一株偶氮染料脱色菌的筛选、鉴定及脱色性能研究

Screening,Identification and Decolorization Performance of an Azo Dye Decolorizing Bacterium

从印染厂附近的土壤中筛选出一株嗜热的高效偶氮染料脱色菌YB322,通过形态学观察及16S rDNA基因序列分析等方法对该菌株进行初步鉴定,发现该菌株与Aneurinibacillus thermoaerophilus极为相似,同源性高达100%。在此基础上进一步探究了该菌株在不同碳源(10 g/L)、氮源(5 g/L)、pH、培养温度以及不同染料浓度和不同结构的偶氮染料下的脱色性能。结果表明,该菌株在pH为6.5、温度为55℃,以葡萄糖为碳源,牛肉膏和蛋白胨混合物为氮源时其脱色效果最佳,48 h内脱色率达到了92.87%。研究还发现菌株对直接黑G染料有着较强的耐受能力,在染料浓度高达500 mg/L下脱色良好,脱色率可达68.11%。此外,该菌株对多种不同结构的偶氮染料(甲基橙、苋菜红、刚果红、直接黑G、直接黑38)亦可表现出良好的脱色降解性能,其脱色率分别可达95.65%、97.99%、94.29%、92.87%、63.9%,展现出了一定的偶氮染料脱色广谱性,该研究对偶氮染料废水的生物处理奠定了理论基础。

A thermophilic high-efficient azo dye decolorizing strain YB322 was screened from the soil near a printing and dyeing plant.The strain was identified by morphological observation and 16S rDNA gene sequence analysis.It was found that the strain is very similar to Aneurinibacillus thermoaerophilus,and the homology can reach as high as 100%.On this basis,the decolorization performance of the strain under different carbon sources,nitrogen sources,pH,culture temperature,and different dye concentrations and different structures of azo dyes was further explored.The results showed that the strain had the best decolorization effect when the pH was 6.5,the temperature was 55 ℃,glucose was used as the carbon source(10 g/L),and the mixture of beef extract and peptone was the nitrogen source(5 g/L).The decolorization rate reached 92.87% within 48 h of incubation.The study also found that the strain had strong tolerance to direct black G dye,and the decolorization was good at a dye concentration of up to 500 mg/L,where the decolorization rate could reach 68.11%.In addition,the strain could also exhibit decolorization and degradation properties of a variety of different structures of azo dyes(methyl orange,amaranth,Congo red,direct black G,direct black 38),and the decolorization rate could reach 95.65%,97.99%,94.29%,92.87%,63.9% respectively,showing a certain broad spectrum of azo dye decolorization.This study further establishes a theoretical foundation for the biological treatment of azo dye wastewater.