In vitro wood decay of Eucalyptus grandis by the basidiomycete fungus Phellinus flavomarginatus

Phellinus flavomarginatus (Basidiomycetes), a white-rot fungus, has been used for the first time in studies on in vitro decomposition of Eucalyptus grandis wood under different water and aeration systems. Decomposition was judged by (i) the macroscopic and ultramicroscopic appearance of degradation, (ii) wood biomass loss, and (iii) enzyme activity (laccase, lignin peroxidase and manganese-dependent peroxidase). E. grandis chips showed white zones from the first (15 days) to the last analysis (60 days). Scanning electron microscopy demonstrated the formation of calcium oxalate crystals and hyphal penetration into pits of vessel elements and through wall fibres, without disruption or separation of fibres. Little wood biomass was lost. The enzyme analyses showed only the presence of manganese-dependent peroxidase; laccase and lignin peroxidase were not detected.