Textile and Paper Engineering Department, ETSEIAT, Universitat Politècnica de Catalunya, Colom 11, E-08222 Terrassa, Spain.
Bioresour Technol. 2010 Jun;101(11):4104-10. doi: 10.1016/j.biortech.2010.01.057. Epub 2010 Feb 7.
The phenols syringaldehyde (SA), acetosyringone (AS) and p-coumaric acid (PCA) were used as natural laccase mediators in combination with a laccase from Pycnoporus cinnabarinus to bleach flax fibres. Their performance was compared with 1-hydroxybenzotriazole (HBT) in terms of enzyme stability, and pulp and effluent properties. HBT and PCA were found to inactivate laccase in the absence of pulp. However, in the presence of unbleached flax pulp stability was increased; for example with PCA, laccase retained 77% of its initial activity, in contrast with complete inactivation in the absence of pulp. This suggests a protective effect of the pulp against denaturalization of the enzyme. All natural mediators resulted in a reduced kappa number after the subsequent alkaline treatment with hydrogen peroxide; the reduction being especially marked with SA (about 2 units - with respect to the control sample) and comparable to that obtained by HBT. Brightness was significantly increased by all natural mediators, but especially by AS and SA (23% with both), which performed very similarly to HBT in this respect. Natural mediators therefore might constitute an effective alternative to synthetic mediators for flax pulp biobleaching. This paper demonstrates for the first time the use of natural mediators in the laccase-assisted delignification of flax pulp and their effect on the properties of the resulting effluents.
丁香醛（SA）、乙酰丁香酮（AS）和对香豆酸（PCA）等酚类物质被用作肉桂孔菌漆酶的天然漆酶介体，用于漂白亚麻纤维。将它们的性能与 1-羟基苯并三唑（HBT）进行比较，主要考虑酶稳定性以及纸浆和废水的性质。结果表明，在没有纸浆的情况下，HBT 和 PCA 会使漆酶失活。然而，在未漂亚麻纸浆存在的情况下，稳定性会增加；例如，对于 PCA，漆酶保留了其初始活性的 77%，而在没有纸浆的情况下则完全失活。这表明纸浆对酶的非天然化具有保护作用。所有天然介体在随后用双氧水进行碱性处理后都会导致卡伯值降低；与对照样品相比，SA 的降低尤为明显（约 2 个单位），与 HBT 的降低相当。所有天然介体都能显著提高白度，但 AS 和 SA 的效果更为明显（两者均提高了 23%），在这方面它们与 HBT 的性能非常相似。因此，天然介体可能是亚麻纸浆生物漂白用合成介体的有效替代品。本文首次证明了在漆酶辅助的亚麻纸浆脱木质素过程中使用天然介体，以及它们对所得废水性质的影响。
