绒毛栓孔菌菌丝体在无营养条件下对偶氮染料刚果红的脱色作用

【目的】在无营养条件下,利用白腐真菌绒毛栓孔菌(Trametes pubescens)菌丝体对染料进行脱色可减少试验成本,提高染料处理的实用性。【方法】将该菌株液体培养的菌丝体在无营养条件下对染料进行脱色,并对其中脱色效果较好的偶氮染料刚果红的脱色过程进行分析。在此过程中,测定了该菌株分泌的胞外胞内酶活力,优化影响因子如初始pH值、温度、染料浓度和盐度,同时利用气相色谱-质谱联用技术分析无营养条件下偶氮染料刚果红的降解产物。植物毒性试验测定刚果红经绒毛栓孔菌菌丝体脱色前后的毒性变化。【结果】菌丝体对偶氮染料刚果红有较好的脱色效果,在初始pH值为2.0,温度为30°C,染料浓度为80 mg/L,盐度为2.5%(质量体积比)时,150 r/min转速下培养7 d后脱色率可达80.52%。在此过程中,菌丝体可被连续使用2次,且其所分泌的酶系可降解染料。此外,通过气相色谱-质谱联用分析得到刚果红的降解产物为萘胺、联苯胺和叠氮萘。植物毒性试验显示在无营养条件下的绒毛栓孔菌菌丝体对染料有明显的脱毒作用。【结论】研究发现绒毛栓孔菌菌丝体在无营养条件下的偶氮染料废水处理中具有广阔的应用前景。

Decolorization of azo dye Congo Red by Trametes pubescens pellets without addition of nutrition

Objective] White-rot fungus Trametes pubescens pellets without addition of nutrition treatment, a novel design, was used to lower the running cost as well as to enhance convenient availability for dye decolorization. Methods] Liquid cultured pellets of T. pubescens were used to decolorize various dyes without addition of nutrition and then the removal process of the azo dye Congo Red with higher decolorization rate was analyzed. During the decolorization process, the extracellular and intracellular enzyme activities were monitored and the impact factors such as initial pH value, temperature, dye concentration and salinity were optimized. Moreover, metabolites of the dye Congo Red degraded by T. pubescens pellets without addition of nutrition were analyzed by gas chromatography-mass spectroscopy (GC-MS). Phytotoxicity experiment was carried out before and after dye decolorization to assess the toxic nature of the metabolites. Results] The pellets could decolorize azo dye Congo Red. After a 7-day incubation period, the highest dye removal of 80.52% was observed under 150 r/min shaking speed at initial pH 2.0, temperature at 30 °C, dye concentration 80 mg/L and salinity 2.5% (W/V). The pellets performed good persistence in repetitive decolorization operations, as well as high potentials toward the degradation of dye Congo Red which could be attributed to the presence of biotransformation enzymes. Additionally, degraded metabolites were identified as naphthalene amine, biphenyl amine and naphthalene diazonium, as evidenced by GC-MS. Phytotoxicity experiment confirmed that the azo dye Congo Red degraded by T. pubescens pellets without addition of nutrition resulted in its detoxification. Conclusion] These findings demonstrate that the T. pubescens pellets have potentials for the azo dye effluents treatment applications without addition of nutrition.