Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, FI-00076 Aalto, Finland.
Stora Enso, Imatra Research Center, Tornansaarenraitti 48, Imatra FI-55400, Finland.
Biomacromolecules. 2021 Nov 8;22(11):4805-4813. doi: 10.1021/acs.biomac.1c01102. Epub 2021 Oct 21.
Prehydrolysis kraft (PHK) pulps account for more than half of the global market of dissolving pulp. Characterized by high reactivity toward dissolution, their performances can still be improved by activation treatments. This study compares the dissolution kinetics in cupriethylenediamine of a hardwood and a softwood PHK pulps before and after their activation by high-solid-content mechano-enzymatic treatments. Three enzyme combinations were tested: endoglucanase (E), xylanase and mannanase (XM), and endoglucanase, xylanase, and mannanase (EXM). Xylanase and mannanase reduced the hemicellulose content of only hardwood (by max. 2.4%). Mixing and carbohydrate depolymerization decreased the dissolution time of hardwood and softwood pulps by a maximum of 63 and 30% with E, 37 and 16% with XM, and 44 and 30% with EXM, respectively. The shortening of the dissolution time was partially hindered by hornification, which increased with hemicellulose degradation. Interestingly, XM accelerated the dissolution while preserving a high weight-average molecular mass.
预水解硫酸盐（PHK）浆占全球溶解浆市场的一半以上。由于其对溶解具有很高的反应性，因此可以通过活化处理来提高其性能。本研究比较了在经过高固含量机械-酶处理活化前后，硬木和软木 PHK 浆在铜乙二胺中的溶解动力学。测试了三种酶组合：内切葡聚糖酶（E）、木聚糖酶和甘露聚糖酶（XM）以及内切葡聚糖酶、木聚糖酶和甘露聚糖酶（EXM）。木聚糖酶和甘露聚糖酶仅降低了硬木的半纤维素含量（最多 2.4%）。混合和碳水化合物解聚作用使硬木和软木浆的溶解时间分别最大缩短了 63%和 30%（使用 E）、37%和 16%（使用 XM）以及 44%和 30%（使用 EXM）。角蛋白化部分阻碍了溶解时间的缩短，而角蛋白化随半纤维素的降解而增加。有趣的是，XM 加速了溶解，同时保持了较高的重均分子量。
