Akhtar Suhail, Ali Khan Amjad, Husain Qayyum
Department of Biochemistry, Faculty of Life Science, Aligarh Muslim University, Aligarh 202002, India.
Bioresour Technol. 2005 Nov;96(16):1804-11. doi: 10.1016/j.biortech.2005.01.004. Epub 2005 Feb 25.
The aim of this study was to evaluate the enzymatic action of partially purified bitter gourd peroxidase for the degradation/decolorization of complex aromatic structures. Twenty-one dyes, with a wide spectrum of chemical groups, currently being used by the textile and other important industries have been selected for the study. Here, for the first time we have shown peroxidases from Momordica charantia (300 EU/gm of vegetable) to be highly effective in decolorizing industrially important dyes. Dye solutions, containing 50-200 mg dye/l, were used for the treatment with bitter gourd peroxidase (specific activity of 99.0 EU/mg protein). M. charantia peroxidases were able to decolorize most of the textile dyes by forming insoluble precipitate. When the textile dyes were treated with increasing concentration of enzyme, it was observed that greater fraction of the color was removed but four out of eight reactive dyes were recalcitrant to decolorization by bitter gourd peroxidase. Step-wise addition of enzyme to the decolorizing reaction mixture at the interval of 1h further enhanced the dye decolorization. The rate of decolorization was enhanced when the dyes were incubated with fixed quantity of enzyme for increasing times. Decolorization of non-textile dyes resulted in the degradation and removal of dyes from the solution without any precipitate formation. Decolorization rate was drastically increased when the textile and other industrially important non-textile dyes were treated with bitter gourd peroxidase in presence of 1.0 mM 1-hydroxybenzotriazole. Complex mixtures of dyes were prepared by taking three to four reactive textile and non-textile dyes in equal proportions. Each mixture was decolorized by more than 80% when treated with the enzyme in presence of 1.0 mM 1-hydroxybenzotriazole. Our data suggest that the peroxidase/mediator system is an effective biocatalyst for the treatment of effluents containing recalcitrant dyes from textile, dye manufacturing, dyeing and printing industries.
本研究的目的是评估部分纯化的苦瓜过氧化物酶对复杂芳香结构的降解/脱色酶促作用。本研究选取了纺织及其他重要行业目前使用的21种具有广泛化学基团的染料。在此，我们首次表明苦瓜（每克蔬菜含300个酶活力单位）中的过氧化物酶在使具有工业重要性的染料脱色方面非常有效。含有50 - 200毫克染料/升的染料溶液用于苦瓜过氧化物酶（比活性为99.0酶活力单位/毫克蛋白质）处理。苦瓜过氧化物酶能够通过形成不溶性沉淀使大多数纺织染料脱色。当用浓度不断增加的酶处理纺织染料时，观察到更大比例的颜色被去除，但八种活性染料中有四种对苦瓜过氧化物酶的脱色具有抗性。以1小时为间隔向脱色反应混合物中逐步添加酶进一步增强了染料脱色效果。当染料与固定量的酶孵育时间增加时，脱色速率提高。非纺织染料的脱色导致染料从溶液中降解并去除，且无任何沉淀形成。当纺织染料和其他具有工业重要性的非纺织染料在1.0毫摩尔1 - 羟基苯并三唑存在下用苦瓜过氧化物酶处理时，脱色速率大幅提高。通过以等比例混合三到四种活性纺织和非纺织染料制备染料复杂混合物。当在1.0毫摩尔1 - 羟基苯并三唑存在下用酶处理时，每种混合物的脱色率超过80%。我们的数据表明，过氧化物酶/介质系统是处理来自纺织、染料制造、染色和印花行业含难降解染料废水的有效生物催化剂。
