Copper Induced Laccase By Panus Conchatus And Its Potential In Dyes Decolorization

Laccase (E.C.1.10.3.2) is a copper-containing oxidase which can catalyse the oxidation ofaromatic compounds. It can also catalyse oxidation of more substrates with the help of smallmolecular mediators. So it is widely used in biological, medical, chemical and environmentalfields. In the thesis, the submerged fermentation of Panus conchatus laccase, and theapplication of laccase in acid green25, methyl orange and malachite green decolorizationwere investigated.Which would, as we wish, provide the theoretical support for laccaseproduction and industrial application.Firstly, the induction of copper on Panus conchatus laccase was evaluated. The highestlaccase activity196084U/L was obtained from Panus conchatus at14thday under inductionof3mmol/L Cu2+. The activity was11-folds higher than that of the control smaple.The crudelaccase were used to decolorize37dyes and the results showed that laccase can catalyse mostof the dyes with or without mediators.Laccase was used to decolorize acid green25. The decolorization was designed and theexperimental data was analyzed by IBM SPSS Statistics19software. Orthogonal wasdesigned by the pH、Temperature、intinal laccase activity、initinal dye concentration andmediator concentration. Test results were inputted to the IBM SPSS Statistics19software andwere analyzed, analysis of variance and statistics of single factor were got, and optimizationconditions were determinted as follows: pH was4.0、Temperature was50℃、intinal laccaseactivity was2.5U/mL、initinal dye concentration was100mg/L、mediator concentration(HOBT) was0.015%(w/v). The final decolorization rate was100%in20min. IBM SPSSStatistics19software has a strong experimental design and data statistical analysis and theconclusion was reliable.Then laccase was used to decolorize Methyl Orange and Malachite Green. the suitablepH value were3.0and5.5; laccase loads were0.8U/mL and5U/mL; dye concentration were20mg/L and10mg/L, and the decolorization rate were92.15%and100%respectively. Theresidual amount of Methyl Orange is1.57mg/L and Malachite Green was absolutely degradedafter treatment with laccase, amount of residual dye in the reaction system is in accord withthe wastewater discharge standard. The crude laccase without any purification steps would reduce the cost of the wastewater treatment with laccase. At the same time, the gooddecolorization results demonstrated the potential implement of laccase in the industries.