菲降解菌株的分离鉴定及特性研究

从某石化公司污水处理厂的活性污泥中分离到1株对菲具有降解活性的菌株AFF,该菌株能够以菲为唯一碳源和能源生长.根据形态特征及16S rRNA基因序列分析,该菌株初步鉴定为Burkholderia sp..在以菲为唯一碳源的培养基中,84 h内菌株对100 mg·L-1菲的降解率可达74.1%.通过液相-质谱联用及紫外可见分光光度法分析,推测该菌株代谢菲的途径为水杨酸途径.测定了降解途径中相关酶的活性,表明该菌株降解酶系中具有邻苯二酚2,3-双加氧酶活性,并证明该酶为诱导酶;确定了粗酶降解邻苯二酚的动力学常数:米氏常数Km为10.93μmol·L-1,最大反应速率Vmax为106.38μmol·min-1,说明酶与邻苯二酚的亲和力较大,邻苯二酚是该酶的良好底物.

Isolation and Characterization of a Phenanthrene-Degrading Bacterial Strain

A bacterial strain that degrades phenanthrene was isolated from activated sludge of wastewater treatment plant from a chemical corporation. The strain can utilize phenanthrene as sole source of carbon and energy. It was identified as Burkholderia sp. according to morphological and 16S rRNA gene sequence analysis. Phenanthrene (100 mg x L(-1)) was removed 74.1% within 84 h by this strain. It was suggested that the strain possessed the salicylic acid pathway by LC-MS and UV methods. And the strain contains an inductive catechol 2,3-dioxygenase (C230). The kinetic constants Km and Vmax were 10.93 micromol x L(-1) and 106.38 micromol x min(-1), receptively. It indicates that the affinity of the endoenzyme to catechol is great and catechol is a better substrate.