Degradation characteristics of 2', 6'-methylethyl-2-chloroacetanilide by strain Delftia sp.T3-6 and its crude enzyme

The characteristics of biodegradation of 2', 6'-methylethyl-2-chloroacetanilide (CMEPA) by Delftia sp. T3-6 strain and its crude endoenzyme were studied in this paper. Results showed that the strain T3-6 iso1ated was effective in degrading CMEPA. Within a retention time of 12 h, the degradation rate of CMEPA increased with the initial concentrations of CMEPA. However, the reaction was restrained as the initial concentration of CMEPA reached 500 mg·L^-1. Within 0.5%~5% inoculum concentration, the degradation rate of CMEPA increased with the increasing bacterial inoculum. The optimum temperature for the degradation of CMEPA by strain T3-6 was 30°C, and the degradation rate of 500 mg·L^-1 CMEPA was over 50% within the range of pH 7~10. The endoenzyme of strain T3-6 played the main role in degrading CMEPA. The optimum temperature and pH of the endoenzyme was 25°C and 8.0. The temperature stability of the endoenzyme was poor and it should be stored below 20°C, while the endoenzyme had preferable stability at 4°C from pH 6 to 9.