Bajpai Pratima, Anand Aradhna, Bajpai Pramod K
Thapar Centre for Industrial Research & Development, Patiala, India.
Biotechnol Annu Rev. 2006;12:349-78. doi: 10.1016/S1387-2656(06)12010-4.
General concern about the environmental impact of chlorine bleaching effluents has led to a trend towards elementary chlorine-free or totally chlorine free bleaching methods. Considerable interest has been focused on the use of biotechnology in pulp bleaching, as large number of microbes and the enzymes produced by them are known to be capable of preferential degradation of native lignin and complete degradation of wood. Enzymes of the hemicellulolytic type, particularly xylan-attacking enzymes xylanases are now used commercially in the mills for pulp treatment and subsequent incorporation into bleach sequences. Certain white-rot fungi can delignify Kraft pulps increasing their brightness and their responsiveness to brightening with chemicals. The fungal treatments are too slow but the enzymes produced from the fungi can also delignify pulps and these enzymatic processes are likely to be easier to optimize and apply than the fungal treatments. This article presents an overview of the developments in the application of lignin-oxidizing enzymes in bleaching of chemical pulps. The present knowledge of the mechanisms on the action of enzymes as well as the practical results and advantages obtained on the laboratory and industrial scale are discussed.
对氯漂废水环境影响的普遍关注导致了向无元素氯或全无氯漂白方法发展的趋势。人们对生物技术在纸浆漂白中的应用产生了浓厚兴趣，因为已知大量微生物及其产生的酶能够优先降解天然木质素并完全降解木材。半纤维素分解型酶，特别是作用于木聚糖的木聚糖酶，目前已在工厂中商业用于纸浆处理并随后纳入漂白流程。某些白腐真菌可以使硫酸盐浆脱木质素，提高其亮度以及对化学增白的响应性。真菌处理速度太慢，但真菌产生的酶也可以使纸浆脱木质素，而且这些酶促过程可能比真菌处理更容易优化和应用。本文概述了木质素氧化酶在化学浆漂白中的应用进展。讨论了目前关于酶作用机制的知识以及在实验室和工业规模上获得的实际结果和优势。
