黄孢原毛平革菌对RBBR脱色降解及其降解机制

Decolorization and degradation mechanism of reactive brilliant blue KN-R(RBBR) by Phanerochaete chrysosporium

为研究白腐真菌对蒽醌染料的生物降解机制,以白腐真菌黄孢原毛平革菌为脱色降解菌株,分析了蒽醌染料活性艳蓝KN-R(RBBR)的浓度、金属离子及脱色参数对染料脱色的影响;采用紫外-可见光谱、红外光谱、气相色谱-质谱(GC-MS)分析和植物种子毒性实验进行降解产物分析,以揭示RBBR可能的降解路径及其产物的毒性。结果表明:在pH 4.2、28℃、5mmol/L的Mn2+条件下,脱色降解200mg/L RBBR,24h脱色率可达95%以上。推测RBBR的降解途径为:RBBR中连接苯环和蒽醌的氮键裂解,产生了1-氨基蒽醌和间-(β-羟乙基砜硫酸酯钠)苯胺。1-氨基蒽醌上的氨基被羟基取代,再经过氧化、脱环、重排产生了邻苯二甲酸,接着邻苯二甲酸氧化开环生成丁二酸;同时,间-(β-羟乙基砜硫酸酯钠)苯胺上的氨基被氧化,生成丁二酸及其他小分子酸、二氧化碳和水。植物种子毒性实验表明,黄孢原毛平革菌对RBBR有较好的脱毒作用。综上,黄孢原毛平革菌能高效降解高浓度的RBBR,同时可显著降低染料对植物的毒害作用。

Phanerochaete chrysosporium was used to study the decolorization effects of anthraquinone dyes by white rot fungi under various parameters of RBBR(initial concentration,pH,temperature and metal ions).UV-Vis absorption spectrum analysis,FTIR analysis,GC-MS analysis and phytotoxicity test were used to analyze the possible degradation pathways of RBBR and the toxicity of the degradation products.The results showed that the decolorization rate can reach more than 95%in 24 h at pH 4.2,28°C and 5 mmol/L Mn2+when RBBR concentration was 200 mg/L.The biodegradation pathway of RBBR was initiated by the cleavage of the nitrogen bond connecting the benzene ring and the anthraquinone of RBBR,then generated 1-aminoanthraquinone and M-(β-hydroxyethyl barium sulfate sodium sulfate)aniline.The amino group on the 1-aminoanthraquinone was substituted by a hydroxyl group,and then oxidized,de-ringed,and rearranged into phthalic acid.The phthalic acid was oxidized to form a small molecule organic acid succinic acid,at the same time,the amino group on the M-(β-hydroxyethyl barium sulfate sodium sulfate)aniline was oxidized to form succinic acid and other small molecular acids,carbon dioxide and water.Phytotoxicity experiment showed that the toxicity of RBBR could be reduced by P.chrysosporium.In conclusion,P.chrysosporium could effectively decolorize high-concentration RBBR,and reduce the toxicity of dyes to plants.