Clarke J H, Rixon J E, Ciruela A, Gilbert H J, Hazlewood G P
Department of Cellular Physiology, Babraham Institute, Cambridge, UK.
Appl Microbiol Biotechnol. 1997 Aug;48(2):177-83. doi: 10.1007/s002530051035.
Enzyme-aided bleaching of softwood and hardwood kraft pulps by glycosyl hydrolase family-10 and -11 xylanases and a family-26 mannanase was investigated. The ability to release reducing sugar from pulp xylan and to enhance bleachability is not a characteristic shared by all xylanases. Of the six enzymes tested, two xylanases belonging to family 11 were most effective at increasing bleachability and improving final paper brightness. None of the enzymes had a deleterious effect on pulp fibre integrity. The efficiency of individual xylanases as bleach enhancers was not dependent on the source microorganism, and could not be predicted solely on the basis of the quantity or nature of products released from pulp xylan. Cooperative interactions between xylanase/xylanase and xylanase/mannanase combinations, during the pretreatment of softwood and hardwood pulps, were investigated. Synergistic effects on reducing-sugar release and kappa number reduction were elicited by a combination of two family-10 xylanases. Pretreatment of kraft pulp with mannanase A from Pseudomonas fluorescens subsp. cellulosa and any one of a number of xylanases resulted in increased release of reducing sugar and a larger reduction in kappa number than obtained with the xylanases alone, confirming the beneficial effects of family-26 mannanases on enzyme-aided bleaching of paper pulp.
研究了糖基水解酶家族10和11的木聚糖酶以及家族26的甘露聚糖酶对针叶木和阔叶木硫酸盐浆的酶辅助漂白作用。从纸浆木聚糖中释放还原糖以及提高可漂性的能力并非所有木聚糖酶都具备的特性。在所测试的六种酶中，属于家族11的两种木聚糖酶在提高可漂性和改善最终纸张亮度方面最为有效。没有一种酶对纸浆纤维完整性有有害影响。单个木聚糖酶作为漂白增强剂的效率并不取决于来源微生物，也不能仅根据从纸浆木聚糖中释放的产物数量或性质来预测。研究了在针叶木和阔叶木浆预处理过程中木聚糖酶/木聚糖酶以及木聚糖酶/甘露聚糖酶组合之间的协同相互作用。两种家族10木聚糖酶的组合对还原糖释放和卡伯值降低产生了协同效应。用荧光假单胞菌纤维素亚种的甘露聚糖酶A和多种木聚糖酶中的任何一种对硫酸盐浆进行预处理，与单独使用木聚糖酶相比，导致还原糖释放增加，卡伯值降低幅度更大，证实了家族26甘露聚糖酶对纸浆酶辅助漂白的有益作用。
