污染土壤中多环芳烃的微生物降解及其机理研究进展

Biodegradation Mechanism of Polycyclic Aromatic Hydrocarbons (PAHs) in Soil: A Review

多环芳烃(PAHs)是一类普遍存在于环境中的难降解危险性"三致"有机污染物。微生物对多环芳烃的降解是去除土壤中多环芳烃的主要途径。研究表明,对于土壤中低分子量多环芳烃类化合物,微生物一般以唯一碳源方式代谢;而大多数细菌和真菌对四环或四环以上的多环芳烃的降解作用一般以共代谢方式开始。本文重点论述了高分子量多环芳烃:芘和苯并(a)芘的微生物降解及其机理。并介绍了多环芳烃污染的微生物 植物联合修复机制,最后展望了污染土壤中多环芳烃的研究趋势。

Many polycyclic aromatic hydrocarbons (PAHs)are known to be toxic, mutagenic and carcinogenic, and their contamination in soil is of great environmental concern. Microbial degradation of PAHs by its enzymatic capacity is the main process of the dissipation of PAHs in soils. Numerous genera of bacteria and fungi with the ability to utilize low molecular weight PAHs as sole carbon and energy sources have been reported. Limited numbers of bacteria and white rot fungi are found be able to cometabolize PAHs with four or more fused aromatic rings, provided that another carbon source is present. The focus of this review is on the high molecular weight PAHs: pyrene and benzopyrene (Bap). This review provides microorganisms with the ability to degrade PAHs, including pathways for their degradation by these organisms. Combined remediation with microorganisms and plants is a new bioremedial technique used in PAHs contaminated soils. In addition, the prospects on the research for PAHs degradation are discussed.