Bacterial degradation and bioremediation of polycyclic aromatic hydrocarbons

Many polycyclic aromatic hydrocarbons (PAHs) are known to be toxic and carcinogenic for humans, and their contamination of soils and aquifers is of great environmental concern. Some microorganisms, mainly from the genera Pseudomonas and Mycobacterium, were found to be capable of transforming and degrading PAHs. These abilities may be useful in removal of PAHs from the environment. The successful application of bacteria to the bioremediation of PAH-contaminated sites requires a deeper understanding of how microbial PAH degradation proceeds. In this review, the bacteria involved and the metabolic pathways for the degradation of many PAHs are summarized and the biological aspects of PAH bioremediation are discussed.