Synthetic Biology and Genome Editing in Actinobacteria

Actinobacteria, particularly the genus Streptomyces, are renowned for their ability to synthesise a vast array of bioactive natural products, including many clinically important antibiotics. Synthetic biology seeks to harness and expand this potential by constructing modular genetic parts, optimising regulatory elements and assembling programmable circuits to direct and enhance metabolite production. Parallel advances in genome-editing technologies, notably CRISPR/Cas systems and targeted endonucleases, have transformed the precision and speed of strain development. Together, these approaches enable the activation of silent biosynthetic gene clusters, fine-tuning of metabolic pathways and rational redesign of cellular chassis to improve yield, reliability and scalability. Achieving these aims requires robust vectors and expression cassettes, reliable control of transcription and translation, and efficient methods for scarless gene deletions, insertions and rearrangements. The integration of synthetic promoters, terminators and ribosome binding sites into optimised editing workflows offers unprecedented opportunities for drug discovery, bioproduction of high-value compounds and the creation of novel chemical scaffolds. Global demand for new antibiotics, anticancer agents and industrial enzymes underscores the strategic importance of equipping actinobacterial hosts with versatile and predictable genetic toolkits.

Research from Nature Portfolio

Efficient selection of targeted gene deletions in genetically uncharacterised actinomycetes has been achieved using a homing endonuclease-based system. A codon-optimised I-SceI nuclease was introduced alongside an 18-base recognition site, producing double-strand breaks that strongly favour homologous recombination. Survival of recombinants requires precise excision or repair, enabling marker-free gene cluster deletions with high fidelity and minimal off-target alterations. This method has proven broadly applicable across diverse actinobacterial strains with low intrinsic recombination frequencies.

To expand the genetic control repertoire, a suite of synthetic regulatory elements has been systematically characterised in Streptomyces. An in vivo ribosome binding site (RBS) selector enables the rapid screening of optimal translation initiation sequences for any gene of interest, while engineered terminators provide up to 100-fold reduction in downstream transcription. A collection of C-terminal degradation tags further allows post-translational modulation of protein stability. Together, these tools form a modular library that supports predictable tuning of gene expression and metabolic flux in actinobacterial hosts.

Synthetic Biology and Genome Editing in Actinobacteria publication trend

The graph below shows the total number of articles in synthetic biology and genome editing in actinobacteria across all publications each year (not limited to Nature Index journals).

Technical terms

CRISPR/Cas system: A programmable nuclease platform that uses RNA guides to introduce site-specific DNA breaks for genome editing.

Biosynthetic gene cluster (BGC): A contiguous set of genes encoding enzymes and regulatory proteins responsible for the synthesis of a natural product.

Synthetic promoter library: A collection of engineered DNA sequences with varying strength to modulate transcription initiation.

Ribosome binding site (RBS): A short RNA sequence upstream of a coding region that recruits ribosomes and influences translation efficiency.

Homing endonuclease I-SceI: A site-specific endonuclease that recognises an 18-base sequence, generating double-strand breaks to stimulate homologous recombination.

References

1. A tunable and reversible thermo-inducible bio-switch for streptomycetes. Nucleic Acids Research (2024).
2. Development of Integrated Vectors with Strong Constitutive Promoters for High-Yield Antibiotic Production in Mangrove-Derived Streptomyces. Marine Drugs (2024).
3. Application of Cas12j for Streptomyces Editing. Biomolecules (2024).
4. Use of the Meganuclease I-SceI of Saccharomycescerevisiae to select for gene deletions in actinomycetes. Scientific Reports (2014).
5. A set of synthetic versatile genetic control elements for the efficient expression of genes in Actinobacteria. Scientific Reports (2018).
6. CRISPR/Cas9-Based Editing of Streptomyces for Discovery, Characterization, and Production of Natural Products. Frontiers in Microbiology (2018).
7. Recent Advances in Silent Gene Cluster Activation in Streptomyces. Frontiers in Bioengineering and Biotechnology (2021).
8. Recent Advances in Synthetic Biology Approaches to Optimize Production of Bioactive Natural Products in Actinobacteria. Frontiers in Microbiology (2019).