Efficacy of Fungus Comb Extracts Isolated from Indo-Malayan Termite Mounds in Controlling Wood-Decaying Fungi

Abstract

The authors have recently investigated the chemical components and bioactivity of fungus comb from Macrotermes gilvus Hagen mounds. The ethyl acetate, methanol, and water extracts of the fungus comb contained active compounds which are preventing the growth of Aspergillus foeti-dus, one of the most economically important wood-staining fungi in Indonesia. In this present study, the bioactivity of the fungus comb extracts was examined against the white-rot fungus Schizophyllum commune Fr. For the purpose of generating a realistic in-service type of environment, the extracts were evaluated according to modified EN-113 after impregnated into wood samples by the vacuum-pressure method, following in-vitro antimicrobial susceptibility test. The results showed that ethyl acetate extract at concentrations ranging from 2 to 6% and methanol extract at a concentration of 6% presented high bioactivity against S. commune. This result was established through optical microscopy images, which demonstrated the absence of fungal mycelia in the vessels of wood samples treated with EtOAc extract at concentrations of 2%, 4%, and 6%, as well as MeOH extract with a concentration of 6%. The toxic values of the ethyl acetate and methanol extracts were determined to be 6.17% and 7.72%, respectively. Based on UPLC-HRMS analysis, azelaic acid, and erucamide were discovered as the dominant components in ethyl acetate extracts, which are anticipated to be the most active compounds. It appears that ethyl acetate extract, as well as methanol extract, can be considered as novel preservative sources for controlling wood-decaying fungi.