Decoloration of industrial dye effluents using immobilized lignin degrading enzymes

进入环境的有色废水越来越受到关注，因为颜色是一种可见的污染物，在世界范围内越来越受到监管。它是不美观的，对环境有负面影响，一些合成染料可能是致癌物或诱变剂。这些废水来自纺织和染料制造业、纸浆和造纸业以及食品加工业。目前大多数物理和/或化学脱色技术不能实现完全脱色，操作困难或过于昂贵;传统的生物废水处理具有低去除效率。 白色腐真菌能使多种染料脱色。尽管使用固定化培养物有优势，但生物膜生长的增加最终导致反应器性能差。使用它们的酶可以避免这个问题，但是可溶性酶在处理废水中是不实用的，因为需要大量的酶，并且酶可能变性。固定在固体基质上可以克服这些缺点。到目前为止，我们已经成功地评估了固定化漆酶，但白色腐真菌产生其他木质素降解酶，如木质素过氧化物酶，锰过氧化物酶和纤维二糖脱氢酶，也脱色。 为了具有有效的过程，需要这些酶的组合。 该提案的长期目标是：（一）开发一种具有成本效益的生物工艺（基于固定化酶），以使染料废水脱色;（二）了解降解机制。第一个目标将通过结合酶来靶向偶氮和蒽醌染料来实现，偶氮和蒽醌染料构成商业上使用的大多数染料。第二个目标将集中在脱色中的表面活性剂的作用，因为这种流出物成分会导致显着的酶抑制。从这项工作中获得的知识也可以应用于其他外源性物质的降解和纸浆和纸张的生物漂白。 这一项目的成果可能有助于加拿大经济，因为它在建造和操作废水处理酶反应器方面创造了就业机会;并通过消除一种可见的和潜在的有毒污染物，改善生活质量和环境。

Colored effluent into the environment is of growing concern, as color is a visible pollutant which is increasingly being regulated worldwide. It is aesthetically unpleasing, negatively impacts the environment and some synthetic dyes may be carcinogens or mutagens. Such effluents arise from textile and dyestuff manufacturing, and the pulp and paper, and food processing industries. Most current physical and/or chemical decoloration technologies do not achieve total decoloration, have operational difficulties or are too expensive; and traditional biological wastewater treatments have low removal efficiencies. White rot fungi can decolorize a wide range of dyes. Although there are advantages to use immobilized cultures, increase in biofilm growth eventually lead to poor reactor performance. Using their enzymes will avoid this problem but soluble enzymes are not practical in treating effluents as large quantities would be needed and the enzymes could be denatured. Immobilization on a solid matrix could overcome these drawbacks. So far, we have successfully evaluated immobilized laccase but white rot fungi produce other lignin-degrading enzymes such as lignin peroxidase, manganese peroxidise and cellobiose dehydrogenase that also decolorize. To have an effective process, combinations of these enzymes are required. The long-term objectives of this proposal are (i) to develop a cost-effective, biological process (based on immobilized enzymes) to decolorize dye effluents and (ii) to understand the degradation mechanisms. The first objective will be achieved by combining enzymes to target azo and anthraquinone dyes which make up a majority of dyes commercially used. The second objective will focus on the role of surfactants in decolorization as this effluent component causes significant enzyme inhibition. The knowledge from this work can also be applied to the degradation of other xenobiotics and biobleaching of pulp and paper. The outcome of this project may contribute to the Canadian economy by creating jobs in the construction and operation of enzyme reactors for wastewater treatment; and improve the quality of life and the environment by removing a visible and potentially toxic pollutant.