[Isolation, identification of methyl tert-butyl ether degradation strain and its degradation kinetics]

A methyl tert-butyl ether degradation strain A1 was isolated from the soil under an old Gingko tree. It was identified preliminarily as Comamonas testosterone by 16S rDNA sequence analysis. The main factors including inoculation amount of microbes, pH, temperature and MTBE concentration that may affect the degradation efficiency of MTBE were further studied. The results indicated that the optimum conditions were as following: pH 7.0, temperature 25 degrees C, inoculation amount of microbes was 2 mL (D600 = 2.523 A), initial MTBE concentration 50 mg/L. Under that condition, MTBE can be reduced by 98.89% with seven days (compared with the blank, the volatilization of MTBE was 46.55%). In addition, the biodegradation process of MTBE can be well described by enzymatic reaction of high concentration inhibition, with the maximum substrate utilization rate 0.872 d(-1), Michaelis-Menten constant 7.832 mg x L(-1), inhibitory constant 130.75 mg x L(-1) respectively.