苯酚降解菌的分离、鉴定及降解特性

以苯酚为唯一碳源进行选择性富集培养,从油污染土壤中筛选出2株菌,命名为Phe0901和Phe0902。在32℃、pH值为7.0、200r/min摇床振荡培养72h,用4-氨基安替比林分光光度法测定2菌株培养液中苯酚含量,结果表明2株菌均能彻底降解初始质量浓度为1000mg/L的苯酚培养液,即Phe0901和Phe0902为苯酚降解菌。经形态学观察、生理生化实验及16SrDNA基因序列比对分析,初步确定Phe0901为假单胞菌属(Pseudomonas)成员;Phe902为芽孢杆菌属(Bacillus)成员。在不同温度下用比浊法探讨降解菌株的生长情况,在不同pH值下用4-氨基安替比林分光光度法测定苯酚降解率,结果表明在32℃、pH值为7.0～7.8时适宜Phe0901的降解,Phe0901培养44h能彻底降解1000mg/L的苯酚;在32℃、pH值为7.0时适宜Phe0902的降解,Phe0902培养70h能彻底降解1000mg/L的苯酚。

Isolation, Identification and Characteristics of Bacterial Strains for Biodegradation of Phenol

Utilizing phenol as sole carbon source, two bacterial strains, named as Phe0901 and Phe0902, were isolated from the oil-contaminated soil through selective enriched culture. The phenol concentrations of the culture fluids of the two strains were determined by the 4-amino-antipyrine spectrophotometric method. Results showed that initial phenol mass concentration 1 000 mg/L could be thoroughly degraded within 72 h of shake cultivation in swing bed at 200 r/min under 32 ℃ and pH = 7.0, indicating that the two strains were phenol degrading bacteria. The two degrading strains were preliminarily identified as genus Pseudomonas and Bacillus respectively through morphological observations, physiological and biochemical tests and 16S rDNA sequencing analysis. The impacts of the two strains under different temperatures and pH values on biodegradability of phenol were evaluated by the turbidimetric method and the 4-amino-antipyrine spectrophotometric method, respectively. The optimum biode- grading conditions of temperature and pH values for each strain were obtained, namely,32 ℃ and pH = 7.0 - 7.8 for Phe0901,32 ℃ and pH = 7.0 for Phe0902, under which initial phenol mass concentration 1 000 mg/L could be completely degraded with- in 44 h for Phe0901and within 70 h for Phe0902.