Degradation of lipophilic wood extractive constituents in Pinus sylvestrisby the white-rot fungi Bjerkandera sp. and Trametes versicolor

The white-rot fungi Trametes versicolor and Bjerkandera spp. are among the most frequent decomposers of angiosperm wood in forest ecosystems and in wo od products in service. Wood extractives have a major impact on wood proper ties and wood utilization. This work evaluated the ability of two white-rot fungal strains (Bjerkandera sp. strain BOS55 and T. versicolor strain LaVe c94-6) to degrade the main lipophilic extractive constituents in Scots pine (Pinus sylvestris L.). The time course of wood decay and wood extractive d egradation was monitored in stationary batch assays incubated for eight wee ks. The strains tested eliminated high levels of total resin, 34 to 51% in two weeks. Wood triglycerides were the most readily degraded extractive com ponents (over 93% elimination in only two weeks). Free fatty acids and resi n acids, which are potential fungal inhibitors, were also rapidly decompose d by the fungal strains. Sterols were used more slowly, nonetheless, the fu ngal degradation of this extractive fraction ranged from 50 to 88% after fo ur weeks.