degradation under the same conditions. Deletion of oplBA, as well as pathways that compete for precursors L-lysine or 5-aminovalerate, increased the titer of valerolactam from undetectable after 48 h of production to ~90 mg/L. This work may serve as a template to rapidly eliminate undesirable metabolism in non-model hosts in future metabolic engineering efforts. P. putida utilizes valerolactam as a sole carbon source and degrades caprolactam. With RB-TnSeq and proteomics we identify the lactam hydrolytic enzyme OplBA. Deleting oplBA prevents P. putida from growing on valerolactam. We increased titers of valerolactam in P. putida from 0 mg/L to ~90 mg/L.
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Affiliation(s)
- Mitchell G Thompson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Luis E Valencia
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Joint Program in Bioengineering, University of California, Berkeley/San Francisco, CA, 94720, USA
| | - Jacquelyn M Blake-Hedges
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Pablo Cruz-Morales
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Centro de Biotecnologia FEMSA, Instituto Tecnologico y de Estudios Superiores de Monterrey, Mexico
| | - Alexandria E Velasquez
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Allison N Pearson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Lauren N Sermeno
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - William A Sharpless
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Veronica T Benites
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yan Chen
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Edward E K Baidoo
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Christopher J Petzold
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Adam M Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jay D Keasling
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Joint Program in Bioengineering, University of California, Berkeley/San Francisco, CA, 94720, USA.,Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.,The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark.,Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institutes for Advanced Technologies, Shenzhen, China
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Development of an autotrophic fermentation technique for the production of fatty acids using an engineered Ralstonia eutropha cell factory. J Ind Microbiol Biotechnol 2019; 46:783-790. [PMID: 30810844 DOI: 10.1007/s10295-019-02156-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/18/2019] [Indexed: 12/11/2022]
Abstract
Massive emission of CO2 into atmosphere from consumption of carbon deposit is causing climate change. Researchers have applied metabolic engineering and synthetic biology techniques for improving CO2 fixation efficiency in many species. One solution might be the utilization of autotrophic bacteria, which have great potential to be engineered into microbial cell factories for CO2 fixation and the production of chemicals, independent of fossil resources. In this work, several pathways of Ralstonia eutropha H16 were modulated by manipulation of heterologous and endogenous genes related to fatty acid synthesis. The resulting strain B2(pCT, pFP) was able to produce 124.48 mg/g (cell dry weight) free fatty acids with fructose as carbon source, a fourfold increase over the parent strain H16. To develop a truly autotrophic fermentation technique with H2, CO2 and O2 as substrates, we assembled a relatively safe, continuous, lab-scale gas fermentation system using micro-fermentation tanks, H2 supplied by a hydrogen generator, and keeping the H2 to O2 ratio at 7:1. The system was equipped with a H2 gas alarm, rid of heat sources and placed into a fume hood to further improve the safety. With this system, the best strain B2(pCT, pFP) produced 60.64 mg free fatty acids per g biomass within 48 h, growing in minimal medium supplemented with 9 × 103 mL/L/h hydrogen gas. Thus, an autotrophic fermentation technique to produce fatty acids was successfully established, which might inspire further research on autotrophic gas fermentation with a safe, lab-scale setup, and provides an alternative solution for environmental and energy problems.
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Lauterbach L, Lenz O. How to make the reducing power of H 2 available for in vivo biosyntheses and biotransformations. Curr Opin Chem Biol 2018; 49:91-96. [PMID: 30544016 DOI: 10.1016/j.cbpa.2018.11.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/15/2018] [Accepted: 11/27/2018] [Indexed: 12/22/2022]
Abstract
Solar-driven electrolysis enables sustainable production of molecular hydrogen (H2), which represents a cheap and carbon-free reductant. Knallgas bacteria like Ralstonia eutropha are able to split H2 to supply energy in form of ATP and NADH, which can be subsequently used to power reactions of interest. R. eutropha employs the Calvin-Benson-Bassham cycle for the fixation of CO2, which is considered as an abundant and non-competing raw material. In this article, we summarize state-of-the-art approaches for H2-driven biosyntheses using engineered R. eutropha. Furthermore, we describe strategies for synthetic H2-driven NADH recycling. Major challenges for technical application and future perspectives are discussed.
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Affiliation(s)
- Lars Lauterbach
- Technische Universität Berlin, Department of Chemistry, Straße des 17. Juni 135, 10623 Berlin, Germany.
| | - Oliver Lenz
- Technische Universität Berlin, Department of Chemistry, Straße des 17. Juni 135, 10623 Berlin, Germany
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