Softwood mechanical pulps have proven to be quite recalcitrant to enzymatic hydrolysis. However, the unhydrolyzed, residual fibers might have potential as nanofibrillated cellulose feedstocks. In the work reported here, a bleached softwood chemi-thermomechanical pulp (CTMP) was neutrally sulfonated (S-BCTMP) in an attempt to enhance fiber accessibility and enzymatic hydrolysis. A 12 h hydrolysis at 10% solid loading with CTec3 cellulases provided optimum conditions with 22% of the pulp hydrolyzed to monosaccharides and about one-third of the original substrate remaining as lignin-containing cellulose nanofibrils (LCNFs). Prolonged hydrolysis (72 h) resulted in 42% hydrolysis of the original substrate with only 16% of the original S-BCTMP recovered as LCNFs. Although the LCNFs contained high levels of lignin (26.8%–38.5%), they were successfully used to prepare transparent films showing a high contact angle (82.8°) and strong UV-blocking properties. It was apparent that enzyme-mediated modification of CTMP has the potential to produce both fermentable sugars and higher-value LCNFs.

中文翻译：

---

从酶水解化学热机械浆生产糖和木质素的纤维素纳米原纤维的潜力

事实证明，软木机械纸浆对酶促水解非常不利。然而，未水解的残留纤维可能具有作为纳米原纤化纤维素原料的潜力。在这里报道的工作中，对漂白的针叶化学热机械浆（CTMP）进行中性磺化（S-BCTMP），以增强纤维的可及性和酶促水解作用。用CTec3纤维素在固体含量为10％的条件下进行12 h水解可提供最佳条件，其中22％的果肉水解为单糖，原始底物的约三分之一保留为含木质素的纤维素纳米原纤维（LCNF）。延长的水解时间（72小时）导致原始底物的水解度为42％，而仅有16％的原始S-BCTMP作为LCNF被回收。尽管LCNFs中木质素含量较高（26.8％–38.5％），它们已成功用于制备具有高接触角（82.8°）和强紫外线阻隔性能的透明薄膜。显然，酶介导的CTMP修饰具有产生可发酵糖和高价值LCNF的潜力。