| China is an expansive and agricultural country. Therefore, the production and usage of pesticide is in large quantity. The problem of rudimental pesticide pollution stands out exceptionally. The usage of pesticide has negative effects, especially the organic phosphor. Because there is not so much pertinency degradating microorganism in nature, the degradation effects are far smaller than the usage. The usage of the pesticides in large quantity leads to three "R"s (residue, resurgence, resistance), among which the rudimental of methamidophos does the most harm. Strengthening the study on microorganism degradation is not only useful for taking efficient measures to eliminate pollutions, but also practical for decontaminating environment, so the study on the degradation of methamidophos is done as follows.1. Bacterium fitration and ultraviolet induced mutation of methamidophos degradating bacterium and filtration of prolific bacterium. The methamidophos degradating bacterium is fitrated from long-time and high-degree-polluted soil, among which we get a bacterium named S-2. It is primarily identified as a pseudomonas. S-2 is a gram-negative bacterium, short-bacilliform, hard and slick on the agar substrate, without producting pigment. It can make use of glucose, sucrose and maltose, but not fructose or tactose. Its tolerant consistency to methamidophos can add up to 2000mg/L, while the most suitable consistency to methamidophos is lOOOmg/L.It can make use of methamidophos as N. What's more, it is effective to degrade methamidophos. S-2 can degrade methamidophos which initial consistency is 0.1% by 65% in six days. Besides, S-2 has a certain degradating effect on dimethoate, but it can hardly degrade dichlorvos and parathion. We also choose two microzyme named S-5 and S-6 and get good effects. The methods of enhancing degradating efficiency largely consist of two parts; the productive bacterium with good capability and the excellent external factors such as fermentation technics, conditions and so on. Since the former plays a determinative role, it's necessary to do a further study on it. Ultraviolet radiation is chosen as inducement to chose the bacterium among which the induced dosage is determined by death rate. The best induced dosage has been drawn that: with a 30W ultraviolet light in a distance of 35 cm, irradiation time is 60 seconds. Induced bacterium with better capability has a worse stability. Only a bacterium named S-232 is comparatively stable, but the degradating rate of S-232's fifth filial generation is reduced by 8—9% than S-2 itself.2. The optimization of the best fermentation condition and mixed fermentation. Different microorganism has different requests for substrate, but initial C and N have the most obvious effects on microorganism fermentation. The initial C, N and pH of S-2 fermentation are studied in experiment and we get the following conclusion: Under the condition of C:N=6:4 and pH=7.0, the effect of degradation is the best. Among thethree factors, the effect of C is the best, which shows that C is the key alimentation of methamidophos degradation. When the proportion of C and N can't be controlled, the best single factors are as follows: the best temperature is 30°C; The best pH is 6.7; and it especially cares for oxygen. Until now, the reports concerning about the microorganism fermentation of methamidophos are all about single microorganism which separately reacts on methamidophos and helps it implement the degradation. Three microorganism picked out are mixed together in different proportion to degrade methamidophos and have made good effects.3. Essential study on degradation mechanism. The approach, outcome and enzyme of microorganism metabolizing methamidophos are known only a little so far. The further study on the approach of S-2 can be produced by metabolism acidity phosphatase, and the degradation of methamidophos mainly happens outside the cell. Under the situation of the methamidophos induce, these degradation enzyme separated from S-2 can accumulate i...
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