Adsorption of hemicellulases onto bleached kraft fibers

The presence of a cellulose binding domain was the main factor which influe nced the adsorption of two Trichoderma reesei mannanases and a Trichoderma longibrachiatum xylanase onto bleached kraft fibers. The mannanase containi ng the binding domain adsorbed to a much greater extent than the mannanase and xylanase without binding domains. Once-dried fibers exhibited lower hem icellulase adsorption than the never-dried fibers. The adsorption onto once -dried fibers was only 30-50% the amount adsorbed onto virgin fibers. Adjus tment of the ionic strength and pH of treatment was used to modify the char ge on the fibers. Ionic strength had opposite effects on mannanase and mann anase core adsorption. Mannanase adsorption increased at high ionic strengt hs, while the mannanase core adsorption decreased. An increase in pH and fi ber charge significantly enhanced the adsorption of xylanase. (C) 1999 Else vier Science B.V. All rights reserved.