A Host-Mimicking Peanut-Based Selective Medium Enhances Isolation, Sporulation, and Metabolomic Profiling of Aspergillus flavus

Aspergillus flavus is a significant foodborne pathogen, responsible for food contamination and invasive aspergillosis. Isolating this pathogen is challenging because traditional media do not reflect the natural environment. In this study, we designed peanut- and corn-based selective media, PSM and CSM, to improve isolation efficacy, growth, sporulation, and metabolic profiles compared with conventional media (PDA and SDA). A novel peanut- and corn-based selective medium (PSM and CSM) improved A. flavus recovery, radial expansion, and sporulation compared with PDA and SDA. These effects were reproducible across isolate origins, indicating that nutrient composition, not strain source, was the key driver. LC-MS/MS-based metabolomic profiling revealed strain- and substrate-specific metabolic phenotypes. Corn- and peanut-based media differentially modulated amino acid metabolism, lipid remodeling, and secondary metabolite biosynthesis. Under host-relevant conditions, the clinical isolate downregulated multiple amino acid pathways and upregulated glycerophospholipid metabolism. Altogether, PSM provides a powerful platform to isolate and functionally evaluate A. flavus, improving phenotypic resolution and revealing biologically relevant metabolic differences hidden in traditional culture. This has implications for clinical mycology, food safety, and mycotoxin studies. These results are exploratory and hypothesis-driven, as the clinical metabolic phenotype was defined in a single clinical isolate, and need to be confirmed on a more diverse and geographically expanded clinical isolate collection before generalization.