Although chlorobenzene is not formed in any significant quantity naturally, the United States chemical industry synthesized 231 million pounds of chlorobenzene in 1992 alone. Chlorobenzene is commonly used in the manufacture of nitrochlorobenzenes, phenol, aniline, and other industrial chemicals. It also functions as a paint solvent, heat-transfer medium, and an intermediate compound in the manufacture of some pesticides. Most chlorobenzene that is discharged into the environment quickly evaporates and is subsequently degraded atmospherically via reactions with photochemically-generated hydroxyl radicals. Enzymes involved in the microbial degradation of chlorobenzene are believed to have evolved from simliar enzymes catalyzing the degradation of benzene and toluene ([http://www.ncbi.nlm.nih.gov/pubmed/8626733|Werlen et al., 1996]). The Japanese Database for Environmental Fate of Chemicals has information on the rates and pathways of Biodegradation of Chlorophenols and Chlorobenzenes in Sediments. 2-Chlorophenol is hydroxylated to form 3-chlorocatechol in several Rhodococcus spp. ([http://www.ncbi.nlm.nih.gov/pubmed/10808489|Finkel`shtein et al., 2000]), Trichosporon cutaneum, T. beigelii and Cryptococcus elinovii ([http://www.ncbi.nlm.nih.gov/pubmed/1429434|K�lin et al., 1992]).