Avaliação do efeito de fungos prospectados do cerrado em madeira de Eucalyptus sp.

Abstract

This study aimed to evaluate the degrading action of fungi isolated from the Cerrado biome on Eucalyptus sp. wood through an accelerated laboratory decay test. Four fungal isolates (T1 to T4) and one control treatment were used, and mass loss and changes in the chemical composition of the wood were analyzed after 12 weeks of incubation in a biochemical oxygen demand (BOD) chamber. The wood samples were subjected to physical and chemical characterization before and after the test, including determination of basic density, extractives content, lignin content (soluble and insoluble), and holocellulose content. Mass loss ranged from 6.10% to 6.72%, with no statistically significant differences among treatments. Although the 12-week exposure period aligns with literature recommendations, the results suggest that, under the test conditions, this duration may not have been sufficient to reveal more expressive differences among the treatments. On the other hand, chemical analyses showed a significant reduction in total lignin content in the fungal treatments, especially in T1, which showed a decrease from 29.66% to 13.59%. This result indicates lignolytic activity of the isolates, even in the absence of substantial mass loss. Additionally, holocellulose content increased in the fungal treatments, particularly in T1 (75.12%), possibly due to selective lignin degradation. It is concluded that, although mass loss did not differ among treatments, the fungi demonstrated the ability to modify the chemical structure of the wood, with emphasis on the preferential degradation of lignin.