Changes of the pH value of impregnated wood during exposure to wood-rotting fungi

Changes of the pH-value of impregnated and unimpregnated wood caused by woo d rotting fungi were studied. Wood, impregnated with two aqueous solutions of copper(II) sulfate and of copper(II) octanoate with ethanolamine, was ex posed to different wood rotting fungi for 2, 4 and 12 weeks. Two of them we re white-rot fungi (Trametes versicolor and Schizophyllum commune), The thi rd species was the brown-rot fungi Antrodia vaillantii, using three differe nt strains of this species. Antrodia vaillantii substantially decreased the pH-value of impregnated and unimpregnated wood before any mass loss appear ed. On the other hand, the white-rot fungus T. versicolor and S. commune ca used a slight increase of the pH of impregnated and unimpregnated wood. It is suggested that a decrease of pH of wood may indicate early stages of dec ay by brown rot fungi.