漆酶/介质系统催化偶氮染料直接橙S脱色

Decolorization of azo-type dye Direct Orange S catalyzed by laccase/mediator system

利用灵芝菌Ganoderma lucidum漆酶的催化作用对偶氮染料直接橙S进行脱色处理,考察脱色反应体系各因素对脱色率的影响,初步探讨漆酶对直接橙S脱色降解机理。结果表明,2,2’-连氮-双(3-乙基苯并噻唑啉-6-磺酸)可显著提升漆酶对直接橙S的脱色效果。直接橙S脱色效果受多种条件的影响,在直接橙S初始浓度50 mg·L^(-1)、漆酶加入量0.26 U·m L^(-1)、2,2’-连氮-双(3-乙基苯并噻唑啉-6-磺酸)10μmol·L^(-1)、pH 6.0、50℃条件下,可获得较好的脱色效果,90min后脱色率可达到62.99%。吸收光谱分析表明,漆酶与2,2’-连氮-双(3-乙基苯并噻唑啉-6-磺酸)的协同氧化导致直接橙S分子结构的改变,是其快速脱色的主要发生机制。

Laccase derived from Ganoderma lucidum,which functions in catalysis,was used to decolorize the azo-type dye Direct Orange S. The factors affecting the decolorization rate of Direct Orange S in the reaction system were investigated and the decolorization and degradation mechanisms were disscussed. ABTS significantly enhanced the decolorization of Direct Orange S. The decolorization efficiency of Direct Orange S was influenced by various conditions. Optimal decolorization was obtained using 50 mg·L^（-1）dye,0. 26 U·m L^（-1）laccase,and 10μmol· L^（-1）ABTS at pH 6. 0 and 50 ℃. Under these initial conditions,the docolorization rate increased to62. 99% in 90 min. An analysis of the absorbtion spectrum showed that cooperative oxydation of laccase and ABTS changed the molecular structure of Direct Orange S,and this mechanism explains the rapid decolorization.