木聚糖酶中纤维素酶对麦草浆生物漂白的影响

Effect of Xylanase Containing Varying Cellulase Contents on Biobleaching of Wheat Straw Pulp

选用产自里氏木霉的含不同纤维素酶量的木聚糖酶进行漂前预处理,研究了具有不同木聚糖酶活与纤维素酶活比值(X/C)和不同纤维素酶系组成(F/C比值不同)的复合酶对浆料性能的影响。结果表明:随着X/C比值的减小,在相同用氯量时漂白浆白度逐渐升高,裂断长和耐破指数逐渐下降;在X/C比值相近条件下,随着F/C比值增加,浆料白度升高,而裂断长和耐破指数则明显下降,木聚糖酶中存在少量纤维素酶有助于纸浆漂白,若外切葡聚糖酶和纤维二糖酶含量过高,则对纸浆强度不利。

Xylanase are used to enhance the bleaching of pulp,it often contains a small amount of cellulsae.In this paper,xylanases with varying cellulase content (different X/C ratio)were used to pretreat wheat straw pulp before bleaching.The effects of different X/C ratio and F/C ratio in xylanase on bleachability and strength of wheat straw pulp were investigated.The results indicated that the bleached pulp brightness increased,the breaking length and burst index decreased with decreasing of X/C ratio in xylanase.At the similar X/C ratio,the bleached pulp brightness was improved and strength was obviously decreased with increasing of F/C ratio in xylanase.Therefore,the presence of a small amount of cellulase in xylanase contributed to the improvement of pulp brightness when the pulp was pretreated with xylanase before bleaching.But higher F/C ratio in xylanase would cause the deterioration of the pulp strength.