Naphthalene is a fused ring bicyclic aromatic hydrocarbon and thus serves as a model for understanding the properties of a large class of environmentally prevalent polycylic aromatic hydrocarbons (PAHs). Naphthalene and its substituted derivatives are commonly found in crude oil and oil products. Certain PAHs are strong human carcinogens leading to widespread interest in the microbial metabolism of these compounds. Several Pseudomonas species can degrade naphthalene starting wtih 1,2 dioxygenation, shown here in the middle branch ([http://www.ncbi.nlm.nih.gov/pubmed/1447127|Eaton et al., 1992]). Naphthalene dioxygenase, the enzyme which initiates this route of bacterial naphthalene metabolism, is used in a biotechnological process to synthesize the blue jean dye indigo. This versatile enzyme has many other catalytic abilities, which are documented in a table of the Reactions of Naphthalene 1,2-Dioxygenase. Bacillus thermoleovorans Hamburg 2 initiates naphthalene degradation with dioxygenation at the 2,3 position ([http://www.ncbi.nlm.nih.gov/pubmed/10653712|Annweiler et al., 2000]), shown here in the left branch. The pathway also includes formation of naphthalene as part of the degradation of 1,2-dihydronaphthalene. This is a minor part of 1,2-dihydronaphthalene degradation; the major route is dioxygenation to 1,2-dihydroxy-1,2,3,4-tetrahydronaphthalene ([http://www.ncbi.nlm.nih.gov/pubmed/7592326|Torok et al., 1995]).