Biocontrol Efficacy of Endophytic Bacteria from Lawsonia inermis L. Against Phytopathogens Fusarium oxysporum and Rhizoctonia solani

BACKGROUND: Bioactive compounds from endophytic bacteria contribute significantly to drug discovery and plant defense. Medicinal plants, such as Lawsonia inermis L., serve as a rich source of microbial endophytes. OBJECTIVE: To isolate and characterise endophytic bacteria from L. inermis leaves and evaluate their bioactive metabolites for antimicrobial and biocontrol potential. MATERIALS AND METHODS: Endophytic bacteria were isolated from surface-sterilised leaves of L. inermis. Morphological and molecular identification, including 16S rRNA gene sequencing and phylogenetic analysis, identified the isolates as Bacillus subtilis, Pseudomonas mosselii, and Sphingomonas aquatilis. Metabolite profiling was performed using Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS). Antifungal activity was tested against Fusarium oxysporum f. sp. lycopersici and Rhizoctonia solani using dual-culture assays. RESULTS: The endophytes demonstrated significant antagonistic activity, inhibiting the growth of fungal mycelia. FTIR spectra indicated the presence of carboxylic, ester, ketone, and alkane functional groups. GC-MS analysis of active fractions revealed several known antimicrobial and pharmaceutical compounds, supporting the observed bioactivity. CONCLUSION: Endophytic bacteria from L. inermis produce bioactive secondary metabolites with potent antifungal activity. These findings suggest their potential as sources of novel biocontrol agents and therapeutic compounds, contributing to the medicinal properties of the host plant.