DDT降解菌2D-1的分离鉴定与降解特性研究

从洪泽湖湿地淤泥中分离得到1株能高效降解DDT的革兰氏阳性细菌2D-1。通过生理生化分析，以及16SrDNA序列同源性比较分析，将2D-1鉴定为蜡状芽抱杆菌（Bacillus cereus）。在基础盐酵母培养基中，接种量5％，摇床转速150r／min，培养温度33℃，pH值6．5的条件下，2D-1菌株在8d内能对总量为53．46mg／L的DDT进行95．64％的降解，对p，p’-DDT、p，p＇-DDE、p，p＇-DDD和o，p＇-DDT的绝对降解浓度分别为5．32、22．98、6．66和16．17mg/L。结果表明，2D-1对4种异构体的适应性不同，p，p＇-DDE是其最适底物，且2D-1瞻解DDT的主娶产物有6种。

Study on the Isolation,Identification and Degradation Characters of Strain 2D-1 for Degrading DDT

A Gram positive bacterium strain 2D-1 for degrading DDT effectively was isolated from the swampy sludge of Hongze Lake. According to its physiological & biochemical characters and the homology analysis of its 16S rDNA sequence, this strain was identified as Bacillus cereus. This strain could degrade 95.64% DDT (total concentration of DDT of 53.46 mg/L) in inorganic salt & yeast cream liquor medium within 8 days under the conditions of 5% inoculation quantity, 150 r/min, 33 ℃ and pH 6.5. The absolute degradation concentrations of p,p′-DDT, p,p′-DDE , p,p′-DDD and o,p′-DDT were 5.32, 22.98, 6.66 and 16.17 mg/L respectively. The results showed that the adaptability of strain 2D-1 to four kinds of DDT isomers was different and p,p′-DDE was the optimum substrate for strain 2D-1. Six kinds of main products would be produced after DDT degradation by 2D-1.