嗜盐菌群对酸性金黄G的脱色特性和机理

Decolorization of methanil yellow G by a halophilic bacterial consortium

摘要:

[目的]为了获得能够在高盐环境下脱色偶氮染料的嗜盐菌群及其降解机理。[方法]采用富集驯化的方法获得一个嗜盐菌群，采用Illumina HiSeq2500测序平台对其群落结构进行测定；采用分光光度法测定了其降解特性；采用GC-MS和红外图谱分析了其降解机理；采用微核实验的方法比较了偶氮染料降解前后的毒性。[结果]该菌群在10%的盐度下，使100 mg/L的酸性金黄G在8 h内脱色。菌群主要由Zobellella、Rheinheimera、Exiguobacterium和Marinobacterium组成。最适宜的脱色条件是：pH=6，酵母粉为碳源，蛋白胨或硝酸钾作为氮源，盐度为1%-10%。酸性金黄G降解产物的毒性比降解前降低。酸性金黄G主要的降解产物是对氨基二苯胺和二苯胺。此外，该菌群还能使酸性大红GR和直接湖蓝5B等多种偶氮染料脱色，具有较好的脱色广谱性。[结论]获得了快速降解偶氮染料的嗜盐菌群及降解机理，为该嗜盐菌群应用于高盐印染废水的处理提供菌种资源和理论支持。

Abstract:

[Objective] In order to obtain highly efficient bacterial consortium that can rapidly decolorize azo dyes in high salinity environment. [Methods] A halophilic bacterial consortium was obtained by enrichment, and its community structure was determined by Illumina HiSeq2500 sequencing platform. The degradation characteristics were determined by spectrophotometry. The degradation mechanism was analyzed by GC-MS and Fourier Transform infrared spectroscopy. The toxicity of azo dye and degradation product were compared by micronuclear test. [Results] At 10% salinity, the bacterial consortium decolorizes methanil yellow G completely in 8 h. The bacterial consortium was composed of Zobellella, Rheinheimera, Exiguobacterium and Marinobacterium. At pH 6.0, with yeast powder as carbon sources, peptone or potassium nitrate as nitrogen sources and 1% NaCl were the optimal decolorization conditions. Decolorization metabolites of methanil yellow G were less toxic than original dye. The main degradation products of methanil yellow G were p-aminodiphenylamine and diphenylamine. In addition, the bacterial consortium also decolorized various azo dyes, such as acid magenta GR and direct lake blue 5B. [Conclusion] A halophilic bacterial consortium for fast degradation of azo dyes was obtained, with the application potential to treat high-salt printing and dyeing wastewater.