2株苯胺降解的分离鉴定及其降解特性研究

从处理印染废水的活性污泥中分离得到2株苯胺降解菌,从菌落、细胞形态、生理生化及16S rRNA基因扩增测序等方面对2株菌进行了鉴定,并比较分析2株菌在好氧与缺氧条件下的苯胺降解、偶氮染料脱色及苯胺脱氨氧化酶基因tdnQ和黄素还原酶基因(fre)的携带情况.结果表明,2株菌属于Pseudomonas属和Shewanella属,分别命名为Pseudomonas sp.AN30和Shewanella sp.DN425.AN30菌株在振荡好氧条件下72h内对250mg/L苯胺的降解率为96.1%,DN425菌株的降解率为13.8%;在静置缺氧条件下AN30菌株的苯胺降解率为39.6%,DN425菌株的降解率仅为8.6%.DN425菌株在静置缺氧条件下4h内可将初始浓度为50 mg/L的偶氮染料酸性大红彻底脱色,而AN30菌株对酸性大红不具有脱色能力.以总DNA为模板,分别用tdnQ基因和fre基因特异性引物进行扩增,2株菌均能扩增出大小分别为380bp和630bp左右的目标条带,显示2菌株均携带有苯胺脱氨氧化酶基因和黄素还原酶基因.

Isolation and Characterization of two Aniline-degrading Strains and Compare of Functional Genes

Two aniline-degrading bacterial strains,AN30 and DN425,were isolated from activated sludge of textile-printing wastewater treatment plant and identified as Pseudomonas sp.and Shewanella sp.,respectively.Under shaking condition,250(mg/L) aniline was removed 96.1% and 13.8% within 72h by strains AN30 and DN425,respectively.Under static condition,their degrading rates were 39.6% and 8.6%,respectively.Under static condition,the decolorizing rate of strain DN425 reached 96% for azo dye Great Red GR in 4h,exhibiting a remarkable color removal capability.However,strain AN30 was not capable of decolorizing Great Red GR.With two sets of specific primers for tdnQ gene and fre gene, the two genes were detected by PCR amplification.The results indicated the two strains possess both tdnQ gene and fre gene.