[Biodegradation of decabromodiphenyl ether by intracellular enzyme obtained from Pseudomonas aeruginosa]

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 x 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 x L(-1), the optimal condition for enzymatic degradation was temperature 30 degrees C 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 x 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 x (L x h)(-1), a Michaelis-Menten constant of 0.642 mg x L(-1), and an inhibitory constant of 1.558 mg x L(-1), respectively.