Advanced fermentation techniques enhance dioxolanone type biopesticide production from Phyllosticta capitalensis.

In the current work, the production of dioxolanone and meroterpene type secondary metabolites under different fermentation conditions by the endophytic fungus Phyllosticta capitalensis (isolate YCC4) isolated from the leaves of the endemic plant Persea indica has been evaluated. Different techniques, such as microparticle-enhanced culture (MPEC: bentonite, talcum powder) and surface adhesion fermentation (SAF: metallic mesh and glass wool) were applied to the culture medium. Ethyl acetate extracts from different fermentations of the isolate YCC4 were analyzed for their content and revealed the following dioxolanone derivatives: metguignardic acid (1), guignardianone C (2), ethyl guignardate (3), guignardianone D (4) and phenguignardic acid methyl ester (5), and meroterpenes: guignardone A (6) and B (7), guignarenone C (8), guignarenone B (9) and guignardone I (10).