1
|
Vercauteren S, Fiesack S, Maroc L, Verstraeten N, Dewachter L, Michiels J, Vonesch SC. The rise and future of CRISPR-based approaches for high-throughput genomics. FEMS Microbiol Rev 2024; 48:fuae020. [PMID: 39085047 PMCID: PMC11409895 DOI: 10.1093/femsre/fuae020] [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: 05/08/2024] [Revised: 07/19/2024] [Accepted: 07/30/2024] [Indexed: 08/02/2024] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) has revolutionized the field of genome editing. To circumvent the permanent modifications made by traditional CRISPR techniques and facilitate the study of both essential and nonessential genes, CRISPR interference (CRISPRi) was developed. This gene-silencing technique employs a deactivated Cas effector protein and a guide RNA to block transcription initiation or elongation. Continuous improvements and a better understanding of the mechanism of CRISPRi have expanded its scope, facilitating genome-wide high-throughput screens to investigate the genetic basis of phenotypes. Additionally, emerging CRISPR-based alternatives have further expanded the possibilities for genetic screening. This review delves into the mechanism of CRISPRi, compares it with other high-throughput gene-perturbation techniques, and highlights its superior capacities for studying complex microbial traits. We also explore the evolution of CRISPRi, emphasizing enhancements that have increased its capabilities, including multiplexing, inducibility, titratability, predictable knockdown efficacy, and adaptability to nonmodel microorganisms. Beyond CRISPRi, we discuss CRISPR activation, RNA-targeting CRISPR systems, and single-nucleotide resolution perturbation techniques for their potential in genome-wide high-throughput screens in microorganisms. Collectively, this review gives a comprehensive overview of the general workflow of a genome-wide CRISPRi screen, with an extensive discussion of strengths and weaknesses, future directions, and potential alternatives.
Collapse
Affiliation(s)
- Silke Vercauteren
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Simon Fiesack
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Laetitia Maroc
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Natalie Verstraeten
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Liselot Dewachter
- de Duve Institute, Université catholique de Louvain, Hippokrateslaan 75, 1200 Brussels, Belgium
| | - Jan Michiels
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Sibylle C Vonesch
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| |
Collapse
|
2
|
Burbano DA, Kiattisewee C, Karanjia AV, Cardiff RAL, Faulkner ID, Sugianto W, Carothers JM. CRISPR Tools for Engineering Prokaryotic Systems: Recent Advances and New Applications. Annu Rev Chem Biomol Eng 2024; 15:389-430. [PMID: 38598861 DOI: 10.1146/annurev-chembioeng-100522-114706] [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] [Indexed: 04/12/2024]
Abstract
In the past decades, the broad selection of CRISPR-Cas systems has revolutionized biotechnology by enabling multimodal genetic manipulation in diverse organisms. Rooted in a molecular engineering perspective, we recapitulate the different CRISPR components and how they can be designed for specific genetic engineering applications. We first introduce the repertoire of Cas proteins and tethered effectors used to program new biological functions through gene editing and gene regulation. We review current guide RNA (gRNA) design strategies and computational tools and how CRISPR-based genetic circuits can be constructed through regulated gRNA expression. Then, we present recent advances in CRISPR-based biosensing, bioproduction, and biotherapeutics across in vitro and in vivo prokaryotic systems. Finally, we discuss forthcoming applications in prokaryotic CRISPR technology that will transform synthetic biology principles in the near future.
Collapse
Affiliation(s)
- Diego Alba Burbano
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Cholpisit Kiattisewee
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Ava V Karanjia
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Ryan A L Cardiff
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Ian D Faulkner
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Widianti Sugianto
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - James M Carothers
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| |
Collapse
|
3
|
Ragland CJ, Shih KY, Dinneny JR. Choreographing root architecture and rhizosphere interactions through synthetic biology. Nat Commun 2024; 15:1370. [PMID: 38355570 PMCID: PMC10866969 DOI: 10.1038/s41467-024-45272-5] [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: 07/17/2023] [Accepted: 01/18/2024] [Indexed: 02/16/2024] Open
Abstract
Climate change is driving extreme changes to the environment, posing substantial threats to global food security and bioenergy. Given the direct role of plant roots in mediating plant-environment interactions, engineering the form and function of root systems and their associated microbiota may mitigate these effects. Synthetic genetic circuits have enabled sophisticated control of gene expression in microbial systems for years and a surge of advances has heralded the extension of this approach to multicellular plant species. Targeting these tools to affect root structure, exudation, and microbe activity on root surfaces provide multiple strategies for the advancement of climate-ready crops.
Collapse
Affiliation(s)
- Carin J Ragland
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Kevin Y Shih
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - José R Dinneny
- Department of Biology, Stanford University, Stanford, CA, 94305, USA.
| |
Collapse
|
4
|
Volke DC, Orsi E, Nikel PI. Emergent CRISPR-Cas-based technologies for engineering non-model bacteria. Curr Opin Microbiol 2023; 75:102353. [PMID: 37413959 DOI: 10.1016/j.mib.2023.102353] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/08/2023]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated proteins (Cas) technologies brought a transformative change in the way bacterial genomes are edited, and a plethora of studies contributed to developing multiple tools based on these approaches. Prokaryotic biotechnology benefited from the implementation of such genome engineering strategies, with an increasing number of non-model bacterial species becoming genetically tractable. In this review, we summarize the recent trends in engineering non-model microbes using CRISPR-Cas technologies, discussing their potential in supporting cell factory design towards biotechnological applications. These efforts include, among other examples, genome modifications as well as tunable transcriptional regulation (both positive and negative). Moreover, we examine how CRISPR-Cas toolkits for engineering non-model organisms enabled the exploitation of emergent biotechnological processes (e.g. native and synthetic assimilation of one-carbon substrates). Finally, we discuss our slant on the future of bacterial genome engineering for domesticating non-model organisms in light of the most recent advances in the ever-expanding CRISPR-Cas field.
Collapse
Affiliation(s)
- Daniel C Volke
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Enrico Orsi
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
| |
Collapse
|
5
|
Bunyat-Zada AR, Ross AC. Highlights of bioinformatic tools and methods for validating bioinformatics derived hypotheses for microbial natural products research. Curr Opin Chem Biol 2023; 76:102367. [PMID: 37453164 DOI: 10.1016/j.cbpa.2023.102367] [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: 12/20/2022] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023]
Abstract
Historically, bacterial natural products have served as an excellent source of drug leads, however, in recent decades the rate of discovery has slowed due to multiple challenges. Rapid advances in genome sequencing science in recent years have revealed the vast untapped encoded potential of bacteria to make natural products. To access these molecules, researchers can employ the ever-growing array of bioinformatic tools at their disposal and leverage newly developed experimental approaches to validate these bioinformatic-driven hypotheses. When used together effectively, bioinformatic and experimental tools enable researchers to deeply examine the full diversity of bacterial natural products. This review briefly outlines recent bioinformatic tools that can facilitate natural product research in bacteria including the use of CRISPR, co-occurrence network analysis, and combinatorial generation of microbial natural products to test bioinformatic hypotheses in the lab.
Collapse
Affiliation(s)
- Amir R Bunyat-Zada
- Department of Chemistry, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Avena C Ross
- Department of Chemistry, Queen's University, Kingston, ON, K7L 3N6, Canada.
| |
Collapse
|
6
|
Winkler KR, Mizrahi V, Warner DF, De Wet TJ. High-throughput functional genomics: A (myco)bacterial perspective. Mol Microbiol 2023; 120:141-158. [PMID: 37278255 PMCID: PMC10953053 DOI: 10.1111/mmi.15103] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/06/2023] [Accepted: 05/21/2023] [Indexed: 06/07/2023]
Abstract
Advances in sequencing technologies have enabled unprecedented insights into bacterial genome composition and dynamics. However, the disconnect between the rapid acquisition of genomic data and the (much slower) confirmation of inferred genetic function threatens to widen unless techniques for fast, high-throughput functional validation can be applied at scale. This applies equally to Mycobacterium tuberculosis, the leading infectious cause of death globally and a pathogen whose genome, despite being among the first to be sequenced two decades ago, still contains many genes of unknown function. Here, we summarize the evolution of bacterial high-throughput functional genomics, focusing primarily on transposon (Tn)-based mutagenesis and the construction of arrayed mutant libraries in diverse bacterial systems. We also consider the contributions of CRISPR interference as a transformative technique for probing bacterial gene function at scale. Throughout, we situate our analysis within the context of functional genomics of mycobacteria, focusing specifically on the potential to yield insights into M. tuberculosis pathogenicity and vulnerabilities for new drug and regimen development. Finally, we offer suggestions for future approaches that might be usefully applied in elucidating the complex cellular biology of this major human pathogen.
Collapse
Affiliation(s)
- Kristy R. Winkler
- Molecular Mycobacteriology Research Unit and DSI/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownRondeboschSouth Africa
| | - Valerie Mizrahi
- Molecular Mycobacteriology Research Unit and DSI/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownRondeboschSouth Africa
- Wellcome Centre for Infectious Diseases Research in AfricaUniversity of Cape TownRondeboschSouth Africa
| | - Digby F. Warner
- Molecular Mycobacteriology Research Unit and DSI/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownRondeboschSouth Africa
- Wellcome Centre for Infectious Diseases Research in AfricaUniversity of Cape TownRondeboschSouth Africa
| | - Timothy J. De Wet
- Molecular Mycobacteriology Research Unit and DSI/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownRondeboschSouth Africa
- Wellcome Centre for Infectious Diseases Research in AfricaUniversity of Cape TownRondeboschSouth Africa
- Department of Integrative Biomedical SciencesUniversity of Cape TownRondeboschSouth Africa
| |
Collapse
|
7
|
Wang X, Zhou N, Wang B. Bacterial synthetic biology: tools for novel drug discovery. Expert Opin Drug Discov 2023; 18:1087-1097. [PMID: 37482696 DOI: 10.1080/17460441.2023.2239704] [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] [Received: 05/03/2023] [Accepted: 07/19/2023] [Indexed: 07/25/2023]
Abstract
INTRODUCTION Bacterial synthetic biology has provided powerful tools to revolutionize the drug discovery process. These tools can be harnessed to generate bacterial novel pharmaceutical compounds with enhanced bioactivity and selectivity or to create genetically modified microorganisms as living drugs. AREAS COVERED This review provides a current overview of the state-of-the-art in bacterial synthetic biology tools for novel drug discovery. The authors discuss the application of these tools including bioinformatic tools, CRISPR tools, engineered bacterial transcriptional regulators, and synthetic biosensors for novel drug discovery. Additionally, the authors present the recent progress on reprogramming bacteriophages as living drugs to fight against antibiotic-resistant pathogens. EXPERT OPINION The field of using bacterial synthetic biology tools for drug discovery is rapidly advancing. However, challenges remain in developing reliable and robust methods to engineer bacteria. Further advancements in synthetic biology hold promise to speed up drug discovery, facilitating the development of novel therapeutics against various diseases.
Collapse
Affiliation(s)
- Xiyan Wang
- College of Chemical and Biological Engineering & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Nan Zhou
- College of Chemical and Biological Engineering & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Baojun Wang
- College of Chemical and Biological Engineering & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
- Research Center of Biological Computation, Zhejiang Laboratory, Hangzhou, China
| |
Collapse
|
8
|
Kiattisewee C, Karanjia AV, Legut M, Daniloski Z, Koplik SE, Nelson J, Kleinstiver BP, Sanjana NE, Carothers JM, Zalatan JG. Expanding the Scope of Bacterial CRISPR Activation with PAM-Flexible dCas9 Variants. ACS Synth Biol 2022; 11:4103-4112. [PMID: 36378874 PMCID: PMC10516241 DOI: 10.1021/acssynbio.2c00405] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
CRISPR-Cas transcriptional tools have been widely applied for programmable regulation of complex biological networks. In comparison to eukaryotic systems, bacterial CRISPR activation (CRISPRa) has stringent target site requirements for effective gene activation. While genes may not always have an NGG protospacer adjacent motif (PAM) at the appropriate position, PAM-flexible dCas9 variants can expand the range of targetable sites. Here we systematically evaluate a panel of PAM-flexible dCas9 variants for their ability to activate bacterial genes. We observe that dxCas9-NG provides a high dynamic range of gene activation for sites with NGN PAMs while dSpRY permits modest activity across almost any PAM. Similar trends were observed for heterologous and endogenous promoters. For all variants tested, improved PAM-flexibility comes with the trade-off that CRISPRi-mediated gene repression becomes less effective. Weaker CRISPR interference (CRISPRi) gene repression can be partially rescued by expressing multiple sgRNAs to target many sites in the gene of interest. Our work provides a framework to choose the most effective dCas9 variant for a given set of gene targets, which will further expand the utility of CRISPRa/i gene regulation in bacterial systems.
Collapse
Affiliation(s)
- Cholpisit Kiattisewee
- Molecular Engineering & Sciences Institute and Center
for Synthetic Biology, University of Washington, Seattle, WA 98195, United
States
| | - Ava V. Karanjia
- Molecular Engineering & Sciences Institute and Center
for Synthetic Biology, University of Washington, Seattle, WA 98195, United
States
- Department of Chemical Engineering, University of
Washington, Seattle, WA 98195, United States
| | - Mateusz Legut
- New York Genome Center, New York, NY 10013, United
States
- Department of Biology, New York University, New York, NY
10013, United States
| | - Zharko Daniloski
- New York Genome Center, New York, NY 10013, United
States
- Department of Biology, New York University, New York, NY
10013, United States
| | - Samantha E. Koplik
- Department of Bioengineering, University of Washington,
Seattle, WA 98195, United States
| | - Joely Nelson
- Molecular Engineering & Sciences Institute and Center
for Synthetic Biology, University of Washington, Seattle, WA 98195, United
States
| | - Benjamin P. Kleinstiver
- Center for Genomic Medicine, Massachusetts General
Hospital, Boston, MA 02114, United States
- Department of Pathology, Massachusetts General Hospital,
Boston, MA 02114, United States
- Department of Pathology, Harvard Medical School, Boston,
MA 02115, United States
| | - Neville E. Sanjana
- New York Genome Center, New York, NY 10013, United
States
- Department of Biology, New York University, New York, NY
10013, United States
| | - James M. Carothers
- Molecular Engineering & Sciences Institute and Center
for Synthetic Biology, University of Washington, Seattle, WA 98195, United
States
- Department of Chemical Engineering, University of
Washington, Seattle, WA 98195, United States
- Department of Bioengineering, University of Washington,
Seattle, WA 98195, United States
| | - Jesse G. Zalatan
- Molecular Engineering & Sciences Institute and Center
for Synthetic Biology, University of Washington, Seattle, WA 98195, United
States
- Department of Chemical Engineering, University of
Washington, Seattle, WA 98195, United States
- Department of Chemistry, University of Washington,
Seattle, WA 98195, United States
| |
Collapse
|
9
|
Sridhar S, Ajo-Franklin CM, Masiello CA. A Framework for the Systematic Selection of Biosensor Chassis for Environmental Synthetic Biology. ACS Synth Biol 2022; 11:2909-2916. [PMID: 35961652 PMCID: PMC9486965 DOI: 10.1021/acssynbio.2c00079] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Indexed: 01/24/2023]
Abstract
Microbial biosensors sense and report exposures to stimuli, thereby facilitating our understanding of environmental processes. Successful design and deployment of biosensors hinge on the persistence of the microbial host of the genetic circuit, termed the chassis. However, model chassis organisms may persist poorly in environmental conditions. In contrast, non-model organisms persist better in environmental conditions but are limited by other challenges, such as genetic intractability and part unavailability. Here we identify ecological, metabolic, and genetic constraints for chassis development and propose a conceptual framework for the systematic selection of environmental biosensor chassis. We identify key challenges with using current model chassis and delineate major points of conflict in choosing the most suitable organisms as chassis for environmental biosensing. This framework provides a way forward in the selection of biosensor chassis for environmental synthetic biology.
Collapse
Affiliation(s)
- Swetha Sridhar
- Systems,
Synthetic, and Physical Biology Graduate Program, Rice University, 6100 Main Street, MS-180, Houston, Texas 77005, United
States
| | - Caroline M. Ajo-Franklin
- Department
of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
| | - Caroline A. Masiello
- Department
of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
- Department
of Earth, Environmental, and Planetary Sciences, Rice University, 6100 Main St, MS-126, Houston, Texas 77005, United
States
| |
Collapse
|
10
|
Dundas CM, Dinneny JR. Genetic Circuit Design in Rhizobacteria. BIODESIGN RESEARCH 2022; 2022:9858049. [PMID: 37850138 PMCID: PMC10521742 DOI: 10.34133/2022/9858049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/31/2022] [Indexed: 10/19/2023] Open
Abstract
Genetically engineered plants hold enormous promise for tackling global food security and agricultural sustainability challenges. However, construction of plant-based genetic circuitry is constrained by a lack of well-characterized genetic parts and circuit design rules. In contrast, advances in bacterial synthetic biology have yielded a wealth of sensors, actuators, and other tools that can be used to build bacterial circuitry. As root-colonizing bacteria (rhizobacteria) exert substantial influence over plant health and growth, genetic circuit design in these microorganisms can be used to indirectly engineer plants and accelerate the design-build-test-learn cycle. Here, we outline genetic parts and best practices for designing rhizobacterial circuits, with an emphasis on sensors, actuators, and chassis species that can be used to monitor/control rhizosphere and plant processes.
Collapse
Affiliation(s)
| | - José R. Dinneny
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
11
|
Call SN, Andrews LB. CRISPR-Based Approaches for Gene Regulation in Non-Model Bacteria. Front Genome Ed 2022; 4:892304. [PMID: 35813973 PMCID: PMC9260158 DOI: 10.3389/fgeed.2022.892304] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/11/2022] [Indexed: 01/08/2023] Open
Abstract
CRISPR interference (CRISPRi) and CRISPR activation (CRISPRa) have become ubiquitous approaches to control gene expression in bacteria due to their simple design and effectiveness. By regulating transcription of a target gene(s), CRISPRi/a can dynamically engineer cellular metabolism, implement transcriptional regulation circuitry, or elucidate genotype-phenotype relationships from smaller targeted libraries up to whole genome-wide libraries. While CRISPRi/a has been primarily established in the model bacteria Escherichia coli and Bacillus subtilis, a growing numbering of studies have demonstrated the extension of these tools to other species of bacteria (here broadly referred to as non-model bacteria). In this mini-review, we discuss the challenges that contribute to the slower creation of CRISPRi/a tools in diverse, non-model bacteria and summarize the current state of these approaches across bacterial phyla. We find that despite the potential difficulties in establishing novel CRISPRi/a in non-model microbes, over 190 recent examples across eight bacterial phyla have been reported in the literature. Most studies have focused on tool development or used these CRISPRi/a approaches to interrogate gene function, with fewer examples applying CRISPRi/a gene regulation for metabolic engineering or high-throughput screens and selections. To date, most CRISPRi/a reports have been developed for common strains of non-model bacterial species, suggesting barriers remain to establish these genetic tools in undomesticated bacteria. More efficient and generalizable methods will help realize the immense potential of programmable CRISPR-based transcriptional control in diverse bacteria.
Collapse
Affiliation(s)
- Stephanie N. Call
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, United States
| | - Lauren B. Andrews
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, United States
- Biotechnology Training Program, University of Massachusetts Amherst, Amherst, MA, United States
- Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, MA, United States
| |
Collapse
|
12
|
Sasaki Y, Yoshikuni Y. Metabolic engineering for valorization of macroalgae biomass. Metab Eng 2022; 71:42-61. [PMID: 35077903 DOI: 10.1016/j.ymben.2022.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 12/18/2022]
Abstract
Marine macroalgae have huge potential as feedstocks for production of a wide spectrum of chemicals used in biofuels, biomaterials, and bioactive compounds. Harnessing macroalgae in these ways could promote wellbeing for people while mitigating climate change and environmental destruction linked to use of fossil fuels. Microorganisms play pivotal roles in converting macroalgae into valuable products, and metabolic engineering technologies have been developed to extend their native capabilities. This review showcases current achievements in engineering the metabolisms of various microbial chassis to convert red, green, and brown macroalgae into bioproducts. Unique features of macroalgae, such as seasonal variation in carbohydrate content and salinity, provide the next challenges to advancing macroalgae-based biorefineries. Three emerging engineering strategies are discussed here: (1) designing dynamic control of metabolic pathways, (2) engineering strains of halophilic (salt-tolerant) microbes, and (3) developing microbial consortia for conversion. This review illuminates opportunities for future research communities by elucidating current approaches to engineering microbes so they can become cell factories for the utilization of macroalgae feedstocks.
Collapse
Affiliation(s)
- Yusuke Sasaki
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yasuo Yoshikuni
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Center for Advanced Bioenergy and Bioproducts Innovation, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Global Institution for Collaborative Research and Education, Hokkaido University, Hokkaido, 060-8589, Japan.
| |
Collapse
|
13
|
Ke J, Zhao Z, Coates CR, Hadjithomas M, Kuftin A, Louie K, Weller D, Thomashow L, Mouncey NJ, Northen TR, Yoshikuni Y. Development of platforms for functional characterization and production of phenazines using a multi-chassis approach via CRAGE. Metab Eng 2021; 69:188-197. [PMID: 34890798 DOI: 10.1016/j.ymben.2021.11.012] [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: 09/20/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 02/08/2023]
Abstract
Phenazines (Phzs), a family of chemicals with a phenazine backbone, are secondary metabolites with diverse properties such as antibacterial, anti-fungal, or anticancer activity. The core derivatives of phenazine, phenazine-1-carboxylic acid (PCA) and phenazine-1,6-dicarboxylic acid (PDC), are themselves precursors for various other derivatives. Recent advances in genome mining tools have enabled researchers to identify many biosynthetic gene clusters (BGCs) that might produce novel Phzs. To characterize the function of these BGCs efficiently, we performed modular construct assembly and subsequent multi-chassis heterologous expression using chassis-independent recombinase-assisted genome engineering (CRAGE). CRAGE allowed rapid integration of a PCA BGC into 23 diverse γ-proteobacteria species and allowed us to identify top PCA producers. We then used the top five chassis hosts to express four partially refactored PDC BGCs. A few of these platforms produced high levels of PDC. Specifically, Xenorhabdus doucetiae and Pseudomonas simiae produced PDC at a titer of 293 mg/L and 373 mg/L, respectively, in minimal media. These titers are significantly higher than those previously reported. Furthermore, selectivity toward PDC production over PCA production was improved by up to 9-fold. The results show that these strains are promising chassis for production of PCA, PDC, and their derivatives, as well as for function characterization of Phz BGCs identified via bioinformatics mining.
Collapse
Affiliation(s)
- Jing Ke
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Zhiying Zhao
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Cameron R Coates
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Michalis Hadjithomas
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Andrea Kuftin
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Katherine Louie
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - David Weller
- USDA Agricultural Research Service, Wheat Health, Genetics and Quality, Washington State University, Pullman, WA, USA; Department of Plant Pathology, Washington State University, Pullman, WA, USA
| | - Linda Thomashow
- USDA Agricultural Research Service, Wheat Health, Genetics and Quality, Washington State University, Pullman, WA, USA; Department of Plant Pathology, Washington State University, Pullman, WA, USA
| | - Nigel J Mouncey
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Trent R Northen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yasuo Yoshikuni
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Center for Advanced Bioenergy and Bioproducts Innovation, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Global Center for Food, Land, and Water Resources, Hokkaido University, Hokkaido, 060-8589, Japan.
| |
Collapse
|