【摘要】 从农药厂排污口下游底泥中分离筛选出1株可降解2-氯苯酚的光合细菌PSB-1D,经过菌落形态特征、细胞形态特征、生理生化特性实验和特征吸收光谱扫描分析后,初步鉴定该菌株为红假单胞菌(Rhodopseudomonas sp.).PSB-1D生长和2-氯苯酚降解关系实验结果表明,该菌能在含2-氯苯酚(50mg/L)的PSB液体培养基中降解2-氯苯酚,培养7d后降解率可达57.26%.进一步实验研究表明不同供氧光照组合、培养基初始pH值、温度、光照度等环境因素对PSB-1D生长和降解2-氯苯酚效果的影响较为显著.在初始pH值为7.0,培养温度为30℃,光照度为4000lx的条件下,将PSB-1D置于含2-氯苯酚质量浓度为50mg/L的PSB培养基中厌氧光照培养7d后,2-氯苯酚降解率可达到62.08%.在此基础上采用Andrews方程对PSB-1D降解2-氯苯酚的动力学过程进行拟合.结果表明PSB-1D降解2-氯苯酚符合高浓度底物抑制的酶促反应类型,其降解动力学参数为rmax=0.309d-1,Km=2.733mg/L,Ki=230.15mg/L.更多还原

【Abstract】 A strain of photosynthetic bacteria named PSB-1D with degradation of o-chlorophenol (2-CP) was isolated and screened from the shallow substrate sludge in downstream side of the sewage outfall of an insecticide factory.The PSB-1D is identified preliminarily as Rhodopseudomonas sp.according to its colony and cell morphological properties,physiological biochemical characteristics and absorption spectrum analysis of living cells.The experiments results of relationship between PSB-1D growth and o-chlorophenol degradation showed that the degradation rate of o-chlorophenol was up to 57.26% after 7 days cultural time.The main environmental factors including way of illumination and oxygen,initial pH,cultural temperature,illumination intensity had distinctly influenced on the o-chlorophenol degradation with PSB-1D.The results showed that the optimum conditions were as following:an anaerobic light,pH 7.0,temperature 30℃,illumination intensity 4 000 lx,initial o-chlorophenol concentration 50 mg /L.Under that cultural condition,the degradation rate of o-chlorophenol could reach to 62.08%.The degradation kinetic data fitted the Andrews model well.In addition,the biodegradation process of o-chlorophenol can be well described by enzymatic reaction of high concentration inhibition,with the maximum substrate utilization rate 0.309 d-1,Michaelis-Menten constant 2.733 mg /L,inhibitory constant 230.15 mg /L respectively.更多还原