Isolation, Identification And Characterization Of Organophosphorus Degrading Strains

Environmental pollution caused by vast utilization of organophosphorus pesticides has becoming more and more serious, which affects the health of human and the economic development of the whole country. The production and utilization of omethoate has been augmented for the forbiddance of methamidophos and prarathion. From this point of view, the organophosphorus pesticides degradation wasstudied, and the bio-degradation of omethoate was focused on.Aiming at obtaining strains with high performance of organophosphoruspesticides degrading ability, this thesis have accomplished its work via screening and identifying strains initially, and then investigating the optimum degrading conditions through studies on their characters.After screening of bacteria, fungi and actinomycete from more than 100 samples which were collected from soil and water seriously polluted by organophosphorus pesticides, a bacterium NWB-36 with high degrading ability was picked out, which was identified as Arthrobacter globiformis initially by observation of its modality and physiological and biochemical test.The genetic stability and broad-spectrum in organophosphorus pesticides degrading was ascertained by investigating the characters of NWB-36. It can decompound omethoate with high efficiency and even survive under 3g/L omethoate. The degradation was related to the trend of the growth of the strain dynamically. Subsequently, the result of the single-factor experiment showed that carbon source, nitrogen source, inoculation size and temperature affected degradation remarkably. Finally the best omethoate degrading condition was ascertained by orthogonal experiment as follow: 1.6% sucrose, 0.10% ammonium bicarbonate, 6% inoculation size and at 34℃, under which the degrading rate reached 47.03%.