红球菌PB-1对高浓度苯酚及苯系物的降解研究

Degradation of High Concentration Phenol and Benzenes by Rhodococcus sp.PB-1

苯酚及一些苯系物是有机合成工业废水中常见的污染物,也是生物处理的难点。从某焦化厂污泥中分离得到一株苯酚高效降解菌,根据生理生化试验和16S rDNA测序,鉴定为红球菌,命名为PB-1,对其降解苯酚的条件进行优化以及该菌株降解底物广谱性进行研究。结果表明:该菌株降解苯酚的最适温度为30~35℃,最适pH值为9.0;当菌体浓度OD600为0.3时,24 h可完全降解1000 mg/L的苯酚;该菌株可耐受2000 mg/L浓度的苯酚,对苯酚72 h的降解率为35.76%;此外,该菌株可适应300 mg/L浓度的喹啉,对1500 mg/L苯胺72 h的降解率达到68.06%;该菌株对苯酚和苯胺的降解均通过邻苯二酚1,2-双加氧酶催化的邻位途径,底物降解彻底,环境友好。红球菌PB-1可降解高浓度苯酚、苯胺,且耐受难降解喹啉类杂环芳香物质,在成分复杂的工业废水处理中具有十分广阔的应用前景。

Phenol and other benzene series are commonly found in the wastewater of organic synthesis industries.These organic compounds are also a difficult problem in biodegradation process.This paper isolates a high-efficiently phenol-degrading bacteria from the sludge of a coking plant,which is identified as a Rhodococcus sp.based on physiological and biochemical characterization and 16 S rDNA sequencing,and named PB-1.Then the paper optimizes the conditions of phenol degradation and studies the degradation of various substrates.The results show that the optimum temperature of phenol degradation is 30~35℃and the optimum pH is 9.0.Under the OD600 of 0.3,the strain could completely degrade 1000 mg/L phenol in 24 h and the degradation rate of 2000 mg/L phenol is 35.76%in 72 h.Besides,the strain is adapted to 300 mg/L quinoline,and the degradation rate of 1500 mg/L aniline reaches 68.06%in 72 h.The strain PB-1 uses catechol 1,2-dioxygenase to degrade phenol and aniline as the ortho-cleavage pathway,and the substrates are completely degraded,so it is environmentally friendly.Rhodococcus sp.PB-1 could degrade high concentration phenol and aniline and tolerate heteroarmatics such as quinolone which is hardly degradable.It is potential for application in the actual treatment of industrial wastewater with complex components.