Delftia sp.T3-6菌株及其粗酶液对2',6'-甲乙基-2-氯乙酰苯胺的降解

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

研究了Delftia sp.T3-6菌株对2’,6’-甲乙基-2-氯乙酰苯胺(CMEPA)的降解特性,以及该菌株胞内酶对CMEPA的酶促特性.结果表明,菌株T3-6对CMEPA有很好的降解性能.反应12 h内,随着CMEPA浓度的增加,反应速度加快;当CMEPA浓度达到500 mg·L-1时,菌体的降解活性受到一定程度的抑制;在菌体接种量为0.5%~5%的范围内,接种量越大,CMEPA的降解转化速率越快.菌株T3-6降解CMEPA的最适温度为30℃,且其在pH 7~10的范围内对500 mg·L-1CMEPA的降解率均可达50%以上.T3-6菌株对CMEPA降解起催化作用的活性酶为胞内酶,该酶的最适反应温度和pH分别为25℃和8.0;该酶的温度稳定性较差,需在20℃以下贮存;但其在4℃下,pH 6~9的缓冲液中均可保持很好的稳定性.

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 ℃,and the degradation rate of 500 mg·L-1CMEPA was over50% 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 ℃ and 8. 0. The temperature stability of the endoenzyme was poor and it should be stored below 20 ℃,while the endoenzyme had preferable stability at 4 ℃ from pH 6 to 9.