一株嗜热偶氮染料脱色菌的分离鉴定及其脱色特性

从纺织厂的工业废水排污口取样，分离筛选出了一株嗜热的高效偶氮染料脱色菌PDR2。通过形态学、生理生化特征以及16S rDNA基因序列分析等方法对该菌株进行鉴定，发现该菌为厌氧芽孢杆菌，与Anoxybacillus sp（GQ471935）同源性最高。此外，分别考察了菌株PDR2在不同碳源、氮源、pH以及培养温度等条件下对偶氮染料直接黑38脱色性能的影响，在此基础上进一步研究了菌株PDR2对不同浓度直接黑38染料的耐受性。结果表明，菌株PDR2在55℃、pH 6.0且以葡萄糖为碳源，牛肉膏和蛋白胨为混合氮源时其脱色效果最佳，且菌株对偶氮染料直接黑38有着较强的耐受能力，在染料浓度低于0.4 g·L-1时其脱色效果良好。在最佳条件下静置培养24 h时，菌株PDR2对0.1 g·L-1直接黑38染料的脱色率高达92.34%，展出了良好的应用潜力。

Isolation and identification of a thermophilic azo dye decolorization bacterium and investigation of its decolorization characteristics

A thermophilic strain (named PDR2) with highly efficient azo dye decolorization ability was successfully isolated after sampling from the wastewater drain outlet of a textile mill. This strain was identified as Anoxybacillus by morphological, physiobiochemical, and 16S rDNA gene sequence analyses. This strain had the highest homology with Anoxybacillus sp. GQ471935. The effects of different carbon and nitrogen sources, pH, and incubation temperatures on the decolorization of azo dye (direct black 38) by strain PDR2 was also investigated. Moreover, the concentration of direct black 38 tolerated by strain PDR2 was also tested. Experimental results showed that the optimal decolorization was observed at 55℃, pH 6.0, with glucose as the carbon source, and beef extract and peptone mixture as the nitrogen source. Further, strain PDR2 was highly tolerant to black 38, and its decolorization ability was good even when the concentration of direct black 38 was lower than 0.4 g·L-1. Moreover, the decolorization ratio of strain PDR2 on 0.1 g·L-1 of direct black 38 could reach 92.34% when this strain was incubated in a stationary state at the optimal condition for 24 h. These findings indicate that the strain PDR2 has great potential in the removal of azo dyes from wastewater in static conditions.