中文摘要：

多溴联苯醚（PBDEs）是一种曾在全球范围内被广泛使用的溴代阻燃剂，具有半挥发性、生物蓄积性、神经毒性和内分泌干扰效应等，严重威胁生态环境和人体健康安全。本研究选择典型好氧降解菌伯克氏菌属LB400，对环境中普遍检出的中低溴联苯醚开展了降解动力学过程研究，探讨了外加碳源作为共代谢底物对降解性能的影响，模拟计算了降解中关键反应路径热力学状态函数性质变化，以揭示其与表观降解速率常数k之间的相关关系。结果表明：联苯作为共代谢底物时PBDEs的去除效率最高，在降解菌的作用下，0～120h内中低溴代PBDEs均能够发生降解，降解过程符合一级反应动力学。羟基化反应可能是PBDEs微生物降解过程的速控步骤，相比于问／对位取代，活性氧自由基如·OH更倾向于攻击苯环碳原子的邻／间位置，这为揭示PBDEs好氧微生物降解的分子作用机制，促进土壤中高效好氧降解菌的选育与污染修复应用提供了科学依据。

英文摘要：

Polybrominated diphenyl ethers （PBDEs） are typified as kinds of brominated flame retardants which are widely used around the world. They have some characteristics like semi-volatilization, bioaccumulation, neurotoxicology and endocrine disrupting effects, which severely threaten the ecological system and human health. In this study, a typical aerobic biodegradation strain LB400 was chosen for the performance of degradation kinetics process of lower and middling PBDEs congeners, which are widely detected in the environment. The influence of extra carbon sources as the co-metabolism substrates on degradation performance was discussed. With the simulative computation of variation of thermodynamical state function of key reaction path during degradation, the relationship between the calculated thermodynamics and biodegradation kinetics constant was revealed as well. It is indicated that the highest degradation rate would be obtained if biphenyl were added as the carbon source. Within 0-120 h, all tested PBDEs could be effectively degraded by LB400, and the process could be well described by the first-order kinetics. Relatively, the initial hydroxylation of PBDEs might be the rate-limiting step in the degradation process, and such reactive oxygen radicals as ＂OH prefers the nucleophilic addition at ortho/meta position to that occurred at meta/para sites of benzene ring This study could help deeply understand the molecular mechanics of PBDEs aerobic biodegradation, provide some scientific proofs on the selection of highly efficient degradation strains in the soil as well as the application in the soil contaminated remediation.