Degradation of unbleached sulphite pulp paper treated in solid state conditions with five species of the brown-rot Gloeophyllum

Wood pulp paper was inoculated with G. abietinum, G. odoratum, G. protractum, G. saepiarium and G. trabeum and incubated in solid state conditions. G. trabeum showed the highest degradation capacity and a clear selectivity towards lignin. The physico-chemical properties of treated pulps showed an incremental increase in brightness in accordance with the fall in Kappa number but breaking length, bursting strength and tearing strength were diminished and the degree of polymerization of cellulose (DP) decreased substantially. We attempted to inhibit cellulose attack, but only EDTA was effective. Under these conditions a clear inhibition in the fall of the DP of cellulose was obtained; the ISO brightness values were increased and Kappa numbers remained near constant in spite of a visible bleaching.