Isolation and characterization of Aspergillus oryzae from Withania coagulans rhizosphere: metabolite profiling and bioactivity assessment

Aspergillus oryzae is recognized for its industrial significance in producing diverse metabolites. Fungi was isolated from Withania coagulans rhizosphere for the first time, employing physicochemical soil analysis. Morphological and molecular identification, utilizing 18S rRNA gene sequencing, confirmed the isolated fungus as A. oryzae. GC–MS chromatography of A. oryzae culture filtrate identified 14 compounds being reported for the first time from this specie. The antimicrobial potential of crude culture filtrate of A. oryzae was evaluated against Multi Drug Resistant bacteria, exhibiting significant activity. Phytotoxic screening on Lemna minor plants demonstrated 90% growth inhibition. Furthermore, culture filtrate displayed insecticidal activity with 40% and 60% mortality observed agaisnt Termites and Blattodea. The findings highlight that rhizosphere of W. coagulans has crucial physicochemical composition that provides stable ecological condition for the survival of bioactive fungal species, a source of secondary metabolites with diverse biological activities, providing valuable insights for potential applications.