Hydrothermal liquefaction of spent mushroom substrate as a source of antifungals
A Barbero-López, Y M López-Gómez, J Carrasco, N Jokinen, R Lappalainen, A Haapala
The aim of this study was to characterize the chemical composition of hydrothermal liquefaction (HTL) products from the spent mushroom substrate (SMS) of Agaricus bisporus (Lange) Imbach and Pleurotus ostreatus (jacq.) P. kumm. using high-resolution 1H nuclear magnetic resonance (NMR), and assess the antifungal properties of these thermal decomposition liquids against wood decaying fungi (Coniophora puteana (Schumach.) P. Karst. and Trametes versicolor (L.) Lloyd). Retention and leachability following the pressure impregnation treatment of Pinus sylvestris sapwood is presented. The results show that the HTL liquid fraction of tested residues contain constituents with antifungal properties, such as phenols, aldehydes and organic acids. Malt agar plates amended with 10% of liquid were able to inhibit the growth of C. puteana and caused 90% inhibition on T. versicolor. The liquids show promising results as potential active ingredients for wood preservative formulations as they inhibit the tested decay fungi and they contain constituents with antifungal properties.