| On the basis of summarizing the related references home and abroad, a series of shake flask experiments had been conducted to study the biodegradation of Dimethyl Phthalate (DMP). Results indicated the DMP degrading strain isolated from the actived sludge at a land fill leachate treatment plant were able to grow on DMP as sole carbon and energy sources. The degradation of DMP by this strain could be divided into 3 phases, acclimatization phase, speedup phase and speed-down phase. Acclimatization phase lengthened when the initial concentration of DMP rose or the number of microorganism reduced. The optimal temperature and pH for DMP biodegradation were 30°C , 7.0. respectively. DMP degradation was advanced when rotate speed was increased or there was PLA in the solution. Phthalate Acid had stimulative and restraining effect to the DMP degradation simultaneity. DMP degradation would be restrained when the dextrose concentration was low, and advanced when the dextrose concentration was high. The kinetics model of DMP degradation could be expressed by an polynomial second-grade equation. The results of non-line curve fitting by using the software named Origin indicated when the temperature, pH, rotate speed, bacteria concentration was 30°C , 7.0, 120r/min, 15mg/L, respectively, and the initial concentration of DMP was 50, 100, 200, 500, 600, 700, 1000mg/L, the half life of DMP was 2.90,4.17,6.29,,16.46, 17.36, 18.01 , 18.98 hours, respectively. And when the bacteria concentration was 0, 3, 6, 15, 30mg/L, the half life of DMP was 34.56, 25.75, 16.46, 13.33 hours, respectively. On the basis of experiment data, a prediction model of DMP degradation set up by BP Neural Network principle was founded by using the software named MATLAB, after training, this BP Neural Network prediction model could emulate and predict the DMP degradation accurately. This DMP-degrading strain was identified by the analysis of 16S rRNA, and was confirmed to belong to the Chryseobacterium, Flavobacteriaceae.
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