环境激素对叔辛基酚降解菌的筛选、鉴定及降解特性

为了研究环境激素4-t-OP(对叔辛基酚)的生物降解,从扬州市汤汪生活污水处理厂二沉池污泥中筛选得到1株能以4-t-OP为唯一碳源进行生长的降解菌株,标示为TW30,16S rRNA测试其为不动杆菌属(Acinetobacter sp.),通过摇瓶试验测试其降解活性.结果表明:在40℃、初始pH为6.0、ρ(4-t-OP)为5 mg/L的无机盐培养基中,5 d后降解率可达99.03%;降解过程满足一级反应模型,降解速率常数(k)为0.875 d-1,半衰期(t1/2)为0.8 d.这说明TW30是一株高效的4-t-OP降解菌.此外,培养温度的升高和额外Ca2+、Mn2+的加入可以提高TW30降解4-t-OP的效率,而在5～25 mg/L范围内提高初始ρ(4-t-OP)以及额外加入磷酸盐、NH4+、Mg2+、Fe2+、Na+、Zn2+、Cu2+等无机盐和葡萄糖、CH3COO-等碳源则会降低降解率. 

Isolation,Identification and Biodegradation Characteristics of a 4-tert-Octylphenol Degradable Bacterial Strain

A bacterial strain labeled as TW30,which can use 4-t-OP(4-tert-Octylphend) as the sole carbon source,was isolated from the activated sludge from the secondary sedimentation tank of the Yangzhou Tangwang Wastewater Treatment Plant.The strain TW30 was identified preliminarily according to the analysis of its 16S rRNA gene sequence as Acinetobacter sp.The results showed that the optimal conditions for 4-t-OP biodegradation in the shaking flasks were 40 ℃ and pH 6.0.Under these conditions,99.03% of the initial 5 mg/L ρ(4-t-OP) was degraded after 5 d culturing.The biodegradation reaction fitted well with the first-order kinetic model,with a degradation constant(k) of 0.875 d-1 and half-life(t1/2) of 0.8 d.The degradation rate of 4-t-OP was enhanced by the increase of temperature and addition of Ca2+ and Mn2+.The rate was deceased by the increase of initial concentration of ρ(4-t-OP) in the range of 5 to 25 mg/L,and by the addition of phosphates,NH4+,Mg2+,Fe2+,Na+,Zn2+,Cu2+,NaAc and glucose.