Abstract: Streptomyces, as an important group of microorganisms, produces a wide range of natural products, including anticancer, antiviral, antifungal, and antiparasitic bioactive compounds, and plays a crucial role in pharmaceuticals, agriculture, and the chemical industry. The secondary metabolites ofStreptomycesmainly consist of polyketide compounds and non-ribosomal peptides. However, due to the extremely complex metabolic network and regulatory mechanisms ofStreptomyces, coupled with the fact that their biosynthetic gene clusters are silent under most environmental conditions, the yield of natural products is low, which limits their application in industrial production. Therefore, studying how to activate silent biosynthetic gene clusters and using molecular biology breeding strategies to increase the production of natural products are of great significance. Given the agricultural significance of secondary metabolites, this review outlined the biosynthetic pathways of polyketide compounds and non-ribosomal peptides inStreptomyces, and summarized the strategies to improve the yield of natural products inStreptomycesin recent years, such as mutation breeding, carbon, nitrogen and phosphorus metabolic pathway modification and heterologous expression. Future research directions integrating high-throughput screening with computational prediction were proposed, aiming to advance the research of secondary metabolites ofStreptomycesand provide a basis for the development and application of polyketide compounds and non-ribosomal peptides.

Key words: Streptomyces; PKS system, NRPS system, heterologous expression, carbon, nitrogen, phosphorus metabolic pathway engineering, mutagenesis breeding