一株邻苯二甲酸二异辛酯高效降解菌的筛选及其降解特性的初步研究

Isolation and Degradation Characters of A DEHP Degrading Bacterial Strain

从某化工厂的活性污泥中分离到一株能高效降解DEHP(邻苯二甲酸二异辛酯)的细菌DW1,该菌株能够以DEHP为惟一碳源和能源生长。根据革兰氏染色的结果以及其形态特征、生理生化特性等对该菌株进行菌种鉴定,初步鉴定该菌株为纤维单胞菌属(Cellulomonassp.),并对该菌株的DEHP降解特性进行了初步研究。研究表明,菌株DW1可以耐受较高浓度的DEHP,在7d的时间内对摇瓶中2000mg·L-1的DEHP降解率达到96%,其降解DEHP的最适温度和pH值分别是30℃和8.0。菌株对DEHP的降解曲线显示,经过短暂的延滞期后培养基中DEHP的降解很快就进入了对数期,在第3d降解率即可达到89%,菌体生长量在第5d进入稳定期。研究了添加土壤浸液对菌株DW1降解DEHP的影响,结果表明,添加少量的外来碳源可以刺激微生物的生长并提高了DEHP的降解率,但过多的外加碳源减缓了细菌对DEHP的降解。

A bacterial strain DW1 that could degrade DEHP was isolated from activated sludge of wastewater treatment plant from a chemical factory. DW1 could take DEHP as sole carbon and energy resources, and was identified to be Cellulomonas sp. based on its morphology, physiological and biochemical properties. DW1 could endure high concentration of DEHP and in flask test degraded 96% of 2 000 mg· L^-1 of the DEHP within a week of incubation in a shaking incubator. The optimal pH and temperature for the growth of DW1 and the degradation of DEHP was 8.0 and 30℃, respectively. The degradation curve of DEHP by DW1 showed that after a short lag phase, the degradation entered exponential phase and the degradation rate reached 89% in 3 days, microbial populations also entered the stationary phase after 5 days. The effect of soil extract to DEHP degradation by DW1 was studied also. Adding a little amount of carbon resource accelerated the growth of microorganisms and the degradation of DEHP, but overusing them would delay the degradation of DEHP.