Aspergillus terreus MAK153 against Fusarium oxysporum: biocontrol, metabolites, and simvastatin docking

This study demonstrates the considerable antagonistic activity of Aspergillus terreus MAK153 against a pathogenic Fusarium oxysporum AUMC3191 isolate. In dual culture assay, soil-isolated Aspergillus terreus Thom effectively hindered F. oxysporum AUMC3191 growth and impressively blocked zearalenone (ZEN) synthesis. Scanning electron microscopy demonstrated significant damage to F. oxysporum hyphae, such as abnormalities, shrinkage, bending, and deformity. Molecular identification through rDNA ITS sequence analysis confirmed the isolate as Aspergillus terreus, registered in GeneBank (Accession No. OR480103). GC/MS profiling of A. terreus MAK153 identified several bioactive secondary metabolites, notably estragole, caryophyllene, 2,4-di-tert-butylphenol, 1-docosene, 1-docosanol, olean-12-ene-3,28-diol, and simvastatin. Statistical analysis revealed a very strong positive correlation (r = 0.99) between chromatographic peak area% and peak area values. The influence of nutrient sources on simvastatin production was evaluated using four culture media. FTIR and HPLC analyses confirmed simvastatin biosynthesis, while HPLC revealed significant medium-dependent variation in yield (p < 0.001). Camellia sinensis Tea broth (CTB) elicited the highest yield, dominating extracellular filtrate accumulation (145.93 ± 1.13 mg/mL). Molecular docking simulations assessed simvastatin's binding affinity to HMG-CoA reductase and 3-ketosteroid reductase, yielding binding energies of -8.0 and -7.8 kcal/mol, respectively. The interactions involved multiple hydrophobic bonds and hydrogen bonds, suggesting simvastatin functions as a multi-target inhibitor capable of disrupting ergosterol biosynthesis at two distinct sites. Notably, this study represents the first computational exploration of simvastatin's interaction with 3-ketosteroid reductase, with implications for estrogen signalling modulation and potential therapeutic applications. KEY POINTS: • Aspergillus terreus MAK153 inhibits F. oxysporum growth and zearalenone production • Aspergillus terreus induces significant hyphal damage in F. oxysporum using SEM • Simvastatin-HMG-CoA and 3-ketosteroid interaction could modulate estrogen-related pathways potentially.