White rot fungi degrade and mineralize lignin through secretion of strong oxidative ligninolytic enzymes, preventing accumulation of dead plant organic matter. Due to the specific structures, different lignolytic enzymes has different mechanism in lignin degradation/oxidation, producing many phenolic compounds. This work explores the phenolic compounds produced at different times by nine fungal species, belonging to the Heterobasidion and Armillaria genera, before and after their inoculation in silver fir (Abies alba Mill.) sawdust under controlled conditions. A total of 81 samples (three replicates for each fungal species and other three replicates kept as a control) were analysed using high-performance liquid chromatography coupled to a hybrid quadrupole-orbitrap mass spectrometer. Eighteen phenolic compounds, including simple phenols, alkylphenyl alcohols, hydroxybenzoketones, hydroxycinnamaldehydes, hydroxybenzaldehydes, hydroxyphenylacetic acids, hydroxycinnamic acids, hydroxybenzoic acids and hydroxycoumarins were detected. In particular, coniferyl alcohol, ferulic acid, p-coumaric acid, acetovanillone, vanillic acid, etc. showed a decreasing trend during degradation process, by contrast an accumulation trend was observed for protocatechuic acid, syringic acid and scopoletin. These results suggested different strategies of silver fir lignin degradation by selected fungal species. PCA revealed a good differentiation between phenolic compounds and the activity of nine fungal species during the three times of silver fir sawdust degradation.
|Titolo:||Fungal impact on lignin degradation and simple phenols formation in silver fir decaying wood|
|Data di pubblicazione:||Being printed|
|Appare nelle tipologie:||1.1 Articolo in rivista|