Characterization of Xylanolytic Enzymes for Potential Applications

摘要

In the study the enzymatic hydrolysis of xylans was shown to be influenced by the heterogeneous structure of the substrate. The role of individual xylan-degrading enzymes in the hydrolysis of xylans was studied using enzyme mixtures of different microbial origin and by purifying and characterizing xylanolytic enzymes of the fungus Trichoderma reesei. A steaming process was studied as a means of separating xylan from cellulose and lignin and as a pretreatment method prior to enzymatic hydrolysis of hardwood carbohydrates. Trichoderma reesei was superior to the other microorganisms tested in terms of both enzyme spectrum and activity levels. The high cellulolytic activity of T. reesei would be beneficial in applications requiring total hydrolysis, but makes this fungus an unsuitable enzyme producer for applications in which selective hydrolysis of xylan is required. The identification and separation of the different xylanolytic enzymes will facilitate further research on the roles of, and cooperation between, cellulolytic, hemicellulolytic and lignin-degrading enzymes in the processing of lignocellulosic raw materials. (Copyright (c) Valtion teknillen tutkimuskesleus (VTT) 1988.)