Cited by 232CRISPR and Genetic EngineeringMicrobial Metabolic Engineering and BioproductionBacterial Genetics and Biotechnology

CRISPR/Cas9 mediated targeted mutagenesis of the fast growing cyanobacterium Synechococcus elongatus UTEX 2973

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Wendt, Kristen E., Ungerer, Justin, Cobb, Ryan E., Zhao, Huimin, Pakrasi, Himadri B.·2016·Microbial Cell Factories

Abstract

BACKGROUND: As autotrophic prokaryotes, cyanobacteria are ideal chassis organisms for sustainable production of various useful compounds. The newly characterized cyanobacterium Synechococcus elongatus UTEX 2973 is a promising candidate for serving as a microbial cell factory because of its unusually rapid growth rate. Here, we seek to develop a genetic toolkit that enables extensive genomic engineering of Synechococcus 2973 by implementing a CRISPR/Cas9 editing system. We targeted the nblA gene because of its important role in biological response to nitrogen deprivation conditions. RESULTS: First, we determined that the Streptococcus pyogenes Cas9 enzyme is toxic in cyanobacteria, and conjugational transfer of stable, replicating constructs containing the cas9 gene resulted in lethality. However, after switching to a vector that permitted transient expression of the cas9 gene, we achieved markerless editing in 100 % of cyanobacterial exconjugants after the first patch. Moreover, we could readily cure the organisms of antibiotic resistance, resulting in a markerless deletion strain. CONCLUSIONS: High expression levels of the Cas9 protein in Synechococcus 2973 appear to be toxic and result in cell death. However, introduction of a CRISPR/Cas9 genome editing system on a plasmid backbone that leads to transient cas9 expression allowed for efficient markerless genome editing in a wild type genetic background.

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  • Over the past decade, significant progress has been achieved in the development of genetic tools for cyanobacterial metabolic engineering, including improved transformation methods, modular DNA assembly systems, synthetic promoters, and CRISPR-based genome editing technologies.

    “Over the past decade, significant progress has been achieved in the development of genetic tools for cyanobacterial metabolic engineering, including improved transformation methods, modular DNA assembly systems, synthetic promoters, and CRISPR-based genome editing technologies [10,16,17].”

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Authors
Wendt, K. E., Ungerer, J., Cobb, R. E., Zhao, H., & Pakrasi, H. B.
Affiliations
  • Washington University in St. Louis (US)
  • University of Illinois Urbana-Champaign (US)
Corresponding author
Pakrasi, Himadri B.
Venue
Microbial Cell Factories
Published
2016-06-23
Volume
15
Issue
1
Pages
115-115
ISSN
1475-2859 (ISSN-L)
OpenAlex
W2470889463
Cited by
232
References
38
Citations by year
2026: 15 · 2025: 15 · 2024: 24 · 2023: 17 · 2022: 29 · 2021: 23 · 2020: 22 · 2019: 34 · 2018: 31 · 2017: 16 · 2016: 6
FWCI
15.07
Type
journal article
Language
en
Open access
Locations
  • Microbial Cell Factories (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) (submittedVersion)
Funders
  • Office of Science
  • National Institute of General Medical Sciences (GM077596)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › CRISPR and Genetic Engineering
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Microbial Metabolic Engineering and Bioproduction
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Bacterial Genetics and Biotechnology
Keywords
CRISPR/Cas9, cyanobacteria, genome editing, conjugative transfer
MeSH terms
Endonucleases, Genetic Techniques, Mutagenesis, Synechococcus, Clustered Regularly Interspaced Short Palindromic Repeats

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