Studies On The Characteristics Of Pyrethroids Degrading Enzyme From Enterobacter Cloacae W10j15

In this study, the HP6890 Gas Chromatography (GC) was used to measure the recovery rates of bifenthrin, mecthrin and cypermethrin in water. The concentration of bifenthrin, mecthrin and cypermethrin were set at 1mg/ L, 10 mg/ L, 100 mg/ L respectively with water. The recovery rates of 3 pesticides were between 95. 47% and 103. 21%, and the coefficient ranged from 2. 21% to 4. 72%.From the soil contaminated by pesticides, an E. cloacae strain wlOjl5 was isolated. This microorganism could use bifenthrin, mecthrin and cypermethrin as its unique carbon source. The best growth conditions for wlOjl5 was pH=7. 0, at 30 C . The degradation rates to bifenthrin, mecthrin and cypermethrin were 52.57%, 50.13%, 54.31% respectively. After 72 hours, the microorganism had the highest enzyme product and the highest enzyme activity of roughly 8U/mL (I) refers to mg/min).The enzyme has the highest degradation rate at pH=7. 5 and 40 C . Bifenthrin, mecthrin and cypermethrin could be degraded 75%, 58% and 78% respectively. The enzyme hasKm=440. 58nmol/mL and Vmax=50. 25nmol/min for bifenthrin;Km=332.23nmol/mL and Vmax=48. 08nmol/min for mecthrin andKm=372.00nmol/mL and Vmax=63. 29nmol/min for cypermethrinoAs far as biphenthrin is concerned, through the procedure of the ammonium sulfate precipitation, the gel gum filter and the ion exchange, the enzyme attains the specific ratio of 125.7U/mg, the purified ratio of 6.37, and the recovery rate of 91.7%. With the SDS-PAGE electrophoresis, the protein presented as a dark line. Compared with the protein marker, the molecular weight of the enzyme is roughly 65 KD. The IEF-PAGE measurement showed pI of the enzyme was 6. 8. The enzyme has 70% of the total degradation activity after one month restoration at 4C.