Isolation, Identification And Characters Of Methamidophos Degrading Bacteria

Two degrading methamidophos bacteria strains were isolated from the soil, they were identified as Staphylococcus capitis and Alcaligenes faecalis., and named as strain D and strain J.Methamidophos residues in soil were determined by gas chromatography. The average recovery rates in water were between 92.8% and 96.4%, and variation coefficients were between 2.2% and 3.9%. The standard curve of formulum was Y=398421+ 2530507X (r=0.9917). The number of living Methamidophos-degrading bacterium was positively coordinated with the OD650mm of its suspension liquid determined by spectrophotometer.the regression equation was y=0.1233x-2.3051 (r=0.9171).Methamidophos-degrading bacteria strain D and strain J were able to utilize methamidophos as the carbon and energy source for growth. Strain D and strain J were cultivating 72 hours in basic culture medium with 500mg/L methamidophos and shaking (180r/min) at 30℃, methamidophos was degraded 58.49% and 65.80% respectively. When strain D combined with strain J, the degradation rate was higher than that of either of strain administered singularly.After 72 hours ,72.93% was degraded. For strain D the optimal methamidophos concentration was 1000 mg/L, but that for strain J was 2000 mg/L.The growth curve results indicated, in basic culture medium with 500mg/L methamidophos and shaking (180r/min) at 30℃, strain D entered grow logarithm long-termly after being cultivated 6 hours, entered grow steadily long-termly 18 hours later, and began to decline 36 hours later.The periods for strain J were 18 hours,30 hours,and 39 hours respectively.Strain D and strain J used in the soil helped to improve the activity of the whole soil microorganism group. There was relatively great influence on the growth of the methamidophos degradating bacterium in pH value of the culture medium. Buffering liquid helped the growth of degrading bacteria even more the culture medium compounded with thedistilled water that the liquid compounded of different pH value. Strain D and Strain J are all growed best while buffering liquid pH value for 6. trained with the basic culture medium and shaking(180r/min) at 30C, the OD650mm value 72 hours later were 1.093 and 1.586 respectively, and the culture medium of different pH value compounded with the distilled water , Strain D and Strain J most right to grow pH value 7 , the OD650mm after 72 hours were 0.756 and 0.858 respectively, and pH value of the culture medium has presented greater change.The mutant strain D1 and strain J3 obtained from strain D and strain J respectively mutated through ultraviolet ray. trained on basic culture medium at 30C, the strain Dl and strain J3 could degrade methamidophos by 52.85% and 56.66% in 3 days respectively, were 5.87% and 5.70% higher. The mutants were generated 10 times on the tube medium containing methamidophos and showed the degradative capacity were stable. After mutation the degradation spectrum did not chang for the both mutants.Add extra carbons source helped to the growth of degrading bacteria.One percent glucose had the higher effect.The bacteria or their cultivation media had no effect on peach aphids survival.But treat mustard root area with 1000 mg/L methamidophos and bacteria suspension liquid spontaneously or alternatively could reduce their mortality rate, and pretreating with bacteria suspension liquid 24 hours earlier affected most...