木聚糖酶预处理对麦草化学机械浆可漂性及白度的改善

探讨了以玉米芯片为碳源制备木聚糖酶及麦草化学机械浆经该木聚糖酶预处理后可漂性和白度的改善效果。结果表明，直接以玉米芯为底物、里氏木霉为菌种产酶效果较好，当底物浓度为18g/L时，木聚糖酶活力可达38．34IU／mL。木聚糖酶预处理有利于改善麦草化机浆的可漂性，促进其过氧化氢漂白，有提高漂白浆白度，降低漂剂消耗。研究表明，当经单段H2O2漂至相同白度时，木聚糖酶预处理后可节约50％的H2O2用量。若麦草CMP酶处理后采用高浓度两段过氧化氢漂白，即XP3P3漂序（H2O2总量为6％0时，白度可达60％（ISO）以上。

ENZYMATIC PRETREATMENT WITH XYLANASE FOR IMPROVING BLEACHABILITY AND BRIGHTNESS OF WHEAT STRAW CHEMOMECHANICAL PULP

Xylanase from Trichoderma ressei Rut C 30 with corncob meal as carbon source was prepared and improvement of bleachability and brightness of wheat straw CMP by xylanase pretreatment were investigated. The results indicated that the activity of xylanase was up to 38.34 IU/mL with 18 g/L(oven dry weight)corncob as the substrate. The xylanase treatment was beneficial to improving the bleachability of wheat straw CMP, enhancing hydrogen peroxide bleaching, increasing the brightness effectively and decreasing the consumption of bleaching agent. The research showed that 50% hydrogen peroxide was saved after enzymic pretreatment when wheat straw CMP was bleached to the same brightness with one stage H 2O 2. Furthermore if wheat straw CMP was bleached with two stage high consistence hydrogen peroxide after enzymatic pretreatment, namely XP 3P 3(total H 2O 2 6%)bleaching sequence, the brightness could be over 60%(ISO).