Study On Degradation Of Chlorpyrifos By Pseudomonas Stutzeri ZH-1

In recent years,destruction of the ecological environment has led to the cropdiseases and pests and reduce agricultural productivity.In order to reduce diseases and pests and increase crop yields,people often choose to spray pesticides.Organophosphorus pesticides,one pesticide that has been used in high-production and multi-use agricultural production at home and abroad,are highly efficient,low-cost,and easy-to-operate in preventing and controlling agricultural pests.However,Organophosphorus pesticides are highly toxic and can inhibit acetylcholinesterase in the body,which results in accumulation of acetylcholine in the body,and then causes neurological disorders.Severely,it cause deaths due to brain edema,pulmonary edema and respiratory paralysis.How to degrade organophosphorus pesticides in the environment has become a hot topic.The subject takes Pseudomonas stutzeri ZH-1 as research object,which is isolated from sludge in Fenhe River.And this project is to study that P.stutzeri ZH-1 degrades different Organophosphorus pesticides and optimizes degradation conditions of chlorpyrifos.And this project studies the degradation characteristics of chlorpyrifos,the localization of degradative enzymes and the degradation of chlorpyrifos in simulated soil.1.This project selects five organophosphorus pesticides,including chlorpyrifos,dichlorvos,malathion,omethoate and dipterex.And it studies the ability of P.stutzeri ZH-1 to degrade these five organophosphorus pesticides.The result shows that the strain ZH-1 has the ability to degrade such five pesticides mentioned above,and reached more than 50%on the10th day.Among them,the degradation rate of chlorpyrifos was the highest,reaching 92.48%on the 5th day.Therefore,chlorpyrifos is selected as the material in the following study.2.The single-factor effect and response surface optimization of ZH-1 wereanalyzed by means of temperature,rotation speed,inoculation quantity and pH.The result indicates that the temperature of 36.7?,the speed is 130.00 rpm,7%inoculated quantity,pH value of 7,the degradation of chlorpyrifos reaches at a rate of 96.48%.3.By adding different concentrations of carbon source,nitrogen source,metal ion,antibiotics,and NaCl of different concentrations on the degradation of chlorpyriasis.The results showed that when 1.0%glucose,0.05%ammonium chloride,10^-4mol/L copper ion,and 0.5%sodium chloride were respectively added,the degradation rate of ZH-1 was more than 96%,and when adding amoxicillin the concentration was 160ug/mL,the degradation rate of chlorpyrifos was only 53.23%.4.By extracting intracellular and extracellular crude enzyme fluids degradeschlorpyrifos.The results showed that the degradation rates of chlorpyrifos in intracellular and extracellular crude enzyme fluids were 88.58%and 14.41%respectively,which reflects that degradation enzymes mainly exists in cells.The results that P.stutzeri ZH-1 degrades chlorpyrifos in simulated soil?sterilized and non-sterilized?shows that the degradation rates of chlorpyrifos in sterile and non-sterile soils by P.stutzeri ZH-1 were 70.79%and 90.07%respectively.When the concentration of chlorpyrifos is 1000 mg/L,the degradation rate of the bacterium is 72.65%.It shows strong tolerance of P.stutzeri ZH-1.The impact of organophosphorus pesticide residues on the environment and peopleis getting more and more serious.The use of microorganism to degrade it will not cause secondary pollution to the environment.The degradation production,phosphate,can also be used as a nutrient absorption and utilization by plants.Therefore,it is a major advancement in environmental protection and agricultural production to use microorganisms for the degradation pf organophosphorus pesticides and other organic pollutants.This study aims to provide a theoretical basis and guidance for the application of P.stutzeri ZH-1 in agricultural production.