Strategies for Enhancing the Yield of the Potent Insecticide Spinosad in Actinomycetes.

Spinosad is a potent insecticide that exhibits an excellent environmental and mammalian profile. However, spinosad production in the original producer, Saccharopolyspora spinosa, is insufficient for the huge global demand. Great efforts have been exerted to improve the production of spinosad. Strategies for spinosad overproduction in actinomycetes are reviewed in this article, including metabolic engineering of the precursor and spinosyn biosynthetic pathway, introduction of regulatory genes, genome-scale metabolic model-guided engineering, mutagenesis, genome shuffling, fermentation process optimization, omics analysis, and the heterologous biosynthesis of spinosad in other actinomycetes. Furthermore, highly productive industrial strains should be used as heterologous hosts for enhancing spinosad biosynthesis in the future. To accelerate the engineering process, the CRISPR/Cas9 system should be established in Sa. spinosa for large-scale genome editing. Notably, the regulatory mechanism of spinosad biosynthesis remains unclear. Thus, the combining multi-omics analysis with high-throughput screening of chemical elicitors would be a promising approach in characterizing the regulatory and signal transduction mechanisms and improving spinosad production in Sa. Spinosa.