Screening, Isolation And Identification Of Cypermethrin Of Insecticides-degrading Strains And Studies On Its Characteristics

The objective of this research is to Collect 5 polluted soil samples in Li Ke pesticide factory of Zheng Zhou. By the isolation and screening of bacterium from soil sample, finded that the number of isolation and screening of Cypermethrin in secticides-degrading stains in the soil sample of pesticide vent and pesticide deposit pool is more than others; A bacterial stain named 3-7 from pesticide deposit pool ,which could degradated Cypermethrin higher, and has been identifided as Glansh At the condition of 28℃,pH7.5 and be in touch with each other,the removal rates of cypermethrin with the content of 250mg/L were 78.1% after 7 days. to the growth curve and the degeneration curve comparison, Degradation of bacterium 3-7 growth the logarithmic phase and is stable period in 12-96h, the strain growth is better and the degeneration rate becomes higher.From orthogonal combination experiment obtains degradation of bacterium 3-7 best growth condition is B3C3A2E4D3. Degradation of bacterium 3-7 best degeneration conditions is B2C4A3E3 D4. Degradation of bacterium 3 - 7 pairs of other pesticide degeneration experiments indicated : Cyhalothrin(54.21%)﹥Fenpropathrin(32.1%)﹥Deltamethrin﹙ 26.73%﹚﹥Fenvalerate﹙ 12.12%﹚﹥Chlorpyrifos﹙ 9.68%﹚﹥methamidophos(10.12%)﹥DDVP(4.26%). Obviously degradation of bacterium 3-7 pairs to plan to eliminate insect Pyrethroids pesticide tohave the specificity.To degradation of bacterium 3 - 7 crude enzymes fluids the enzyme vigor findings to indicate that, cells crude diastase liquor in pH=7.0 and under 30℃responses condition responded 20min achieves 88.3% to Cypermethrin degeneration rate; Outside the opposite cells crude diastase liquor in pH=7.0 and under 30℃responses condition responded 20min has not degraded the ability to cypermethrin.Withdraws in cells crude diastase liquor to use the centrifugal speed is the 12000r/min.In degradation of bacterium 3-7 cells crude diastase liquor indicated to the different pesticide of substrates degeneration rate determination result that, the enzyme is highest in all determinations concentration of substrates to Cypermethrin degeneration potency (in pH7.0 and under 30℃responses condition responded 20min the degeneration rate is 89.43%。 Cypermethrin(89.43%)> Fervalerate (82.65%) > Imidacloprid (73.14%)> methamidophos (53.18%)> Chlorpyrifos (40.32%). Obviously degradation of bacterium 3-7 pairs to plan to eliminate insect Pyrethroids pesticide tohave the specificity.In degradation of bacterium 3-7 cells crude diastase liquor under 30℃,20min condition, all has the varying degree in the pH5.7-8.0 scope to Cypermethrin the degeneration, most suitable pH is 7.6, its degeneration rate is 86.54%. In degradation of bacterium 3-7 cells crude diastase liquor under pH7.6 responded under the 20min condition, 20-50℃between all has the varying degree in the temperature to Cypermethrin the degeneration, the optimum temperature is 40℃, its degeneration rate is 83.06%. Will degrade degradation of bacterium 3 - 7 cells crude diastase liquor to put the most suitable pH value in the cushion fluid, will keep warm 1h in 25-60℃scopes, however Cypermethrin responded 20min indicated to the different temperature stable determination result, cells crude diastase liquor in 20℃below stability will be best, its degeneration rate will be 37.6%. In degradation of bacterium 3-7 butchers cells crude diastase liquor indicated to the different pH stable determination result that, cells crude diastase liquor keeps warm 1h after the pH5.7-8.0 phosphoric acid cushion fluid to be stablest to Cypermethrin degeneration under pH7.6, the degeneration rate is 66.67%.In the rape room the pot-culture orthogonal experiment statistical analysis result indicated that, affects Cypermethrin degeneration rate size is in turn the response time, spurts bacterium quantity, the processing way, the spraying time and spurts the dose; Degradation of bacterium 3-7 pair of Cypermethrin degrades the optimized condition for the sprayingtime is A1D3E3C2B2. The verification test result indicated after affects 7d to degrade degradation of bacterium 3-7 pair of Cypermethrin degeneration rate is 92.3%, in the rape Cypermethrin residue allowance is 0.03mg/kg, conforms to thecountry standing operating procedure.