氯过氧化物酶与苯酚降解菌株的协同降解动力学研究

氯过氧化物酶(CPO)催化苯酚与H_2O_2发生过氧化反应生成邻苯二酚,能减轻苯酚对降解菌株的抑制作用,加快降解菌株对苯酚的生物降解.实验结果表明:在2 h内适量的H2O2存在时10 U/L的CPO可以使300 mg/L苯酚降解率达到67.85%,而CPO与降解菌株协同作用下苯酚降解率则可达到70.72%,比单一菌株降解率8.52%提高了62.2%.在降解体系中补充邻苯二酚进一步揭示了CPO氧化苯酚的中间产物有利于菌体细胞形成共基质效应,提高细胞的苯酚生物降解效率.降解动力学分析显示:在苯酚质量浓度为100~1 200 mg/L时,CPO与菌株协同降解体系的最大比降解速率qmax=0.000195 h-1,基质饱和常数Ks=1.0501 mg/L,基质抑制常数KI=5.1272 mg/L.

Dynamics of phenol synergistic biodegradation by Chloroperoxidase and bacterial strains

Chloroperoxidase (CPO) can catalyze phenol reacting peroxide reaction generating with H₂O₂ to catechol,which can reduce the inhibitory effect of phenol degradating generating bacterial strains.At the meantime,it can accelerate the rate of phenol''s biodegradation.The results show that 10 U/L of CPO has 67.85% conversion rate of 300 mg/L phenol within 2 h with an appropriate amount of H₂O₂.While the degradation rate of phenol degradation under synergy of strain and CPO is up to 70.72%,increased by 62.2% comparing with a single strain degradation rate (8.52%).Supplementary catechol in the reaction system can further verified that the intermediate products can be good for forming the co-substrate effect in bacteria,thereby improving the phenol degradation efficiency of biological bacterial cells.Biodegradation dynamics analysis shows that the maximum specific degradation rate of the CPO and strain synergistic.The maximum specific degradation rate q_max=0.000195 h^-1,the matrix saturation constant K_s=1.0501 mg/L,and the substrate inhibition constant K_I=5.1272 mg/L when phenol concentration in the range of 100~1 200 mg/L.