Alicycliphilus denitrificans Ylb10的Cr(Ⅵ)还原性质研究

Study on the Cr(Ⅵ) reduction properties of Alicycliphilus denitrificans Ylb10

从求索溪底泥中,成功分离并获得一株具有高效还原Cr(Ⅵ)的菌株Ylb10。利用生理生化法和16S rDNA测序法对Ylb10菌株进行鉴定。并采用二苯碳酰二肼分光光度法测定Cr(Ⅵ),对其还原特性进行探究。结果表明,Ylb10菌是革兰氏阴性菌,与Alicycliphilus denitrificans的16S rDNA相似率为98.07%。Ylb10能很好地利用α-羟基-丁酸、L-乳酸、丙酸、乙酸、L-天冬氨酸、L-谷氨酸、L-丙氨酸、L-丝氨酸等底物。Ylb10菌相比摇床培养条件,在静置培养时能更好地还原Cr(Ⅵ),最佳还原Cr(Ⅵ)的pH值为8~9。当Cr(Ⅵ)的浓度低于200 mg/L时,该菌株能够将Cr(Ⅵ)还原,其中50 mg/L Cr(Ⅵ) 18 h的还原率达到96.45%,100 mg/L Cr(Ⅵ) 24 h的还原率达到93.83%,200 mg/L Cr(Ⅵ)浓度60 h还原效率为99.06%。由此得出,Alicycliphilus denitrificans Ylb10菌是一株高效六价铬还原菌,在处理铬污染的水质及土壤方面有很高的应用潜力。

From the bottom mud of Qiusuo Creek, a strain Ylb10 with high efficiency in reducing Cr(Ⅵ) was successfully isolated and obtained. The Ylb10 strain was identified by physiological and biochemical methods and 16 S rDNA sequencing method, and the Cr(Ⅵ) was determined by diphenylcarbazide spectrophotometry to investigate its reduction characteristics. The results showed that Ylb10 was Gram-negative, and the 16 S rDNA similarity rate with Alicycliphilus denitrificans was 98.07%. Ylb10 could make good use of α-hydroxy-butyric acid, L-lactic acid, propionic acid, acetic acid, L-aspartic acid, L-glutamic acid, L-alanine, L-serine and other substrates.Compared that with the shaker culture conditions, Cr(Ⅵ) could be better reduced during standing culture, and the optimal pH of Cr(Ⅵ) reduction was 8-9. When the concentration of Cr(Ⅵ) was lower than 200 mg/L, the strain could reduce all Cr(Ⅵ), of which, at 50 mg/L Cr(Ⅵ) concentration, it had a reduction rate of 96.45% in 18 hours;at 100 mg/L Cr(Ⅵ), it had the reduction rate of 93.83% in 24 hours, and the reduction efficiency at 200 mg/L Cr(Ⅵ) concentration in 60 hours was 99.06%. It could be concluded that Alicycliphilus denitrificans Ylb10 was a high-efficiency hexavalent chromium reducing bacteria, and It had high application potential in the treatment of chromium-contaminated water quality and soil.