In this work, the wood of six indigenous and two exotic species, previously extracted with different solvents, was exposed to the fungus Gloeophyllum trabeum, with the objective of determining which solvent was most efficient in removing the substances responsible for their resistance to decay. The samples were reduced to sawdust and extracted with cold and hot water, with a mixture of ethanol/toluene, dichloromethane, and methanol, and also totally extracted with hot water with ethanol-toluene and ethanol. After extraction, the samples were inoculated with the fungus, inside a plastic container. The results showed the remarkable resistance of Cedrela fissilis wood, even after total extraction, as evidenced by its low mass loss; the solvents were unable to remove the substance or substances that confer that durability. Non-extracted Amburana cearensis, Vanillosmopsis erythropappa, Machaerium scleroxylon and eucalypts (Corymbia citriodora and Eucalyptus gummifera) showed their typical resistance; when totally extracted, however, their mass loss was very high. As regarding individual solvents, in V. erythropappa and eucalypts, dichloromethane was the most efficient in removing the substance responsible for resistance. C. citriodora wood showed a low mass loss when it was extracted with cold and hot water, dichloromethane and natural (not extracted). Wood of A. cearensis extracted with the mixture ethanol/toluene had the most severe weight loss, while in M. scleroxylon the most efficient solvent was methanol.
Extractives; natural durability; Gloeophyllum trabeum and woods
