1
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Christi K, Hudson J, Egan S. Current approaches to genetic modification of marine bacteria and considerations for improved transformation efficiency. Microbiol Res 2024; 284:127729. [PMID: 38663232 DOI: 10.1016/j.micres.2024.127729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/25/2024] [Accepted: 04/15/2024] [Indexed: 05/26/2024]
Abstract
Marine bacteria play vital roles in symbiosis, biogeochemical cycles and produce novel bioactive compounds and enzymes of interest for the pharmaceutical, biofuel and biotechnology industries. At present, investigations into marine bacterial functions and their products are primarily based on phenotypic observations, -omic type approaches and heterologous gene expression. To advance our understanding of marine bacteria and harness their full potential for industry application, it is critical that we have the appropriate tools and resources to genetically manipulate them in situ. However, current genetic tools that are largely designed for model organisms such as E. coli, produce low transformation efficiencies or have no transfer ability in marine bacteria. To improve genetic manipulation applications for marine bacteria, we need to improve transformation methods such as conjugation and electroporation in addition to identifying more marine broad host range plasmids. In this review, we aim to outline the reported methods of transformation for marine bacteria and discuss the considerations for each approach in the context of improving efficiency. In addition, we further discuss marine plasmids and future research areas including CRISPR tools and their potential applications for marine bacteria.
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Affiliation(s)
- Katrina Christi
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, Faculty of Science, The University of New South Wales, Kensington, NSW, Australia
| | - Jennifer Hudson
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, Faculty of Science, The University of New South Wales, Kensington, NSW, Australia
| | - Suhelen Egan
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, Faculty of Science, The University of New South Wales, Kensington, NSW, Australia.
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2
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Kim G, Kim HJ, Kim K, Kim HJ, Yang J, Seo SW. Tunable translation-level CRISPR interference by dCas13 and engineered gRNA in bacteria. Nat Commun 2024; 15:5319. [PMID: 38909033 PMCID: PMC11193725 DOI: 10.1038/s41467-024-49642-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 06/13/2024] [Indexed: 06/24/2024] Open
Abstract
Although CRISPR-dCas13, the RNA-guided RNA-binding protein, was recently exploited as a translation-level gene expression modulator, it has still been difficult to precisely control the level due to the lack of detailed characterization. Here, we develop a synthetic tunable translation-level CRISPR interference (Tl-CRISPRi) system based on the engineered guide RNAs that enable precise and predictable down-regulation of mRNA translation. First, we optimize the Tl-CRISPRi system for specific and multiplexed repression of genes at the translation level. We also show that the Tl-CRISPRi system is more suitable for independently regulating each gene in a polycistronic operon than the transcription-level CRISPRi (Tx-CRISPRi) system. We further engineer the handle structure of guide RNA for tunable and predictable repression of various genes in Escherichia coli and Vibrio natriegens. This tunable Tl-CRISPRi system is applied to increase the production of 3-hydroxypropionic acid (3-HP) by 14.2-fold via redirecting the metabolic flux, indicating the usefulness of this system for the flux optimization in the microbial cell factories based on the RNA-targeting machinery.
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Affiliation(s)
- Giho Kim
- School of Chemical and Biological Engineering, Seoul National University, Seoul, Republic of Korea
| | - Ho Joon Kim
- School of Chemical and Biological Engineering, Seoul National University, Seoul, Republic of Korea
| | - Keonwoo Kim
- School of Chemical and Biological Engineering, Seoul National University, Seoul, Republic of Korea
| | - Hyeon Jin Kim
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, South Korea
| | - Jina Yang
- Department of Chemical Engineering, Jeju National University, Jeju-si, South Korea
| | - Sang Woo Seo
- School of Chemical and Biological Engineering, Seoul National University, Seoul, Republic of Korea.
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, South Korea.
- Institute of Chemical Processes, Seoul National University, Seoul, South Korea.
- Bio-MAX Institute, Seoul National University, Seoul, South Korea.
- Institute of Bio Engineering, Seoul National University, Seoul, South Korea.
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3
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Ha Y, Ma HR, Wu F, Weiss A, Duncker K, Xu HZ, Lu J, Golovsky M, Reker D, You L. Data-driven learning of structure augments quantitative prediction of biological responses. PLoS Comput Biol 2024; 20:e1012185. [PMID: 38829926 DOI: 10.1371/journal.pcbi.1012185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 05/20/2024] [Indexed: 06/05/2024] Open
Abstract
Multi-factor screenings are commonly used in diverse applications in medicine and bioengineering, including optimizing combination drug treatments and microbiome engineering. Despite the advances in high-throughput technologies, large-scale experiments typically remain prohibitively expensive. Here we introduce a machine learning platform, structure-augmented regression (SAR), that exploits the intrinsic structure of each biological system to learn a high-accuracy model with minimal data requirement. Under different environmental perturbations, each biological system exhibits a unique, structured phenotypic response. This structure can be learned based on limited data and once learned, can constrain subsequent quantitative predictions. We demonstrate that SAR requires significantly fewer data comparing to other existing machine-learning methods to achieve a high prediction accuracy, first on simulated data, then on experimental data of various systems and input dimensions. We then show how a learned structure can guide effective design of new experiments. Our approach has implications for predictive control of biological systems and an integration of machine learning prediction and experimental design.
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Affiliation(s)
- Yuanchi Ha
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- Center for Quantitative Biodesign, Duke University, Durham, North Carolina, United States of America
| | - Helena R Ma
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- Center for Quantitative Biodesign, Duke University, Durham, North Carolina, United States of America
| | - Feilun Wu
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Andrea Weiss
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Katherine Duncker
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- Center for Quantitative Biodesign, Duke University, Durham, North Carolina, United States of America
| | - Helen Z Xu
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Jia Lu
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- Center for Quantitative Biodesign, Duke University, Durham, North Carolina, United States of America
| | - Max Golovsky
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Daniel Reker
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- Center for Quantitative Biodesign, Duke University, Durham, North Carolina, United States of America
| | - Lingchong You
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- Center for Quantitative Biodesign, Duke University, Durham, North Carolina, United States of America
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, United States of America
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4
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Ma Y, Ye JW, Lin Y, Yi X, Wang X, Wang H, Huang R, Wu F, Wu Q, Liu X, Chen GQ. Flux optimization using multiple promoters in Halomonas bluephagenesis as a model chassis of the next generation industrial biotechnology. Metab Eng 2024; 81:249-261. [PMID: 38159902 DOI: 10.1016/j.ymben.2023.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 12/16/2023] [Accepted: 12/24/2023] [Indexed: 01/03/2024]
Abstract
Predictability and robustness are challenges for bioproduction because of the unstable intracellular synthetic activities. With the deeper understanding of the gene expression process, fine-tuning has become a meaningful tool for biosynthesis optimization. This study characterized several gene expression elements and constructed a multiple inducible system that responds to ten different small chemical inducers in halophile bacterium Halomonas bluephagenesis. Genome insertion of regulators was conducted for the purpose of gene cluster stabilization and regulatory plasmid simplification. Additionally, dynamic ranges of the multiple inducible systems were tuned by promoter sequence mutations to achieve diverse scopes for high-resolution gene expression control. The multiple inducible system was successfully employed to precisely control chromoprotein expression, lycopene and poly-3-hydroxybutyrate (PHB) biosynthesis, resulting in colorful bacterial pictures, optimized cell growth, lycopene and PHB accumulation. This study demonstrates a desirable approach for fine-tuning of rational and efficient gene expressions, displaying the significance for metabolic pathway optimization.
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Affiliation(s)
- Yueyuan Ma
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jian-Wen Ye
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yina Lin
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xueqing Yi
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xuan Wang
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Huan Wang
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ruiyan Huang
- Garrison Forest School, Owings Mills, MD, 21117, USA
| | - Fuqing Wu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qiong Wu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xu Liu
- PhaBuilder Biotech Co. Ltd., Beijing, 101309, China
| | - Guo-Qiang Chen
- School of Life Sciences, Tsinghua University, Beijing, 100084, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China; MOE Key Laboratory for Industrial Biocatalysts, Dept Chemical Engineering, Tsinghua University, Beijing, 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China.
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5
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Pfeifer BA, Beitelshees M, Hill A, Bassett J, Jones CH. Harnessing synthetic biology for advancing RNA therapeutics and vaccine design. NPJ Syst Biol Appl 2023; 9:60. [PMID: 38036580 PMCID: PMC10689799 DOI: 10.1038/s41540-023-00323-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 11/15/2023] [Indexed: 12/02/2023] Open
Abstract
Recent global events have drawn into focus the diversity of options for combatting disease across a spectrum of prophylactic and therapeutic approaches. The recent success of the mRNA-based COVID-19 vaccines has paved the way for RNA-based treatments to revolutionize the pharmaceutical industry. However, historical treatment options are continuously updated and reimagined in the context of novel technical developments, such as those facilitated through the application of synthetic biology. When it comes to the development of genetic forms of therapies and vaccines, synthetic biology offers diverse tools and approaches to influence the content, dosage, and breadth of treatment with the prospect of economic advantage provided in time and cost benefits. This can be achieved by utilizing the broad tools within this discipline to enhance the functionality and efficacy of pharmaceutical agent sequences. This review will describe how synthetic biology principles can augment RNA-based treatments through optimizing not only the vaccine antigen, therapeutic construct, therapeutic activity, and delivery vector. The enhancement of RNA vaccine technology through implementing synthetic biology has the potential to shape the next generation of vaccines and therapeutics.
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Affiliation(s)
- Blaine A Pfeifer
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | | | - Andrew Hill
- Pfizer, 66 Hudson Boulevard, New York, NY, 10001, USA
| | - Justin Bassett
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY, USA
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6
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Arboleda-García A, Alarcon-Ruiz I, Boada-Acosta L, Boada Y, Vignoni A, Jantus-Lewintre E. Advancements in synthetic biology-based bacterial cancer therapy: A modular design approach. Crit Rev Oncol Hematol 2023; 190:104088. [PMID: 37541537 DOI: 10.1016/j.critrevonc.2023.104088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/18/2023] [Accepted: 07/31/2023] [Indexed: 08/06/2023] Open
Abstract
Synthetic biology aims to program living bacteria cells with artificial genetic circuits for user-defined functions, transforming them into powerful tools with numerous applications in various fields, including oncology. Cancer treatments have serious side effects on patients due to the systemic action of the drugs involved. To address this, new systems that provide localized antitumoral action while minimizing damage to healthy tissues are required. Bacteria, often considered pathogenic agents, have been used as cancer treatments since the early 20th century. Advances in genetic engineering, synthetic biology, microbiology, and oncology have improved bacterial therapies, making them safer and more effective. Here we propose six modules for a successful synthetic biology-based bacterial cancer therapy, the modules include Payload, Release, Tumor-targeting, Biocontainment, Memory, and Genetic Circuit Stability Module. These will ensure antitumor activity, safety for the environment and patient, prevent bacterial colonization, maintain cell stability, and prevent loss or defunctionalization of the genetic circuit.
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Affiliation(s)
- Andrés Arboleda-García
- Systems Biology and Biosystems Control Lab, Instituto de Automática e Informática Industrial, Universitat Politècnica de València, Spain
| | - Ivan Alarcon-Ruiz
- Gene Regulation in Cardiovascular Remodeling and Inflammation Group, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain; Departamento de Biología Molecular, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Lissette Boada-Acosta
- Centro de Investigación Biomédica en Red Cáncer, CIBERONC, Madrid, Spain; TRIAL Mixed Unit, Centro de Investigación Príncipe Felipe-Fundación Investigación del Hospital General Universitario de Valencia, Valencia, Spain; Molecular Oncology Laboratory, Fundación Investigación del Hospital General Universitario de Valencia, Valencia, Spain
| | - Yadira Boada
- Systems Biology and Biosystems Control Lab, Instituto de Automática e Informática Industrial, Universitat Politècnica de València, Spain
| | - Alejandro Vignoni
- Systems Biology and Biosystems Control Lab, Instituto de Automática e Informática Industrial, Universitat Politècnica de València, Spain.
| | - Eloisa Jantus-Lewintre
- Centro de Investigación Biomédica en Red Cáncer, CIBERONC, Madrid, Spain; TRIAL Mixed Unit, Centro de Investigación Príncipe Felipe-Fundación Investigación del Hospital General Universitario de Valencia, Valencia, Spain; Molecular Oncology Laboratory, Fundación Investigación del Hospital General Universitario de Valencia, Valencia, Spain; Department of Biotechnology, Universitat Politècnica de València, Valencia, Spain
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7
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Wang Y, Demirer GS. Synthetic biology for plant genetic engineering and molecular farming. Trends Biotechnol 2023; 41:1182-1198. [PMID: 37012119 DOI: 10.1016/j.tibtech.2023.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/03/2023] [Accepted: 03/09/2023] [Indexed: 04/03/2023]
Abstract
Many efforts have been put into engineering plants to improve crop yields and stress tolerance and boost the bioproduction of valuable molecules. Yet, our capabilities are still limited due to the lack of well-characterized genetic building blocks and resources for precise manipulation and given the inherently challenging properties of plant tissues. Advancements in plant synthetic biology can overcome these bottlenecks and release the full potential of engineered plants. In this review, we first discuss the recently developed plant synthetic elements from single parts to advanced circuits, software, and hardware tools expediting the engineering cycle. Next, we survey the advancements in plant biotechnology enabled by these recent resources. We conclude the review with outstanding challenges and future directions of plant synthetic biology.
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Affiliation(s)
- Yunqing Wang
- Department of Bioengineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Gozde S Demirer
- Department of Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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8
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Pandey N, Davison SA, Krishnamurthy M, Trettel DS, Lo CC, Starkenburg S, Wozniak KL, Kern TL, Reardon SD, Unkefer CJ, Hennelly SP, Dale T. Precise Genomic Riboregulator Control of Metabolic Flux in Microbial Systems. ACS Synth Biol 2022; 11:3216-3227. [PMID: 36130255 PMCID: PMC9594778 DOI: 10.1021/acssynbio.1c00638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Engineered microbes can be used for producing value-added chemicals from renewable feedstocks, relieving the dependency on nonrenewable resources such as petroleum. These microbes often are composed of synthetic metabolic pathways; however, one major problem in establishing a synthetic pathway is the challenge of precisely controlling competing metabolic routes, some of which could be crucial for fitness and survival. While traditional gene deletion and/or coarse overexpression approaches do not provide precise regulation, cis-repressors (CRs) are RNA-based regulatory elements that can control the production levels of a particular protein in a tunable manner. Here, we describe a protocol for a generally applicable fluorescence-activated cell sorting technique used to isolate eight subpopulations of CRs from a semidegenerate library in Escherichia coli, followed by deep sequencing that permitted the identification of 15 individual CRs with a broad range of protein production profiles. Using these new CRs, we demonstrated a change in production levels of a fluorescent reporter by over two orders of magnitude and further showed that these CRs are easily ported from E. coli to Pseudomonas putida. We next used four CRs to tune the production of the enzyme PpsA, involved in pyruvate to phosphoenolpyruvate (PEP) conversion, to alter the pool of PEP that feeds into the shikimate pathway. In an engineered P. putida strain, where carbon flux in the shikimate pathway is diverted to the synthesis of the commodity chemical cis,cis-muconate, we found that tuning PpsA translation levels increased the overall titer of muconate. Therefore, CRs provide an approach to precisely tune protein levels in metabolic pathways and will be an important tool for other metabolic engineering efforts.
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Affiliation(s)
- Naresh Pandey
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Steffi A. Davison
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Malathy Krishnamurthy
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Daniel S. Trettel
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Chien-Chi Lo
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Shawn Starkenburg
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Katherine L. Wozniak
- Chemistry
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Theresa L. Kern
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Sean D. Reardon
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Clifford J. Unkefer
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Scott P. Hennelly
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Taraka Dale
- Bioscience
Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States,
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9
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Liu YX, Zhuo XZ, Li SY. The Transcription Activator AtxA from Bacillus Anthracis was Employed for Developing a Tight-Control, High-Level, Modulable, and Stationary-Phase Specific Transcription Activity in Escherichia Coli. Synth Biol (Oxf) 2022; 7:ysac014. [PMID: 36046151 PMCID: PMC9424709 DOI: 10.1093/synbio/ysac014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 06/16/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022] Open
Abstract
The strong transcriptional activity of the virulent gene pagA in Bacillus anthracis has been proven to be anthrax toxin activator (AtxA)-regulated. However, the obscure pagA transcription mechanism hinders practical applications of this strong promoter. In this study, a 509-bp DNA fragment [termed 509sequence, (−508)-(+1) relative to the P2 transcription start site] was cloned upstream of rbs-GFPuv as pTOL02B to elucidate the AtxA-regulated transcription. The 509sequence was dissected into the −10 sequence, −35 sequence, ATrich tract, SLI/SLII and upstream site. In conjunction with the heterologous co-expression of AtxA (under the control of the T7 promoter), the −10 sequence (TATACT) was sufficient for the AtxA-regulated transcription. Integration of pTOL02F + pTOLAtxA as pTOL03F showed that the AtxA-regulated transcription exhibited a strong specific fluorescence intensity/common analytical chemistry term (OD600) of 40 597 ± 446 and an induction/repression ratio of 122. An improved induction/repression ratio of 276 was achieved by cultivating Escherichia coli/pTOL03F in M9 minimal medium. The newly developed promoter system termed PAtxA consists of AtxA, the −10 sequence and Escherichia RNA polymerase. These three elements synergistically and cooperatively formed a previously undiscovered transcription system, which exhibited a tight-control, high-level, modulable and stationary-phase-specific transcription. The PAtxA was used for phaCAB expression for the stationary-phase polyhydroxybutyrate production, and the results showed that a PHB yield, content and titer of 0.20 ± 0.27 g/g-glucose, 68 ± 11% and 1.5 ± 0.4 g/l can be obtained. The positive inducible PAtxA, in contrast to negative inducible, should be a useful tool to diversify the gene information flow in synthetic biology.
Graphical Abstract
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Affiliation(s)
- Ying-Xing Liu
- Department of Chemical Engineering, National Chung Hsing University , Taichung 402, Taiwan
| | - Xiao-Zhen Zhuo
- Department of Chemical Engineering, National Chung Hsing University , Taichung 402, Taiwan
| | - Si-Yu Li
- Department of Chemical Engineering, National Chung Hsing University , Taichung 402, Taiwan
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University , Taichung 402, Taiwan
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Ma Y, Zheng X, Lin Y, Zhang L, Yuan Y, Wang H, Winterburn J, Wu F, Wu Q, Ye JW, Chen GQ. Engineering an oleic acid-induced system for Halomonas, E. coli and Pseudomonas. Metab Eng 2022; 72:325-336. [PMID: 35513297 DOI: 10.1016/j.ymben.2022.04.003] [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: 01/22/2022] [Revised: 03/11/2022] [Accepted: 04/20/2022] [Indexed: 11/17/2022]
Abstract
Ligand-induced system plays an important role for microbial engineering due to its tunable gene expression control over timings and levels. An oleic acid (OA)-induced system was recently constructed based on protein FadR, a transcriptional regulator involved in fatty acids metabolism, for metabolic control in Escherichia coli. In this study, we constructed a synthetic FadR-based OA-induced systems in Halomonas bluephagenesis by hybridizing the porin promoter core region and FadR-binding operator (fadO). The dynamic control range was optimized over 150-fold, and expression leakage was significantly reduced by tuning FadR expression and positioning fadO, forming a series of OA-induced systems with various expression strengths, respectively. Additionally, ligand orthogonality and cross-species portability were also studied and showed highly linear correlation among Halomonas spp., Escherichia coli and Pseudomonas spp. Finally, OA-induced systems with medium- and small-dynamic control ranges were employed to dynamically control the expression levels of morphology associated gene minCD, and monomer precursor 4-hydroxybutyrate-CoA (4HB-CoA) synthesis pathway for polyhydroxyalkanoates (PHA), respectively, in the presence of oleic acid as an inducer. As a result, over 10 g/L of poly-3-hydroxybutyrate (PHB) accumulated by elongated cell sizes, and 6 g/L of P(3HB-co-9.57 mol% 4HB) were obtained by controlling the dose and induction time of oleic acid only. This study provides a systematic approach for ligand-induced system engineering, and demonstrates an alternative genetic tool for dynamic control of industrial biotechnology.
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Affiliation(s)
- Yueyuan Ma
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xiangrui Zheng
- School of Life Sciences, Tsinghua University, Beijing, 100084, China; Department of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Yina Lin
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Lizhan Zhang
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yiping Yuan
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Huan Wang
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - James Winterburn
- Department of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Fuqing Wu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qiong Wu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jian-Wen Ye
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China; Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China; Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.
| | - Guo-Qiang Chen
- School of Life Sciences, Tsinghua University, Beijing, 100084, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China; MOE Key Laboratory for Industrial Biocatalysts, Dept Chemical Engineering, Tsinghua University, Beijing, 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing, China.
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11
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Nikel PI, Benedetti I, Wirth NT, de Lorenzo V, Calles B. Standardization of regulatory nodes for engineering heterologous gene expression: a feasibility study. Microb Biotechnol 2022; 15:2250-2265. [PMID: 35478326 PMCID: PMC9328736 DOI: 10.1111/1751-7915.14063] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 12/21/2022] Open
Abstract
The potential of LacI/Ptrc, XylS/Pm, AlkS/PalkB, CprK/PDB3 and ChnR/PchnB regulatory nodes, recruited from both Gram‐negative and Gram‐positive bacteria, as the source of parts for formatting expression cargoes following the Standard European Vector Architecture (SEVA) has been examined. The five expression devices, which cover most known regulatory configurations in bacteria were assembled within exactly the same plasmid backbone and bearing the different functional segments arrayed in an invariable DNA scaffold. Their performance was then analysed in an Escherichia coli strain of reference through the readout of a fluorescence reporter gene that contained strictly identical translation signal elements. This approach allowed us to describe and compare the cognate expression systems with quantitative detail. The constructs under scrutiny diverged considerably in their capacity, expression noise, inducibility and ON/OFF ratios. Inspection of such a variance exposed the different constraints that rule the optimal arrangement of functional DNA segments in each case. The data highlighted also the ease of standardizing inducer‐responsive devices subject to transcriptional activation as compared to counterparts based on repressors. The study resulted in a defined collection of formatted expression cargoes lacking any cross talk while offering a panoply of choices to potential users and help interoperability of the specific constructs.
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Affiliation(s)
- Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs Lyngby, 2800, Denmark
| | - Ilaria Benedetti
- Systems and Synthetic Biology Program, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, 28049, Spain
| | - Nicolas T Wirth
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs Lyngby, 2800, Denmark
| | - Víctor de Lorenzo
- Systems and Synthetic Biology Program, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, 28049, Spain
| | - Belén Calles
- Systems and Synthetic Biology Program, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, 28049, Spain
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12
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Fordjour E, Mensah EO, Hao Y, Yang Y, Liu X, Li Y, Liu CL, Bai Z. Toward improved terpenoids biosynthesis: strategies to enhance the capabilities of cell factories. BIORESOUR BIOPROCESS 2022; 9:6. [PMID: 38647812 PMCID: PMC10992668 DOI: 10.1186/s40643-022-00493-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 01/04/2022] [Indexed: 02/22/2023] Open
Abstract
Terpenoids form the most diversified class of natural products, which have gained application in the pharmaceutical, food, transportation, and fine and bulk chemical industries. Extraction from naturally occurring sources does not meet industrial demands, whereas chemical synthesis is often associated with poor enantio-selectivity, harsh working conditions, and environmental pollutions. Microbial cell factories come as a suitable replacement. However, designing efficient microbial platforms for isoprenoid synthesis is often a challenging task. This has to do with the cytotoxic effects of pathway intermediates and some end products, instability of expressed pathways, as well as high enzyme promiscuity. Also, the low enzymatic activity of some terpene synthases and prenyltransferases, and the lack of an efficient throughput system to screen improved high-performing strains are bottlenecks in strain development. Metabolic engineering and synthetic biology seek to overcome these issues through the provision of effective synthetic tools. This review sought to provide an in-depth description of novel strategies for improving cell factory performance. We focused on improving transcriptional and translational efficiencies through static and dynamic regulatory elements, enzyme engineering and high-throughput screening strategies, cellular function enhancement through chromosomal integration, metabolite tolerance, and modularization of pathways.
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Affiliation(s)
- Eric Fordjour
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Emmanuel Osei Mensah
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Yunpeng Hao
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Yankun Yang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Xiuxia Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Ye Li
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China
| | - Chun-Li Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China.
| | - Zhonghu Bai
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
- Jiangsu Provincial Research Centre for Bioactive Product Processing Technology, Jiangnan University, Wuxi, China.
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13
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Yadavalli SS, Yuan J. Bacterial Small Membrane Proteins: the Swiss Army Knife of Regulators at the Lipid Bilayer. J Bacteriol 2022; 204:e0034421. [PMID: 34516282 PMCID: PMC8765417 DOI: 10.1128/jb.00344-21] [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] [Indexed: 11/20/2022] Open
Abstract
Small membrane proteins represent a subset of recently discovered small proteins (≤100 amino acids), which are a ubiquitous class of emerging regulators underlying bacterial adaptation to environmental stressors. Until relatively recently, small open reading frames encoding these proteins were not designated genes in genome annotations. Therefore, our understanding of small protein biology was primarily limited to a few candidates associated with previously characterized larger partner proteins. Following the first systematic analyses of small proteins in Escherichia coli over a decade ago, numerous small proteins across different bacteria have been uncovered. An estimated one-third of these newly discovered proteins in E. coli are localized to the cell membrane, where they may interact with distinct groups of membrane proteins, such as signal receptors, transporters, and enzymes, and affect their activities. Recently, there has been considerable progress in functionally characterizing small membrane protein regulators aided by innovative tools adapted specifically to study small proteins. Our review covers prototypical proteins that modulate a broad range of cellular processes, such as transport, signal transduction, stress response, respiration, cell division, sporulation, and membrane stability. Thus, small membrane proteins represent a versatile group of physiology regulators at the membrane and the whole cell. Additionally, small membrane proteins have the potential for clinical applications, where some of the proteins may act as antibacterial agents themselves while others serve as alternative drug targets for the development of novel antimicrobials.
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Affiliation(s)
- Srujana S. Yadavalli
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
- Department of Genetics, Rutgers University, Piscataway, New Jersey, USA
| | - Jing Yuan
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
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14
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Moore JC, Ramos I, Van Dien S. OUP accepted manuscript. J Ind Microbiol Biotechnol 2022; 49:6520437. [PMID: 35108392 PMCID: PMC9118995 DOI: 10.1093/jimb/kuab088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/20/2021] [Indexed: 11/13/2022]
Abstract
Optimization of metabolism to maximize production of bio-based chemicals must consistently balance cellular resources for biocatalyst growth and desired compound synthesis. This mini-review discusses synthetic biology strategies for dynamically controlling expression of genes to enable dual-phase fermentations in which growth and production are separated into dedicated phases. Emphasis is placed on practical examples which can be reliably scaled to commercial production with the current state of technology. Recent case studies are presented, and recommendations are provided for environmental signals and genetic control circuits.
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Affiliation(s)
| | - Itzel Ramos
- BP Biosciences Center, San Diego, CA 92121, USA
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15
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Shallom D, Naiger D, Weiss S, Tuller T. Accelerating Whole-Cell Simulations of mRNA Translation Using a Dedicated Hardware. ACS Synth Biol 2021; 10:3489-3506. [PMID: 34813269 PMCID: PMC8689694 DOI: 10.1021/acssynbio.1c00415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In recent years, intracellular biophysical simulations have been used with increasing frequency not only for answering basic scientific questions but also in the field of synthetic biology. However, since these models include networks of interaction between millions of components, they are extremely time-consuming and cannot run easily on parallel computers. In this study, we demonstrate for the first time a novel approach addressing this challenge by using a dedicated hardware designed specifically to simulate such processes. As a proof of concept, we specifically focus on mRNA translation, which is the process consuming most of the energy in the cell. We design a hardware that simulates translation in Escherichia coli and Saccharomyces cerevisiae for thousands of mRNAs and ribosomes, which is in orders of magnitude faster than a similar software solution. With the sharp increase in the amount of genomic data available today and the complexity of the corresponding models inferred from them, we believe that the strategy suggested here will become common and can be used among others for simulating entire cells with all gene expression steps.
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Affiliation(s)
- David Shallom
- School of Electrical Engineering, Tel Aviv University, Tel Aviv 69978, Israel
| | - Danny Naiger
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shlomo Weiss
- School of Electrical Engineering, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tamir Tuller
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 69978, Israel
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16
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Hogenkamp F, Hilgers F, Bitzenhofer NL, Ophoven V, Haase M, Bier C, Binder D, Jaeger KE, Drepper T, Pietruszka J. Optochemical Control of Bacterial Gene Expression: Novel Photocaged Compounds for Different Promoter Systems. Chembiochem 2021; 23:e202100467. [PMID: 34750949 PMCID: PMC9299732 DOI: 10.1002/cbic.202100467] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/02/2021] [Indexed: 12/05/2022]
Abstract
Photocaged compounds are applied for implementing precise, optochemical control of gene expression in bacteria. To broaden the scope of UV‐light‐responsive inducer molecules, six photocaged carbohydrates were synthesized and photochemically characterized, with the absorption exhibiting a red‐shift. Their differing linkage through ether, carbonate, and carbamate bonds revealed that carbonate and carbamate bonds are convenient. Subsequently, those compounds were successfully applied in vivo for controlling gene expression in E. coli via blue light illumination. Furthermore, benzoate‐based expression systems were subjected to light control by establishing a novel photocaged salicylic acid derivative. Besides its synthesis and in vitro characterization, we demonstrate the challenging choice of a suitable promoter system for light‐controlled gene expression in E. coli. We illustrate various bottlenecks during both photocaged inducer synthesis and in vivo application and possibilities to overcome them. These findings pave the way towards novel caged inducer‐dependent systems for wavelength‐selective gene expression.
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Affiliation(s)
- Fabian Hogenkamp
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf at Forschungszentrum Jülich Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC)
| | - Fabienne Hilgers
- Institute of Molecular Enzyme Technology Heinrich Heine University Düsseldorf at Forschungszentrum Jülich, Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC)
| | - Nora Lisa Bitzenhofer
- Institute of Molecular Enzyme Technology Heinrich Heine University Düsseldorf at Forschungszentrum Jülich, Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC)
| | - Vera Ophoven
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf at Forschungszentrum Jülich Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC)
| | - Mona Haase
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf at Forschungszentrum Jülich Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC)
| | - Claus Bier
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf at Forschungszentrum Jülich Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC)
| | - Dennis Binder
- Institute of Molecular Enzyme Technology Heinrich Heine University Düsseldorf at Forschungszentrum Jülich, Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC)
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology Heinrich Heine University Düsseldorf at Forschungszentrum Jülich, Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC).,Institute of Bio- and Geosciences (IBG-1: Biotechnology), Forschungszentrum Jülich GmbH, 52426, Jülich, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology Heinrich Heine University Düsseldorf at Forschungszentrum Jülich, Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC)
| | - Jörg Pietruszka
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf at Forschungszentrum Jülich Stetternicher Forst, 52426, Jülich, Germany.,Bioeconomy Science Center (BioSC).,Institute of Bio- and Geosciences (IBG-1: Biotechnology), Forschungszentrum Jülich GmbH, 52426, Jülich, Germany
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17
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Torres‐Bacete J, Luís García J, Nogales J. A portable library of phosphate-depletion based synthetic promoters for customable and automata control of gene expression in bacteria. Microb Biotechnol 2021; 14:2643-2658. [PMID: 33783967 PMCID: PMC8601176 DOI: 10.1111/1751-7915.13808] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/14/2021] [Indexed: 12/14/2022] Open
Abstract
Industrial biotechnology gene expression systems relay on constitutive promoters compromising cellular growth from the start of the bioprocess, or on inducible devices, which require manual addition of cognate inducers. To overcome this shortcoming, we engineered an automata regulatory system based on cell-stress mechanisms. Specifically, we engineered a synthetic and highly portable phosphate-depletion library of promoters inspired by bacterial PHO starvation system (Pliar promoters). Furthermore, we fully characterized 10 synthetic promoters within the background of two well-known bacterial workhorses such as E. coli W and P. putida KT2440. The promoters displayed an interesting host-dependent performance and a wide strength spectrum ranging from 0.4- to 1.3-fold when compared to the wild-type phosphatase alkaline promoter (PphoA). By comparing with available gene expression systems, we proved the suitability of this new library for the automata and effective decoupling of growth from production in P. putida. Growth phase-dependent expression of these promoters could therefore be activated by fine tuning the initial concentration of phosphate in the medium. Finally, the Pliar library was implemented in the SEVA platform in a ready-to-use mode allowing its broad use by the scientific community.
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Affiliation(s)
- Jesús Torres‐Bacete
- Department of Systems BiologyCentro Nacional de Biotecnología (CSIC)Madrid28049Spain
- Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy‐Spanish National Research Council (SusPlast‐CSIC)MadridSpain
| | - José Luís García
- Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy‐Spanish National Research Council (SusPlast‐CSIC)MadridSpain
- Department of Microbial and Plant BiotechnologyCentro de Investigaciones Biológicas (CIB)Centro Nacional de Biotecnología (CSIC)MadridSpain
| | - Juan Nogales
- Department of Systems BiologyCentro Nacional de Biotecnología (CSIC)Madrid28049Spain
- Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy‐Spanish National Research Council (SusPlast‐CSIC)MadridSpain
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18
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Tietze L, Lale R. Importance of the 5' regulatory region to bacterial synthetic biology applications. Microb Biotechnol 2021; 14:2291-2315. [PMID: 34171170 PMCID: PMC8601185 DOI: 10.1111/1751-7915.13868] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 01/02/2023] Open
Abstract
The field of synthetic biology is evolving at a fast pace. It is advancing beyond single-gene alterations in single hosts to the logical design of complex circuits and the development of integrated synthetic genomes. Recent breakthroughs in deep learning, which is increasingly used in de novo assembly of DNA components with predictable effects, are also aiding the discipline. Despite advances in computing, the field is still reliant on the availability of pre-characterized DNA parts, whether natural or synthetic, to regulate gene expression in bacteria and make valuable compounds. In this review, we discuss the different bacterial synthetic biology methodologies employed in the creation of 5' regulatory regions - promoters, untranslated regions and 5'-end of coding sequences. We summarize methodologies and discuss their significance for each of the functional DNA components, and highlight the key advances made in bacterial engineering by concentrating on their flaws and strengths. We end the review by outlining the issues that the discipline may face in the near future.
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Affiliation(s)
- Lisa Tietze
- PhotoSynLabDepartment of BiotechnologyFaculty of Natural SciencesNorwegian University of Science and TechnologyTrondheimN‐7491Norway
| | - Rahmi Lale
- PhotoSynLabDepartment of BiotechnologyFaculty of Natural SciencesNorwegian University of Science and TechnologyTrondheimN‐7491Norway
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19
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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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20
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Recent advances in tuning the expression and regulation of genes for constructing microbial cell factories. Biotechnol Adv 2021; 50:107767. [PMID: 33974979 DOI: 10.1016/j.biotechadv.2021.107767] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 12/14/2022]
Abstract
To overcome environmental problems caused by the use of fossil resources, microbial cell factories have become a promising technique for the sustainable and eco-friendly development of valuable products from renewable resources. Constructing microbial cell factories with high titers, yields, and productivity requires a balance between growth and production; to this end, tuning gene expression and regulation is necessary to optimise and precisely control complicated metabolic fluxes. In this article, we review the current trends and advances in tuning gene expression and regulation and consider their engineering at each of the three stages of gene regulation: genomic, mRNA, and protein. In particular, the technological approaches utilised in a diverse range of genetic-engineering-based tools for the construction of microbial cell factories are reviewed and representative applications of these strategies are presented. Finally, the prospects for strategies and systems for tuning gene expression and regulation are discussed.
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21
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Haskett TL, Tkacz A, Poole PS. Engineering rhizobacteria for sustainable agriculture. THE ISME JOURNAL 2021; 15:949-964. [PMID: 33230265 PMCID: PMC8114929 DOI: 10.1038/s41396-020-00835-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/29/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023]
Abstract
Exploitation of plant growth promoting (PGP) rhizobacteria (PGPR) as crop inoculants could propel sustainable intensification of agriculture to feed our rapidly growing population. However, field performance of PGPR is typically inconsistent due to suboptimal rhizosphere colonisation and persistence in foreign soils, promiscuous host-specificity, and in some cases, the existence of undesirable genetic regulation that has evolved to repress PGP traits. While the genetics underlying these problems remain largely unresolved, molecular mechanisms of PGP have been elucidated in rigorous detail. Engineering and subsequent transfer of PGP traits into selected efficacious rhizobacterial isolates or entire bacterial rhizosphere communities now offers a powerful strategy to generate improved PGPR that are tailored for agricultural use. Through harnessing of synthetic plant-to-bacteria signalling, attempts are currently underway to establish exclusive coupling of plant-bacteria interactions in the field, which will be crucial to optimise efficacy and establish biocontainment of engineered PGPR. This review explores the many ecological and biotechnical facets of this research.
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Affiliation(s)
- Timothy L. Haskett
- grid.4991.50000 0004 1936 8948Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB UK
| | - Andrzej Tkacz
- grid.4991.50000 0004 1936 8948Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB UK
| | - Philip S. Poole
- grid.4991.50000 0004 1936 8948Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB UK
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22
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Shahzadi I, Al-Ghamdi MA, Nadeem MS, Sajjad M, Ali A, Khan JA, Kazmi I. Scale-up fermentation of Escherichia coli for the production of recombinant endoglucanase from Clostridium thermocellum. Sci Rep 2021; 11:7145. [PMID: 33785771 PMCID: PMC8009960 DOI: 10.1038/s41598-021-86000-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 03/01/2021] [Indexed: 02/01/2023] Open
Abstract
Endoglucanase (EC 3.2.1.4) catalysing the hydrolysis of β-1.4-glycosidic linkage of cellulose molecules is an enzyme of tremendous industrial importance. The present study describes a response surface methodology based predicted model to deduce a set of fermentation conditions for optimum growth and activity of recombinant endoglucanase in E. coli BL21 (DE3). Numerous significant parameters including fermentation media composition, temperature (Celsius), pH and agitation rate (rpm) were analysed systemically by employing central composite design. This effort reports highly efficient recombinant endoglucanase overproduction (6.9 gl-1 of biomass) with 30% expression by E. coli in modified M9NG media incubated at 37 °C and pH 7 agitated at 200 rpm. Addition of 3 mM glucose and 24 mM glycerol in the M9NG media has shown positive effect on the enzyme yield and activity. The CMCase activity experimentally estimated was found to be 1185 U/mg with the optimized parameters. The outcomes of both the responses by the predicted quadratic model were found in consensus with the obtained values. Our results well depicted the favourable conditions to further scale-up the volumetric yield of other relevant recombinant enzymes and proteins.
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Affiliation(s)
- Iram Shahzadi
- grid.440564.70000 0001 0415 4232Institute of Molecular Biology and Biotechnology, University of Lahore, Defence Road Campus, Lahore, 54590 Pakistan
| | - Maryam A. Al-Ghamdi
- grid.412125.10000 0001 0619 1117Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, 21589 Saudi Arabia
| | - Muhammad Shahid Nadeem
- grid.412125.10000 0001 0619 1117Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, 21589 Saudi Arabia
| | - Muhammad Sajjad
- grid.440564.70000 0001 0415 4232Institute of Molecular Biology and Biotechnology, University of Lahore, Defence Road Campus, Lahore, 54590 Pakistan ,grid.11173.350000 0001 0670 519XSchool of Biological Sciences, University of the Punjab, Lahore, 54590 Pakistan
| | - Asif Ali
- grid.440564.70000 0001 0415 4232Institute of Molecular Biology and Biotechnology, University of Lahore, Defence Road Campus, Lahore, 54590 Pakistan
| | - Jalaluddin Azam Khan
- grid.412125.10000 0001 0619 1117Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, 21589 Saudi Arabia
| | - Imran Kazmi
- grid.412125.10000 0001 0619 1117Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, 21589 Saudi Arabia
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23
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Santala S, Santala V, Liu N, Stephanopoulos G. Partitioning metabolism between growth and product synthesis for coordinated production of wax esters in Acinetobacter baylyi ADP1. Biotechnol Bioeng 2021; 118:2283-2292. [PMID: 33666232 DOI: 10.1002/bit.27740] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/17/2021] [Accepted: 02/27/2021] [Indexed: 11/11/2022]
Abstract
Microbial storage compounds, such as wax esters (WE), are potential high-value lipids for the production of specialty chemicals and medicines. Their synthesis, however, is strictly regulated and competes with cell growth, which leads to trade-offs between biomass and product formation. Here, we use metabolic engineering and synergistic substrate cofeeding to partition the metabolism of Acinetobacter baylyi ADP1 into two distinct modules, each dedicated to cell growth and WE biosynthesis, respectively. We first blocked the glyoxylate shunt and upregulated the WE synthesis pathway to direct the acetate substrate exclusively for WE synthesis, then we controlled the supply of gluconate so it could be used exclusively for cell growth and maintenance. We show that the two modules are functionally independent from each other, allowing efficient lipid accumulation while maintaining active cell growth. Our strategy resulted in 7.2- and 4.2-fold improvements in WE content and productivity, respectively, and the product titer was enhanced by 8.3-fold over the wild type strain. Notably, during a 24-h cultivation, a yield of 18% C-WE/C-total-substrates was achieved, being the highest reported for WE biosynthesis. This study provides a simple, yet powerful, means of controlling cellular operations and overcoming some of the fundamental challenges in microbial storage lipid production.
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Affiliation(s)
- Suvi Santala
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
| | - Ville Santala
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
| | - Nian Liu
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Gregory Stephanopoulos
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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24
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Food synthetic biology-driven protein supply transition: From animal-derived production to microbial fermentation. Chin J Chem Eng 2021. [DOI: 10.1016/j.cjche.2020.11.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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25
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Kastenhofer J, Rajamanickam V, Libiseller-Egger J, Spadiut O. Monitoring and control of E. coli cell integrity. J Biotechnol 2021; 329:1-12. [PMID: 33485861 DOI: 10.1016/j.jbiotec.2021.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 12/15/2022]
Abstract
Soluble expression of recombinant proteins in E. coli is often done by translocation of the product across the inner membrane (IM) into the periplasm, where it is retained by the outer membrane (OM). While the integrity of the IM is strongly coupled to viability and impurity release, a decrease in OM integrity (corresponding to increased "leakiness") leads to accumulation of product in the extracellular space, strongly impacting the downstream process. Whether leakiness is desired or not, differential monitoring and control of IM and OM integrity are necessary for an efficient E. coli bioprocess in compliance with the guidelines of Quality by Design and Process Analytical Technology. In this review, we give an overview of relevant monitoring tools, summarize the research on factors affecting E. coli membrane integrity and provide a brief discussion on how the available monitoring technology can be implemented in real-time control of E. coli cultivations.
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Affiliation(s)
- Jens Kastenhofer
- TU Wien, Institute of Chemical, Environmental and Bioscience Engineering, Research Division Biochemical Engineering, Research Group Integrated Bioprocess Development, Gumpendorfer Strasse 1a, 1060, Vienna, Austria
| | - Vignesh Rajamanickam
- TU Wien, Institute of Chemical, Environmental and Bioscience Engineering, Research Division Biochemical Engineering, Research Group Integrated Bioprocess Development, Gumpendorfer Strasse 1a, 1060, Vienna, Austria
| | - Julian Libiseller-Egger
- TU Wien, Institute of Chemical, Environmental and Bioscience Engineering, Research Division Biochemical Engineering, Research Group Integrated Bioprocess Development, Gumpendorfer Strasse 1a, 1060, Vienna, Austria
| | - Oliver Spadiut
- TU Wien, Institute of Chemical, Environmental and Bioscience Engineering, Research Division Biochemical Engineering, Research Group Integrated Bioprocess Development, Gumpendorfer Strasse 1a, 1060, Vienna, Austria.
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Wan X, Pinto F, Yu L, Wang B. Synthetic protein-binding DNA sponge as a tool to tune gene expression and mitigate protein toxicity. Nat Commun 2020; 11:5961. [PMID: 33235249 PMCID: PMC7686491 DOI: 10.1038/s41467-020-19552-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 10/20/2020] [Indexed: 12/17/2022] Open
Abstract
Versatile tools for gene expression regulation are vital for engineering gene networks of increasing scales and complexity with bespoke responses. Here, we investigate and repurpose a ubiquitous, indirect gene regulation mechanism from nature, which uses decoy protein-binding DNA sites, named DNA sponge, to modulate target gene expression in Escherichia coli. We show that synthetic DNA sponges can be designed to reshape the response profiles of gene circuits, lending multifaceted tuning capacities including reducing basal leakage by >20-fold, increasing system output amplitude by >130-fold and dynamic range by >70-fold, and mitigating host growth inhibition by >20%. Further, multi-layer DNA sponges for decoying multiple regulatory proteins provide an additive tuning effect on the responses of layered circuits compared to single-layer sponges. Our work shows synthetic DNA sponges offer a simple yet generalizable route to systematically engineer the performance of synthetic gene circuits, expanding the current toolkit for gene regulation with broad potential applications. Decoy binding sites are natural regulators of gene expression. Here the authors design synthetic DNA sponges that fine tune the performance of synthetic gene circuits in a simple yet systematic manner, expanding the synthetic biology toolkit for gene regulation.
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Affiliation(s)
- Xinyi Wan
- School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FF, UK.,Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Filipe Pinto
- School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FF, UK.,Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - Luyang Yu
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.,Joint Research Centre for Engineering Biology, Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, 314400, China
| | - Baojun Wang
- School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FF, UK. .,Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3FF, UK. .,College of Life Sciences, Zhejiang University, Hangzhou, 310058, China. .,Joint Research Centre for Engineering Biology, Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, 314400, China.
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Exploring the synthetic biology potential of bacteriophages for engineering non-model bacteria. Nat Commun 2020; 11:5294. [PMID: 33082347 PMCID: PMC7576135 DOI: 10.1038/s41467-020-19124-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 09/25/2020] [Indexed: 12/26/2022] Open
Abstract
Non-model bacteria like Pseudomonas putida, Lactococcus lactis and other species have unique and versatile metabolisms, offering unique opportunities for Synthetic Biology (SynBio). However, key genome editing and recombineering tools require optimization and large-scale multiplexing to unlock the full SynBio potential of these bacteria. In addition, the limited availability of a set of characterized, species-specific biological parts hampers the construction of reliable genetic circuitry. Mining of currently available, diverse bacteriophages could complete the SynBio toolbox, as they constitute an unexplored treasure trove for fully adapted metabolic modulators and orthogonally-functioning parts, driven by the longstanding co-evolution between phage and host. Non-model bacteria offer unique and versatile metabolisms for synthetic biology. In this Perspective, the authors explore the limited availability of well-characterised biological parts in these species and argue that bacteriophages represent a diverse trove of orthogonal parts.
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28
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Tanna T, Ramachanderan R, Platt RJ. Engineered bacteria to report gut function: technologies and implementation. Curr Opin Microbiol 2020; 59:24-33. [PMID: 32828048 DOI: 10.1016/j.mib.2020.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/22/2020] [Accepted: 07/26/2020] [Indexed: 12/15/2022]
Abstract
Advances in synthetic biology and microbiology have enabled the creation of engineered bacteria which can sense and report on intracellular and extracellular signals. When deployed in vivo these whole-cell bacterial biosensors can act as sentinels to monitor biomolecules of interest in human health and disease settings. This is particularly interesting in the context of the gut microbiota, which interacts extensively with the human host throughout time and transit of the gut and can be accessed from feces without requiring invasive collection. Leveraging rational engineering approaches for genetic circuits as well as an expanding catalog of disease-associated biomarkers, bacterial biosensors can act as non-invasive and easy-to-monitor reporters of the gut. Here, we summarize recent engineering approaches applied in vivo in animal models and then highlight promising technologies for designing the next generation of bacterial biosensors.
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Affiliation(s)
- Tanmay Tanna
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland; Department of Computer Science, ETH Zurich, Universitätstrasse 6, 8092 Zürich, Switzerland
| | - Raghavendra Ramachanderan
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Randall J Platt
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland; Department of Chemistry, University of Basel, Petersplatz 1, 4003 Basel, Switzerland; Botnar Research Centre for Child Health, Basel, Switzerland.
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29
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Volke DC, Friis L, Wirth NT, Turlin J, Nikel PI. Synthetic control of plasmid replication enables target- and self-curing of vectors and expedites genome engineering of Pseudomonas putida. Metab Eng Commun 2020; 10:e00126. [PMID: 32215253 PMCID: PMC7090339 DOI: 10.1016/j.mec.2020.e00126] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/23/2020] [Accepted: 02/29/2020] [Indexed: 02/07/2023] Open
Abstract
Genome engineering of non-conventional microorganisms calls for the development of dedicated synthetic biology tools. Pseudomonas putida is a Gram-negative, non-pathogenic soil bacterium widely used for metabolic engineering owing to its versatile metabolism and high levels of tolerance to different types of stress. Genome editing of P. putida largely relies on homologous recombination events, assisted by helper plasmid-based expression of genes encoding DNA modifying enzymes. Plasmid curing from selected isolates is the most tedious and time-consuming step of this procedure, and implementing commonly used methods to this end in P. putida (e.g. temperature-sensitive replicons) is often impractical. To tackle this issue, we have developed a toolbox for both target- and self-curing of plasmid DNA in Pseudomonas species. Our method enables plasmid-curing in a simple cultivation step by combining in vivo digestion of vectors by the I-SceI homing nuclease with synthetic control of plasmid replication, triggered by the addition of a cheap chemical inducer (3-methylbenzoate) to the medium. The system displays an efficiency of vector curing >90% and the screening of plasmid-free clones is greatly facilitated by the use of fluorescent markers that can be selected according to the application intended. Furthermore, quick genome engineering of P. putida using self-curing plasmids is demonstrated through genome reduction of the platform strain EM42 by eliminating all genes encoding β-lactamases, the catabolic ben gene cluster, and the pyoverdine synthesis machinery. Physiological characterization of the resulting streamlined strain, P. putida SEM10, revealed advantageous features that could be exploited for metabolic engineering. Plasmid-curing is the most time-consuming step in genome engineering approaches. We have developed a system for easy target- and self-curing of plasmid DNA. Synthetic control of replication and highly-specific in vivo DNA digestion were used. Plasmid curing with this system displays an efficiency >90% in a 24-h cultivation. Quick genome engineering facilitated genome reduction of P. putida.
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Affiliation(s)
- Daniel C Volke
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Laura Friis
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Nicolas T Wirth
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Justine Turlin
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kgs Lyngby, Denmark
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Batianis C, Kozaeva E, Damalas SG, Martín‐Pascual M, Volke DC, Nikel PI, Martins dos Santos VA. An expanded CRISPRi toolbox for tunable control of gene expression in Pseudomonas putida. Microb Biotechnol 2020; 13:368-385. [PMID: 32045111 PMCID: PMC7017828 DOI: 10.1111/1751-7915.13533] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/20/2019] [Accepted: 12/26/2019] [Indexed: 01/15/2023] Open
Abstract
Owing to its wide metabolic versatility and physiological robustness, together with amenability to genetic manipulations and high resistance to stressful conditions, Pseudomonas putida is increasingly becoming the organism of choice for a range of applications in both industrial and environmental applications. However, a range of applied synthetic biology and metabolic engineering approaches are still limited by the lack of specific genetic tools to effectively and efficiently regulate the expression of target genes. Here, we present a single-plasmid CRISPR-interference (CRISPRi) system expressing a nuclease-deficient cas9 gene under the control of the inducible XylS/Pm expression system, along with the option of adopting constitutively expressed guide RNAs (either sgRNA or crRNA and tracrRNA). We showed that the system enables tunable, tightly controlled gene repression (up to 90%) of chromosomally expressed genes encoding fluorescent proteins, either individually or simultaneously. In addition, we demonstrate that this method allows for suppressing the expression of the essential genes pyrF and ftsZ, resulting in significantly low growth rates or morphological changes respectively. This versatile system expands the capabilities of the current CRISPRi toolbox for efficient, targeted and controllable manipulation of gene expression in P. putida.
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Affiliation(s)
- Christos Batianis
- Laboratory of Systems and Synthetic BiologyWageningen & Research University6708WageningenThe Netherlands
| | - Ekaterina Kozaeva
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of Denmark2800Kgs. LyngbyDenmark
| | - Stamatios G. Damalas
- Laboratory of Systems and Synthetic BiologyWageningen & Research University6708WageningenThe Netherlands
| | - María Martín‐Pascual
- Laboratory of Systems and Synthetic BiologyWageningen & Research University6708WageningenThe Netherlands
| | - Daniel C. Volke
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of Denmark2800Kgs. LyngbyDenmark
| | - Pablo I. Nikel
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of Denmark2800Kgs. LyngbyDenmark
| | - Vitor A.P. Martins dos Santos
- Laboratory of Systems and Synthetic BiologyWageningen & Research University6708WageningenThe Netherlands
- Lifeglimmer GmbH12163BerlinGermany
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