Strain-dependent bioactive-lipid interactions govern oxidative stability and antimicrobial functionality in Lentinula edodes.

The use of edible mushrooms as natural food-preserving ingredients depends on their ability to simultaneously suppress lipid oxidation and microbial proliferation; however, these functions are rarely evaluated within an integrated strain-resolved biochemical framework. In this study, five Indian-origin Lentinula edodes strains (DMRO-34, DMRO-35, DMRO-356, DMRO-623, and DMRO-388s) cultivated under identical conditions were systematically compared to determine how strain-dependent bioactive profiles influence lipid stability, antioxidant buffering, and antimicrobial efficacy. Fatty acid profiling revealed pronounced strain-dependent variation (p < 0.05), with polyunsaturated fatty acids (PUFAs) dominating the lipid fraction (≈52-82% of total fatty acids). Despite this high degree of unsaturation, lipid peroxidation differed markedly among strains, with malondialdehyde levels ranging from 19.2 to 77.3 nmol g-1 dry weight, indicating that oxidative stability cannot be explained by lipid composition alone. Instead, antioxidant capacity-assessed through radical-scavenging, metal-chelating activity, ascorbic acid, and total antioxidant capacity assays-closely aligned with lipid peroxidation outcomes. All strains exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria and Candida albicans, with clear strain-specific differences. Quantitative MIC and MBC/MFC analyses further revealed substantial variation in growth-inhibitory and bactericidal/fungicidal activity, paralleling trends observed for antioxidant buffering and oxidative stability. Notably, strain DMRO-356 combined high PUFA content with low lipid peroxidation, strong antioxidant buffering capacity, and enhanced antimicrobial activity, suggesting effective endogenous stabilization of PUFA-rich lipid systems. Correlation analysis further indicated that preservation-relevant functionality in L.edodes arises from coordinated interactions between lipid architecture and endogenous bioactive metabolites rather than isolated compositional traits. Together, these findings highlight strain selection as a key determinant of functional performance and support a function-driven approach for identifying L.edodes germplasm with potential applications in natural food preservation systems.