This pathway shows the aerobic degradation of 1-Methylnaphthalene by Pseudomonas putida CSV86. 1-Methylnaphthalene is a bicyclic aromatic hydrocarbon which is found in crude oil and other petroleum products and appears in the environment as a pollutant. The degradation of polycyclic aromatic hydrocarbons (PAHs) like 1-Methylnaphthalene is of great interest because many of these PAHs are known human carcinogens. A soil isolate, Pseudomonas putida CSV86 is able to grow using 1-and 2-Methylnaphthalene as the sole sources of carbon and energy (Mahajan et al., 1994). The organism degrades 1-methylnaphthalene by two pathways: In the first, an aromatic ring hydroxylation pathway, the unsubstituted ring of methylnaphthalene is doubly hydroxylated yielding cis-1,2-dihydroxy-1,2-dihydro-8-methylnaphthalene, which is further oxidized to methyl salicylate and methyl catechol and enters into TCA cycle. In the second, a detoxification pathway, the methyl group is hydroxylated to form 1-hydroxymethylnaphthalene which is further oxidized to 1-naphthoic acid and excreted into the medium as a dead end product as organism P. putida CSV86 failed to grow on 1-naphthoic acid as a sole source of carbon and energy (Mahajan et al., 1994). Other organisms able to degrade 1-Methylnaphthalene include Marinobacter sp. NCE312, Neptunomonas naphthovorans, and the fungus Cunninghamella elegans. Naphthalene dioxygenase, an enzyme in this pathway, 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.