This study aims to find a high-efficiency degradation strain which can biodegrade the 2,3,7,8-Tetrachlorodibenzo-P-dioxin (2,3,7,8-TCDD). In this paper, a new fungus strain was isolated from activated sludge of Dagu Drainage River in Tianjin which was able to degrade 2,3,7,8-TCDD in the medium. Based on its morphology and phylogenetic analysis of its 18S rDNA sequence, the strain was identified as Penicillium sp. QI-1. Response surface methodology using central composite rotatable design of cultural conditions was successfully employed for optimization resulting in 87.9 % degradation of 2,3,7,8-TCDD (1 µg/mL) within 6 days. The optimum condition for degrading 2,3,7,8-TCDD was at 31℃ and pH 7.4. The biodegradation process was fitted to a first-order kinetic model. The kinetic equation was C_t=0.939e^− 0.133t and its half-life was 5.21d. The fungus strain degraded 2,3,7,8-TCDD to form intermediates, they were 4,5-Dichloro-1,2-benzoquinone, 4,5-Dichlorocatechol, 2-Hydrooxy-1,4-benzoquinone, 1,2,4-Trihydroxybenzene and β-ketoadipic acid. A novel degradation pathway for 2,3,7,8-TCDD was proposed based on analysis of these metabolites. The results suggest that Penicillium sp. QI-1 may be an ideal microorganism for biodegradation of the 2,3,7,8-TCDD-contaminated environments.

这项研究的目的是找到一种可以将2,3,7,8-四氯二苯并-P-二恶英（2,3,7,8-TCDD）生物降解的高效降解菌株。本文从天津市大沽排水河道的活性污泥中分离出一种新的真菌菌株，能够在培养基中降解2,3,7,8-TCDD。根据其形态和18S rDNA序列的系统发育分析，该菌株被鉴定为青霉菌。QI-1。成功地采用了采用培养条件的中央复合可旋转设计的响应面方法进行优化，从而在6天内使2,3,7,8-TCDD（1 µg / mL）降解了87.9％。降解2,3,7,8-TCDD的最佳条件为31℃和pH 7.4。生物降解过程适合一级动力学模型。动力学方程为C _t= 0.939e ^{− 0.133t}，半衰期为5.21d。真菌菌株降解了2,3,7,8-TCDD形成中间体，它们是4,5-二氯-1,2-苯醌，4,5-二氯邻苯二酚，2-羟基-1,4-苯醌，1,2 ，4-三羟基苯和β-酮己二酸。基于对这些代谢物的分析，提出了一种新的2,3,7,8-TCDD降解途径。结果表明青霉菌。QI-1可能是对2,3,7,8-TCDD污染环境进行生物降解的理想微生物。