一株苯酚降解菌的筛选及降解动力学特性

利用富集驯化的培养方法,从首钢焦化厂废水处理系统中的二沉池出水中,分离筛选出一株能够高效降解苯酚的菌株B3对其16S rDNA序列进行分析,并选择Monod方程和Andrews方程分别研究该菌在不同苯酚浓度条件下的降酚动力学模式。结果表明,B3为蜡状芽孢杆菌(Bacillus cereus);苯酚浓度较低时,苯酚对菌株的生长基本不产生抑制作用,用Monod模型对B3降酚动力学过程进行拟合,其动力学参数V max=0.03 h-1,K s=25.53 mg/L;苯酚浓度较高时,按照Andrews模型对B3降酚动力学过程进行非线性最小二乘曲线拟合,其动力学参数V max=0.08 h-1,K s=147.52 mg/L,K i=384.96 mg/L。根据动力学方程,推论菌株B3降解对于浓度238.30 mg/L的苯酚具有最佳降解效果。

Selection of phenol degradation bacteria and characteristic of degradation kinetics

A bacterium strain named as B3 with high phenol-degrading efficiency was isolated from the second pond water out of Shougang Coking Plant wastewater treatment system. The 16S rDNA gene sequence analysis was applied to the bacteria classification. Monod equation was used to research the degradation dynamics model of B3 bacteria to phenol at low concentrations,while Andrews equation was applied toward phenol at high concentrations. The results showed that strain B3 was identified as Bacillus cereus. The Monod kinetic model can adequately describe the dynamic behavior of the phenol biodegradation of the strain of B3 when phenol was at low concentration,the kinetic parameters were:Vmax=0.03 h^-1,Ks=25.53 mg/L;while the Andrews kinetic model can be used to describe the dynamic behavior of the phenol biodegradation of the strain of B3 when phenol at high concentration,and the kinetic parameters were:Vmax = 0.08 h^-1,Ks=147.52 mg/L,Ki=384.96 mg/L. It was thought that B3 strain has the best degradation towards to phenol at the concentration of 238.30 mg/L.