孔雀石绿脱色菌的分离鉴定及降解特性研究

Isolation and identification of malachite green-degrading bacteria and their degradation characteristics

文章从印染厂污水处理系统的活性污泥中筛选分离3株对孔雀石绿有脱色能力的菌株,编号分别为MG-2、MG-6和MG-7。根据其形态学特征以及16SrDNA序列分析,初步鉴定为肠杆菌属(Enterobactersp.)和埃希氏菌属(Escherichia sp.)。3株菌的最适脱色条件为:pH=7.0,温度为30℃,厌氧和兼氧。在最适脱色条件下,3株菌对质量浓度为60mg/L的孔雀石绿脱色率都在94%以上,其中菌株MG-2所需脱色时间最短,菌株MG-6次之,菌株MG-7脱色时间最长;3株菌对盐度有一定的耐适性,属于耐盐菌;3株菌的脱色都是因为胞外酶的作用。

Three bacteria strains with decoloring capability for malachite green were isolated from acti- vated sludge of printing and dyeing mill sewage treatment system. They were named as strain MG-2, MG-6 and MG-7 and were identified as Enterobacter sp. and Escherichia sp. by their morphological characteristic and 16S rDNA sequence analysis. The obtained results were that theoptimum pH for decolorization was 7.0, and optimum temperature was 30 ℃. The decolorization under anoxic and an- aerobic condition was better than aerobic. Under the optimum decolorization conditions, the decolori- zation rates of 60 mg/L malachite green were more than 94%, and strain MG-2 required the shortest time for decolorization, followed by strain MG-6 and MG-7. The strains belong to salt-tolerant bacte- ria, having a certain adaptive to salinity. The decolorization of three strains were because of the role of extracellular enzymes.