Decolorization of Malachite Green by a Newly Isolated Penicillium sp. YW 01 and Optimization of Decolorization Parameters

摘要

Triphenylmethane dyes are aromatic xenobiotic compounds that are widely considered to be one of the mostnrecalcitrant pollutants discharged into the environment. A fungus Penicillium sp. having decolorization capa-ncities for Malachite Green was isolated from contaminated soil, given name YW 01. Plackett-Burman and Box-nBehnken designs were used to screen the effects of decolorization factors and obtain the optimum conditions forndecolorization of Malachite Green, respectively. Sucrose concentration had a significantly negative effect on thendecolorization of Malachite Green, whereas the effects of initial pH and inoculum size were significantly positiven( p < 0.05). Optimum conditions by Box-Behnken design for the decolorization process were sucrose concentra-ntion 9.02 g/L, initial pH 6.0, and inoculum size 3.5 g (wet weight). 98.23% decolorization was observed forn25mg/L dye concentration after 6 days under optimum conditions, which was close to the predicted valuen98.93%. Induction in the activities of lignin peroxidase and NADH-dependent 2,6-dichlorophenolindophenolnreductase was observed during Malachite Green decolorization, indicating these enzymes involved in the de-ncolorization process. Information from pseudo-first-order kinetic function for decolorization process of Mala-nchite Green (R2n= 0.9221) implied the decolorization half-life of Malachite Green by Penicillium sp. YW 01 wasn0.92 day, indicating that Penicillium sp. YW 01 was efficient for the degradation of Malachite Green and usefulnfor the biological treatment of dye effluents.