两种漆酶改性方法及其在造纸纤维改性中的应用

Two Kinds of Laccase Modification Method and Its Application in Papermaking Fiber Modification

由于漆酶在高温和其它极端环境下不稳定、易失活,使漆酶改性纤维的条件受到一定限制。因此,有必要对漆酶进行一定的改性处理,使其活性、稳定性提高。本文基于漆酶氨基酸残基末端的活性基团氨基(-NH2)和羧基(-COOH)分别与二氧化硫脲和L-苯丙氨酸甲酯盐酸盐发生反应使漆酶活性、稳定性提高的改性方法。通过研究发现,L-苯丙氨酸甲酯盐酸盐改性后的漆酶和二氧化硫脲改性后的漆酶活性分别提高209%、50%,稳定性前者提高50%,后者变化不大。将改性漆酶/组氨酸用于OCC浆,添加L-苯丙氨酸甲酯盐酸盐改性漆酶/组氨酸的纸张比添加未改性漆酶/组氨酸的纸张抗张强度、耐破度以及撕裂度分别提高13%、10%、9%;添加二氧化硫脲改性漆酶/组氨酸的纸张比添加未改性漆酶/组氨酸的纸张抗张强度、耐破度以及撕裂度分别提高5%、7%、6%。因此,用二氧化硫脲和L-苯丙氨酸甲酯盐酸盐改性漆酶方法可行,漆酶活性和稳定性均得到较大提高。

Poplar P-RC APMP pulp was chosen as raw materials for fines generation and collecting, then the Zeta potential of pulp, white water cationic demand, the retention of fines and paper＇s property of traditional papermak- ing and co-flocculation process were studied. The results shows that compared with the traditional papermaking process, the co-flocculation process can improve the retention rate of fines and filler up to 5.98% and 6.28% re- spectively, increase brightness, opacity and strength properties of the paper, but it is not conducive to the bulk of the paper. The absolute value of Zeta potential and white water cationic demand in the traditional process are higher than those in the co-flocculation process.