一株2,2’,4,4’-四溴联苯醚(BDE-47)厌氧降解菌的筛选鉴定及降解特性

Isolation, identification, and the degradation characteristics of a BDE-47 degrading strain

为去除环境中BDE-47的残留,通过以BDE-47为碳源的选择性培养基驯化,从电子垃圾拆解厂的土壤中分离出了1株厌氧降解BDE-47的纯菌种,命名为XM,并研究其对BDE-47的降解特性.经16S rDNA鉴定,XM属于兼性肠杆菌（Enterobacter sp.）,当BDE-47浓度为525μg/L,初始接菌量为7.1×10^5 cells/mL时,培养35 d后降解率为35.8%,降解产物中检测到BDE-28.BDE-47的降解反应符合一级动力学,拟合结果为ln Ct=-0.104t＋6.22.选择以铁离子、硝酸根和硫酸根作为降解过程中外加的电子受体,BDE-47的降解率明显提高,分别为49.8%、59.1%和67.3%.以上研究结果表明,菌株XM能够有效地降解BDE-47,在电子垃圾污染的生物修复方面具有较好的参考和应用价值.

In an effort to remove BDE-47 residues from the environment, a bacterial strain that is capable of utilizing BDE-47 as the sole carbon source was isolated and screened from soil collected from an e-waste recycling area in Tianjin to analyze the degradation properties. The strain was preliminarily identified as Enterobacter sp. according to a 16 S r DNA gene sequence analysis. The strain degraded 35.8% of 525 μg/L of BDE-47 in 35 d when the initial concentration of bacteria was 7.1 × 10^5 cells/mL. The product of the biodegradation of BDE-47 was BDE-28. The biodegradation of BDE-47 fit well with first-order kinetics, and its degradation kinetics was ln Ct =-0.104 t ＋ 6.22. With the addition of an electron acceptor, such as Fe^3＋, SO4^2-and NO3^-, the BDE-47 degradation rate was significantly increased to 49.8%, 59.1%, and 67.3%, respectively. The above results revealed that the strain could degrade BDE-47, which is of importance in the application of environmental bioremediation of BDE-47.