焦化废水中苯酚降解菌筛选及其降解性能

焦化废水中苯酚类及其衍生物的降解率高低是焦化废水COD是否达标排放的关键.采用不同培养基和菌种驯化方法,从焦化废水厂活性污泥中分离筛选获得4株苯酚降解菌,经生理生化和16S rDNA分子鉴定,A1为球杆菌属Sphaerobacter,C1为鲍曼不动杆菌Acinetobacter baumannii;D2为睾丸酮丛毛单胞菌Comamonas testosterone;D3为Novosphingobiumnaphthalenivorans.4株降酚菌均具有较高的苯酚耐受力和降解效率,是生物法处理酚类污染废水优质的种质资源.菌株D2不仅对苯酚具较高耐受力达到2 000 mg.L-1、且在48 h内可将初始浓度为1 000 mg.L-1的苯酚完全降解.环境因子考察研究表明,pH为7.5～8.5,温度为30～40℃范围内,转速为150 r.min-1,是菌株D2的最优降解条件,本研究结果为构建高效处理焦化废水基因工程菌提供了微生物基础.

Screening and Characterization of Phenol Degrading Bacteria for the Coking Wastewater Treatment

Phenolic compounds removal is a key issue for the coking wastewater discharge on COD index requirements.Using different media and methods to domesticate species,we have successfully screened and isolated four phenol-degrading bacteria from the activated sludge in the coking plant.Four phenol-degrading bacteria are identified through traditional methods of physiological and biochemical analysis and 16S rDNA identification.Strain A1 belongs to Sphaerobacter,strain C1 belongs to Acinetobacter baumannii,strain D2 belongs to Comamonas testosterone,strain D3 belongs to Novosphingobium naphthalenivorans.All four phenol-degrading bacteria have the high tolerance to coking wastewater and degradation efficiency of phenol.Results showed that they are the high-quality germplasm resources used in phenolic pollution wastewater biological treatment.It was found that strain D2 did not only have higher phenol tolerance up to 2 000 mg·L-1 but also had higher efficiency of phenol degradation,the phenol with 1 000 mg·L-1 initial concentration would be totally degraded in 48 h.By investigating environmental factors,the optimal conditions for phenol degradation by the strain D2 was 30-40℃,pH 7.5-8.5 at more than 150 r·min-1 of shaking rate,it possesses an optimal application in reality.The results provide the microbial basis for construction of gene engineering bacteria used in the coking wastewater treatment.