Protein engineering of xylanase for pulp bleaching applications

摘要

Trichoderma reesei xylanase II has been sued ocmmercially for several years in pulp belaching applications. protein engineering was used to increase the operating temperature of this enzyme. Muations within the N-teminal 29 amino acids increased the temperature optimum of the enzyme by 5-10 deg C over the natural T.reesei enzyme. Several high temperature xylanase mautants were expressed in T. reesei using the promoter of the T. reesei using the promoter of the T. reesei cellobiohydrolase I gene. The best transformants produced over 500 XU/mg of xylanase activity measured at 65 deg C activities in shake flask cultures.