Fungicidal Effect of Lippia Alba Essential Oil on a White-rot Fungus

Lippia alba is a plant that has antifungal activity against Aspergillus, Penicillium and Trichoderma genera as well as against human pathogenic microorganisms; however, there are no records on its effect on basidiomycetes which are responsible for white rot of wood. The objective of this study was to evaluate the antifungal activity of L. alba for the control of the white-rot fungus Pleurotus ostreatus. From L. alba leaves, essential oil (EO) was extracted by hydrodistillation, alcoholic extract (AE) was obtained through alcoholic maceration, and aqueous extract (QE) from aqueous infusion. Each extract was added to several culture media to evaluate the fungicidal effect on P. ostreatus. AE and QE do not have fungicidal activity. P. ostreatus does not survive EO when concentrations are higher than 1,0 mL L-1 in malt extract liquid culture medium, or higher than 9,0 mL L-1 in particulate sawdust solid culture medium. The physical state of the cultivation medium affects the fungicidal action of EO. In surfaces subject to greater volatility, the minimum fungicidal concentration of the EO is 25,0 mL L-1. Altogether, L. alba EO is a potential alternative of biological control of basidiomycetes of white rottenness in wood.