研究了混合光合细菌PSB-DR在不同光照、接种量和pH值下对2,4,6-三氯苯酚(2,4,6-TCP)的生物降解特性,确定了PSB-DR生物降解2,4,6-TCP的优化控制条件.结果表明,光照培养下,接种量30%,初始pH值7.0时2,4,6-TCP降解效率最高.在此条件下,50mg/L的2,4,6-TCP经5d后降解率达到82.3%.培养基中醋酸钠的加入对2,4,6-TCP降解有明显的抑制作用.PSB-DR静息细胞对2,4,6-TCP的降解符合高浓度底物抑制的酶促反应类型,其降解动力学参数rmax=1.746h-1,Km=38.333mg/L,Ki=260.87mg/L.
Degradation of 2,4,6-trichlorophenol(2,4,6-TCP) by mixed cultures photosynthetic bacteria PSB-DR at different illumination,inoculum density and initial pH were investigated.The degradation conditions were optimized to be incubation with an inoculum density of 30% and initial pH 7.0 under light.About 82.3% of 2,4,6-TCP with initial concentration of 50mg/L was removed after 5d incubation under the condition.The addition of sodium acetate into the substrate greatly suppressed 2,4,6-TCP biodegradation.The degradation of 2,4,6-TCP could be well described by the enzymatic reaction of high concentration inhibition,with the maximum substrate utilization rate 1.746h-1,Michaelis-Menten constant 38.333mg/L and inhibitory constant 260.87mg/L,respectively.