| 铜绿假单胞菌胞内酶粗提液对十溴联苯醚的降解 |
| 摘要点击 2833 全文点击 1237 投稿时间：2012-07-29 修订日期：2012-09-10 |
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| 中文关键词 铜绿假单胞菌 胞内酶 十溴联苯醚 酶降解 动力学 |
| 英文关键词 Pseudomonas aeruginosa intracellular enzyme decabromodiphenyl ether (BDE-209) enzymatic degradation kinetics |
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| 中文摘要 |
| 探讨了铜绿假单胞菌粗酶液对十溴联苯醚(BDE-209)的降解特性,结果表明,该菌株胞内酶在12 h内对1 mg·L-1的BDE-209降解率达到了69.22%,温度、pH值、酶蛋白浓度及底物BDE-209浓度均会影响胞内酶粗提液对BDE-209的降解效率. 当BDE-209浓度为1 mg·L-1时, BDE-209适宜的酶促降解条件为: 温度30℃, 反应pH值7.5,且降解率随着酶浓度的增加而增大. 胞内酶对BDE-209的降解过程符合一级动力学反应模型,底物浓度为1 mg·L-1时降解速率最快,半衰期为6.9 h. 胞内酶降解BDE-209符合高浓度底物抑制的酶促反应类型,其基本降解动力学参数为rmax=0.133 mg·(L·h)-1, Km=0.642 mg·L-1,Ki=1.558 mg·L-1. |
| 英文摘要 |
| The degradation characteristics of decabromodiphenyl ether (BDE-209) by crude enzyme from Pseudomonas aeruginosa were investigated. The results revealed that the degradation efficiency of the intracellular enzyme excreted from this bacterial strain reached 69.22% after incubation with 1 mg·L-1 BDE-209 for 12 h. Temperature, pH, enzyme concentration and BDE-209 concentration all influenced the ability of crude enzyme to degrade BDE-209. When the BDE-209 concentration was 1 mg·L-1, the optimal condition for enzymatic degradation was temperature 30℃ and pH 7.5, and the degradation rate increased with increasing enzyme concentration. The degradation process of BDE-209 by intracellular enzyme of the strain conformed to the first-order kinetic model. The highest reaction rate was achieved when the initial concentration of BDE-209 was 1 mg·L-1 and the half-life of this substrate was 6.9 h. In addition, the biodegradation of BDE-209 can be well described by enzymatic reaction of high concentration substrate inhibition, with a maximum substrate utilization rate of 0.133 mg·(L·h)-1, a Michaelis-Menten constant of 0.642 mg·L-1, and an inhibitory constant of 1.558 mg·L-1, respectively. |
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