Biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons by bacteria.

Interest in the biodegradation mechanisms and environmental fate of polycyclic aromatic hydrocarbons (PAHs) is prompted by their ubiquitous distribution and their potentially deleterious effects on human health. PAHs constitute a large and diverse class of organic compounds and are generally described as molecules which consist of three or more fused aromatic rings in various structural configurations (5). The biodegradation of PAHs by microorganisms is the subject of many excellent reviews (references 16, 17, 18, 30, 88, and 92, for example), and the biodegradation of PAHs composed of three rings is well documented. In the last decade, research pertaining specifically to the bacterial biodegradation of PAHs composed of more than three rings has been advanced significantly. The bacterial biodegradation of PAHs with more than three rings, which are often referred to in the biodegradation literature as high-molecular-weight (HMW) PAHs, is the subject of this minireview.