In vitro Antimicrobial Activity of Secondary Metabolites of an Endophytic Aspergillus brunneoviolaceus Isolated from Bryophyllum pinnatum (Lam.) Oken

The antimicrobial properties of secondary metabolites produced by the endophytic Aspergillus brunneoviolaceus associated with the Nigerian plant Bryophyllum pinnatum were investigated in this study. Standard procedures were followed for fungal isolation and identification, as well as fermentation and extraction of fungal secondary metabolites. The agar-well diffusion method was used to assess the antimicrobial activity of the fungal extract. At 1 mg/mL, the fungal extract demonstrated broad spectrum antibacterial activity against the test bacteria (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Bacillus subtilis), with inhibition zone diameters (IZD) ranging from 14 to 16 mm. The extract also exhibited antifungal activity with an IZD of 16 mm produced against Candida albicans. The findings of this study indicate that endophytic A. brunneoviolaceus associated with B. pinnatum has the potential to be a promising source of novel antimicrobial compounds with pharmaceutical importance.