中文摘要：

采用AU系列不同型号木聚糖酶对杨木硫酸盐浆进行了漂白预处理。实验结果显示，AU系列木聚糖酶比较适于杨木硫酸盐浆漂白预处理。AU-1木聚糖酶在温度75℃，酶用量10IU／g（以绝干浆计，下同），pH值为7的预处理条件下，漂白纸浆白度（ISO，下同）为78．1％，与未经过酶预处理的漂白浆相比，纸浆白度提高1．8个百分点；AU-2木聚糖酶最佳预处理条件为温度90℃、酶用量10IU／g、pH值8，此条件下漂白浆白度为77．6％，白度提高1．1个百分点；AU-3木聚糖酶最佳预处理温度为70℃，酶用量为101U／g和pH值为8时，漂白纸浆白度高达78．9％，白度提高2．7个百分点。Au系列木聚糖酶预处理可改善杨木硫酸盐浆的漂白性能，降低漂白化学药剂用量。Au-3木聚糖酶助漂效果好于Au-1和AU-2木聚糖酶。

英文摘要：

The effects of AU xylanases pretreatment on bleachability of poplar kraft pulp were studied. The results showed that AU xylanases were suitable for the bleaching pretreatment of poplar kraft pulp. The resulting brightness of AU-1 xylanase-treated pulp was 78.1% （ ISO, same as in following） under the optimum pretreatment conditions of temperature 75 ℃ , 10 IU/g（ as oven dry pulp）, and pH value 7.0, 1.8 percentage point higher than that of the non-pretreated pulp. For AU-2 xylanase pretreatment, the optimal conditions were 90 ℃, 10 IU/g and pH value 8.0, on which the resulting brightness of the treated pulp reached 77.6 %, an increase of 1. 1 percentage point, compared with that of non-pretreated pulp. The resulting brightness of AU-3 xylanase-pretreated pulp was 78.9 using pretreatment temperature 70 ℃ , dosage of AU-3 xylanase 10 IU/g and pH value 8.0, respectively, and an increase of 2.7 percentage point. Bleachability of poplar kraft pulp can be improved by AU xylanases pretreatment, and the cost of bleaching chemicals can be reduced as well. The pretreatment effectiveness of AU-3 xylanases is superior to those of AU-1 and AU-2 xylanases.