Mechichi Tahar, Mhiri Nejla, Sayadi Sami
Laboratoire des Bioprocédés, Centre de Biotechnologie de Sfax BP "K", 3038 Sfax, Tunisia.
Chemosphere. 2006 Aug;64(6):998-1005. doi: 10.1016/j.chemosphere.2005.12.061. Epub 2006 Feb 13.
The decolourization of the recalcitrant dye RBBR by the culture filtrate of Trametes trogii and its isolated laccase was investigated. Both filtrates from Cu-induced cultures as well as purified laccase decolourized the dye RBBR. The purified laccase decolourized the dye down to 97% of 100 mg l(-1) initial concentration of RBBR when only 0.2U ml(-1) of laccase was used in the reaction mixture. The effects of different physicochemical parameters were tested and optimal decolourization rates occurred at pH 5 and at a temperature of 50 degrees C. Decolourization of RBBR occurred in the presence of metal ions which could be found in textile industry effluents. Of all the metal ions tested, FeCl2 was the most inhibiting for the decolourization. HBT was shown to have no effect on the decolourization of RBBR at low concentration, while at a concentration of 5 mM it slightly inhibited decolourization. The presence of aromatic compounds was found to be inhibiting for the decolourization at a concentration of 10 mM, but not at 0.1 mM, while at 1 mM only ortho-diphenols were inhibiting. Probing the effect of methanol it was found that higher concentrations caused a decrease in the decolourization rate of RBBR. The effect of laccase inhibitors on the decolourization of RBBR was tested with L-cysteine, SDS and EDTA. It was demonstrated that L-cysteine was the most inhibiting substrate for the decolourization while SDS was only inhibiting at 10 mM concentration and ETDA was not inhibiting at all tested concentrations.
研究了毛栓菌培养滤液及其分离的漆酶对难降解染料RBBR的脱色作用。铜诱导培养物的滤液以及纯化的漆酶都能使染料RBBR脱色。当反应混合物中仅使用0.2U ml(-1)的漆酶时，纯化的漆酶能将初始浓度为100 mg l(-1)的RBBR染料脱色至97%。测试了不同理化参数的影响，在pH 5和50℃温度下出现最佳脱色率。RBBR在纺织工业废水中可能存在的金属离子存在下发生脱色。在所有测试的金属离子中，FeCl2对脱色的抑制作用最强。结果表明，低浓度的HBT对RBBR的脱色没有影响，而在浓度为5 mM时，它对脱色有轻微抑制作用。发现芳香族化合物在浓度为10 mM时对脱色有抑制作用，但在0.1 mM时没有，而在1 mM时只有邻二酚有抑制作用。研究甲醇的影响时发现，较高浓度会导致RBBR脱色率降低。用L-半胱氨酸、SDS和EDTA测试了漆酶抑制剂对RBBR脱色的影响。结果表明，L-半胱氨酸是对脱色抑制作用最强的底物，而SDS仅在浓度为10 mM时具有抑制作用，ETDA在所有测试浓度下均无抑制作用。
