醌介导染料脱色菌株的分离鉴定及特性

实验分离获得1株能够利用醌化合物使磺酸化偶氮染料脱色的菌株JL,通过形态特征、16S rDNA与16S-23S区间序列分析表明,该菌株为蜡状芽孢杆菌(命名为Bacillus cereus JL).菌株JL使酸性大红3R脱色的最佳条件为葡萄糖浓度1g/L, pH值为5~7,温度30℃,接种量0.25g/L.蒽醌-2-磺酸(AQS)、蒽醌-2,6-二磺酸(AQDS)和2-羟基-1,4-萘醌(Lawsone)均能显著提高酸性大红3R的脱色速率,其中AQS的促进作用最为明显.研究发现, 0.1mmol/L AQS能够使菌株JL对2.0mmol/L酸性大红3R保持较高的脱色速率,而且能使多种偶氮染料脱色,表现出较好的底物广谱性.利用高效液相色谱-质谱鉴定了AQS介导的酸性大红3R脱色产物,表明酸性大红3R的偶氮键发生断裂, AQS在这一过程中仅起到电子传递的作用.

Isolation, identification and characteristics of quinone compounds enhancing dye-decolorizing bacterium

In the presence of quinone compounds, a strain (designated as JL) with the capacity to decolorize azo dyes was isolated. The strain was identified as Bacillus cereus JL based on morphological, 16S rDNA and 16S-23S spacer region sequence analysis. The optimal conditions for the decolorization of Acid Red 3R by strain JL were: 1g/L glucose, pH 5~7, 30℃, inoculation amount 0.25g/L. Anthraquinone-2-sulfonate (AQS), anthraquinone-2,6-disulfonate (AQDS) and 2-hydroxy-1,4-naphthoquinone (Lawsone) could improve the decolorization rate of Acid Red 3R,and AQS was most effective. Addition of 0.1 mmol/L AQS significantly increased the decolorization rate of 2.0mmol/L Acid Red 3R by strain JL,and the strain could decolorize other six azo dyes. According to the decolorization product of Acid Red 3R identified using HPLC-MS, strain JL could make cleavage for azo bond and AQS only acted as redox mediator in whole process.