Isolation And Identification Of Organophorus Pesticide Degreding Bacterium And Studies On Biological Quality

The bacterium that can degredate organophosphorus pesticide play an important in dealing with its pollution. In this paper, By using selective media, two methamidophos-degrading bacterium (M|, M2), two dimethoate-degrading bacterium(D1, 02) and a omethoate-degrading bacterium(O) were isoliated from the sewage of pesticides-containing and the soil around pesticide factory. After identifing, we can know that MI is Pseudomonas eruginosa. sp, M2 is Pseudomonas mendocina. sp, D| is Bacillus brevis. sp, D2 is Pseudomonas alcaligenes. sp, O is Bacillus sphaericus. sp. They were able grow on organo phosphorus pesticides as sole carbon, nitroge and energy sources. In 0.5g/L organophosphate-inorgan salt medium at 30℃ (180r/min), M1, M2 could degrade 79.6% and 74.5% methamidophos. D1, D2 could degrate 71.9% and 69.7% dimethoate, O Could degradate 63.6% omethoate. They had higher endurance in organopho-spate pesticides solution. Their lethal concentration were: 30g/L(M1), 15g/L(M2), 30g/L(D1), 14g/L(D2), 20g/L(O), At the same time, five strains could also degrate methamidophos, dimethoate and Omethoate pesticides.Chose the bacterium MI whitch has the highest degrading effect and studyit's biological qualities. Result from the study demonstrated: with full oxygen the optimum concentation, pH and temperature for growth were 0.5g/L, 7.0 and 30 ℃, some metal ions could inhibit the groth and degradation of methamidophos. Other carbon and nitrogen sources in lower concentration which could enhance the degradation rate of methamidophos.The result of experiment pointed out than the best living-concentration of other three strains were 0.5g/L(D)) . 1.0g/L(D2), and 0.5g/L(O). The best pH were 8.0(Di), 8.0~9.0(D2) and 7.0(O). The best temperature were: 30℃(D1), 40 ℃'(D2)and 30℃(O).