Biocontrol Potential of Bacterial‐Derived Lipopeptide From the Fruit Endophyte of <i>Datura stramonium</i> Against Fungal Phytopathogen

ABSTRACT Biosurfactants are amphiphilic molecules produced by microbes or plant extracts, known for their unique properties; therefore, they are of research interest. This study investigates the potential of biosurfactants from an endophytic bacterial strain isolated from the fruit of Datura stramonium . Four isolates were screened for biosurfactant production, and through preliminary tests, one isolate was selected and identified as Enterobacter species. The culture conditions for biosurfactant production were optimized, and stability under salinity and temperature was analyzed. Under optimized conditions, a 137% increase in biosurfactant production was reported. Further FTIR and GC–MS analysis revealed the biosurfactant to be a lipopeptide‐type compound with cationic characteristics. This lipopeptide was tested against plant pathogens Phytophthora capsici and Pythium aphanidermatum for its antifungal activity. A complete inhibition of P. capsici was observed at 1000 μg/mL concentration, whereas P. aphanidermatum showed no inhibition. Microscopic analysis of biosurfactant‐treated pathogen showed swollen, disintegrated hyphae with excessive lateral branching, indicating the biosurfactant‐induced stress response. To the best of our knowledge, this study is the first to report the use of biosurfactant from Datura's fruit endophyte and its antifungal property.