Structure and Bio-degradation of Chlorinated Lignin

未漂白的硫酸盐纸浆经氯漂白后，针叶木硫酸盐浆中的残余木素比针叶木硫酸盐纸浆更易溶于水。针叶木硫酸盐浆产生的大部分可吸附有机氯(AOX)和总有机碳(TOX)存在于氯阶段(C阶段)的废水中，而不是E阶段的废水中，这与针叶木硫酸盐浆的情况形成了鲜明的对比。通过氧气处理，硫酸盐浆中相当一部分残存木素被转化为对氯具有高活性的部分。在这种活性木质素中产生的有机氯形成一种不稳定的有机氯，它很容易被亲核试剂的攻击除去。AOX法不能给出C段出水有机氯含量的精确值。这是因为C段废水中存在不稳定的有机氯。当漂白废水中发现的一种典型的氯有机物-氯愈创木酚被黄孢原毛平革菌处理时，甲基化反应和酚羟基的氧化(脱氢)反应是竞争反应。在整个真菌生命过程中，甲基化反应是活跃的，而苯酚氧化活性只有在次生代谢过程中才可见。当反应体系中存在酚类化合物时，藜芦醇氧化木质素过氧化物酶的活性完全被抑制。

When unbleached kraft pulps are subjected to chlorine bleaching, residual lignin in hardwood kraft pulps become soluble in water more easily than that in softwood kraft pulps. Majority of adsorbable organic chlorine (AOX), and total organic carbon (TOX), produced from hardwood kraft pulps, were found to be present in chlorine stage (C-stage) effluent rather than in E-stage effluent, which makes a contrast to those of softwood kraft pulp. By oxygen treatment, a considerable part of residual lignin in kraft pulp was converted to a part which is highly reactive to chlorine. A organic chlorine produced in such a reactive lignin forms a unstable organic chlorine, which is easily removed by an attack of a nucleophile. AOX method does not give an accurate value for organic chlorine content of C-stage effluent. The reason for this was attributable to the presence of unstable organic chlorine in C-stage effluent.Methylation reaction and oxidation (dehydrogenation) reaction of phenolic hydroxyl group are competing reaction when phenolic compounds such as a chlorinated guaiachol, a typical chloroorganic found in bleaching effluent, is treated by Phanerochaete chrysosporium. Methylation reaction is active throughout the fungus life, while phenol oxidation activity is visible only during a secondary metabolism.Veratryl alcohol oxidation activity of ligninperoxidase is inhibited completely when phenolic compound are present in a reaction system.