Chemical Engineering Department, ETSEIAT, Universitat Politècnica de Catalunya, Colom 11, E-08222 Terrassa, Spain.
Textile and Paper Engineering Department, ETSEIAT, Universitat Politècnica de Catalunya, Colom 11, E-08222 Terrassa, Spain.
Bioresour Technol. 2014;152:253-8. doi: 10.1016/j.biortech.2013.11.014. Epub 2013 Nov 16.
Enzymatic delignification with laccase from Trametes villosa used in combination with chemical mediators (acetosyringone, acetovanillone and 1-hydroxybenzotriazole) to improve the totally chlorine-free (TCF) bleaching of kenaf pulp was studied. The best final pulp properties were obtained by using an LHBTQPo sequence developed by incorporating a laccase-mediator stage into an industrial bleaching sequence involving chelation and peroxide stages. The new sequence resulted in increased kenaf pulp delignification (90.4%) and brightness (77.2%ISO) relative to a conventional TCF chemical sequence (74.5% delignification and 74.5% brightness). Also, the sequence provided bleached kenaf fibers with high cellulose content (pulp viscosity of 890 g·mL(-1) vs 660 g·mL(-1)). Scanning electron micrographs revealed that xylanase altered fiber surfaces and facilitated reagent access as a result. However, the LHBTX (xylanase) stage removed 21% of hexenuronic acids in kenaf pulp. These recalcitrant compounds spent additional bleaching reagents and affected pulp properties after peroxide stage.
用糙皮侧耳木聚糖酶与化学媒介物（乙酰丁香酮、乙酰香草酮和 1-羟基苯并三唑）联合进行酶促脱木质素，以改善剑麻浆全无氯（TCF）漂白。通过将漆酶-媒介物阶段纳入螯合和过氧化物阶段的工业漂白序列来开发 LHBTQPo 序列，可以获得最佳的最终纸浆性能。与传统的 TCF 化学序列（74.5%脱木质素和 74.5%白度）相比，新序列导致剑麻浆脱木质素（90.4%）和亮度（77.2%ISO）提高。此外，该序列为漂白后的剑麻纤维提供了高纤维素含量（纸浆粘度为 890 g·mL(-1) 比 660 g·mL(-1)）。扫描电子显微镜照片显示，木聚糖酶改变了纤维表面，从而促进了试剂的进入。然而，LHBTX（木聚糖酶）阶段去除了剑麻浆中 21%的己糖醛酸。这些抗性化合物需要额外的漂白试剂，并在过氧化物阶段后影响纸浆性能。
