孔雀石绿脱色菌的分离鉴定及染料脱色后毒性研究

Isolation, characterization and toxicity of a malachite green degradation bacterial strain

摘要:

【目的】从印染污水处理厂污泥中筛选孔雀石绿脱色菌，并分析比较染料脱色前后毒性。【方法】采用平板稀释涂布法筛选分离纯化菌株，通过扫描电镜、16S rRNA基因序列分析对菌株进行初步鉴定，采用蚕豆根尖微核毒性试验和小球藻毒性试验对染料脱色前后毒性进行分析。【结果】从印染污水处理厂污泥中筛选出一株高效孔雀石绿脱色菌。经过16S rRNA基因序列分析，鉴定该菌株为Klebsiella sp. JD。菌株的菌落边缘规则，圆形，灰白色粘稠，以接种环挑之，易拉成丝，表面光滑。通过对比小球藻在脱色前后的生长率和抑制率以及蚕豆微核率和污染指数分析出脱色后的染料毒性大大降低。【结论】筛选得到一株新的孔雀石绿脱色菌，该菌降解效率高，可降低染料毒性，对修复染料污染的水体有一定的现实意义。

Abstract:

[Objective] An efficient malachite green degradation bacterial strain was isolated from the actived sludge sample collected from wastewater-treating system of dye manufacturer, and the toxicity of malachite green before and after decolorization was contrasted through some methods. [Methods] A decolor bacteria was isolated by dilution plating procedure and was then identified by scanning electron microscope (SEM) and 16S rRNA gene analysis. The toxicity of malachite green before and after decolorization was evaluated through biological toxicity tests using Chlorella and Vicia faba as test material. [Results] The strain separated from the wastewater-treating system of dye manufacturer was identified as Klebsiella sp. JD on the basis of 16S rRNA gene analysis. Klebsiella sp. JD biochemical colony which was gray and viscous shows a regular circle shape. With the touch of inoculation loop, the colony was draw into wire easily and the wire had a smooth surface. By comparing with the growth rate and inhibiting rate of Chlorella, the MCN‰ and PI of Vicia faba, it could be found that the toxicity of malachite green decreased after decolorization. [Conclusion] A malachite green degradation bacterial strain is isolated in this research. The efficient strain can reduce the toxicity of dye, which has a practical significance in the remediation of dye contaminated water.