Metabolic Model-Driven Optimization of Streptomyces Metabolic Network for High-Yield Production of Gougerotin

In this study, a genome-scale metabolic model (GEM) of Streptomyces noursei strain CK-15 was constructed, integrating the biosynthetic pathway of gougerotin. Based on UPA algorithm analysis, three extracluster regulatory targets- AHCi , PUNP1 ( PNP ), and metK -were identified and validated by gene overexpression experiments. All engineered strains showed accelerated sporulation and enhanced antimicrobial activity in fermentation broth. Notably, overexpression of AHCi , PUNP1 , and metK increased gougerotin yields by 43.08%, 238%, and 32.87%, respectively, reaching titers of 1.08 g/L, 2.56 g/L, and 1.01 g/L. Proteomic analysis revealed that AHCi regulated pathways involved in membrane transport, environmental information processing, amino acid metabolism, and tRNA biosynthesis; PUNP1 enhanced cofactor, nucleotide metabolism, and energy supply; while metK elevated intracellular SAM levels to promote methylation and peptide precursor biosynthesis, concurrently maintaining stable central carbon metabolism and efficient product efflux. This study elucidates the synergistic roles of these regulatory targets in gougerotin biosynthesis and provides a novel strategy for enhancing microbial secondary metabolite production via metabolic model-based optimization.