一株阴沟肠杆菌对BTEX的降解特性研究

Investigation of biodegrading characteristics of BTEX by Enterobactergergoviae strain: NBRC 105706

从污水处理厂废水中分离筛选出一株以BTEX为唯一碳源的阴沟肠杆菌，命名为btex-4，菌种鉴定为Enterobactergergoviaes train：NBRC 105706。btex-4菌在温度为30℃，底物浓度为100 mg/L，pH =7.0，150 r/min 条件下对 BTEX 的降解率依次为90.04%、90.13%、92.68%、95.83%。菌株在pH=6~8的范围内，可以正常生长并在72 h内将底物全部降解。同时btex-4可以降解25~200 mg/L的BTEX，当底物浓度低于25 mg/L时，菌株生长缓慢，当底物浓度高于100 mg/L时，会对乙苯的降解产生抑制，乙苯的降解速率降低。另外，该菌株可以适应10~30℃的温度变化，且随着温度的升高，降解率和降解速率随之升高。

The article obtained a BTEX degrading strain by the screening and domestication,named btex-4 and identified as Enterobactergergoviae strain：NBRC 105706 which was a newly discov-ered species able to degrade BTEX. With the culture of btex-4,it was able to utilize BTEX as the sole carbon source,and entered stable phase at 12h,then into decline phase after 54h. The research indicated that on the condition of 30℃,pH=7. 0,BTEX total mass concentration 100 mg/L,the in-dividual removal of B,T,E,X was 90. 04%、90. 13%、92. 68%、95. 83% in 48 h. With the cir-cumstances from 10℃ to 30℃,pH=6-8,and substrate concentration from 25mg/L to 200mg/L, bacterial grew well,proofing the good adaptability. The best pH for this strain was pH =7,and BTEX were removed completely in 72h with pH=6-8. Moreover,When the substrate concentration was lower than 25mg/L,the growth of the strain was slower,and higher than 100mg/L,the degrada-tion of ethylbenzene was suppressed to reduce the degradation rate. In addition,during 10℃ and 30℃,the degradation rate increased as the temperature increased.