Characterization of endoglucanase rich Trichoderma reesei cellulase mixtures and their effect on alkaline solubility of dissolving pulp

Dissolving grade pulps are used to manufacture regenerated cellulosic fibres. One promising process for the production of regenerated fibres utilises endoglucanse rich cellulases in the modification of dissolving pulp into alkaline soluble form. The aim of this paper was to characterise cellulases produced by Trichoderma reesei that are available in large quantities and study their effect on the dissolving grade softwood pulp, especially on its alkaline solubility. All the studied cellulases had endoglucanse activity and they decreased the intrinsic viscosity of the pulp. The degradation of cellulose into solubilised sugars increased with the cellulases containing also cellobiohydrolases. The monocomponent endoglucanases enhanced alkaline solubility of the pulp more than the multicomponent cellulases and produced alkaline solutions with higher fluidity. The studies showed that the type of the cellulases in the enzyme mixture has significant effect on the amount of solubilised sugars during the enzyme treatment and on the alkaline solubility of the pulp.