Polycyclic aromatic hydrocarbon biodegradation rates: a structure-based study.
Polycyclic aromatic hydrocarbon biodegradation rates: a structure-based study.
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DOI：
10.1021/es048939y
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发表时间：
2005-04
影响因子：
11.4
通讯作者：
Kristine H. Wammer;C. Peters
中科院分区：
文献类型：
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作者：
Kristine H. Wammer;C. Peters
本研究旨在考察分子结构在决定多环芳烃(PAHs)生物降解率中的作用。实验室实验是在水体系中进行的，数据分析的方式允许确定一级生物降解率，而不受物理化学过程的生物利用度限制。使用了好氧混合培养，这种混合培养已经在广泛的多环芳烃上得到了浓缩。这项研究中包括的22种多环芳烃的大小从两个到四个环不等，包括带有5个碳环和烷基取代基的化合物。观测到的生物降解率仅为1个数量级，远低于现场典型观察到的降解率。这支持了其他类型的研究结果，这些研究得出结论，环境中多环芳烃生物降解率的大部分观察到的变化来自控制化合物的生物利用度的过程，而不是控制吸收或生物转化的过程。观察到的速率差异可归因于α位置上存在5-碳环或烷基取代基。使用了可能与生物降解过程中的限速步骤相关的各种分子描述符，试图建立多环芳烃生物降解率的定量结构-活性关系。没有发现显著的相关性，但与相关酶相互作用的速率限制仍然是可能的。
This study was designed to examine the role of molecular structure in determining the biodegradation rates of polycyclic aromatic hydrocarbons (PAHs). Laboratory experiments were performed in aqueous systems, and data were analyzed in a manner that allowed determination of first-order biodegradation rates independent of bioavailability limitations from physical-chemical processes. An aerobic mixed culture was used, which had been enriched on a broad range of PAHs. The 22 PAHs included in this study ranged in size from two to four rings and included compounds with 5-carbon rings and alkyl substituents. The range of observed biodegradation rates was only 1 order of magnitude, which is much less than that which is typically observed in the field. This supports the findings of other types of studies, which conclude that most of the observed variation in environmental PAH biodegradation rates comes from processes controlling the bioavailability of the compounds and not processes controlling uptake or biotransformation. Rate differences that were observed were attributable either to the presence of a 5-carbon ring or an alkyl substituent in an alpha position. Various molecular descriptors that might be expected to correlate with rate-limiting steps in the biodegradation process were used in an attemptto develop a quantitative structure-activity relationship for the PAH biodegradation rates. No significant correlations were found, but rate limitation from interactions with the relevant enzymes remains a possibility.