Enterobacter sp. CV-v对甲基橙的脱色特性与条件优化

从浙江温州分离筛选到1株甲基橙高效脱色菌株CV-v,经16S rRNA基因序列分析表明,该菌株属于Enterobacter sp.属.单因素实验结果表明:当pH值在5.0~9.0之间时,培养48h以后,该菌株对甲基橙的脱色率均在80%以上;脱色的最适温度范围为30~40℃之间;所测碳源中的葡萄糖和麦芽糖、氮源中的牛肉膏和酵母粉对脱色的促进效果最为显著,且Ca2+和Mg2+也对脱色有显著的促进效应;此外,当接种量达到7%(V:V)以后,48h的脱色率即可达近100%.响应面设计实验结果显示,该菌株对甲基橙脱色的最优操作条件为:pH 8.0,葡萄糖1.7g/L,酵母粉3.0g/L,氯化镁3.0mmol/L及培养温度35.9℃.验证实验结果表明在最优条件下,该菌株在10h内对甲基橙的脱色率可达88.0%.总体而言,该菌株在偶氮染料脱色中的应用潜能较大.

Characteristics of methyl orange decolorization by Enterobacter sp. CV-v and parameter optimization

A highly efficient methyl orange-decolorizing strain CV-v was isolated in Wenzhou, Zhejiang. Results of 16S rRNA gene analysis indicated that this strain belongs to the Enterobacter genus. Data from one-factor-a-time experiments showed that methyl orange decolorization rate by the strain could reach over 80% after 48h at pH 5.0~9.0. The optimal temperature for decolorization was between 30~40oC. Among the tested carbon and nitrogen sources, glucose, maltose, beef extract, and yeast extract could significantly enhance the decolorization. Besides, Ca2+ and Mg2+ could also significantly enhance the decolorization. Meanwhile, almost completely decolorization was observed after 48h when the inoculums size reached to 7% (V:V). Moreover, the results of response surface design revealed that the optimal conditions for decolorization were pH 8.0, 1.7g/L glucose, 3.0g/L yeast extract, 3.0mmol/L MgCl2, and at 35.9oC. Finally, the results of verification tests indicated that methyl orange decolorization by the strain could reach 88.0% after 10h under the optimal conditions. In general, this strain has a great potential in azo dye decolorization.